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Abstract: The pulp and paper industry both uses and produces large amounts of energy and rising fuel prices bring along significant challenges to the sector. Several strategies can be applied in order to remain competitive e.g. an increase in energy efficiency, a switch in fuel and/or a novel energy conversion technology. In this study, we investigate if improved energy conversion strategies can reduce energy costs, primary energy use and CO2 emissions of paper mills within different European countries (The Netherlands, Poland and Sweden). Our results show that differences in history and availability of resources has led to different conversion strategies in the three countries. We found that a natural gas combined cycle, which is largely implemented in The Netherlands due to long term domestic availability of natural gas, has the lowest primary energy demand. Due to a long history of low electricity prices, CHP has not been common in Sweden. Many Swedish mills use biomass as an energy source and due to low CO2 emissions of the national grid the CO2 emission profile of the Swedish paper industry is very low. Our results imply that future conversion routes for the Swedish paper and board industry are again wood based; in case of increasing electricity prices these would be biomass gasification based CHP solutions. With a reduction of 800kg CO2/ton paper on average, a switch from coal to biomass would reduce CO2 emissions in the Polish pulp and paper industry with approximately 0.6Mton/year. A carbon price of 20–25€/ton would, according to our results, be enough to provoke this switch. Due to the high share of natural gas, the CO2 emission reduction potential of the Dutch paper industry (1.5Mton/year) is even larger than in Poland. Due to high biomass prices and relative low CO2 emission profile of natural gas, a carbon prices of more than 60€/ton CO2 would be needed to provoke a switch in The Netherlands. Provided with few alternatives, the most effective strategy in The Netherlands would be an increase in energy efficiency. [Copyright &y& Elsevier]

Gene expression responses of paper birch (Betula papyrifera) leaves to elevated concentrations of CO2 and O3 were studied with microarray analyses from three time points during the summer of 2004 at Aspen FACE. Microarray data were analyzed with clustering techniques, self-organizing maps, K-means clustering and Sammon''s mappings, to detect similar gene expression patterns within sampling times and treatments. Most of the alterations in gene expression were caused by O3, alone or in combination with CO2. O3 induced defensive reactions to oxidative stress and earlier leaf senescence, seen as decreased expression of photosynthesis- and carbon fixation-related genes, and increased expression of senescence-associated genes. The effects of elevated CO2 reflected surplus of carbon that was directed to synthesis of secondary compounds. The combined CO2 +O3 treatment resulted in differential gene expression than with individual gas treatments or in changes similar to O3 treatment, indicating that CO2 cannot totally alleviate the harmful effects of O3. [Copyright &y& Elsevier]

• Freestanding carbon paper confined with ultrafine lithiophilic TiO 2 is in-situ synthesized from MXene and CO 2. • Freestanding C/TiO 2 paper is firstly employed as dendrite-free Li metal anodic host. • The growth behaviors of metallic Li on C/TiO 2 is systematically probed. • Lithiophilic TiO 2 seeds and conductive 3D carbon synergistically induce dendrite-free Li deposition. • C/TiO 2 @Li paper enables full cell with improved electrochemical performance. Lithium (Li) metal anode is deemed as one of the most fascinating anodes due to its high energy density. Nonetheless, low Coulombic efficiency and safety issues caused by detrimental Li dendrites growth severely hamper its practical application. Herein, we construct an ultrafine TiO 2 confined in 3D freestanding carbon paper by one-step green in-situ oxidation of Ti 3 C 2 T x MXene film with greenhouse gas CO 2. The lithiophilic TiO 2 seeds and freestanding 3D carbon matrix can synergistically induce uniform Li deposition and buffer the volume changes during lithium striping and deposition, which ensure improved electrochemical performance with high Coulombic efficiency and low overpotential, etc. The growth process of metallic Li on C/TiO 2 is also systematically investigated. Moreover, the C/TiO 2 @Li||LiFePO 4 full batteries present a stable cycling performance over 250cycles at 1.0C and superior rate performance. Additionally, this work proposes an alternative way to utilize CO 2 , which may alleviate greenhouse effect and boost sustainable development. These results may be useful for both the design of dendrite-free lithium metal batteries and the sustainable utilizing of CO 2. [ABSTRACT FROM AUTHOR]

This comment addresses several points regarding data interpretation in a recent paper in the Journal, which results in an inaccurate interpretation of experimental data on CO 2 diffusion in water. The experimental data were interpreted by Fick's law of diffusion, while the existence of convection was disregarded. [ABSTRACT FROM AUTHOR]

In this paper, wastepaper gasification with carbon dioxide or steam has been investigated in the presence of molten carbonate catalysts. The reactions of wastepaper with steam or carbon dioxide have been compared. Hydrogen was the main product on the condition of steam used as reactant gas, but in the case where carbon dioxide was used, the amount of carbon monoxide generated from wastepaper gasification greatly increased via the Boudouard reaction. Different ratios of mixtures of lithium, sodium and potassium carbonates as the catalysts have been tested; the lithium carbonate was found to play a critical role. The reaction rate of carbon conversion was approximately first order for low carbon conversions. Both the rate constants and the activation energies have been calculated at different temperatures (923–1023 K). In additions, the flexibility of this technique was examined with three different types of wastepaper. The results suggest that this process can promote effective use of wastepaper and recovery of carbon dioxide. At 1023 K, a high value of cold gas efficiency of about 95% was acquired. [Copyright &y& Elsevier]

Reduction in the consumption of operational (primary) energy and emissions of harmful gases has recently become the focus of attention of the civil engineering sector. In this context, there is also emphasized the energy consumption and emission production values associated with the whole life cycle of the construction materials used, which is referred to as "bundled energy consumption" and "bundled emissions". This paper analyses the energy performance certificates in combination with the SBToolCZ methodology. Sustainability Building Tool is a methodology designed to assess the sustainability of buildings. This methodology is used to assess the environmental impact of buildings at different stages of their life cycle, such as production, operation and demolition of the building. The amount of carbon dioxide and sulphur dioxide produced during the life cycle of buildings was determined by analysing and extending the building assessment data by the SBToolCZ methodology, which was subsequently valued and incorporated into the lifetime costs. The data from 17 case studies from the Czech environment were analysed. Taking these environmental impacts into account, valuing them and analysing the cash flows of investors and society shows the importance of paying increased attention to sustainable construction and reducing its negative impact on the environment and climate. Research data shows that 30% of the operating costs of buildings are the societal costs associated with CO 2,eqv. and SO 2,eqv. production. [ABSTRACT FROM AUTHOR]

[Display omitted] • This paper proposes the concept of room-temperature solar-powered CH 4 reforming. • The non-metallic element (Br, N and S) doped TiO 2 is prepared. • The doped catalysts X-TiO 2 were used in photocatalytic methane reforming. • The structure–activity relationship was studied by density functional theory. • Based on isotope tracer results, a possible photocatalytic mechanism was proposed. • The catalytic performance of S-TiO 2 is 22–65 times that of bulk TiO 2 catalyst. • The possible catalytic mechanism was verified by in situ infrared characterization. Given the increasingly severe climate and energy crises, this paper proposes the concept of "room-temperature solar-powered CH 4 reforming", intended to achieve carbon emission reduction and efficiently use carbon-containing resources. However, traditional semiconductors as catalysts have some problems, such as few catalytic active sites and fast recombination of photogenerated electrons and holes, resulting in low efficiency of photocatalytic CH 4 reforming. For this reason, a series of doped catalysts X-TiO 2 (X = Br, N, and S) are prepared by introducing nonmetallic elements into the TiO 2 lattice to construct oxygen defects. Notably, the CO yield of the S-TiO 2 catalyst was 1048 μ mol g−1, 65 times higher than the catalytic performance of bulk TiO 2. Based on the functional density theory (DFT) calculation, the interaction between the S active site and the performance of photocatalytic CH 4 reforming with oxygen defects is discussed in detail. The synergistic effect of the S site and the oxygen defect has been shown to rapidly activate C = O and C-H bonds at room temperature. Finally, based on the tracer experiment and DFT calculation, a possible mechanism of photocatalytic CH 4 reforming at room temperature is proposed. This work provides a new research direction for achieving carbon neutrality at room temperature and a feasible technical scheme for the large-scale application of photocatalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] • A new arrangement of a single flash geothermal power plant with a transcritical carbon dioxide recovery cycle is presented. • Energy analysis and exergy have been performed for both BASIC and recovery performance modes. • The results show that the proposed system in the recovery mode with a net power of 401.40 kW, energy efficiency of 53.6%, and exergy efficiency of 46.32% has been calculated. • Compared to the basic operating mode, the total output values of energy, energy efficiency and exergy efficiency show an increase of 149.9 kW, 2.39% and 12.12%, respectively. The use of new energy sources, such as geothermal energy, is rapidly expanding worldwide, and it is a viable alternative to fossil fuels. This paper proposes a geothermal power generation system (combined single flash geothermal cycle with transcritical carbon dioxide recovery cycle). To improve system performance, a recuperator is used to recover some of the heat loss. The proposed system simulation is performed in EES software and then validated by previous research. The proposed system is analyzed from the perspective of energy and exergy. The effects of the proposed system separator pressure, carbon dioxide turbine inlet pressure and carbon dioxide condenser outlet temperature on energy efficiency, exergy efficiency and system net power output have been investigated. Findings show that the proposed system in recovery mode has a net power output of 401.40 kW, energy efficiency of 53.6 percent, and exergy efficiency of 46.32 percent, which are significantly higher than the basic mode's values of 149.9 kW, 2.39 percent, and 12.12 percent, respectively. [ABSTRACT FROM AUTHOR]

Machining chips are a potentially versatile material feedstock to be used in a range of solid-state and melt based manufacturing processes. The poor current understanding of the behaviour of chips in such processes limits the likelihood of practical adoption of such materials on an industrial scale. The re-use (as opposed to recycling or landfilling) of machining waste offers both economic and environmental savings. Iron and steel production causes up to 9 %, and aluminium up to 1.5 % of global process and energy CO 2 emissions. It is proposed that between 0.24 % and 0.5 % (117 Mt CO 2) of global CO 2 emissions could be saved by reusing steel machining chips and between 0.13 % and 0.22 % (51 Mt CO 2) via re-use of aluminium chips, through mitigation of recycling associated emissions or emissions from generation of new steel. Re-use of large manufacturing scrap, i.e. the majority of such scrap, increases these values to savings of 1 % and 0.86 % of global CO 2 emissions for steel and aluminium respectively in the best scenario. This work gives a perspective on the potential for chips to retain value and be re-used in manufacturing process streams. The paper guides the reader from the generation and control of machining chips, to the principles of material consolidation. The principles of material densification by both solid state and laser deposition based methods are described, and current and potential manufacturing processes which can use chips as a feedstock are critically reviewed in terms of their practicalities and final properties. A perspective on potential CO 2 savings is described, providing the underpinning motivation behind this work. It is shown there is significant potential for versatile manufacturing using machining chips by both solid-state and laser-based processing of chips into finished products. An argument is also presented for a new approach to processing large-scrap, e.g. from the automotive manufacturing industry, as well as end-of-life automotive scrap, into smaller chips ready for re-use. [Display omitted] • This review assesses the challenges associated with recovering chips which are generated by machining processes and repurposing this. • The machining science which gives rise to this is discussed alongside technological opportunities to make better use of this. • Sankey diagrams illustrate where and how new technologies may be implemented. [ABSTRACT FROM AUTHOR]

• Mass transfer of supercritical fluids. • Application of supercritical CO 2 extraction. • Mass transfer phenomena. • Overview literature correlations mass transfer coefficients. In many chemical engineering processes mass transfer is a frequently encountered phenomenon. One of the upcoming processes is extraction with supercritical fluids (SCF), especially the use of supercritical carbon dioxide (scCO 2). In order to design extraction processes it is very important to understand and describe the mass transfer steps, and also to be able to determine and estimate the mass transfer coefficients. Dimensionless mass transfer correlations together with mass balance models (process models) are highly recommend to ensure a maximum versatility. However, up till now most mass transfer correlations are related and validated to regular solid–liquid, liquid–liquid or gas–liquid systems and are not automatically and directly applicable for SCF due to the unique properties of supercritical fluids. Moreover, in the case of SCF extraction, natural convection can occur and interfere with forced mass transfer. For forced convection Sherwood depends on Reynolds and Schmidt where for natural convection Sherwood depends on only Grashof and Schmidt. In this paper an overview will be given of the dimensionless mass transfer correlations for scCO 2 from experimental data in terms of Sherwood, Reynolds and Schmidt for packed bed, annular duct, liquid film and hollow fiber membranes. [ABSTRACT FROM AUTHOR]

• This paper considers the control of CO 2 transcritical and subcritical systems. • A model-free real-time optimization approach (i.e. Extremum Seeking Control) is used. • Thanks to the availability of a test rig, two case studies are investigated: a refrigeration system and a heat pump unit. • The performances of the ESC have been compared with those provided by the Liao's correlation, which is well-known in the literature. In this paper, the energy-efficient operation of single-stage refrigerating carbon dioxide vapour compressor units operating in transcritical and subcritical conditions is discussed from an experimental point of view. The performance of this kind of systems strongly depends on the operating conditions and in particular on the vapour compression cycle (VCC) high pressure. Because of the limited knowledge of certain system parameters and the difficulty of developing and implementing effective model-based control strategies, the problem of determining the optimal value for the VCC high pressure that leads to the maximum system performance is here faced by means of a model-free approach. More specifically, an Extremum Seeking Control (ESC) scheme, which can search for the unknown or slowly varying optimum input with respect to a certain performance index, is adopted. In particular, thanks to the availability of an unusual test rig, different CO 2 system configurations, i.e. a refrigeration system and a heat pump unit, have been tested. In this scenario, the performances of the ESC have been compared with those provided by the Liao's correlation, which is well-known in the literature. [ABSTRACT FROM AUTHOR]

Highlights • A CO 2 -cooled FW has been proposed in this paper. • A high heat flux with radiation heat flux and particle heat flux has been applied on FW. • Different wall roughness position of channel has been shown. • Different wall roughness value has been given. • Sensitivity particle heat flux has been studied in this paper. Abstract The Demonstration Fusion Reactor in Europe (EU-DEMO) is considered to be the last step before building a commercial fusion power plant. Up to now, He has been chosen as gas coolant for three of the four candidate breeding blankets proposed for the EU-DEMO, being the Helium Cooled Pebble Bed (HCPB) among them. The choice of He coolant is supported, among other features, by its superior heat transfer capabilities, its transparency to neutrons and chemical inertness. However, the use of this coolant in DEMO poses some feasibility questions, like the large coolant inventory, resulting in possible safety issues, as well as the large circulating power. On the other side, CO 2 has been the fluid coolant choice in the nuclear fission industry for gas-cooled reactors since the 1950s. The key advantage of this gas is its larger density, which results in more compact components, lower coolant inventories, lower circulating powers and thus better plant thermal efficiency. This, coupled also with a relatively high molecular stability at moderate temperatures (up to 600 °C), its larger availability and lower price make CO 2 an attractive coolant for a pebble bed breeding blanket, as an alternative to He. As a Plasma Facing Component, the First wall (FW) is one of the components under the most challenging environment. Currently, the FW region at the upper port inboard location is expected to suffer the most critical heat flux loads. Indeed, a peak charged particle heat flux 0.99 MW/m2 together with a radiation heat flux of 0.18 MW/m2 is foreseen at this location. This paper reports the thermal-hydraulic analyses carried out to find the practical heat flux limits by using CO 2 as coolant. The analyses have been performed by using the commercial computational fluid dynamics (CFD) code ANSYS CFX. Different augmented technical wall roughness areas have been considered, for a best heat transfer-to-pressure drop ratio. Sensitivity analyses have been performed as well for higher peak particle heat fluxes, evidencing that a CO 2 -cooled FW can dissipate peak heat fluxes up to 1.8 MW/m2 keeping the circulator power in a reasonable range. [ABSTRACT FROM AUTHOR]

[Display omitted] • A philic-CO 2 supercarbon was derived from rice husk waste by a new process. • It possessed the max specific surface area in reported biochars (4230 m2 g−1) • It possessed the max CO 2 uptake capacity in the reported biochars (341.5 mg g−1) • This study gave a new way to generate rich ultra-micropores and C-F groups in char. A super-carbon material as adsorbents of CO 2 were prepared with rice husk waste by a new two-step process, pyrolysis-activation and HF post-desilication process. This paper was focused on investigating the boosting effect and mechanism of post-desilication. It was found that the function of the post-desilication was considerably different from that of the reported pre-desilication. It could not only effectively remove Si element from rice husk biochar (RHC) but also significantly improve its performance, producing a super-biocarbon with a well-developed pore structure, rich C-F groups, and a 4230-m2 g−1 surface area, which is the max surface area of known biocarbon. It could adsorb 341.5 mg g−1 CO 2 , a max CO 2 adsorption capacity of reported biocarbon, and its CO 2 /N 2 and CO 2 /H 2 O adsorption selectivity index reached as high as 22.2 and 2.1, respectively. The large surface area was mainly originated from the expansion effect of SiF 4 gas from the post-desilication, generating numerous ultra-microspores, while these C-F groups were generated by the co-reactions of the post-desilication. The ultra-high adsorption capacity was mainly from the fill-adsorption driven by the size effect of these ultra-micropores and the strong CO 2 -affinity of C-F groups, and the adsorption selectivity was confirmed to depend on water-resistant and CO 2 -philic characteristics of its C-F groups by theoretical calculations and experimental observations. These findings presented not only an advanced CO 2 -capture material but also a facile way to tailor textural structure of other biochars. [ABSTRACT FROM AUTHOR]

The use of sacrificial agents in photocatalysis is a powerful resource to enhance the performance of photoactive materials. Despite its importance, the effect of the amount of sacrificial agent is not properly described in the literature. In this paper, we have focused on the role of EtOH in the photoreduction of CO 2 to CH 4 using Cu-P25 photocatalysts in a flow reactor. We found that the production of CH 4 increased with the concentration of EtOH, achieving an outstanding CH 4 production yield of 235 µmol/(g·h) for a flow of 0.25 µmol/min of EtOH in the gas stream, hinting at the important role of the sacrificial agent in the reaction. The catalytic results together with the characterization of the materials highlight the need to achieve a minimum surface coverage of EtOH on the surface of the catalyst to control the reaction pathway. The adsorption of EtOH is a key factor in boosting the catalytic activity of the best-performing catalyst and producing CH 4 from CO 2 photoreduction and C 2 H 4 O from the photooxidation of EtOH, obtaining two easily separable interesting products for industrial applications in one reaction. • Ethanol was used as sacrificial agent to boost the photocatalytic reduction of CO 2. • The scavenger (EtOH) is a key part of the reaction pathway in the CO 2 photoreduction. • Cu x O in intimate contact with the TiO 2 phase increases the lifetime of the e--h+ pair. • Cu-doped TiO 2 is an excellent tandem catalyst capable of producing C 2 H 4 O and CH 4. [ABSTRACT FROM AUTHOR]

• Shadow pricing is a popular method for abatement cost estimation. • Most previous studies ignore the materials balance condition. • Materials balance consistent Convex Nonparametric Least Squares estimator developed. • Shadow prices for 160 US power producers from stochastic and deterministic models. • Abatement costs severely understated when the materials balance is ignored. Marginal abatement cost is an essential input to optimal environmental policies. Shadow pricing has become a popular method for estimating abatement costs subject to parsimonious data requirement. This paper provides a novel contribution to the literature on shadow pricing by considering the implication of the materials balance principle for shadow prices. To that end, the paper establishes a Convex Nonparametric Least Squares estimator for the weak G-disposable production model, which for the first time enables modeling a composite error term and joint estimation of the production frontier and contextual variables within this production model framework. Applying the Directional Distance Function, environmental efficiencies and shadow prices for carbon dioxide emissions are estimated for a sample of power producers using both stochastic and deterministic frontier models. Average shadow price estimates for carbon dioxide range between 14,000 and 40,000 $/ton CO 2 for the weak G-disposable model and between 70 and 77 $/ton CO 2 for the conventional production model that ignores the materials balance. These findings cast doubt on previous shadow price estimates since a majority of comparable studies ignore the strict technical relationship among pollution-generating inputs and bad outputs under the materials balance condition. [ABSTRACT FROM AUTHOR]

Transition metal carbides as promising electrode materials for lithium ions batteries (LIBs) have attracted wide attentions due to high conductivity and capacity. In this paper, dual-phase VC-C as anode materials of LIBs is designed and synthesized through green and controllable in-situ electroconversion from CO 2 and NaVO 3 in molten salt. Three products including dual-phase VC-C (VC–C), vanadium carbide doped by carbon (VC-DC) and carbon doped by vanadium carbide (C-DVC), are prepared by the effective regulation during molten salt electrolysis. It is confirmed that dual-phase VC-C as anode materials of LIBs exhibits the best charge/discharge performance and cycling stability. At current density of 0.1 A g−1, the stable reversible capacity can reach to 652.3 mAh g−1. Even at a high current density of 1.0 A g−1, the reversible capacity maintains about 300 mAh g−1 after 600 cycles. The capacity retention is as high as 98.4%. The average capacity loss of per cycle is only 0.0027%. The dual-phase VC-C through sustainable electroconversion from CO 2 and NaVO 3 in molten salt is of good promising anode materials for LIBs. [ABSTRACT FROM AUTHOR]

The economic advantage of membrane-based CO 2 separation technology is more prominent with the development of high-performance membrane materials. The amino-containing fixed carrier membranes with excellent CO 2 separation performance show great potential, especially in post-combustion CO 2 capture. However, the reaction and transport mechanism between CO 2 and amino groups has rarely been systematically investigated due to the limitation of experimental characterization. In this paper, quantum chemistry computations and molecular dynamic simulations are used to analyze the effect of amino density and water in fixed carrier membranes containing primary amino groups. Research result shows that as the spacing between amino groups increases, bicarbonate plays an increasing role in the facilitated transport mechanism due to the gradual increase of reaction energy barrier in carbamate scheme. In the dry PVAm, the reaction energy barrier is 69 % higher than the bicarbonate mechanism and the diffusion coefficient is two orders of magnitude lower than the humid PVAm, which are the reasons for limiting the facilitated transport mechanism and membrane separation performance. Water molecules can provide a polar environment conducive to reactions, directly participate in the reaction process and form highly mobile continuous water clusters for gas high-speed diffusion. Regulating the nitrogen atom spacing of amino group to be less than 3.1 Å and constructing abundant CO 2 transport channels may achieve weakly humidity-dependent facilitated transport membranes. [Display omitted] • The reaction mechanism between CO 2 and primary amino groups is studied systematically. • Low amino density leads to high reaction energy barrier. • Water molecules assist in proton transfer to facilitate the reactions. [ABSTRACT FROM AUTHOR]

In recent years, a two-phase thermosyphon loop (TPTL) with auxiliary devices has been widely studied to improve the application effect of the TPTL in data centers. This paper proposed a controllable CO 2 TPTL with valve regulation. The valves were positioned on the riser and downcomer, respectively. Through experimental investigations, the dynamic response characteristics of the TPTL under different regulation modes were thoroughly analyzed. A comparative study of the regulation performance across various modes was conducted. The results demonstrated that valve regulation substantially broadened the normal working load range (NWLR) of the TPTL. Under modes R, D, and RD, the NWLR expanded to 590–1300 W, 340–1300 W, and 340–1300 W, respectively, from the original range of 700–1300 W. Following valve regulation, the temperatures and pressure drops of the TPTL underwent transient changes, with varying amplitudes. Among the three regulation modes, mode D exhibited the most stable dynamic response process and showcased the most effective regulation performance. • A controllable CO 2 TPTL with three valve regulation modes. • Dynamic response characteristics of the TPTL after valve regulation. • Normal working load range of TPTL was effectively expanded by valve regulation. • Regulation performance was the best when adjusting the valve on the downcomer. [ABSTRACT FROM AUTHOR]

With the intensification of ecological environment problems and the improvement of public awareness of ecological civilization construction, as well as the global warming and climate change caused by excess CO 2 in the atmosphere, the problem of excessive CO 2 emission has received extensive attention globally in recent years and researchers have focused their attention on the technology of CO 2 capture, utilization and storage (CCUS). CO 2 cycloaddition with epoxide, as an efficient approach to fix and convert CO 2 , can solve the environmental concerns and reduce the dependence on fossil fuels simultaneously, is a promising way for CO 2 utilization. The CO 2 cycloaddition process usually requires catalysts, and zeolite-like imidazolate frameworks (ZIFs) have received extensive attention as a novel and effective catalyst due to its unique physical and chemical properties. Many ZIFs based or derived catalysts with different structures and functions have been developed to achieve efficient catalysis of CO 2 cycloaddition with epoxide. In addition, effects have been made to design suitable catalytic materials and reveal the process mechanism, thus promote the industrialization of the process. In this paper, the recent research progress in the use of ZIFs based or derived catalysts to catalyze this reaction is reviewed, with emphasis on the design, mechanism for the catalysis, as well as the challenges and future prospect for the catalytic system. • ZIFs and ZIFs-based materials for catalytic CO 2 cycloaddition are reviewed. • Design concept of ZIFs and ZIFs-based catalysts and reaction mechanism are summarized. • The challenges and future prospect are concluded for the catalytic system. [ABSTRACT FROM AUTHOR]

The pyro-hydrolysis method is a crucial way to treat calcium chloride (CaCl 2)-containing solid waste to achieve environmental friendliness and efficient utilization. In this paper, we have conducted both DFT (density functionary theory calculation) calculations and experiments by flowing carbon dioxide (CO 2) and steam (H 2 O) on the CaCl 2 in a fluidized bed. The thermogravimetric analysis reveals that the pro-hydrolysis reaction can proceed more vigorously at temperatures ranging from 300 to 500 °C. The structure characterization of residues collected from the pyro-hydrolysis of CaCl 2 was characterized using X-ray diffraction (XRD), X-ray Photoelectron Spectrometer (XPS), and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS). The XRD patterns show that a small amount of CaCl 2 was decomposed into calcium chloride hydroxide (Ca(OH)Cl) in a fluidized bed with O 2 at temperatures above 450 °C. Nevertheless, with the presence of CO 2, CaCl 2 can convert into calcium carbonate (CaCO 3) at a lower temperature. The SEM-EDS displays a swelling structure that appears on the CaCl 2 particles surface after the thermal decomposition with CO 2 , and the content of Cl element at a specific position is significantly reduced. DFT calculations is shown that when CO 2 and H 2 O are bonded to form a carbonic acid complex adsorbed on the surface, the energy barrier for the rupture of the H-OH bond and Ca-Cl bond is dramatically decreased, and the dissociated H+ combined with the Cl- to form hydrogen chloride (HCl). The overall reaction pathway only adsorbs 1.099 eV energy. This research is useful for promoting knowledge of the chlorine evolution mechanism for pyro-hydrolysis of CaCl 2 in CO 2 atmosphere. [Display omitted] • CO 2 promotes the conversion of CaCl 2 into CaCO 3 below 500 °C. • The microstructures of CaCl 2 after CO 2 -assisted pyro-hydrolysis facilitates the release of Cl element. • The CO 2 and H 2 O molecules are bonded to form a carbonic acid complex to compensate for the reaction energy requirement. [ABSTRACT FROM AUTHOR]

Acid gas enrichment (AGE) is a new method to increase the H 2 S conversion in conventional Clause process. In this paper effect of methyl diethanolamine (MDEA) flow rate, MDEA temperature, acid gas flow rate, and AGE tower pressure on the outlet H 2 S and CO 2 concentration and energy consumption have been studied. A novel procedure based on enthalpy of combustion in the reaction furnace and incinerator is conducted for energy consumption calculations. By changing MDEA and inlet acid gas flow rates, a maximum H 2 S concentration in the enriched stream could be attainable. Increasing MDEA temperature will decrease maximum H 2 S concentration and enriched acid flow rate; also, CO 2 concentration in off-gas will be decreased. By increasing AGE pressure, maximum H 2 S concentration in the enriched stream will be diminished. At higher MDEA flow rates, lower AGE pressures will bring higher H 2 S concentration in enriched acid gas stream. According to flame temperature simulation in the reaction furnace, energy consumption is directly related to H 2 S concentration in the sulfur recovery unit (SRU) feed stream. Results show that maximum H 2 S concentration in the enriched acid gas stream has the best conditions from energy point of view. At optimum conditions, H 2 S concentration in enriched acid gas is 62.45 mol%, which has been increased by 24.8%, compared with existing plant conditions, and energy consumption has been decreased by 25.05 GJ/h, and CO 2 concentration in off-gas is 94.94 mol%. • Study the effect of process variables on the AGE streams by ProTreat software. • Determine the relation between reaction furnace temperature and H 2 S concentration. • Generate an EES procedure for heat of combustion in reaction furnace. • Evaluate the fuel gas consumption and therefore energy consumption. • Multi-objective optimization based on the TOPSIS method. [ABSTRACT FROM AUTHOR]

Efficient cooling of the trans-critical CO 2 vapor compression cycle to improve system performance is a crucial research topic. This paper proposes an innovative approach called distribution compression (DC) to achieve the same effect as subcooling in a trans-critical CO 2 thermodynamic cycle. In the DC system, the trans-critical CO 2 at the gas cooler outlet is no longer further cooled but subjected to a secondary pressure boost and releases heat in ordinary heat sink conditions as in the gas cooler. Thermodynamics calculated the change in performance of the DC system under different working conditions with different secondary boost ratios. The optimal secondary boost ratio related to evaporation and gas cooler outlet temperatures under optimal discharge pressure based on the baseline system was obtained. The results show that compared with the baseline system, the DC system can effectively improve the system performance, and the maximum refrigeration COP increase is between 8.2 % ∼ 10.76 %, and the maximum heating COP increase is between 5.37 % ∼ 6.34 %. The cooling or heating capacity increase can reach up to about 26 %. The ideal secondary boost ratio in a DC system is not highly demanding, and the increased input power for the second input power for the secondary boost will not exceed 20 % relative to the baseline system. Comparing the COP of the DC system over current systems that only use a single subcooling technology still shows advantages. The DC system provides a new idea to improve the performance of the trans-critical CO 2 vapor compression cycle. [ABSTRACT FROM AUTHOR]

The fluid inclusions in mantle rocks and melt indicated that a large amount of CO 2 fluid exists in the deep earth, which is of great significance for understanding the deep carbon cycle and the composition of mantle. However, it was also suggested that carbonate minerals were likely to be the main host of mantle carbon. At the same time, the distribution and behavior of carbon in the mantle still remain a puzzle. In this paper, the adsorption behavior and occurrence characteristics of supercritical CO 2 in magnesite (MgCO 3) pores were studied by the Grand Canonical Monte Carlo method (GCMC) under the different conditions of CO 2 pressures (0–100 ​MPa), temperatures (350–1500 ​K) and the pore sizes (7.5–30 ​Å). The simulated results showed that the adsorption of CO 2 in magnesite was a physical adsorption, which was mainly controlled by the intermolecular force. The gas adsorption became more stable when the adsorption site shifted from the high energy site to the low energy site with increasing pressure (P) and decreasing temperature (T) and pore size. At the same time, the variations of excess adsorption amounts of CO 2 in the pores of magnesite (N excess) under the different conditions were quantitatively calculated. It was found that the N excess decreased with increasing T, but increased with increasing P and pore size. The results favor understanding the CO 2 migration, seismic precursor observations, and heat transfer process in the deep earth. Image 1 • Simulation proved adsorption of CO 2 ​in magnesite is a physical adsorption and mainly controlled by intermolecular forces. • CO 2 ​adsorption in magnesite pore became more stable with increasing pressure and decreasing temperature and pore size. • The smaller pores of magnesite have a stronger adsorption for CO 2 ​than that bigger size ones. • Excess adsorption amounts of CO2 in magnesite pore decrease with increasing T, but increase with increasing P and pore size. [ABSTRACT FROM AUTHOR]

This paper assesses the potential of plastics valorization by pyrolysis and in line catalytic dry reforming for syngas production. Previous studies showed the suitability of a continuous process made up of a conical spouted bed reactor for fast pyrolysis and a fluidized bed reactor for catalytic steam reforming. In order to step further in the application of this technology under dry reforming conditions, equilibrium simulation was approached to analyze process performance, as the development and optimization of this technology for the production of high-quality syngas requires understanding in detail the complex influence of process parameters. Thus, this study deals with the influence of main process parameters, namely, temperature, CO 2 /C ratio and the type of plastic, on the process performance. Furthermore, the role played by steam co-feeding in the dry reforming in order to adjust syngas H 2 /CO ratio was evaluated by varying the steam/carbon ratio. The obtained results clearly show that a strict control of process conditions is required to ensure high conversion to syngas and avoid undesired reactions, such as reverse WGS. Among the plastics studied, polyolefins are those of highest potential for syngas production, but polystyrene allows producing a high quality syngas through a combined reforming strategy. [Display omitted] • Pyrolysis-dry reforming process ensures the joint valorization of CO 2 and plastics. • Equilibrium simulation approach was used for the evaluation of plastics dry reforming. • The role of temperature, type of plastic, CO 2 /C and S/C ratios was evaluated. • H 2 productions higher than 11% can be obtained in the dry reforming of polyolefins. • Combined dry-steam reforming allows for tuning the syngas H 2 /CO ratio. [ABSTRACT FROM AUTHOR]

Mesoporous FeAlOx based catalysts were designed through framework-confined strategy for the oxidative dehydrogenation of 1-butene with CO 2. Framework-confined catalyst improved the mobility of oxygen species and released more active oxygen species, and thus 1-butene conversion and 1, 3-Butadiene (BD) selectivity increased. Cr and Ca doped could improve the basicity of the catalyst and had a higher utilization rate of CO 2. [Display omitted] • A framework-confined strategy was used to effectively improve the lattice oxygen. • The doping of Cr species could effectively improve the stability and reduce the coke formation. • The doping of Ca species could effectively improve the basicity of the catalyst and the utilization rate of CO 2. The activation of oxygen species is always a challenging problem in the oxidative dehydrogenation (ODH) of 1-butene with CO 2. The oxygen species play an important role in improving the conversion, yield, selectivity, and stability of FeAlO x -based catalysts. In this paper, the framework-confined (FC) strategy was used to active the oxygen species. The changed crystalline phase from Fe 2 O 3 to FeAlO 4 illustrated the introduction of Fe species destroyed the Al 2 O 3 lattice and more active oxygen species were released. Compared with the WI-Fe 2 O 3 /Al 2 O 3 samples, the ratio of active lattice oxygen was increased from 0.03 to 0.1 and the ratio of Fe3+ was also increased from 0.63 to 0.76 in the FC-FeAlO x samples. After doping with other metal species, the ratio of active lattice oxygen was further increased. The 1-butene conversion could reach 80 % and the 1, 3-Butadiene selectivity could reach 33 % over the FC-FeCrAlO x samples. Besides this, the FC-FeCrAlO x samples showed an outstanding thermal stability, which might be caused that Cr species could reduce the coke formation. The FC-FeCaAlO x samples had a higher utilization rate of CO 2 , which might be caused that Ca species could improve the basicity of the catalyst. [ABSTRACT FROM AUTHOR]

Given the all-encompassing environmental challenge facing the automotive industry the weight of the car is one essential factor that has an effect on CO2 emissions for both conventional cars and for Electric Vehicles and Hybrid Electric Vehicles. Even though automakers understand and have largely mastered the technical difficulties involved with alternatives to the all-steel body, the mainstream industry has nevertheless for the most part retained it. The purpose of this paper is to explore the SåNätt lightweight project as a concrete example of how two Swedish automakers (Saab and Volvo) have approached the lightweight challenge, but also to conceptualize the project in terms of what hinders and enables environmental innovations in the automotive industry. The result of the study indicates fundamentally different approaches between the automakers. While Saab focused on radical development of new concepts aiming to build a supplier structure for collaboration, Volvo focused on incremental development emphasizing short-term implementation. The empirical data also reveals a tendency for Volvo to be more deeply committed to its infrastructure for body manufacturing (the production of the all-steel body), thus hindering more radical changes. The paper concludes by highlighting a paradox emerging from the case, questioning whether established actors in the automotive industry can effectively deal with the environmental challenge. [ABSTRACT FROM AUTHOR]

Abstract: CO2-enhanced oil recovery (CO2-EOR) has emerged as a major option for productively utilizing CO2 emissions captured from electric power and other industrial plants. Not only can oil fields provide secure, well characterized sites for storing CO2, they can also provide revenues to offset the costs of capturing CO2. Though utilization of captured CO2 emissions for enhanced oil recovery has been underway for some time, further advances in CO2-EOR technology could significantly improve the technology's applicability as a revenue generator for CO2 capture and a large-scale CO2 storage option. With application of “next generation” CO2-EOR technologies in geologically favorable settings, the volume of CO2 stored could exceed the CO2 content of the oil produced. The paper draws significantly on the recently completed report sponsored by the U.S. Department of Energy, National Energy Technology Laboratory (U.S. DOE/NETL) and prepared by Advanced Resources International entitled, “Improving Domestic Energy Security and Lowering CO2 Emissions with “Next Generation” CO2-EOR”. The paper introduces the feasibility of applying “next generation” CO2-EOR technologies to new, challenging areas, such as to residual oil zones (ROZs) below and beyond the structural confinement of existing oil fields and to offshore oil fields. The paper provides a case study that tracks the performance and the economics of CO2-EOR in the Permian Basin of West Texas. While much of the information in the paper is drawn from the CO2-EOR experiences in North American oil fields, the paper also examines the CO2 utilization and storage potential from applying “next generation” CO2-EOR technology to the large oil fields of the world, drawing on extensions of work performed by Advanced Resources International for the IEA Greenhouse Gas R&D Programme. The paper concludes with two key messages. First, with application of “next generation” technologies to a broader set of oil resources, the market for utilization of CO2 for enhanced oil recovery is much larger than previously assumed. Second, the revenues from the sale of captured CO2 emissions, along with research that reduces the costs of CO2 capture, can greatly accelerate the time when CCS (now CCUS) can be applied at wide scale. [Copyright &y& Elsevier]

Abstract: The Alberta Carbon Trunk Line Update on the Words's Largest Carbon Capture and Storage Project Enhance Energy Inc. (Enhance), located in Alberta, Canada, specializes in Enhanced Oil Recovery (EOR) and Carbon Capture and Storage (CCS). Along with its partner North West Redwater Partnership (NWRP), Enhance has developed a fully integrated CCS project incorporating gasification, CO2 capture, transportation, storage and EOR. The project utilizes proven technology to provide a critical CO2 gathering and distribution infrastructure, which will enable the cost-effective management of CO2 emissions in Alberta, Canada. The project also demonstrates how Alberta's vast bitumen resources can be produced amid tightening environmental standards. At the heart of the proposed project is the Alberta Carbon Trunk Line (ACTL), a 16”, 240km pipeline, which will be fully operational in 2015. Laterals have been designed to allow for multiple entry points. CO2 will be collected from various emitters such as coal fired power plants, upgrading/refining operations, petrochemicals and natural gas processing plants in and around Alberta's lndustrial Heartland. The CO2 will then be transported to aging reservoirs in southern Alberta for storage in EOR projects. The ACTL will be able to access reservoirs which are capable of storing over two billion tonnes of CO2, and producing an additional one billion barrels of high quality light crude oil using CO2 EOR. The ACTL will initially capture and store up to 1.6 million tonnes/year of CO2 from the Agrium fertilizer manufacturing facilities and North West Redwater Partnership Sturgeon Refinery (NWRPSR). At full capacity the ACTL project will store 14.6 million tonnes/year of CO2, the equivalent of removing 2.6 million cars from Alberta's roads, the ACTL project will be the word's largest Once fully operational CCS development. This paper will provide an update on the progress being made on the project as the ACTL has moved passed the regulatory phase and is now completing detailed engineering, with procurement underway. The ACTL has received regulatory approval for its pipeline construction and landowners along the entire pipeline route are supportive of the project. The presentation will address the project's development and stress the importance of the support from stakeholders. The paper will also outline the benefits of the project, and will explain how it balances environmental sustainability and economic viability while garnering public support The project is significantly advanced and is being financially supported by the Governments of Alberta and the Government Canada; the former through the Carbon Capture and Storage Program in the amount of $495MM CDN, and the latter through the ecoEnergy Technology Initiative and Clean Energy Fund in the amount of $63MM CDN. The estimated total cost of the full project is $1.15B CDN. Susan Cole will present the paper at the GHG-T 11 Conference. Susan is the founder and President of Enhance. Ms. Cole is a professional engineer with over 20 years of experience in the energy industry. Prior to founding Enhance, Ms. Cole was manager of the Weyburn CO2 Project in Saskatchewan, Canada, which is the largest industrial CO2 capture, transportation, and EOR/secure storage project in the world. She managed initial approval, facility construction and start-up phases of this project. As project manager she was responsible for the project implementation, including overall project coordination, economic modeling and start up. The Weyburn project is currently injecting over 6,000 tonnes of CO2 a day (or two million tonnes of CO2 a year) and is very similar in design and concept to the ACTL CCS-EOR project. [Copyright &y& Elsevier]

Abstract: Following the introduction of the European Union Emissions Trading Scheme in 2005, the size of the carbon market has been growing at a tremendous rate. To meet the emissions reduction targets, the regulated parties can choose to participate in the allowance-based market by purchasing the spot allowances. Commencing in 2008, the regulated parties are also allowed to purchase the offset credits to meet their allowance limit. Given the risky nature of the offset credits, this paper evaluates the hedging performance of dynamic hedge ratios for the carbon offset credit (certified emissions reduction) market in the EU-ETS. To the best of our knowledge, this paper is the first attempt to evaluate the hedging performance of dynamic and constant hedge ratios in the carbon offset credit market. Based on the variance reduction and utility improvement measurements, the findings generally support the use of static hedge ratios over the more sophisticated, dynamic hedge ratios. [Copyright &y& Elsevier]

Abstract: The application of Carbon Capture and Storage (CCS) technology to energy-intensive processes is starting to attract attention, presenting an opportunity for developing multi-user CO2 transportation networks. Recognising that most industrial facilities have not been designed with CCS in mind, this paper begins by looking at the practical issues associated with retrofitting CCS to industrial facilities. It then explores the technical and legal issues associated with building a CO2 network. This is followed by an analysis of the costs involved. Having identified the key issues, a case study from North East England is presented as an example of what is possible in an area of high CO2 emissions. The paper concludes by considering the issues involved in sizing a CO2 network which can evolve to meet future needs and linking that to the development of policy. [Copyright &y& Elsevier]

As a country with the highest CO 2 emissions and at the turning point of socio-economic transition, China's effort to reduce CO 2 emissions will be crucial for climate change mitigation. Yet, due to geospatial variations of CO 2 emissions in different cities, it is important to develop city-specific policies and tools to help control and reduce CO 2 emissions. The key question is how to identify and quantify these variations so as to provide reference for the formulation of the corresponding mitigation policies. This paper attempts to answer this question through a case study of 26 cities in the Yangtze River Delta. The CO 2 emissions pattern of each city is measured by two statistics: Gini coefficient to describe its quantitative pattern and Global Moran's I index to capture its spatial pattern. It is found that Gini coefficients in all these cities are all greater than 0.94, implying a highly polarized pattern in terms of quantity; and the maximum value for Global Moran's I index is 0.071 with a standard deviation of 0.021, indicating a weak spatial clustering trend but strong difference among these cities. So, it would be more efficient for these cities at current stage to reduce CO 2 emissions by focusing on the large emission sources at certain small localities, particularly the very built-up areas rather than covering all the emission sources on every plot of the urban prefectures. And by a combination of these two metrics, the 26 cities are regrouped into nine types with most of them are subject to type HL and ML. These reclassification results then can serve as reference for customizing mitigation policies accordingly and positioning these policies in a more accurate way in each city. Image 1 • Most updated China high resolution emission database (CHRED). • CO2 emission is examined on a grid scale (1 km*1 km). • A two-dimension framework is used to capture the emission feature. • Cities are grouped with more customized mitigation policies. [ABSTRACT FROM AUTHOR]

• Wellbore and reservoir coupled fluid flow and heat transfer model is presented. • Thermal characteristics of CO 2 in wellbore are comprehensively analyzed. • Effect of CO 2 pressure work on wellbore temperature distribution is studied. • Heat insulation effect of central tube with three-layer structure is discussed. • Effects of wellbore sizes on CO 2 fluid flow and heat transfer are studied. Research efforts towards CO 2 enhanced geothermal systems (CO 2 -EGS) are increasing due to potentially high heat extraction efficiencies. It is well known that CO 2 properties are highly sensitive to the temperature and pressure and have noticeable effects on CO 2 -EGS heat extraction. Consequently, an understanding of wellbore CO 2 fluid flow and heat transfer mechanisms is necessary when considering variable CO 2 properties. In this paper, a coupled wellbore and reservoir fluid flow and heat transfer model is used to estimate multilateral-well CO 2 -EGS efficiency. The model is calibrated and validated by field data from the HGP-A well in Hawaii. Schematically, concentric tubulars are used allowing single well injection and production. Multiple cases are analyzed using this model. These include effects of CO 2 pressure work on wellbore CO 2 fluid flow and heat transfer, assessment of differences in heat extraction using varying wellbore sizes and central tubing insulation lengths, and evaluations of efficiencies under different injection-production well configurations. Results show that CO 2 pressure work can induce a dramatic temperature reduction in the central tubing of the multilateral-well CO 2 -EGS. The majority of pressure loss occurs in the formation and central tubing. The optimized design suggests that a three-layer central tubing with a central diameter of 0.19 m will maximize heat insulation and heat extraction. The effect of annulus diameter on heat extraction is negligible. Also, a lower injection well configuration results in a higher outlet temperature, thermal power output, and lower pressure losses compared to an upper injection well configuration. These results provide significant suggestions for wellbore designs that can potentially optimize multilateral-well CO 2 -EGS efficiency. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • The paper addresses the problem of designing an industrial symbiosis network. • Mass integration is used to create opportunities for the conversion of CO 2 into value-added chemicals. • A multiscale targeting approach is developed. • Optimization is used to aid process synthesis with economic and environmental objectives. Abstract Carbon dioxide (CO 2) has significant potential as a chemical feedstock as it is an abundant source of carbon atoms, entails zero or negative acquisition costs and utilization reduces environmental impact. However, significant challenges remain as the use of this feedstock involves unfavorable thermodynamics in reaction and separation, material transportation and end use application. Opportunities exist to overcome these limitations especially within eco-industrial parks which involve a group of facilities cooperating by exchanging materials and energy. An important class of EIPs, Carbon-Hydrogen-Oxygen SYmbiosis Networks (CHOSYN), has been recently introduced to integrate hydrocarbon streams from multiple plants while allowing for chemical conversion (in addition to the conventional exchange, separation, and allocation) through a multiscale targeting approach. The objective of this work is to address the problem of designing a CHOSYN with the conversion of CO 2 into value-added chemicals while reducing the carbon footprint for the whole system. A multi-scale synthesis and optimization approach is proposed. First, atomic-level information coupled with economic data are used to establish benchmarks for the utilization of process streams, the purchase of external sources, and the discharge of CO 2. A pre-synthesis approach is adopted to develop optimal policies for the CO 2 -separation technologies. Candidate CO 2 -utilization reactions are integrated with the existing plants to produce value-added chemicals while addressing economic and environmental objectives. Carbon-footprint constraints are added based on life-cycle analysis of the used sources and energy associated with the various reaction and separation steps. This systematic procedure captures significant interactions between surrounding CO 2 sources and CO 2 sinks while reducing the difficulty of selection and design of the CO 2 capture process. A case study is developed and solved to demonstrate the application of this new method. [ABSTRACT FROM AUTHOR]

The composition and size of the passenger car fleet is often influenced by legislation and policy, including taxation, scrappage, and vehicle registration policies. Numerous measures at national and international level have been investigated to reduce the air pollution and/or climate change impacts of passenger fleets. However, the objectives of climate change and air pollution policy occasionally are conflicting, and this has resulted in a number of well publicised policy shortcomings. This paper outlines the development of a fleet emissions control (FEC) framework which enables the dynamic and adaptive optimisation of fleet emissions through changes in taxation policy in Ireland. The data for analysis was obtained from national sources including datasets from the national emission inventory and COPERT model. Applications of regression-based modelling and statistical analysis were conducted to predict fleet, mileage, and emissions changes. The results of the FEC framework showed that no increase in NO x emissions, above 2007 levels, could be achieved at a cost of a small increase in CO 2 in 2016 (+1.8%). This could be achieved by taxation policy primarily resulting in a shift away from small engine diesel vehicles (<1.4 L) in the fleet which were responsible for the largest contribution to emissions. In the transition of vehicle fleets to full electrification or full decarbonisation, the FEC framework developed here offers the potential to formulate practical and optimised adjustments in static taxation systems. These adjustments will assist in achieving the requirements of national policies on reducing emission. • A Fleet Emissions Control Framework for passenger cars was developed enabling practical optimisation of fleet emissions. • Incentivising one vehicle category over another, is a complex process with potentially positive and negative outcomes. • Incentivising diesel or petrol each have negative consequences. • Policy should incentivise a fleet composition which optimises the total emission. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract The establishment of a miscible phase between CO 2 and crude oil can significantly improve CO 2 flooding efficiency. However, the minimum miscibility pressure (MMP) between CO 2 and crude oil is usually higher than the fracture pressure of the formation, how to reduce the MMP between CO 2 and crude oil is very important, and there are fewer related studies. Our inspiration for reducing MMP comes from the unique dispersion characteristics of CO 2 in alcohol, the intermolecular force of crude oil may decrease due to the existence of alcohols. In this paper, the CO 2 solubility and the oil volume expansion with adding a variety of alcohols (1-butanol, 1-pentanol and 1-hexanol) were measured by a visible high temperature and high pressure cell from 7 MPa to 20 MPa at 343.15 K. The MMP between CO 2 and crude oil is predicted by measuring the interfacial tension (IFT) between CO 2 and crude oil from 2 MPa to 43.3 MPa at 343.15 K. The results showed that the CO 2 solubility in crude oil and the oil volume expansion were greatly improved due to the addition of alcohols. Especially 1-butanol, 1-pentanol and 1-hexanol were mixed by 8:1:1(volume ratio), 5% (volume ratio) alcohols mixture was added to the crude oil, the CO 2 solubility in crude oil increased by 28.74% at 345.15 K and 19 MPa, and the volume expansion coefficient of crude oil also increased by 4.45% at 345.15 K and 14 MPa. It is encouraging to note that the MMP between CO 2 and crude oil decreases by 9.21% after adding 5% alcohols mixture into crude oil. This article is able to provide a new technique for reducing the MMP between CO 2 and crude oil in the field of enhanced oil recovery. [ABSTRACT FROM AUTHOR]

In the process of transporting refrigerated vehicle, the respiration of agricultural products after collection produces CO 2 and other gases, resulting in pollution, deterioration, and waste. This paper uses TDLAS technology to design the CO 2 detection system in refrigerated compartments, which is specially designed to deal with external disturbance factors such as detector noise, optical interference fringes and low temperature in refrigerated compartments. At last, it analyzes several CO 2 data preprocessing methods, for example, starting point alignment, bulky error rejecting, sampling point wavelength corresponding, multicycle average, smooth filtering and eigenvalue extraction. The experiment shows that the data preprocessing method of current tuning in this system can accurately detect CO 2 in refrigerated compartments. The total average relative concentration error is 1.2%, and the root mean square error is 0.07%, which provides a reliable technical support to food quality improve and refrigerated preservation of agricultural products. [ABSTRACT FROM AUTHOR]

Abstract The development of renewable energies was impressive in recent years on a global scale. This produced changes regarding production processes, citizens' habits, industrial investments and consumer decisions. In this context, the policy-maker played a crucial role. The subsidies are able to determine the development of a specific market. Biogas market spread globally, while biomethane market concentrated in some territories. Green gas can be used as vehicle fuel or injected into the gas grid but also burnt for co-generation. The present work proposes a techno-economic analysis for an existing biogas plant. In particular, the analysis was focused on the comparison between two possible strategic plans, in order to establish which one was the best in terms of profitability: the first one is the expansion of the plant to upgrade biogas to biomethane, whereas the second one is to continue the production of biogas as planned when the plant was constructed. The Discounted Cash Flow (DCF) method was proposed in this paper, and the Net Present Value (NPV) is the main index used. One 250 m3/h biomethane plant located in Italy using pressure swing adsorption (PSA) technique is analysed. The results demonstrated the positive environmental impact deriving from the use of zeolites synthesized from spent fly ash and the profitability is verified only in some scenarios. However, they are limited only to the construction of new biomethane plants, while the upgrading of existing biogas plants are always unprofitable. A Break-Even Point (BEP) analysis quantifies the value of subsidies of biogas and biomethane by which the profitability could be reached. Biomethane can contribute to the development of circular economy models, while the sustainability targets are achieved only in some scenarios. [ABSTRACT FROM AUTHOR]

Abstract: Dimethyl ether (DME) has been discussed as a potential fuel for both combustion and fuel cell applications. This paper evaluates the ability for membranes to separate DME from syn-gas components, such as H2 and CO. Separations from CO2 and CH4 also are discussed. Experiments performed include permeability and selectivity of these gases through poly(4-methyl-1-pentene) (TPX) and poly(dimethylsiloxane) (PDMS) using variable temperature mixed gas experiments. The DME data is the first to be reported through these membranes. In this paper, the chosen polymers reflect both rubbery and semicrystalline materials. Rubbery polymers tend to be weakly size sieving, which, in this work, has resulted in larger permeabilities, lower separation factors, and lower activation energies of permeation (E p). Conversely, the semicrystalline TPX membranes showed much greater sensitivity to penetrant size; although the gas condensability also played a role in transport. [Copyright &y& Elsevier]

Abstract: With the growing concern about climate change, interest towards reducing CO2 emissions has increased. Geological storage of CO2 is perceived to be one of the most promising methods that could provide significant reduction in CO2 emissions over the short and medium term. Since a major concern regarding geological storage is the possibility of leakage, trapping CO2 in the solid form is quite attractive. Unlike mineral trapping, the kinetics of CO2-hydrate formation is quite fast, providing the opportunity for long-term storage of CO2. In this paper, we study storage of CO2 at conditions similar to those at depleted gas pools of Northern Alberta. Thermodynamic calculations suggest that CO2 hydrate is stable at temperatures that occur in a number of formations in Northern Alberta, in an area where significant CO2 emissions are associated with production of oil sands and bitumen. Numerical simulation results presented in this paper suggest that, upon CO2 injection into such depleted gas reservoirs, pressure would initially rise until conditions are appropriate for hydrate formation, enabling storage of large volumes of CO2 in solid form. These results show that, because of tight packing of CO2 molecules in the solid (hydrate), the CO2 storage capacity of these pools is many times greater than their original gas-in-place. This provides a local option for storage of a portion of the CO2 emissions there. [Copyright &y& Elsevier]

Abstract: Climate change mitigation is a dynamic area that, as it is addressed, brings new challenges to other environmental aspects. Carbon capture and storage (CCS) plants are the latest development in a series of environmental controls and have some distinctive features that could potentially lead to other wider environmental problems. Whilst CCS represents a significant step towards cutting greenhouse gas emissions, consideration needs to be given to the potential wider environmental consequences especially in terms of pollutant emissions and local air quality impacts. Challenges remain for existing plants which will need to consider the most cost-effective strategies for installation of CCS plant balanced against managing air quality impacts as dispersion characteristics change. In the case of post-combustion carbon dioxide (CO2) capture technology, which is the focus of this paper, removal of CO2 from the main flue gas stream requires diversion of the flue gas through the CCS process, before it arrives at the exhaust stack. This flue gas stream may be all or part of the total plant flow or for multi-unit plants may be diverted from specific power generation units into the CCS plant before exhausting to atmosphere, either through returning back to the existing stack or through a new dedicated stack. This diversion and subsequent emission in itself poses an engineering challenge. In particular, the integration of the CCS process with the existing plant must also ensure that the diverted flue gas still achieves adequate dispersion as it contains residual levels of pollutants such as nitrogen oxides (NOx) and sulphur dioxide (SO2), despite the fact that the CCS process itself may reduce some of these pollutant levels further as a process by-product. Power plants which incorporate CCS will still be required to adhere to the appropriate pollutant emission limits and ensure effective dispersion to minimise the risk of breaching local air quality standards. This paper draws on experience gained through post-combustion CCS projects and addresses the potential effects of CCS on air quality, in the case of carbon capture retrofits. The findings of this paper are relevant to project developers, power generators and policymakers globally who have an interest in the potential for CCS to provide an emissions abatement option for existing thermal assets in the short and long term. [Copyright &y& Elsevier]

Abstract: In this paper, the possibilities and conditions for CCS applications in Finland are assessed. The study includes an overview of Finland’s current climate and energy policy framework, mapping of large CO2 emission point sources and identification of possible CO2 transportation and storage alternatives. The future role of CCS in the Finnish energy system is further assessed with energy and emission scenarios created with a comprehensive model called TIMES-Nordic. There are several large CO2 emission sources in Finland that could be potential candidates for CCS, including steel works, power and heat generating plants, as well as oil refineries. In 2008, the 12 largest facilities in the Finnish emission trading registry accounted for 30% of the total CO2 emissions in Finland. Since the Finnish bedrock is not suitable for large-scale geological storage of CO2, captured CO2 would most likely have to be transported to the North Sea or Barents Sea for long-term storage. Most of the largest CO2 emitting facilities are located on the coast line of Finland, which facilitates transportation of CO2 by ship. The current Finnish climate and energy policy largely focuses on increasing the share of renewable energy and nuclear power in energy conversion, which leaves less room for CCS. The preliminary results from the scenario calculations indicate that the share of CO2 mitigation by CCS in Finland would be less than 10 Mt/a CO2 by 2050. However, Finland has also large, stationary CO2 emissions originating from biomass combustion in the pulp and paper industry. When assuming that biogenic CO2 emissions would be included into the emission trading system, the CCS potential rises up to 18 Mt/a CO2 by 2050. [Copyright &y& Elsevier]

Abstract: The storage of CO2 in deep saline aquifers is due to the large available capacities and the common occurrence of these formations one of the major options for carbon dioxide sequestration. Besides the multiphase flow aspects geochemical, thermal and mechanical processes may alter the conditions within the reservoir as well as in the cap rock. Whereas single aspects of these processes can be investigated with experiments a multi-process simulator allows evaluating their combined consequences for the storage system over short and long time scales. In this paper the newly coupled software ECLIPSE-OpenGeoSys is presented that allows a combined simulation of multiphase flow, transport and geochemical reactions. ECLIPSE provides a fast and efficient solution for the multiphase flow whereas the open-source scientific software OpenGeoSys is used for calculating transport and geochemical reactions. This paper presents the code structure of the interface. Furthermore the coupled software is successfully applied to benchmarks [Copyright &y& Elsevier]

Abstract: Evidence from experimental investigations, natural analogue studies and demonstration projects support the assertion that significant quantities of CO2 will not leak from a properly selected and managed CO2 storage complex. However, site operators must nevertheless justify the expectation of secure CO2 containment to regulators and other stakeholders. Secure containment will depend upon well seal stability inter alia. This paper presents fully-coupled geochemical models of well seal stability, focusing on cement degradation. The models have been developed with the ambition of reducing the simulated chemical system to the simplest possible configuration that is able to reproduce key features from experimental and field observations. Simplifying the models in this way makes them suitable for inclusion in larger scale system-level models of the storage system, where the use of highly-detailed chemical models can be impractical. Two sets of models were constructed in order to simulate: (1) a cement carbonation experiment (9 days in duration); and (2) field observations of cement degradation from the ‘SACROC’ site (30 years of reaction time). Although some model input parameters are uncertain, the experimental system was successfully simulated and the model was subsequently ‘up-scaled’ and applied to the SACROC core data. Over longer time-scales (102–103 years), the effects of parameter and thermodynamic data uncertainties on model output are more significant than at shorter time-scales. Although further work is required to bound the effects of these uncertainties, this paper illustrates the practicality of constructing simplified fully-coupled models to explore the significance of uncertainties by carrying out sensitivity calculations. [Copyright &y& Elsevier]

Abstract: The main role of INERIS (French National Institute for Industrial Environment and Risks) is to assess and avert accidental and chronic risks to both people and the environment linked to industrial installations, chemical substances and underground operations. INERIS is thus involved in research consortiums for underground storages of wastes, hydrocarbons or carbon dioxide. Concerning carbon dioxide storage, INERIS works for many years on defining and testing monitoring methods. As a French expert, the institute also performs integrated risk assessment studies. This paper focuses on the last improvements concerning the monitoring methods developed or patented by INERIS. Because the institute was created from the research centre of the former French national coal mining company, it has a well-established know-how in monitoring gas atmospheres. Having developed monitoring methods for mining contexts, INERIS has tools to constrain gas migrations in subsurface: [1.] to determine gas flux between soil and atmosphere with dynamic accumulation chambers; [2.] to determine gas concentrations in unsaturated zones through integrated gas sensor systems linked to subsurface boreholes (from 0 to about 300 meters depth). Initially designed for mining context, these two methods have been tested and proven for the monitoring of CO2 geological storage contexts. For example between 2005 and 2007, INERIS was one of the five partners involved in the “GeoCarbone MONITORING” research project. This project was funded by the French Research Agency and aims at defining methods to monitor CO2 storage sites. Today the institute is involved in other projects studying pilot sites. In this paper we present results collected in analog contexts to CO2 storage sites. We will discuss in which conditions the carbon isotopic signature can help to determine the possible origins of the gas analyzed in our devices and to better understand the physical and chemical processes which can have led to the studied gas compositions. We will also highlight the fact that in some cases, there is a real need of using isotopic tracing methods otherwise the identification of these different processes cannot be done easily. [Copyright &y& Elsevier]

Abstract: A significant number of efforts are underway to develop and assess technologies that will lead to technically and economically viable routes to reduce the CO2 emissions of fossil energy systems, particularly coal-fired power plants. Developing technologies to reduce emissions from these sources is essential for controlling atmospheric levels of CO2 because of the widespread reliance on coal as an inexpensive and abundant energy source. Two major systems-level design challenges exist. The first is how to design new plants that incorporate CCS technology. The second is how to retrofit existing plants to capture CO2. Both design challenges can benefit from an optimization approach, which considers the application of multiple potential technologies and analyzes ways in which the whole plant-wide system can be integrated to increase overall efficiency. This paper will present a modular framework for the analysis and optimization of power generation systems with CCS that helps to meet these design challenges. In order to more completely understand the economic and operational tradeoffs associated with the various potential carbon capture technologies, and how they can be applied to new and existing plants, a unified, systemic framework has been developed to provide a common basis for evaluation. Given the complexity of the design problem and the fact that new technologies are continually being developed, this framework is modular in nature and incorporates algorithms for the selection, integration and optimization of carbon capture technologies for both new and existing plants. In addition to the framework itself, this paper discusses simulation modules representing various capture technologies and power plant components. The framework provides the means to link the various modules together in order to provide a holistic, systems perspective of plant wide operations. Results of analyses and optimization scenarios performed with the framework are also presented. [Copyright &y& Elsevier]

Abstract: Portland cement can play a major role in providing cost-effective, long-term zonal isolation for CO2 capture and storage (CCS) used to mitigate climate change. However, achieving zonal isolation with Portland cement under supercritical CO2 environment for the required 1,000 year trapping period may be challenging. Some laboratory researchers report that Portland cement disintegrates when exposed to CO2, leading to potential leakage into the atmosphere or other to underground zones. Other researchers cite Portland cement samples from 30–50 year old CO2 EOR wells where sealing integrity was maintained, even though carbonation was found. In this paper we will discuss reasons likely for this disparity between research lab test results and actual well performance data. Carbonation of Portland cement is a thermodynamically favorable process and therefore difficult to avoid. But the effects can be minimized by various reactive chemical components optimized for the specific thermodynamic conditions. Our research shows partial carbonation of Portland cement is not detrimental unless the mechanical integrity is insufficient to provide effective zonal isolation. For these studies we have developed CO2 treatment test cells capable of producing conditions up to 200 °F and 2,000 psi. In addition, various analytical instruments including x-ray diffraction (XRD), thermo-gravimetric analysis (TGA) and mechanical properties measurement devices have been used for this study. In this paper we will discuss the importance of understanding the percentage of carbonation and depth of CO2 penetration, and how to control these factors by optimizing the cement blend. Interestingly, we found the amount of Portlandite { Ca(OH)2} that forms due to cement hydration and the cement-to-water ratio dictates the depth of penetration as well as percentage carbonation. The implications of this in relation to the long term chemical integrity of the cement sheath under downhole CCS conditions is discussed. This paper also includes the results of recent studies on the changes in mechanical properties of a properly optimized Portland cement blend for a period of up to one year. During this period, measurements were made at different time intervals to examine cement specimen treated with CO2 at 200 °F and 2,000 psi in the presence of water. The results show carbonation without any sign of loss of mechanical or sealing integrity that could lead to zonal isolation failure. Results from a separate set of experiments show the following: (1) Carbonation could be minimized by reducing the Portland cement content by adding Pozzolanic materials and by reducing the permeability and (2) Carbonation could help heal micro-cracks that may be caused by various well operations or ageing. However, such carbonation-induced healing is limited only to a certain width of cracks. In summary of this research, it is recommend that: (1) a high quality primary cement job be performed in adherence to all industry best practices; (2) the cement blend be properly optimized to minimize long-term CO2 corrosion; and (3) the sheath be designed for long-term mechanical integrity. This paper will discuss a comprehensive approach that may be taken to help ensure longer-term effective zonal isolation in new CO2 wells and remedial solutions for old wells and for plugging and abandoning wells. [Copyright &y& Elsevier]

Abstract: This paper deals with the electrical resistivity monitoring of the Ketzin CO2 injection pilot (CO2ReMoVe EC project) through time-lapse CSEM measurements. There, 3 boreholes about 800 m deep have been especially designed for current injection at reservoir (sandstone) depth. CO2 is directly injected in a saline (∼240 g/l) aquifer. Prior modelling results indicated that the increase of electrical resistivity generated by the CO2 plume (gaseous and liquid CO2 phases) supposed to be highly resisitive, would generate measurable changes in the EM fields on the surface, when injecting current directly inside the reservoir. In order to highlight and follow these expected resistivity changes, 3 CSEM surveys were performed in August 2008 (baseline prior to injection), June 2009 and August 2010. Each time, 13 EM stations have been recorded during current injection of a square wave at 3 frequencies (0.125 Hz, 0.5 Hz and 4 Hz) in two configurations (“double mise à la masse” (2×MAM) and “mise à la masse–surface” (MAM-Surface)). This paper only presents results of the 2×MAM configuration at 0.5 Hz. In spite of a very noisy area (gas pipes, high voltage power lines), we measured signal amplitude 10 times higher than noise amplitude. We show that EM fields vectors (both inphase and quadrature components) measured on the surface are very similar to the forward modelling EM responses computed with COMSOL Multiphysics ® . Models also show that electric field spatial distribution is strongly affected by a thin and resistive layer (35 m–200 Ωm) of anhydrite above the reservoir, making E field diverging from the boreholes whereas a dipolar pattern was expected for the dipole current injection used here. Moreover, while June 2009 survey highlighted the expected strong increase of electric field (increase of resistivity), August 2010 survey showed electric field amplitudes similar to the 2008 baseline survey, revealing therefore major changes of the reservoir properties. Finally, the directional sensitivity of the 2×MAM array is tested through modelling residuals computed for five CO2 plume spatial distributions. Results show that a north-eastward migration of the CO2 plume is expected to fit field data. [Copyright &y& Elsevier]

Abstract Titanium alloys, like Ti-6Al-4V, are widely used in the aerospace industry for the excellent resistance/weight ratio. The machinability of the Ti-6Al-4V is poor due to the high temperature close to the cutting edge and high cutting pressure on the cutting edge; consequently it limits the tool life and the productivity. In order to overcome to such issues, cryogenic machining has been adopted from many years. Liquid nitrogen and liquid carbon dioxide are the most common gases for cryogenic machining, and several researchers worked on turning and indexable milling cutters. In this paper the liquid carbon dioxide (CO 2) machining with solid end mills have been investigated. The end mills have internal holes in order to use CO 2 through the spindle. The aim is to investigate the difference against conventional coolant and the effect of dimension and position of the internal channels, in terms of tool wear and tool life. Thanks to different internal channel design, the intention is to better understand the mechanism of cryogenic machining using CO 2 ; several attempts were done from the researchers from the entire world, but significant variation in results has been found. The tool has been tested in straight pass and down side milling; the workpiece material is Ti-6Al-4V. [ABSTRACT FROM AUTHOR]

Abstract: This special issue of the Journal of Cleaner Production focuses on “Energy for Sustainable Future”. It is designed to mirror the increasing relevance of renewable energy sources and improved efficiency as crucial topics for practitioners in industry, for governmental policy makers, as well as for civic service providers, researchers, and educators. The purpose of this special issue is to serve as a catalyst for dialogue. The global warming related to CO2 emissions, coupled with steeply rising energy prices and the recent global financial institutional melt-down are causing massive societal concerns and give rise to increasing demand for ways to improve societal and individual energy efficiency and for ways to shift increasingly to alternative, low or non-carbon based energy systems. Until recently, industrial energy efficiency improvements have focused on improvements on efficiency rather than on the integration of renewable sources. The aim of this special issue is the identification of policies to support the development and implementation of technologies and management approaches we can employ to make the transition to more sustainable societies. The collection of papers in this special issue provide a foundation for students, researchers, scholars, practitioners and policy makers interested in making sustainable development more than a metaphor. The papers include focus upon ways for: [(a)] Improving industrial process to achieve improvements in energy efficiency. [(b)] Minimising waste disposals and reducing their impact through better management. [(c)] Reducing CO2 emissions by making progress toward lower carbon, renewable energy based systems, [(d)] Improving production of biofuels and hydrogen production systems, facilitated by employing cleaner production and novel LCA tools. [(e)] Improving integration of advanced materials and energy efficient equipment in different industrial sectors. Current and future developments in national and world economies are closely connected to sustainable, efficient and safe usage of raw materials and upon energy based on cleaner production concepts and approaches that are ecologically and economically appropriate for the short and for the long-term future of society. These challenges have received considerable attention in the media and scientific journals over the last several years. The idea of developing a specialised conference focussed upon them was put forward on various occasions. Focus upon them became reality on the 5th and 6th May 2008 in the historic Castle of Veszprém, Hungary, the current premises of the Hungarian Academy of Science which hosted the Workshop. The Workshop was a stimulating event and an overwhelming success, with nearly 100 contributors from Africa, North America, Asia and Europe, representing 28 countries. After a comprehensive selection and thorough reviewing procedure 11 papers were selected for this special issue. [Copyright &y& Elsevier]

Abstract: Laser beam machining (LBM) is one of the most widely used thermal energy based non-contact type advance machining process which can be applied for almost whole range of materials. Laser beam is focussed for melting and vaporizing the unwanted material from the parent material. It is suitable for geometrically complex profile cutting and making miniature holes in sheetmetal. Among various type of lasers used for machining in industries, CO2 and Nd:YAG lasers are most established. In recent years, researchers have explored a number of ways to improve the LBM process performance by analysing the different factors that affect the quality characteristics. The experimental and theoretical studies show that process performance can be improved considerably by proper selection of laser parameters, material parameters and operating parameters. This paper reviews the research work carried out so far in the area of LBM of different materials and shapes. It reports about the experimental and theoretical studies of LBM to improve the process performance. Several modelling and optimization techniques for the determination of optimum laser beam cutting condition have been critically examined. The last part of this paper discusses the LBM developments and outlines the trend for future research. [Copyright &y& Elsevier]