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This paper examines the impact of the CO2 laser parameters on the tensile strength, which is one of the most important properties of paper packaging in the process of cutting paper material. The study was performed on a paper material sample Fbb Board/Ningbo Spark C1S Ivory Board by examination of the influence of four independent variables: paper material grammage, cutting speed, laser power, and resolution on the tensile strength by using definitive screening design. Optimum process conditions of four variables that maximize the tensile strength were predicted and validated accordingly. Results confirm that laser power, paper material grammage, and cutting speed are the main process parameters that mostly affect the tensile strength. Besides individual parameters, two statistically significant interactions were obtained: laser power and cutting speed, and cutting speed and laser resolution. Maximum tensile strength values (20.37 N/mm) were achieved using the laser power of 60.6%, cutting speed of 3.24%, resolution of 2500 Hz, and a paper material grammage of 326.85 g/m2. With laser power at middle values and at a lower speed, a maximum tensile strength value can be obtained. Increasing the laser power and cutting speed will produce a slight lowering of tensile strength. [ABSTRACT FROM AUTHOR]

Zinc nanoparticles were electro-deposited along the fibres of carbon paper (CP) substrate uniformly in a salt-induced pre-phase separation region solution. The as-prepared Zn/CP electrode was used for electro-reduction of CO 2 and exhibited a Faradaic efficiency towards CO of 97.6% with a current density of 340 mA cm−2 in an H-type cell, which is the best result to date. [Display omitted] Efficient electrode design is crucial for the electrochemical reduction of CO 2 to produce valuable chemicals. The solution used for the preparation of electrodes can affect their overall properties, which in turn determine the reaction efficiency. In this work, we report that transition metal salts could induce the change of two-phase ionic liquid/ethanol mixture into miscible one phase. Pre-phase separation region near the phase boundary of the ternary system was observed. Zinc nanoparticles were electro-deposited along the fibres of carbon paper (CP) substrate uniformly in the salt-induced pre-phase separation region solution. The as-prepared Zn(1)/CP electrode exhibits super-wettability to the electrolyte, rendering very high catalytic performance for CO 2 electro-reduction, and the Faradaic efficiency towards CO is 97.6% with a current density of 340 mA cm −2, which is the best result to date in an H-type cell. [ABSTRACT FROM AUTHOR]

Flexible calcium carbonate (FCC) was developed as a functional papermaking filler for high loaded paper, which was a fiber-like shaped calcium carbonate produced from the in situ carbonation process on the cellulose micro-or nanofibril surface. Chitin is the second most abundant renewable material after cellulose. In this study, a chitin microfibril was utilized as the fibril core for making the FCC. Cellulose fibrils for the preparation of FCC were obtained by fibrillation of the TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical) treated wood fibers. The chitin fibril was obtained from the β-chitin from the born of squid fibrillated in water by grinding. Both fibrils were mixed with calcium oxide and underwent a carbonation process by the addition of carbon dioxide, thus the calcium carbonate attached on the fibrils to make FCC. When used in papermaking, both the FCC from chitin and cellulose gave a much higher bulk and tensile strength simultaneously than the conventional papermaking filler of ground calcium carbonate, while maintaining the other essential properties of paper. The FCC from chitin caused an even higher bulk and higher tensile strength than those of the FCC from cellulose in paper materials. Furthermore, the simple preparation method of the chitin FCC in comparison with the cellulose FCC may enable a reduction in the use of wood fibers, process energy, and the production cost of paper materials. [ABSTRACT FROM AUTHOR]

A free-standing cathode without any binder, conductor, and current collector is attractive due to its reduced weight and cost. This study introduces nitrogen-rich and hierarchical porous carbon fibers in the form of a free-standing carbon paper synthesized by NaBH 4 -aided electrospinning and subsequent CO 2 annealing. This modified process leads to a large mesopore volume of 1.007 cm3 g−1 and exposes the nitrogen inside the polymer to the surface of the fiber, resulting in the outstanding surface nitrogen content of 19.38 wt% with abundant pyridinic-N and pyrrolic-N of 16.24 wt% in total surface atoms, while eliminating any further treatment for increasing porosity or coating the polar active sites. The resultant material impregnated by sulfur and filtered by a graphene solution is directly employed as a cathode without any additives. As a result, the capacity is maintained at 696 mAh g−1 up to the 500th cycle at 0.2 C, and 645 mAh g−1 at a high current density of 5.0 C. Even with a high sulfur loading of 6.11 mg cm−2, a remarkable areal capacity of 3.09 mAh cm−2 is recorded after 500 cycles at 0.2 C with the free-standing form preserved. Image 1 • NaBH 4 -added electrospinning and subsequent heat treatment under CO 2 atmosphere. • High meso pore volume of 1.007 cm3 g−1, and surface nitrogen contents of 19.38 wt%. • Employed as a cathode without any additives due to a free-standing paper form. • High sulfur amount of 6.11 mg cm−2, and capacity of 3.09 mAh cm−2 for 500 cycles. [ABSTRACT FROM AUTHOR]

For the electro-reduction of CO 2 to syngas, the fabrication of electrodes with excellent and adjustable catalytic performance is a critical step. In this work, Ni particles encapsulated in N-doped carbon nanotubes on carbon paper (Ni@N-CNTs/CP) composites were designed and prepared via an in-situ chemical vapor deposition method. As confirmed by different characterization techniques, the Ni@N-CNTs are successfully synthesized, and the surface of the CP is evenly covered by the Ni@N-CNTs. The effects of Ni content and treating temperature on the textural properties of composites are carefully investigated. The Ni@N-CNTs/CP composites are directly employed as the electrode for electro-reduction of CO 2 , and the action mechanisms of the N species, Ni particles, and N-CNTs structure are explored as well. The electrode exhibits excellent catalytic activity and high stability, reaching a specific current of 10 mA cm−2. The H 2 /CO ratio in the achieved syngas can be tuned in the range of 5/1 to 1/1.5. Image 1 • A in-situ CVD method was employed to fabricate an electrode for electro-reduction of CO 2. • The as-synthesized Ni@N-CNTs evenly cover on the whole surface of CP. • The Ni@N-CNTs/CP electrode exhibits high CO 2 reduction activity and stability. • The ratio of H 2 /CO can be adjusted in the range of 5/1 to 1/1.5. • The action mechanism of different components are detailedly investigated. [ABSTRACT FROM AUTHOR]

A scalable papermaking process was employed herein to manufacture cellulosic papers from native and phosphorylated cellulose microfibers (referred to as CMF and PCMF, respectively) impregnated with polyethyleneimine (PEI) for Direct Air Capture (DAC) applications. These papers were analyzed in terms of their physico-chemical properties using several techniques. The impact of PEI content on desorbing the co-adsorbed H 2 O and CO 2 from the air, as well as on the anisotropic microporous network, was explicitly analyzed. The results indicated that phosphorylation promotes the uptake of both CO 2 and H 2 O in the corresponding neat and PEI-loaded papers, reaching a superior CO 2 adsorption capacity of ∼0.7–0.9 mmol.g−1 for PCMF papers versus 0.07–0.3 mmol.g−1 for CMF papers. Furthermore, the CMF and PCMF papers exhibited H 2 O adsorption capacities in the range of 1.5–1.8 mmol.g−1 and 2.2–3.8 mmol.g−1, respectively. This work further highlights the combined role of phosphorylation and favorable PEI impregnation in tuning the cellulose CO 2 adsorption properties under humid conditions, facilitating the rapid release of the adsorbed CO 2 under mid conditions. [Display omitted] • Manufacturing of scalable solid cellulosic papers with amine functionalities and enhanced carbon capture. • Microstructural and chemical characterization of amine functionalized paper with various amine ratios. • Valorization of Alfa biomass in Carbon capture applications. • The combined role of phosphorylation and PEI impregnation in tuning the H 2 O and CO 2 co-adsorption properties. [ABSTRACT FROM AUTHOR]

Lime mud, a kind of industrial waste that produced in paper mill, was proposed as CO2 sorbent in calcium looping process. The carbonation performance of the lime mud was investigated in a dual‐fixed bed reactor (DFR) and a thermogravimetric analyzer (TGA). The carbonation kinetics of the lime mud in the chemical reaction controlled stage was analyzed by a surface reaction‐controlled kinetic model. The results show that the lime mud presents much poorer carbonation performance during the chemical reaction controlled stage compared with the limestone, mainly due to the high content of chlorine in the lime mud. A prewash treatment process was used to decrease the chlorine content to mitigate the sintering of the lime mud when calcined at high temperature. After prewash treatment, the prewashed lime mud shows much higher CO2 capture capacity during the chemical reaction controlled stage compared with the lime mud. A prolonged carbonation process successfully further enhances the microstructure and improves the carbonation performance of the prewashed lime mud in the chemical reaction controlled stage. The lime mud can be effectively used as CO2 sorbent in calcium looping process after prewash treatment and the following prolonged carbonation treatment. [ABSTRACT FROM AUTHOR]

A recent commentary by Santhosh and Ravindran on our paper (Int. J. Hydrogen Energy 2014, 39:10,606) demonstrated that the interaction between H 2 and MXene (Sc 2 C and Ti 2 C) phases are not Kubas-type and should be of weak physisorption, and thus made a conclusion that 2D Sc 2 C and Ti 2 C are not suitable for practical hydrogen storage applications. In this responses, we recalculated hydrogen adsorption on 2D Sc 2 C and Ti 2 C by using different exchange-correlation functionals. And based on the calculated results, bare MXenes (especially the Ti 2 C) are suitable as hydrogen storage materials at temperatures of several tens degrees lower than room temperature. And the hydrogen adsorptions on the MXenes terminated with oxygen group were also investigated. Among the Ti 2 C, Sc 2 C and their oxygen-functional counterparts, the binding energy of H 2 on Sc 2 CO 2 surface is the closest to the ideal range of 0.16–0.42 eV/H 2 at ambient conditions, and thus the Sc 2 C with oxygen group is expected to be more suitable as hydrogen storage materials. [ABSTRACT FROM AUTHOR]

A completely lab-made paper/graphene-based 3D pop-up device (3D-PP) for the analysis of carbaryl (CBR), a pesticide widely used in crop production, is proposed. The device is composed of a nitrocellulose sensor equipped with reduced graphene oxide (rGO) and a foldable 3D paper pop-up. The rationale of the device is based on 3D and 2D configurations to allow the whole analytical procedure. In the 3D arrangement sample pre-concentration and hydrolysis occur; after folding (2D), contact with the complementary nitrocellulose-based sensor is ensured. The sensor, constituted by nanostructured graphene film, allows to obtain the necessary electroanalytical performance. 3D-PP has been shaped and nanostructured using a CO 2 -laser plotter and finished using low-cost benchtop instruments, ensuring in-series manufacturing of the device modules. 3D-PP includes the main steps required for CBR determination, i.e. (i) pre-concentration/purification, (ii) hydrolysis, (iii) medium neutralization, and (iv) electrochemical detection. 3D-PP was challenged for CBR quantification in model solutions and different grain samples. The response linearity (1.5–33 μM) and LOD (0.4 μM) obtained ensures CBR determination at the European-law admitted maximum residue levels (MRL). As proof of applicability, to simulate contaminates samples, different grains (i.e. soft and durum wheat, kamut, and barley) were spiked, before extraction, with CBR at three concentration levels corresponding to 0.5x, 1x, and 1.5x MRL; in all cases, quantitative and reproducible recoveries were obtained (93–109%; RSD ≤ 6%, n = 3). 3D-PP is produced using cellulosic components and solvent-free approaches, includes all CBR analysis steps, and returns reliable results in 15 min, resulting portable and usable with a smartphone [Display omitted] • A paper/graphene-based device for integrated carbaryl (CBR) analysis is proposed. • CO 2 -laser was used to shape and nanostructure the paper-based platform. • Complete CBR analysis is strategically enclosed in a 3D foldable paper pop-up (3D-PP). • 3D-PP design and sensing ability allow CBR residues analysis at EU-law limits. • 3D-PP analysis ability was proven in soft and durum wheat, kamut, and barley. [ABSTRACT FROM AUTHOR]

Pyrolysis of paper mill sludge (PMS) was conducted to produce syngas (H 2 and CO) and fabricate magnetic biochar (PMS biochar) for use as an adsorbent for As(V). The enhanced generation of CO was observed in the CO 2 atmosphere due to reactions triggered by CO 2 . Particularly, the generation of syngas from pyrolysis of PMS in CO 2 (9.6 mol% at 720 °C) was superior to the cases of pyrolysis of acid-washed PMS ( i.e. , minerals-eliminated PMS) in CO 2 (2.9 mol% at 720 °C), which evidences catalytic effects attributed by Fe and Ca species contained in PMS. Based on the results of X-ray diffraction (XRD), pyrolysis of PMS in CO 2 led to the conversion of Fe species into magnetite (Fe 3 O 4 ) solid phase that imparted the magnetic property to the biochar (saturation magnetization: 28.4 emu g −1 ). The PMS biochar exhibited high As(V) adsorption capacity of 34.1 mg g −1 in a given condition, which could be attributed to the great adsorption affinity of Fe 3 O 4 /CaCO 3 mixture toward As(V). The integrated approach for the utilization of PMS could satisfy growing demand for renewable energy and environmental sustainability. [ABSTRACT FROM AUTHOR]

The present study investigated the fresh, hardened, and physicochemical properties of CO 2 -cured belite-rich cement (BRC) paste incorporating hygiene tissue paper (HTP) as an additive. HTP was added at 0.5% and 1.0% by wt. of BRC paste. The BRC paste was prepared at a water-to-cement ratio of 0.4 and cured under water and carbonation. The results demonstrated that upon carbonation, the incorporation of HTP at 1.0% increases the CO 2 uptake and compressive strength of specimens by 18.60% and 22.29%, respectively. A pore structure analysis shows a decrease in the threshold pore size diameter with an increase in the HTP content for CO 2 -cured samples. An SEM analysis revealed precipitation and impregnation of calcites in and around the HTP microfiber particles. The incorporation of HTP under water curing on the other hand did not significantly influence the strength or the physicochemical properties. It was observed that HTP contributes to improving the properties of CO 2 -cured BRC paste in two ways; the porous structure of HTP provides pathways for the deep permeation of CO 2 into the matrix, and the surface of HTP offers an additional area for calcite precipitation. [ABSTRACT FROM AUTHOR]

This work presents an unconventional use of capacitively coupled contactless conductivity detector (C4D) for detection of gas absorption by moist paper with potential application for chemical analysis. To be suitable for measuring conductivity of moist paper absorbent, the C4D sensor was therefore designed in planar configuration. A layer of dry filter paper, only 20 mm × 25 mm in size, was placed on the C4D sensor and the device installed inside a specifically designed vaporization chamber. A vial (16 mm i.d., 8 mm high) containing a 150-μL solution of sodium bicarbonate was placed alongside. The filter paper was loaded with 110 μL of deionized water through an injection hole in the cover lid. A 100-μL aliquot of 2 M hydrochloric acid solution was directly dispensed into the vial through a second hole in the lid to generate CO 2 gas from the bicarbonate solution. It was observed that the C4D sensor gave real-time response that corresponded to the absorption of the gas and subsequent production of H+ and HCO 3 − in the moist paper. The monitored signal reached a constant value at 160 s after the addition of the acid. Chemistry of the absorption process and equivalent circuit for the C4D are proposed. Direct measurement of cement powder was chosen to demonstrate the potential use of this device for quantifying the CaCO 3 content of the cement. The calibration curve for 0.5–3 mg CaCO 3 was linear for signals recorded at 160 s: V dc = (0.172 ± 0.005) · (mg CaCO 3) + (0.016 ± 0.009), with coefficient of determination of 0.9965. Linear calibrations were also observed when the signals were monitored at various time less than 160 s. The limit of quantitation (3 SD of intercept/slope) was 0.17 mg CaCO 3. The method provided acceptable precision with %RSD of 4.6 (2 mg CaCO 3 , n = 10). Image 1 • Unconventional use of planar contactless conductivity detector is presented. • Real-time in-situ detection of CO 2 absorption by moist paper was demonstrated. • The absorption chemistry by moist paper and C4D equivalent circuit are proposed. • Potential application in direct measurement of cement powder is demonstrated. [ABSTRACT FROM AUTHOR]

Pulp and paper mill sludge (PPMS) is applied on agricultural soils as an organic fertilizer. Although it is well accepted that land application of PPMS has benefits for soils and crops, information on PPMS-induced soil N 2 O emissions is still limited. We assessed the effect of substituting mineral N fertilizer for PPMS on soil N 2 O emissions after a single application at planting on a clay loam cropped to wheat ( Triticum aestivum L.) over two snow-free seasons in eastern Canada. Fertilization treatments consisted of 0, 25, 50, 75, and 100% of crop N requirements derived from N supplied by PPMS, the remaining N being supplied as urea-N. Soil CO 2 and CH 4 emissions were also measured and not affected by the fertilizer addition; a slight CH 4 oxidation occurred. Area-based N 2 O emissions from PPMS fertilization (4.4 to 12.1 kg N 2 O-N ha −1 ) were similar or higher than from urea alone (3.4 and 6.2 kg N 2 O-N ha −1 ). Although crop yields were not affected by the type of fertilizer, yield-based N 2 O emissions, N uptake efficiency and N surplus (applied N minus aboveground N uptake in crop biomass) indicated that N availability from the mineral fertilizer was higher than from PPMS for the wheat crop. However, treatments with PPMS had fertilizer-induced N 2 O emission factors (FIEF, applied N lost as N 2 O-N; 0.8 to 3.1%) similar to urea alone (−0.3 and 4.5%). Although substituting urea-N with PPMS in agricultural fields might reduce N 2 O emissions under moderate soil moisture conditions, PPMS land application produced greater N 2 O emissions under high soil moisture conditions. Further research on a variety of agricultural practices is needed before concluding that including PPMS in the fertilization plan could result in a global GHG abatement as compared to mineral fertilizers under the cool climate of eastern Canada. [ABSTRACT FROM AUTHOR]

Utilization of the quality-upgraded waste paper in the manufacture of paper and board will reduce the wood consumption and pulping energy. While the optical property of the fibers from recycled old newspaper is very poor, in-situ calcium carbonate formation on those fibers by injecting carbon dioxide to the mixed slurry of those pulp and calcium oxide improved their brightness. Upgrading recycled old newspaper to substitute more expensive wood furnish, such as recycled old magazine, was successfully demonstrated in the present study. This study showed that the in-situ calcium carbonate formation process improved the optical quality of the recycled old newspaper by covering colored impurities with newly formed calcium carbonate, and improved calcium carbonate retention in papermaking process by attaching them to fibers. The strength reduction by the presence of newly formed calcium carbonate in the paper was recovered by adding strength agent. High ash retention at high ash content under the strong turbulence in the modern paper mill was achieved by the application of the in-situ calcium carbonate formation method. The quality-upgrade of recycled fibers and cost saving in the manufacture of duplex paperboard were demonstrated in the mill trial. [ABSTRACT FROM AUTHOR]

A colorimetric assay was developed which has the capability of determining urea in biological samples. It is an origami paper-based sensor consisting of silver nanoparticles that were synthesized by using two different capping agents: thiomalic acid and maltol. The function of the assay relied on hydrolysis of urea to ammonia and carbon dioxide in the presence of urease. The products interacted with nanoparticles which caused aggregation. Interestingly, thiomalic acid capped with silver nanoparticles were selective to ammonia, and the other nanoparticles synthesized by maltol responded to carbon dioxide. These interactions turned the color of nanoparticles from yellow to brown and red, respectively. The resulting colorations were captured by a floatable scanner. A routine image analysis software was utilized to provide the response of the assays. The method was applied to individually determine ammonia, carbon dioxide, and urea. The linear range was 0.06 mg.dL−1-170.0 mg.dL−1 for ammonia, 0.08 mg.dL−1-220.0 mg.dL−1 for carbon dioxide, and 0.5 mg.dL−1-200.0 mg.dL−1 for urea. The respective limits of detection were 0.03 mg.dL−1, 0.06 mg.dL−1, and 0.18 mg.dL−1. No interferences were found in the detremination of urea. The method demonstrates a reliable performance for determination of urea in both saliva and blood samples. [ABSTRACT FROM AUTHOR]

The Swedish pulp and paper industry accounts for half of industrial final energy use in Sweden and 2.3 % in EU-27. On the basis of a disaggregated set of physical production data, a Logarithmic Mean Divisia Index decomposition method is applied to disentangle the influence from activity, structure and energy efficiency improvement (EEI) on its fuel, electricity and primary energy use. An extended analysis tracks the fossil energy use and carbon dioxide (CO) emissions to discern past and present developments of industrial decarbonisation. In 1984-2011, the total production output increased by 49 %, whereas growth in primary energy use was limited to 26 %. Compared with an activity-based scenario, 50 PJ of primary energy use has been avoided through EEI and 6 PJ through structural change. The production has become oriented towards more electricity-intensive but less fuel-intensive segments. The electricity use EEI was negligible until year 2000 but sizeable thereafter as it started to outpace the counteracting impact from structural change. Results are consistent with previous bottom-up evaluations, and the policy context is further elaborated in a discussion about the role of relevant energy and climate policies in facilitating the enhanced EEI observed over the last decade. [ABSTRACT FROM AUTHOR]

The combustion of biomass and waste paper sludge in a fluidized bed is ecologically profitable. However, a large amount of by-product with high hydraulic reactivity is produced and is considered as wastes. Most of the time the waste paper fly ash (WPFA) goes to landfills, therefore new utilization methods are necessary. In some countries, the high content of metallic and metalloids trace elements (MMTE) in WPFA, more specifically Barium (Ba) and Lead (Pb) makes its valorization difficult. In this paper, the Lightweight Aggregates (LWA) was produced from WPFA by granulating with water in high-intensity granulator. Since WPFA is rich in CaO, the addition of water promotes rapid setting and hydration compared to other types of ash. In this study, different granulation parameters were investigated, such as the rotation modes between the steel pan and the impeller, the rotation speed of the steel pan, the granulation time, in order to improve the mass percentage of the targeted LWA (2–16 mm). In order to evolve the immobilization potential of Ba and Pb, a carbonation process was performed, exposing the manufactured LWA to pure carbon dioxide (CO 2) gas at laboratory scale. The physical, morphological, thermal and mechanical characterizations were performed on LWA for use in mortars, concretes or civil engineering constructions. Results have demonstrated the influence of the rotation mode between the steel pan and the on the distribution of WPFA inside the steel pan and the change in the growth rate of the granules can be observed. Increased density and improved compressive strength with low porosity and water absorption were also found in LWA after carbonation. This was due to the occurrence of both a carbonation reaction and a hydration reaction. Furthermore, the results of thermogravimetry and SEM-EDS confirmed the formation of hydrated phases (ettringite, carboaluminates), also the formation of calcite in the pores and the external surface of the LWA. Regarding environmental aspects, the results have revealed that Ba and Pb were well immobilized in the solid matrix after carbonation. [Display omitted] • LWA was manufactured from WPA without any agglomerating agents. • The physical-chemical properties of LWA were improved after carbonation. • The resulted LWA meet the requirements of NF EN -13,055-1. • The microstructure of LWA was studied before and after carbonation. • Influence of time, mode and rotation speed on the size of the manufactured LWA. [ABSTRACT FROM AUTHOR]

In 2017, a carbon emissions trading market will be launched nationwide by the China government. Calculating the enterprise carbon emissions is an important prerequisite and basis for trading. This paper discussed types of greenhouse gases, calculation boundaries and methods, energy consumption, carbon emissions, and intensity of a representative integrated pulp and paper mill in China based on China Guidance and Greenhouse Gas Protocol Tools. The results showed that there were 435,000 tonnes (t) of CO2 emissions from that mill in 2014 that did not contain emissions of biomass energy, which was 8 times higher than that of fossil energy. The pulp carbon intensity based on the mill was 0.230 t CO2/Adt, which accounted for 7.50% to 57.4% in other pulps' based on the product. Intensity based on Gross Domestic Product (GDP) was 1.090 t CO2e/1000 USD and accounted for 56.8% intensity in the China paper industry. The intensity based on sales accounted for 52.6% in the firstclass enterprise in the developed country. It also showed that intensity was influenced by the species of raw material, energy, and products, which provided the mill with measures for energy saving and emissions reduction to obtain the redundant carbon emissions in the trading. [ABSTRACT FROM AUTHOR]

Currently, developing highly active and low-cost electrocatalytic materials for oxygen evolution reaction (OER) is an enormously grand challenge. Herein, we developed a novel and highly active Mn doped Co 2 Fe layer double hydroxide (LDH) electrocatalyst for OER. We discovered that these electrocatalytic materials can be directly grown on carbon papers to construct high-specific-surface-area electrode, which shows the lowest overpotential of 266 mV at 10 mA cm−2. Furthermore, after introducing Mn element, DFT + U calculation found that the ∗OOH of Fe-site on Co 2 Fe 0.67 Mn 0.33 LDH could draw more electrons than Co 2 Fe LDH due to the electronegativity differences between Fe-site on Co 2 Fe 0.67 Mn 0.33 LDH and Fe-site on Co 2 Fe LDH, which is reason that the energy level of Fe 3d (e g) was obviously downshifted by d-d repulsion of Mn 3d and Fe 3d in the neighboring sites of Co 2 Fe 0.67 Mn 0.33 LDH after doped Mn element, which leads to reduce charge-transfer energy from O 2p to Fe 3d (e g) to promote oxygen evolution processes for OER. Meanwhile, the band gap is also decreased after doped Mn element in Co 2 Fe LDH due to the downshifted e g orbital energy of Fe 3d. This study gives a general avenue to design and developing efficiently active LDH electrocatalysts for OER in the future. • Both bimetallic CoFe LDH and Mn doped CoFe LDHs directly grown on carbon paper are successfully synthesized. • The Co 2 Fe 0.67 Mn 0.33 LDH@NFs exhibits a small overpotential of 236 mV at 10 mA cm−1 for OER. • DFT + U studies reveal that the observed superb OER activity could be attributed to d-d repulsion of Mn 3d and Fe 3d. [ABSTRACT FROM AUTHOR]

Based on surface science, adsorption of mineral oil, water, gas products (typified by CO2 and CH4), and acids (typified by formic acid) on meta-aramid insulation paper has been investigated by molecular dynamics simulations. When the adsorption process finishes, the free volume fraction in the crystalline region is very small owing to the stable molecular arrangement of fiber. In addition, the number of pores on the surface of the meta-aramid fiber and the pore size are small, and the stable configuration of hydrogen bonds plays an important role, so it is difficult for the mineral oil and aging products to enter the meta-aramid crystalline region. The irregular arrangement of molecules in the amorphous region means that it is easier for the mineral oil and aging products to enter the amorphous region than the crystalline region, and the influence of these substances on the amorphous region is greater than that on the crystalline region. The order of the adsorption strengths of the four types of aging products on meta-aramid fiber is formic acid > water > CO2 > CH4. Therefore, it is necessary to monitor the acid and water contents in transformers with meta-aramid insulation paper as the solid insulation material. [ABSTRACT FROM AUTHOR]

Highlights • Synthetic CaO-based CO 2 sorbent was prepared using paper fibre as a biotemplate. • Synthetic sorbent is mainly composed of CaO and Ca 12 Al 14 O 33. • Synthetic sorbents possess microtube-like structure with superior CO 2 uptake. • Synthetic sorbent has improved sintering resistance in severe calcination condition. Abstract Calcium looping is regarded as an effective and viable way to address CO 2 emissions. To overcome the loss-in-capacity problems of calcium-based sorbents with the number of calcium looping cycles, a novel CaO/Ca 12 Al 14 O 33 sorbent with a microtube-like structure was prepared from carbide slag and Al(NO 3) 3 ·9H 2 O using paper fibre as a biotemplate. The CO 2 capture performance and microstructure of the novel synthetic sorbent under calcium looping conditions were investigated. The results show that the utilization of the biotemplate is good to retain the high cyclic CO 2 capture reactivity of the synthetic sorbent. Due to the unique hollow porous structure, the CO 2 capture capacity of the synthetic sorbent containing 7.5 wt% Al 2 O 3 retains 0.56 and 0.33 g/g after 30 cycles under mild and severe calcination conditions, respectively, which are 2.56 and 2.11 times higher than those of carbide slag under the same respective calcination conditions. With the presence of 10% steam in the carbonation atmosphere, the CO 2 capture capacity of the synthetic sorbent retains 0.55 g/g under the severe calcination conditions after 10 cycles. The native hierarchical biostructure of paper fibre is preserved in the synthetic sorbent. CaO and Ca 12 Al 14 O 33 are uniformly distributed in the synthetic sorbent, resulting in a high sintering resistance during multiple CO 2 capture cycles. CO 2 can penetrate through the microtube-like structure of the synthetic sorbent from two directions, i.e., from the outer surface and inner surface. This phenomenon effectively enlarges the contact area between CO 2 and CaO. The CaO/Ca 12 Al 14 O 33 sorbent with a hollow porous structure by means of a biotemplate appears promising in the calcium looping technology for CO 2 capture. [ABSTRACT FROM AUTHOR]

History has been kind to Christian Bohr (1855-1911). His name is attached eponymously to three different areas of respiratory physiology. The first is the Bohr dead space, which refers to the portion of the tidal volume that does not undergo gas exchange. The second is the increase in oxygen affinity of hemoglobin caused by the addition of carbon dioxide to the blood. This is known as the Bohr effect and is a very important feature of gas exchange, both in the lung and in peripheral tissues. Both of these contributions by Bohr are familiar to most students. Bohr's third contribution refers to the calculation of the changes in the PO2 of blood as oxygen is loaded in the pulmonary capillary, the so-called Bohr integration. This contribution is less well known now, partly because of the advent of digital computing, but it was important in its day. The analysis is challenging because the very nonlinear shape of the oxygen dissociation curve means that the PO2 difference between the alveolar gas and the capillary blood, which is the driving pressure for diffusion, changes in a complicated way. All three papers are in German, and two of them are long and tedious to read. English translations are available, but few people read the papers, despite the fact that the first two articles are very frequently cited. In the present article, Bohr's contributions are reviewed, and some parts of the articles that are particularly difficult to understand are clarified. [ABSTRACT FROM AUTHOR]

The global energy system is in transition. It is attempting to reach net‐zero greenhouse gas emissions by 2050. The systemic changes mean that the role of bioenergy will change. The potential of bioenergy to make a flexible contribution to the energy system is key for the achievement of global emission reduction ambitions and the functioning of the low‐carbon energy system and economy. As the volume of sustainably available biomass resources is limited, defining the contributions from bioenergy to a low‐carbon energy system and finding balances – and ideally synergies – between the different possible energy and climate system services that biomass can provide will be very important. The recognized system services include, among others, the flexible operation of bioenergy plants to integrate variable renewable energy sources and to provide negative carbon dioxide (CO2) emissions. Interest in flexible operation of bioenergy value chains, bioenergy with carbon capture and utilization as well as synergies with renewable hydrogen‐based value chains has increased recently. The objective of this paper is to present a holistic definition of flexible bioenergy as a system service based on the work conducted in International Energy Agency (IEA) Bioenergy Technology Collaboration Programme's Task 44 Flexible Bioenergy and System Integration, and to provide some practical examples. The paper also presents the different bioenergy system services and considers their definitions and interactions, as this is important in energy system design. The definition of flexible bioenergy shows that the flexibility provision from bioenergy goes far beyond the traditional definition of providing short‐term flexibility in the power sector. Indicators to demonstrate the value of services as well as further quantitative assessment of synergies and trade‐offs are needed to valorize the different services from bioenergy and create viable business cases. [ABSTRACT FROM AUTHOR]

The synergistic effect between metals is of great significance for improving the performance of materials, but the mechanism of synergistic catalytic of bimetallic has rarely been reported in the hydrolysis of sodium borohydride (NaBH 4 , SB). In this paper, a flower shaped Co 2 FeO 4 catalyst with high catalytic performance was selected from a series of Co x M 3-x O 4 (M = Fe, Ni, Cu) catalysts by controlling the composition. Based on the results of XPS characterization and density functional theory (DFT) calculation, the influence of component control on catalytic performance was discussed and explained from the perspective of electronic structure, and the "valence band center" and "D-band center" descriptors were introduced into the SB hydrolysis reaction. The simulation analysis results showed that the synergistic effect between Co–Fe elements resulted in the smallest center shift of the D band, the smallest binding energy of the hydrolysis reaction, and the best promoting effect on the electronic structure, manifested as the best catalytic performance. The calculation results were consistent with the XPS characterization results and the experimental results of hydrolysis performance testing, revealing the principle of bimetallic synergistic effect on catalytic performance. The synergistic effect between metals is of great significance for improving the performance of materials, but the mechanism of synergistic catalytic of bimetallic has rarely been reported in the hydrolysis of sodium borohydride (NaBH 4 , SB). In this paper, a flower shaped Co 2 FeO 4 catalyst with high catalytic performance was selected from a series of Co x M 3-x O 4 (M = Fe, Ni, Cu) catalysts by controlling the composition. Based on the results of XPS characterization and density functional theory (DFT) calculation, the influence of component control on catalytic performance was discussed and explained from the perspective of electronic structure, and the "valence band center" and "D-band center" descriptors were introduced into the SB hydrolysis reaction. The simulation analysis results showed that the synergistic effect between Co–Fe elements resulted in the smallest center shift of the D band, the smallest binding energy of the hydrolysis reaction, and the best promoting effect on the electronic structure, manifested as the best catalytic performance. The calculation results were consistent with the XPS characterization results and the experimental results of hydrolysis performance testing, revealing the principle of bimetallic synergistic effect on catalytic performance. [Display omitted] • Flower-like Co 2 FeO 4 showed the best catalytic performance. • The "D-band center" and "valence -band center" of Co 2 MO 4 were studied. • Composition and electronic control improve the catalytic performance of Co 2 MO 4. • The adsorption configuration of H 2 O on the Co 2 MO 4 (311) surface was studied. [ABSTRACT FROM AUTHOR]

Key long-lived greenhouse gases (CO2, CH4, and N2O) are perhaps among the best-studied components of the Earth's atmosphere today; however, attempts to predict or explain trends or even shorter-term variations of these trace gases are not always successful. Infrared spectroscopy is a recognized technique for the ground-based long-term monitoring of the gaseous composition of the atmosphere. The current paper is focused on the analysis of new data on CO2, CH4, and N2O total columns (TCs) retrieved from high resolution IR solar spectra acquired during 2009–2022 at the NDACC atmospheric monitoring station of St. Petersburg State University (STP station, 59.88°N, 29.83°E, 20 m asl.). The paper provides information on the FTIR system (Fourier-transform infrared) installed at the STP station, and an overview of techniques used for the CO2, CH4, and N2O retrievals. Trends of key greenhouse gases and their confidence levels were evaluated using an original approach which combines the Lomb–Scargle method with the cross-validation and bootstrapping techniques. As a result, the following fourteen-year (2009–2022) trends of TCs have been revealed: (0.56 ± 0.01) % yr−1 for CO2; (0.46 ± 0.02) % yr−1 for CH4; (0.28 ± 0.01) % yr−1 for N2O. A comparison with trends based on the EMAC numerical modeling data was carried out. The trends of greenhouse gases observed at the STP site are consistent with the results of the in situ monitoring performed at the same geographical location, and with the independent estimates of the global volume mixing ratio growth rates obtained by the GAW network and the NOAA Global Monitoring Laboratory. There is reasonable agreement between the CH4 and N2O TC trends for 2009–2019, which have been derived from FTIR measurements at three locations: the STP site, Izaña Observatory and the University of Toronto Atmospheric Observatory. [ABSTRACT FROM AUTHOR]

Activated carbon fiber paper (ACFP) has the potential for adsorption due to their high surface area and low through resistance. In this work, free-standing ACFP was developed from fibrillated polyacrylonitrile (PAN) fiber through wet forming process combined with subsequent pre-oxidation, carbonization and CO 2 activation. A PFI refiner was used to prepare fibrillated PAN fibers with a beating degree of 7, 11, 25 and 60 oSR, respectively. As expected, PAN fibers with high beating degree improved surface area and fine fiber content, which resulted in the dense structure and low porosity of paper, thus influencing later stabilization and pyrolysis, as well as final properties of ACFP. With the increase of beating degree, the oxygen content of pre-oxidized PAN paper increased, but the cyclization index first decreased and then increased. ACFP with higher beating degree possessed higher BET surface area, pore volume and CO 2 uptake capacity. ACFP, prepared from freeze-dried PAN paper, performed better in physicochemical properties than that from plate-press drier under the same beating degree. This study exhibited that ACFP can be a special material featured by scale production, lightweight, and high microporosity of chemical adsorption and separation. [Display omitted] • ACFPs were prepared from fibrillated PAN fiber through wet forming process. • Effects of pore structure of PAN papers on physicochemical properties of ACFPs • CO 2 adsorption on ACFPs was a combined effects of physisorption and chemisorption. [ABSTRACT FROM AUTHOR]

[Display omitted] • Filter paper is used as carbon source to prepare highly porous N-doped carbon. • KHCO 3 is chosen as the activator because it is safe and non-corrosive. • Addition of urea at the activation step significantly improves the surface area. • At 0 °C and 20 bar, the carbon shows high CO 2 uptake of 19.65 mmol/g. Herein, we presented the preparation of N-doped porous carbon from lab used filter paper. Filter paper was first carbonized at 500 °C. The obtained carbon was then pyrolyzed with KHCO 3 and urea. Effects of KHCO 3 activation on the carbons' physicochemical properties were thoroughly investigated. The derived carbon materials were also tested for CO 2 adsorption with pressure up to 20 bar. The carbons exhibited very high CO 2 uptake of 19.65 mmol/g at 0 °C and 20 bar. The correlations between adsorption performances and the carbons' physicochemical properties at 1/20 bar were analyzed and discussed. [ABSTRACT FROM AUTHOR]

Abstract: Photocatalytic reduction of CO2 with H2O vapor is gaining increased interest because it is a promising “green chemistry” route for the direct conversion of CO2 to value‐added chemicals driven by solar energy. To increase the efficiency of photocatalytic conversion, most efforts are made by exploring various photocatalysts while little effort on advanced light management. For the first time, it is demonstrated that bio‐degradable transparent paper with excellent light diffusivity can effectively enhance the light utilization of photocatalytic reactions when attached on the device surface, and thus greatly increase the conversion efficiency. As a proof‐of‐concept, a graphitic carbon nitride (g‐C3N4) photocatalyst with transparent paper attached, exhibited 1.5 times higher photocatalytic activity than bare g‐C3N4 in the reduction of CO2 under visible light irradiation. The improved catalytic performance can be ascribed to the (1) refractive index matching and (2) enhanced light absorption via prolonged light traveling path in transparent paper, which decreases the light reflection at surface and traps the absorbed light inside, leading to an increased light absorption at the active layer of the device. The transparent paper with a controllable light management behavior has an unprecedented potential for applications in photocatalysis as a general method for improved light utilization. [ABSTRACT FROM AUTHOR]

This article presents an algorithm for modelling an Adaptive Neuro Fuzzy Inference System (ANFIS) for power transformer paper conditions in order to estimate the transformer's expected life. The dielectric characteristics, dissolved gasses, and furfural of 108 running transformers were collected, which were divided into 76 training datasets and another 32 testing datasets. The degree of polymerization (DP) of the transformer paper was predicted using the ANFIS model based on using the dielectric characteristics and dissolved gases as input. These inputs were analyzed, and the best combination was selected, whereas CO + CO2, acidity, interfacial tension, and color were correlated with the paper's deterioration condition and were chosen as the input variables. The best combination of input variables and membership function was selected to build the optimal ANFIS model, which was then compared and evaluated. The proposed ANFIS model has 89.07% training accuracy and 85.75% testing accuracy and was applied to a transformer paper insulation assessment and an estimation of the expected life of four Indonesian transformers for which furfural data is unavailable. This proposed algorithm can be used as a furfural alternative for the general assessment of transformer paper conditions and the estimation of expected life and provides a helpful assistance for experts in transformer condition assessment. [ABSTRACT FROM AUTHOR]

A paper-based electrochemical dual-function biosensor capable of determining pH and TCO2 was synthesized for the first time using an iridium oxide pH electrode and an all-solid-state ion electrode (ASIE). In the study, to obtain highly reliable results, the biosensor was equipped with a real-time pH correction function before TCO2 measurements. Compared to traditional liquid-filling carbon dioxide detection sensors, the utilization of ferrocene endows our novel sensor with abundant positive sites, and thus greatly improves its performance. Conversely, the introduction of MXene with conductivity close to that of metals reduces electrode resistance, which is beneficial for accelerating the electrochemical reaction of the sensor and reducing LOD. After optimization, the detection range of TCO2 is 0.095 nM–0.66 M, with a detection limit of as low as 0.023 nM. In addition, the sensor was used in real serum sample-spiked recovery experiments and comparison experiments with existing clinical blood gas analyzers, which confirmed the effectiveness of its clinical application. This study provides a method for the rational design of paper-based electrochemical biosensors and a new approach for the clinical detection of blood carbon dioxide. [ABSTRACT FROM AUTHOR]

Electric‐driven conversion of carbon dioxide (CO2) to carbon monoxide (CO) under mild reaction conditions offers a promising approach to mitigate the greenhouse effect and the energy crisis. Surface engineering is believed to be one of the prospective methods for enhancing the electrocatalytic activity of CO2 reduction. Herein, hydroxyl (OH) groups were successfully introduced to cadmium nanosheets to form cadmium and cadmium hydroxide nanocomposites (i. e. Cd/Cd(OH)2 nanosheets) via a facile two‐step method. The as‐prepared Cd/Cd(OH)2/CP (CP indicates carbon paper) electrode displays excellent electrocatalytic activity for CO2 reduction to produce CO. The Faradaic efficiency of CO reaches 98.3 % and the current density achieves 23.8 mA cm−2 at −2.0 V vs. Ag/Ag+ in a CO2‐saturated 30 wt% 1‐butyl‐3‐methylimidazole hexafluorophosphate ([Bmim]PF6)‐65 wt% acetonitrile (CH3CN)‐5 wt% water (H2O) electrolyte. And the CO partial current density can reach up to 71.6 mA cm−2 with the CO Faradaic efficiency of more than 85 % at −2.3 V vs. Ag/Ag+, which stands out against Cd/CP, Cd(OH)2/CP, and Cd/CdO/CP electrodes. The excellent electrocatalytic performance of the Cd/Cd(OH)2/CP electrode can be attributed to its unique structural properties, suitable OH groups, perfect interaction with electrolyte, abundant active sites and fast electron transfer rate. [ABSTRACT FROM AUTHOR]

• The CMC from office waste paper was synthesized completely within 30 min at ambient temperature by ultrasonic-assisted technique. • The degree of substitution of obtained CMC product was 0.75. This report demonstrates the fastest technique to successfully achieve carboxymethyl cellulose (CMC) from office paper waste, within 30 min at ambient temperature using ultrasonic-assisted method as a source of energy. The obtained CMC was characterized using FTIR, TGA, and NMR techniques to confirm its structure. The FTIR spectrum showed characteristic peaks of carboxymethyl groups and its salt at the wavenumbers of 1585 (C=O) and 1412 (C-O) cm−1. The TGA results of CMC exhibited the loss of carbon dioxide at ca. 260 – 300 °C. Moreover, a higher ash yield of the obtained CMC indicated the substitution of carboxymethyl in the structure. The CMC product structure was confirmed using 13C- and HMBC 2D-NMR. The HMBC 2D-NMR results indicated a correlation between carbonyl and methylene carbons of carboxymethyl groups and protons of pyranose ring, implying that pyranose ring was substituted successfully by monocholoroacetic acid (MCA). The optimal conditions were obtained by using 4.11 ml of 30%w/v NaOH and 1.4 g of MCA in 40 ml of isopropanol at ambient temperature. The resulting CMC showed 0.75 degree of substitution at 18.75 W/ml ultrasonic intensity. Image, graphical abstract [ABSTRACT FROM AUTHOR]

The pulp and paper (P&P) sector is a dynamic manufacturing industry and plays an essential role in the Austrian economy. However, the sector, which consumes about 20 TWh of final energy, is responsible for 7% of Austria's industrial CO2 emissions. This study, intending to assess the potential for improving energy efficiency and reducing emissions in the Austrian context in the P&P sector, uses a bottom-up approach model. The model is applied to analyze the energy consumption (heat and electricity) and CO2 emissions in the main processes, related to the P&P production from virgin or recycled fibers. Afterward, technological options to reduce energy consumption and fossil CO2 emissions for P&P production are investigated, and various low-carbon technologies are applied to the model. For each of the selected technologies, the potential of emission reduction and energy savings up to 2050 is estimated. Finally, a series of low-carbon technology-based scenarios are developed and evaluated. These scenarios' content is based on the improvement potential associated with the various processes of different paper grades. The results reveal that the investigated technologies applied in the production process (chemical pulping and paper drying) have a minor impact on CO2 emission reduction (maximum 10% due to applying an impulse dryer). In contrast, steam supply electrification, by replacing fossil fuel boilers with direct heat supply (such as commercial electric boilers or heat pumps), enables reducing emissions by up to 75%. This means that the goal of 100% CO2 emission reduction by 2050 cannot be reached with one method alone. Consequently, a combination of technologies, particularly with the electrification of the steam supply, along with the use of carbon-free electricity generated by renewable energy, appears to be essential. [ABSTRACT FROM AUTHOR]

[Display omitted] • Compared to N 2 , the pyrolysis of MSW and PS was more complete under CO 2 atmosphere. • The evolution of six typical pyrolysis products were illustrated by TG-FTIR. • MgO could act as a catalyst to promote the pyrolysis reaction of blends. • Through DAEM, the activation energy in two stages were about 170 and 300 kJ/mol. In order to explore a harmless and resource-based way to treat municipal solid waste (MSW) and paper sludge (PS), the co-pyrolysis MSW and PS was studied in this paper. Firstly, MSW and PS had the lower residue mass, and MSW had higher pyrolysis index under CO 2 atmosphere, compared with the one under N 2 atmosphere. Hence, the CO 2 was used as the carrier gas in the following study. Secondly, under CO 2 atmosphere, the co-pyrolysis of MSW and PS with and without MgO were researched. With the increasing of PS ratio, the pyrolysis performance of the blends decreased constantly. MgO act as catalyst could improve the pyrolysis characteristic index of the blends. However, MgO was an inorganic salt and it would affect the synergistic effect of MSW and PS. The curves of online evolutions of all the gas products and the functional groups had an obvious peak at around 500 ℃. The activation energy of the blends in the first step (<600 ℃) were around 170 kJ/mol and reached more than 300 kJ/mol of the second step (600−1000 ℃). In addition, the adding of MgO could decrease the activation energy of MSW, 50M50P and PS. Finally, 50M50P-M was suitable for treating more sludge. And these results could offer some referential information for designing and optimizing the co-pyrolysis technology for MSW and PS. [ABSTRACT FROM AUTHOR]

As the second most predominant greenhouse gas, methane-targeted emission mitigation holds the potential to decelerate the pace of global warming. Satellite remote sensing is an important monitoring tool, and we review developments in the satellite detection of methane. This paper provides an overview of the various types of satellites, including the various instrument parameters, and describes the different types of satellite retrieval algorithms. In addition, the currently popular methane point source quantification method is presented. Based on existing research, we delineate the classification of methane remote sensing satellites into two overarching categories: area flux mappers and point source imagers. Area flux mappers primarily concentrate on the assessment of global or large-scale methane concentrations, with a further subclassification into active remote sensing satellites (e.g., MERLIN) and passive remote sensing satellites (e.g., TROPOMI, GOSAT), contingent upon the remote sensing methodology employed. Such satellites are mainly based on physical models and the carbon dioxide proxy method for the retrieval of methane. Point source imagers, in contrast, can detect methane point source plumes using their ultra-high spatial resolution. Subcategories within this classification include multispectral imagers (e.g., Sentinel-2, Landsat-8) and hyperspectral imagers (e.g., PRISMA, GF-5), contingent upon their spectral resolution disparities. Area flux mappers are mostly distinguished by their use of physical algorithms, while point source imagers are dominated by data-driven methods. Furthermore, methane plume emissions can be accurately quantified through the utilization of an integrated mass enhancement model. Finally, a prediction of the future trajectory of methane remote sensing satellites is presented, in consideration of the current landscape. This paper aims to provide basic theoretical support for subsequent scientific research. [ABSTRACT FROM AUTHOR]

This paper explores green hydrogen-based carbon dioxide (CO 2) hydrogenation for the production of oxygenates, presenting it as a pivotal strategy for mitigating carbon emissions and advancing sustainable energy solutions. The conversion of CO 2 into oxygenates through hydrogenation emerges as a promising avenue, particularly in the context of transportation applications where the storage of hydrogen poses challenges. The substitution of fossil diesel and gasoline fuels with green hydrogen-derived dimethyl ether, or methanol/ethanol, is advantageous from a life cycle analysis (LCA) CO 2 emission perspective even without the capture of the CO 2. However, the greatest sustainability appeal is contingent on the crucial aspect of capturing CO 2 when utilizing these fuels, which is an aspect currently absent in the literature. This narrative review comprehensively explores catalytic processes, mechanisms, sustainability perspectives, and the current state of research in this evolving area. It encompasses both the production of oxygenates through CO 2 hydrogenation and the subsequent utilization of these oxygenates in fuel cells or combustion systems, emphasizing the integration of CO 2 capture technologies. The paper contributes to the discourse surrounding the environmental and technological dimensions of energy storage ecosystems, providing a holistic view of their potential to foster sustainable energy solutions. [ABSTRACT FROM AUTHOR]

ZnZrOx has been used in large quantities for the preparation of light olefins from CO2, but the relationship between structure and performance remains unclear at present. In this paper, ZnZrOx were prepared by co-precipitation method, and a series of oxides with different sizes were prepared by varying the calcination temperatures. Subsequently, these oxides were combined with SAPO-34 to create a composite bifunctional catalyst for the synthesis of light olefins by CO2 hydrogenation, in which the impact of nanocrystal size effect was examined. The catalytic performance significantly increased as the nanocrystal size reduced from 18 to 12 nm. However, when the nanocrystal size was further decreased to 8 nm, the catalytic performance decline. Characterizations revealed a gradual increase in the number of oxygen vacancies with decreasing nanocrystal size. However, the oxide with the smallest nanocrystal size, prepared by varied calcination temperatures, did not yield the optimal catalytic performance due to sintering occurring during the reaction process. The results show that the assumption that smaller nanocrystal sizes inherently equate to improved catalytic performance is not universally valid, and stability must be considered when the nanocrystal size is decreased. The bifunctional catalysts used in this paper for the prepared light olefins from CO2 in yield as high as 13.8%, which is higher than most previous reports. [ABSTRACT FROM AUTHOR]

Christian environmental ethics have always navigated the thin line between the Scylla of pantheism and the Charybdis of deism. On the one hand, removing God from the world avoids pantheism but can inadvertently render the divine a distant, absentee father who cares little about what we do with the environment. On the other hand, if we bring the Creator too close to creation, we may begin to blur the distinction between them, fringing on pantheism. While making nature divine might at first seem to heighten the environmental desecration of the earth by making it a literal de-sacralizing of the sacred, this may be only a surface-level reading (or, at least, only true of very carefully nuanced versions of pantheism). For the pantheist, God would not just be the trees but the machines that log them; God would not just be the polar bears but the carbon dioxide that is evicting them. God would be no more present in that which is desecrated than in that which does the desecration (e.g., God would be one with the pesticides, bulldozers, and factory smoke). By making God everything, it becomes difficult to call any person, act, legislation, or event godless. This paper offers Henry More's view of divine space as a constructive, Platonic Christian middle way between these two extremes, charting a God who is spatially present to nature without being pantheistically reducible to it, in the same way that space is intimately close to the objects within it while nonetheless remaining distinct from them. The bulk of the paper counters potential opponents to this proposal, specifically defending Morean space from the charge that it would break down the Creator–creature distinction and/or cave to the environmental Scylla of pantheism. [ABSTRACT FROM AUTHOR]

• 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]

Pulp and paper is considered to be the fourth most energy-intensive industry (EII) worldwide. However, as most of the CO 2 emissions are of biomass origin, this sector has the potential to become a carbon-negative industry. This study proposes a new concept for conversion of the pulp and paper industry to carbon negative that relies on the inherent CO 2 capture capability of the Kraft process. The techno-economic performance of the proposed carbon-negative system, based on calcium looping (CaL) retrofitted to a pulp and paper plant, was evaluated. The effect of CaL design specifications and cost assumptions on the thermodynamic and economic performance were evaluated. Under the initial design assumptions, the reference pulp and paper plant was shown to turn from electricity importer to electricity exporter with the cost of CO 2 avoided equal to 39.0 €/tCO 2. The parametric study showed that an increase in the fresh limestone make-up rate resulted in a linear increase of the specific primary energy consumption for CO 2 avoided (SPECCA) and a reduction in the amount of electricity exported to the electric grid. This translates into an increase in the price of pulp and newsprint, and the cost of CO 2 avoided. This study has also demonstrated that the pulp and paper industry has high potential to become carbon negative. It has been shown that carbon capture and storage would become economically viable in this industry if the negative CO 2 emissions are recognised and a negative CO 2 emissions credit of at least 41.8 €/tCO 2 is implemented. • Concept of the Kraft process with inherent CO 2 capture. • Calcium looping for CO 2 capture is integrated in the lime cycle. • Reference pulp and paper plant turns from importer to exporter of electricity. • Pulp and paper industry has a high potential to become carbon negative. • Economic feasibility needs the inclusion of biogenic emissions in emission trading. [ABSTRACT FROM AUTHOR]

In order to improve the whiteness of fly ash, the particles were coated by in-situ precipitation of calcium carbonate. After different mass ratios of calcium oxide to fly ash were mixed into water, a certain amount of carbon dioxide was bubbled into the mixture to form a precipitated calcium carbonate deposit on the surface of fly ash. With the help of scanning electron microscopy (SEM), the process and the coating mechanism of the unmodified and modified fly ash were studied. The results showed that when a 1:1 mass ratio of calcium oxide to fly ash was implemented, the whiteness of fly ash was increased from 30.3 (the original fly ash) to 74.0 (the modified fly ash). After appropriately controlling for the rate of carbon dioxide, the whiteness was improved to meet the standard for filler in the papermaking industry, and also great advantages in paper physical strength were demonstrated. [ABSTRACT FROM AUTHOR]

This work proposes to utilize supercritical CO 2 as a reaction medium for the acetylation of Hanji, a traditional Korean cellulose textile, to enhance its water repellency while retaining the other properties. We first examined the phase behavior of acetic anhydride and CO 2 mixtures, then a series of experiments were performed and statistically analyzed to find optimal operating conditions. Good surface hydrophobicity was attained in the optimized process within 4 h, shorter than classical non-catalytic liquid and gaseous processes. Hanji's tensile strength was also enhanced in the proposed process by a factor of 1.1, while it was aggravated in classical liquid processes. Hanji samples were slightly discolored in the proposed method, but the degree of discoloration was below the perception level. These results suggest that the proposed method has great potential to be used for the functionalization of cellulose-based textiles with a wide range of industrial applications. [Display omitted] • ScCO 2 -mediated acetylation was optimized to enhance Hanji's surface hydrophobicity. • Surface hydrophobicity is improved in scCO 2 -mediated acetylation within 4 h. • Tensile index increases by 11% in scCO 2 -mediated acetylation. • Tensile index decreases by 20% in classical acetylation methods. • Cellulose discoloration in scCO 2 -mediated acetylation is mild. [ABSTRACT FROM AUTHOR]

To reveal the deflagration hazard and propagation law of hydrogen-enriched natural gas (H 2 NG) in closed spaces, this paper studied the deflagration characteristic parameters under different H 2 blended ratio (λ) and inert gas dilution fraction (X dilution) in slender closed pipelines with steel circular hole obstacles. The results indicate that the positive feedback mechanism's sustained effect, failure, and re-action leads to a "three-zone" distribution of H 2 NG explosion overpressure along the pipeline, namely the acceleration, attenuation, and rebound zones. The maximum explosion overpressure (P max), maximum pressure rise rate ((dP/dt) max), and peak shock wave propagation velocity (V p) all increase with the increase of λ. The rise of λ has the most significant enhancement effect on (dP/dt) max , while the enhancement effect on V p is the smallest. This is because the main reasons affecting their increase are different. P max , (dP/dt) max , and V p exhibit exponential decay with increased N 2 and CO 2. However, CO 2 has a more significant inhibitory effect on the H 2 NG deflagration process. When X CO2 = 25% and X CO2 = 30%, the deflagration process of H 2 NG with λ = 20% and λ = 80% can be inhibited entirely, respectively, which has important guiding significance for the safe application of H 2 NG. • The evolution law of deflagration shock waves in slender closed pipelines by H 2 NG was researched. • Effects of H 2 blended ratio and N 2 /CO 2 dilution fraction on H 2 NG deflagration characteristics were revealed. • The effects of N 2 /CO 2 dilution fraction on the P max , (dP/dt) max , and V p were predicted by an exponential model. [ABSTRACT FROM AUTHOR]

This paper presents and analyzes a finite volume scheme for a fully degenerate parabolic system modeling the compressible two-phase flow, such as water-gas, problem in porous media considering the effects of temperature. The problem is written in terms of the phase formulation, i.e. the saturation of one phase, the pressure of the second phase and the temperature are primary unknowns. We use a first-order time implicit Euler scheme. The spatial discretization uses a fully coupled fully implicit cell-centered two-point flux approximation scheme where upwinding of the flux across an interface between two control volumes is performed for each fluid phase. Under physically relevant assumptions on the data, we prove the maximum principle for both saturation and temperature. We obtain a priori estimates and we show that the discrete problem is well posed. Also, we exploit various a priori estimates as well as compactness arguments to establish the convergence of the numerical scheme toward the weak solution. The open-source platform DuMu X was employed for the implementation of the developed algorithm based on the above scheme. Numerical result are presented to demonstrate the efficiency of this scheme. The test addresses the evolution in 2D of CO 2 injection into a layered aquifer. The algorithm's convergence with first order is validated by our numerical results, which support the theoretical results. To our best knowledge, this is the first convergence result of a finite volume scheme in the case of nonisothermal immiscible compressible two-phase flow in porous media. [ABSTRACT FROM AUTHOR]

Chemical equilibrium represents the highest efficiency achievable by a thermochemical cycle under specific operational conditions. This study delves into two-step thermochemical water splitting cycles, which dissociate water into hydrogen (H 2) and oxygen (O 2) via sequential thermal reduction and re-oxidation processes. Building on the thermal reduction analysis presented in Part 1, this paper zeroes in on the re-oxidation reaction within the optimal reactor framework – the counter-current reactor. It elucidates the equilibrium pathway, delineating the progression of chemical equilibrium at each incremental stage of re-oxidation. Using ceria (CeO 2) as a model redox-active metal oxide, the investigation analyzes the influence of operational parameters on the re-oxidation reaction. Findings reveal the theoretical feasibility of maintaining near constant temperature (±2.5 °C) during re-oxidation, achieving a total extent of reduction of 0.038 and a hydrogen conversion yield of 32%. While near adiabatic operation is also achievable, practicality is constrained by a maximum total extent of reduction of 6.5·10−3. The study also explores the economic implications of thermochemical water splitting, particularly focusing on the steam-to-hydrogen output ratio. It highlights the severe economic hurdles associated with hydrogen yields below approximately 1%. Furthermore, the investigation reveals that the addition of inert gas to the re-oxidation step offers no significant advantages. Concluding the analysis, a comparative assessment exposes negligible differences in outcomes when substituting carbon dioxide (CO 2) for water (H 2 O) as the oxidant in low-temperature scenarios (800 °C). This comprehensive study not only advances the understanding of re-oxidation dynamics in thermochemical water splitting but also informs practical and economic considerations crucial for the advancement of this technology. • Reversible/equilibrium re-oxidation pathway defined for water splitting cycles. • Reversible quasi-constant temperature and quasi-adiabatic re-oxidation is feasible. • Limited impact of gas purity on re-oxidation at fixed flow/minimum temperature. • Inert gas addition offers no thermodynamic advantage in re-oxidation. • Low re-oxidation temperatures expand the solution space for high cycle efficiency. [ABSTRACT FROM AUTHOR]

Syngas, which is used as both a fuel and a raw material, presents numerous safety risks during its utilization. In this paper, the effects of H 2 /CO ratio (R = 0%, 30%, 50%, 70% and 100%) and CO 2 dilution ([CO 2 ] = 0%–20%) on the explosion behaviors of syngas/air mixtures with different equivalence ratios (φ = 0.8, 1.0, 1.6, and 2.5) are examined via experiments and numerical calculations. The results show that the peaks of explosion pressure and OH* spectral intensity are significantly influenced by the H 2 percentage in the syngas. The introduction of CO 2 notably decreases these parameters in oxygen-rich and severe oxygen-poor states. Additionally, the flame propagation speed noticeably increases with increasing H 2 proportion in the syngas. The influence of CO 2 on the buoyancy instability of the spherical flame of syngas is considered negligible when compared to that of other combustible gases, such as CH 4. Nevertheless, the presence of CO 2 decreases the density ratio between the unburned gas and burned gas and increases the flame thickness of syngas/air mixtures. This trend reduces the cellular instability of the spherical flame, particularly in severe oxygen-poor states. Notably, there is a definite correlation between the formation of cellular flames and the rise rate of explosion pressure. The cellular structure on the flame surface becomes more pronounced when the rise rate of explosion pressure increases. Conversely, it develops later or is noticeably inhibited. Furthermore, the main reaction pathways are H 2 → ∙OH → H 2 O 2 → H 2 O and H 2 → ∙OH → CO → CO 2 during the syngas explosion process. ∙OH is critical in the entire chain reaction because it promotes the conversion of H 2 to H 2 O and acts as a vital connection between the reactants H 2 and CO in the explosion process. • The P max and I max were investigated with H 2 addition and CO 2 dilution. • The cellular instability of the spherical flame was analyzed. • The interaction of flame development and explosion pressure was revealed. • The main reaction pathways during the syngas explosion process were examined. [ABSTRACT FROM AUTHOR]

Legislation regulating the sustainability requirements for hydrogen technologies relies more and more on life cycle assessments (LCAs). Due to different scopes and development processes, different pieces of EU legislation refer to different LCA methodologies, with differences in the way multifunctional processes (i.e., co-productions, recycling, and energy recovery) are treated. These inconsistencies arise because incentive mechanisms are not standardized across sectors, even though the end product, hydrogen, remains the same. The goal of this paper is to compare the life-cycle greenhouse gas (GHG) emissions of hydrogen from four production pathways depending on the multifunctional approach prescribed by the different EU policies (e.g., using substitution or allocation). The study reveals a large variation in the LCA results. For instance, the life-cycle GHG emissions of hydrogen co-produced with methanol is found to vary from 1 kg CO 2 -equivalent/kg H 2 (when mass allocation is considered) to 11 kg CO 2 -equivalent/kg H 2 (when economic allocation is used). These inconsistencies could affect the market (e.g., hydrogen from a certain pathway could be considered sustainable or unsustainable depending on the approach) and the environment (e.g., pathways that do not lead to a global emission reduction could be promoted). To mitigate these potential negative effects, we urge for harmonized and strict guidelines to assess the life-cycle GHG emissions of hydrogen technologies in an EU policy context. Harmonization should cover international policies too, to avoid the same risks when hydrogen will be traded based on its GHG emissions. The appropriate methodological approach for each production pathway should be chosen by policymakers in collaboration with the LCA community and stakeholders from the industry based on the potential market and environmental consequences of such choice. • LCA methodologies for hydrogen-related policies are currently not fully harmonized. • Four hydrogen production pathways involving multifunctionality were analysed. • GHG emissions of hydrogen vary significantly with the LCA methodology adopted. • Inconsistencies can lead to market distortions, inefficiencies, and confusion. • There is an urgent need for harmonized and strict LCA guidelines for H2 production. [ABSTRACT FROM AUTHOR]

Increased warming in the Arctic is of great concern. This is particularly due to permafrost degradation, which is expected to accelerate microbial breakdown of soil organic carbon, with its further release into the atmosphere as carbon dioxide (CO2). The fine-scale variability of CO2 fluxes across highly mosaic Arctic tundra landscapes can provide us with insights into the diverse responses of individual plant communities to environmental change. In the paper, we contribute to filling existing gaps by investigating the variability of CO2 flux rates within different landscape units for dominant vegetation communities and plant species across typical tundra of the southern part of the Taimyr Peninsula, Siberia. In general, the variability of soil CO2 flux illustrates a four-fold increase from non-vascular vegetation, mainly lichens and mosses (1.05 ± 0.36 µmol m−2 s−1), towards vascular plants (3.59 ± 0.51 µmol m−2 s−1). Barren ground ("frost boils") shows the lowest value of 0.79 ± 0.21 µmol m−2 s−1, while considering the Arctic "browning" phenomenon, a further substantial increase of CO2 flux can be expected with shrub expansion. Given the high correlation with top soil temperature, well-drained and relatively dry habitats such as barren ground and non-vascular vegetation are expected to be the most sensitive to the observed and projected temperature growth in the Arctic. For mixed vegetation and vascular species that favor wetter conditions, soil moisture appears to play a greater role. Based on the modeled seasonal pattern of soil CO2 flux and precipitation records, and applying the rainfall simulations in situ we outlined the role of precipitation across enhanced CO2 emissions (i.e., the "Birch" effect). We found that a pulse-like growth of soil CO2 fluxes, observed within the first few minutes after rainfall on vegetated plots, reaches 0.99 ± 0.48 µmol m−2 s−1 per each 1 mm of precipitation, while barren ground shows 55–70% inhibition of CO2 emission during the first several hours. An average additive effect of precipitation on soil CO2 flux may achieve 7–12% over the entire growing season, while the projected increased precipitation regime in the Arctic may strengthen the total CO2 release from the soil surface to the atmosphere during the growing season. [ABSTRACT FROM AUTHOR]