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Presents a study that investigated the biodegradability and disintegration of paper product and its effects on compost quality. Effect of lignin content of materials in the low biodegradability level based on microbial degradation and measurement of carbon dioxide evolution; Degradation of nylon bags; Results of data analysis.

As the world No.1 emitter of carbon dioxide (CO2), China has made up its mind to act on climate change. After trials in six pilot regions- Shenzhen, Shanghai, Beijing, Guangdong, Tianjin, Hubei, and Chongqing- a nationwide ETS has been established and implemented in line with the Thirteenth Five-Year Plan period (2016–2020). This paper simulates the effect of a national ETS in China using GTAP 9.1 database and a revised GTAP-E model. The simulation results show that the ETS is very effective in emissions reduction but will cause a mild economic contraction. At the sectoral level, the energy and resource sectors and energy intensive sectors are to be hit hard while most other sectors are affected negatively but insignificantly. [ABSTRACT FROM AUTHOR]

The diffusion behaviour of hydrogen, carbon monoxide, carbon dioxide, methane, acetylene, ethylene and ethane in oil and paper medium was examined using molecular dynamics to reveal the diffusion mechanism of gas molecules in transformer oil–paper insulation system at the microscopic level. These compounds are commonly used in the dissolved gas analysis of power transformers and produced during the ageing process of oil–paper composite insulating material. Two groups of models were constructed using molecular dynamics simulation software to simulate the diffusion behaviour of the aforementioned seven types of small gas molecules in oil and paper. The diffusion coefficients, displacement features, free volume characteristics and interaction energies of the gas molecules were investigated. In particular, the diffusion micro-mechanism of the gas molecules was observed. The differences in diffusion features among the gas molecules were discussed, and the factors influencing the diffusion of the gas molecules were compared. Simulation results indicate that the diffusion coefficients of gas molecules in cellulose is an order of magnitude lower than that in oil, and the diffusion coefficients of these gas molecules in the two types of insulation media have different orders. Free volume of gas molecules is the main factor that influences the diffusion behaviour in oil, whereas intermolecular interaction is the main influencing factor of diffusion behaviour in cellulose. [ABSTRACT FROM PUBLISHER]

Based on KAMa pulp and paper mill, a polygeneration system integrated with a black liquor gasifier is proposed. The effects of CO2 captured by oxygen-fuel combustion and Selexol absorption on the performance of the polygeneration system are studied in terms of both thermodynamic performance and cost assessment. Using the Aspen Plus simulator, the performance of the studied polygeneration systems are analyzed from the perspectives of the first and second laws of thermodynamics. Compared with the reference system, the first law efficiency of the polygeneration system increased from 15.7% to 29.3%, with an investment increment of 17.9%. The investment incremental rates for CO2 capture by oxyfuel combustion and Selexol absorption are 15.1% and 16.7%, respectively. Energy penalty due to CO2 capture and compression is 0.61 MJ electricity/kg CO2, avoided in the oxygen-fuel method at a cost of $29.6/tonne CO2. However, energy penalty can reach 1.03 MJ product (electricity and methanol) per kg CO2, avoided in the Selexol absorption CO2 capture process at a cost of $46.0/tonne CO2. [ABSTRACT FROM AUTHOR]

In the last ten years, as international environmental protection consciousness has increased, the study and applications of green building, green construction materials and energy savings as well as reduction of carbon dioxide have become urgent issues for governments. In Taiwan, joss papers are burned in more than 11,731 registered shrines or temples in traditional Chinese deity or ancestor worship ceremonies during special holidays or occasions. Instead of placing this large amount of burned joss paper ash (BJPA) in landfills, this study proposes recycling BJPA by replacing some cement with calcined BJPA (CBJPA) in mortar specimens. After BJPA samples were calcined at a high kiln temperature, mortar samples were created using CBJPA to replace cement at seven different levels: 0%, 5%, 10%, 15%, 20%, 25% and 30%. Tests like setting time and compressive strength were performed for macro-analyses; scanning electron microscopy–energy dispersive spectroscopy, X-ray diffraction and thermal gravimetric analysis/differential thermal analysis were carried out for the microstructure and chemical composition analyses. The test results showed that the compressive strengths of specimens with different levels of CBJPA replacement were apparently less than those of the control group (0% CBJPA) at all curing times. The compressive strength and setting time both decreased as the fraction of CBJPA in the mortar increased. Furthermore, because the hydration product did not cement and the mortar specimen structure was loose, the expected strength improvement from the pozzolanic reaction provided by the CBJPA was not clearly observed. [ABSTRACT FROM PUBLISHER]

Lime is a product derived from the thermal decomposition of limestone (mainly calcium carbonate, CaCO3) into quicklime (CaO) and carbon dioxide (CO2), also called calcination. Controlled reaction with water is used to manufacture hydrated lime (Ca(OH)2) products. Lime is used in a wide variety of applications: metals industry, construction materials sector, civil engineering, environmental protection, agriculture, and chemical industry. Lime production is one of the sources of anthropogenic CO2 emissions resulting in global warming and ocean acidification. However, a proportion of the CO2 emitted during the calcination is reabsorbed by the lime during the product life within its different applications. This process called carbonation is thermodynamically favoured because it is exothermal. It allows permanent CO2 storage in a stable product since the lime combines with gaseous CO2 reforming CaCO3. This paper reports a comprehensive literature review on the carbonation potential of lime in different applications. The total carbonation potential is assessed as carbonation rate, i.e. the ratio between the CO2 reabsorbed through carbonation during the operational life of lime and the CO2 emitted during limestone calcination. This study provided preliminary evidence that, based on the current EU market, on average 23–33% of lime process emissions are carbonated during the use phase. Carbonation over time is also analysed for the lime applications where information is available. For three applications, namely water, flue gas cleaning and pulp and paper, the carbonation reaction is instantaneous. Up to 22% of the calcination emissions are absorbed within five years based on the current EU market. [ABSTRACT FROM AUTHOR]

As the industrial revolution progresses, carbon dioxide (CO2) and sulfur dioxide (SO2) are major concerns because they are the main contributors to greenhouse gases. The concentration of these harmful gases in the industry is very high, which is emitted by workers and industrial materials. Therefore, it is required to maintain a safe percentage of CO2, SO2, and other harmful gases in the air of industry and ensure safety from fire accidents. This paper presents a compressor driven system that could capture harmful gases including CO2 and SO2 from the polluted air of different industries and households. The captured and separated CO2 works as a fire extinguishing agent to safeguard fire accidents for large industries and households. Thus, this system ensures a protected working place and a healthy atmosphere for industrial workers. Besides, this system can be applied in place of the exhaust gas recirculation (EGR) system in small industries and for a four-wheeler, internal combustion engine, as this system could capture and separate the harmful carbon dioxide and sulfur dioxide. This paper also presents a developed model of different polymeric membranes to simulate the separation of carbon dioxide after the post-combustion process. Computational Fluid Dynamics (CFD) has been performed by COMSOL 5.5 to observe the carbon dioxide separation by polymeric membranes like polycarbonate (0.07 mol/m3) and polytetrafluoroethylene (0.1 mol/m3) polymeric membranes for specific pore sizes which is comparable to experimental data (0.05 mol/m3). [ABSTRACT FROM AUTHOR]

This paper conducts a computational investigation of the phase behaviour of $ \textrm{C}{\textrm{H}_4} $ C H 4 - $ \textrm{C}{\textrm{O}_2} $ C O 2 binary system, utilising the SAFT-VR Mie equation of state alongside molecular dynamics (MD) simulations. Molecular parameters for pure $ \textrm{C}{\textrm{H}_4} $ C H 4 and $ \textrm{C}{\textrm{O}_2} $ C O 2 compounds were obtained by fitting the SAFT-VR Mie EOS to vapour pressure and saturated liquid density experimental data. The research first validates the SAFT-VR Mie EOS on thermodynamic properties and vapour–liquid equilibria for different compositions, pressures, and temperatures of pure $ \textrm{C}{\textrm{H}_4} $ C H 4 , $ \textrm{C}{\textrm{O}_2} $ C O 2 , and $ \textrm{C}{\textrm{H}_4} $ C H 4 - $ \textrm{C}{\textrm{O}_2} $ C O 2 mixtures with the newly extracted parameters. The study confirms the EOS's accurate prediction of coexistence properties, including pressure, density, and phase-equilibrium curve. MD simulations were performed using the LAMMPS software package, with Mie force field parameters derived from this study for non-bonded interactions. Simulations were conducted using three other force fields (OPLS-UA, UFF, and GAFF) to compare their performance with our approach. The simulation results were compared to laboratory data, or REFPROP, in the absence of laboratory data. The results showed a relatively good agreement, indicating that combining SAFT-VR Mie EOS and MD simulations is a reliable predictive tool for designing gas processing and gas storage applications involving $ \textrm{C}{\textrm{H}_4} $ C H 4 - $ \textrm{C}{\textrm{O}_2} $ C O 2 mixtures. This approach also mitigates the need for expensive and hazardous high-pressure laboratory techniques. [ABSTRACT FROM AUTHOR]

Despite extensive works have been devoted to study the scale inhibition behavior, the performance of inhibitors is still not fully understood. In this paper, we present a laboratory study to elucidate the impact of water composition on the performance of some commonly used phosphonate and polymeric calcium carbonate scale inhibitors, in highly supersaturated brines at high temperature. Calcium tolerance inhibitor chemicals with various molecular structures are studied using dynamic scale loop test method at 150 °C. Brine composition is varied by changing the non-stoichiometry of scaling lattice ions, e.g., ( Ca 2 + ) / ( CO 3 2 − ) ratio, over a wide range. Test results indicate that the effectiveness of inhibitors can be significantly changed by the scaling ion ratio. In general, the efficacy of inhibitors decreases significantly with calcium concentration in the test brine even at constant supersaturation state and temperature, and also the performance ranking of the different inhibitor chemistries can be changed with brine composition. This could be caused by the alternations of interactions between inhibitor molecules and the surface of calcium carbonate scale crystals. Findings from this study suggest that the effect of scaling ion ratio must be considered in scaling risk assessment and for the optimization of inhibitor treatment programs. [ABSTRACT FROM AUTHOR]

CO2capture from gaseous effluents is one of the great challenges faced by chemical and environmental engineers, as the increase in CO2levels in the Earth atmosphere might be responsible for dramatic climate changes. From the existing capture technologies, the only proven and mature technology is chemical absorption using aqueous amine solutions. However, bearing in mind that this process is somewhat expensive, it is important to choose the most efficient and, at the same time, the least expensive solvents. For this purpose, a pilot test facility was assembled and includes an absorption column, as well as a stripping column, a heat exchanger between the two columns, a reboiler for the stripping column, pumping systems, surge tanks and all necessary instrumentation and control systems. Some different aquous amine solutions were tested on this facility and it was found that, from a set of six tested amines, diethanol amine is the one that turned out to be the most economical choice, as it showed a higher CO2loading capacity (0.982 mol of CO2per mol of amine) and the lowest price per litre (25.70 €/L), even when compared with monoethanolamine, the benchmark solvent, exhibiting a price per litre of 30.50 €/L. [ABSTRACT FROM AUTHOR]

Sweep efficiency of stagnant and poorly drained reservoir zones is extremely relevant task during gas and chemical flooding of hard-to-recover reserves. The paper presents the results of the field implementation of the in-situ CO2 generation technology to recovery of residual oil reserves and increase the sweep efficiency factor. The article presents the results of theoretical and laboratory studies, as well as field cases of an energy- and resource-saving method for oil recovery increase and improving oil production. The results of the reservoir stimulation confirmed the increase in the total incremental oil production after treatment operation on recovering residual oil reserves on. [ABSTRACT FROM AUTHOR]

Reducing greenhouse gas emissions or collecting and converting existing greenhouse gases has become a global concern. One of the most effective methods of utilizing CH4 and CO2 resources is the dry reforming of methane (DRM). Transition metal carbide catalysts have attracted wide attention because of their excellent catalysis performance and carbon deposition resistance. However, pure-phase carbides are easily oxidized and deactivated at atmospheric pressure in DRM reactions. There is a problem of poor dispersion (Mo2C 17 m² /g). Therefore, this paper summarizes the effects of adding active sites and supported carbides on the DRM reaction, discusses the role of active sites and supports in the catalyst, and introduces the different preparation methods of transition metal carbides. This paper also reviews the catalyst mechanism of transition metal carbides in DRM reactions. Nevertheless, the current research in this field needs to be deepened. Therefore, it is necessary to strengthen the exploration of various catalyst preparation methods and mechanisms, so as to realize future improvement in this field. [ABSTRACT FROM AUTHOR]

Negative emissions technologies (NETs) for carbon dioxide removal (CDR) are increasingly important responses to achieve global climate change targets, but to date, there has been insufficient attention to land-based NETs (including afforestation, biochar, and other measures) as an agrarian challenge for the global South. This paper explores the implications of different NETs for land, labor, capital, and politics in rural spaces and contributes to articulating agrarian climate justice by demonstrating the potentially unjust implications of many NETs. The paper concludes with how these measures might be designed to be less negative for rural peoples in future implementation. [ABSTRACT FROM AUTHOR]

This paper examines the environmental Kuznets curve (EKC) hypothesis in Nordic countries (Denmark, Finland, Iceland, Norway and Sweden) over the period 1981–2018. The link between economic growth and carbon dioxide (CO2) emissions is analysed. The study includes causality analysis and controls for cross-sectional dependence (CSD), slope heterogeneity, stationarity and cointegration patterns. Estimations validate the EKC hypothesis for Denmark and Iceland, but not for Norway and Sweden. Finland data show no significantly visible trend. [ABSTRACT FROM AUTHOR]

This article discusses the proceedings of the "7th IIR Gustav Lorentzen Conference" held on May 28-31, 2006, in Trondheim, Norway. Several interesting papers, both academic and practical, were presented on "Natural Working Fluid Systems." It elaborated on the newly commercialized products using natural fluids. It presents an overall perspective of natural working fluids with an emphasis on carbon dioxide.

This paper addresses the impact of political regimes on carbon emissions (CO2) from a historical perspective, covering the period of 1970–2015. Our sample consists of 153 countries that we follow for 20 years before the transition (1970–1990) and 26 years after it (1990–2015). During transition, post-Communist states experienced a decline in CO2, when controlling for economic variables. Transition had a positive impact on the environment only in cases when it was associated with democratization. When transition has led to consolidation of autocratic regimes, CO2 has increased. [ABSTRACT FROM AUTHOR]

This paper studies CO2 emissions at a global level. The authors use Dynamic Optimisation to derive the minimum penalty cost on countries every single time. They then use an Imputation Distribution Procedure to allocate the minimum penalty cost among countries. Their work provides the extension of the Shapley value cost allocation as a penalty to reduce CO2 emissions. The paper has implications for how to provide initiatives to improve cooperation on reducing CO2 emissions at an international level. Results show that a reduction in cost of only one country can be harmful for other countries. In this way, some countries can end up or worse off in a case where all countries experience a uniform decrease in their penalty cost. Therefore, the findings of this work suggest a low penalty-cost scenario that helps the countries fight for pollution reduction and provide fruitful links for policy-makers. They show that the Clean Development Mechanism (CDM) of the Kyoto Protocol could be implemented by the Shapley value cost allocation. [ABSTRACT FROM AUTHOR]

Growing food demand, environmental degradation, post-harvest losses and the dearth of resources encourage the decision makers from developing nations to integrate the economic and environmental aspects in food supply chain network design. This paper aims to develop a bi-objective decision support model for sustainable food grain supply chain considering an entire network of procurement centres, central, state and district level warehouses, and fair price shops. The model seeks to minimise the cost and carbon dioxide emission simultaneously. The model covers several problem peculiarities such as multi-echelon, multi-period, multi-modal transportation, multiple sourcing and distribution, emission caused due to various motives, heterogeneous capacitated vehicles and limited availability, and capacitated warehouses. Multiple realistic problem instances are solved using the two Pareto based multi-objective algorithms. Sensitivity analysis results imply that the decision makers should establish a sufficient number of warehouses in each producing and consuming states by maintaining the suitable balance between the two objectives. Various policymakers like Food Corporation of India, logistics providers and state government agencies will be benefited from this research study. [ABSTRACT FROM AUTHOR]

With the rapid development of regional economy, energy consumption and carbon dioxide emission increase sharply. This study examines the relationship between carbon dioxide emissions and regional economic growth. Based on the mean value decomposition method of double logarithm, the model was built to identify the key indexes affecting the decomposition, and the carbon emission formula was calculated to obtain the regional carbon dioxide emission. Based on the actual data, the kuznets curve model is established to represent the relationship between CO2 emission and regional economic growth in logarithm form. The unit root test, co-integration test and granger causality test are carried out for the correlation sequences in the kuznets curve model in order to realize the research on the relationship between CO2 emission and regional economic growth. This paper discusses the relationship between carbon dioxide emission and regional economic growth through an example. It shows that the relationship between carbon dioxide emission and regional economic growth is inversely u-shaped, and there is a kuznets curve between the two. According to the result of empirical analysis, the paper puts forward some suggestions to reduce energy consumption and improve energy efficiency, which is helpful to improve social and economic structure and promote social and economic development. [ABSTRACT FROM AUTHOR]

This study aims to estimate the potential economic benefits, energy and CO2emissions reductions when using trusted third-party digital repository (TTPR) services in one individual bank, and within the banking industry in Korea. First, the cost, benefit and net benefit of using TTPR services in the banking industry are estimated. Second, the net induced output effect is estimated. Third, based on an environmentally extended input–output analysis, CO2emissions reduction was estimated as 1924.32 tons in 2009 and the energy consumption reduction as 640.70 TOE. Fourth, the total economic benefit, which is the sum of the net induced output effect and economic value of CO2emissions reductions, is approximately $11.04 million. The findings demonstrate that energy consumption and CO2emissions reductions are meaningful enough to result in significant economic benefits. Therefore, the Korean government should promote the use of TTPR services in the entire industry. [ABSTRACT FROM AUTHOR]

The paper reviewed the current perspectives on the development of carbon dioxide (CO2) sequestration through its process conversion into calcite. The process occurs in either geological or biological systems. However, geological sequestration is an expensive process, which is slow in comparison to bio-sequestration. Recently, the bio-sequestration of atmospheric CO2 into the soil using microorganisms such as algae has been investigated. However, the algae cannot be used in the bio-concrete due to their nature as phototrophic organisms. In contrast, bacteria are the most potent organisms in bio-concrete technology. The use of bacterial species in the bio-aerated concrete bricks (B-ACB) and its potential to bio-sequestrate CO2 represents a future strategy to reduce high CO2 pollution. Bacterial cells can capture CO2 by accelerating the carbonation processes, which convert CO2 into calcium carbonate (CaCO3) via carbon anhydrase and urease enzymes. The present paper aimed to highlight and discuss the applicability of bacteria in the B-ACB for capturing and storing CO2. It is evident from the literature that the new trends to use bio-concrete might contribute to the reduction of CO2 by accelerating the carbonation process and strengthening the B-ACB. [ABSTRACT FROM AUTHOR]

Due to the Coronavirus 2019 (COVID-19) pandemic social distance became a necessary strategy adopted in order to curb the fast-rise of infection. However, this strategy adopted by the government has impacted the socio-economic activities and lives of citizens as such new adaptive measures had to be put in place to cope with the pandemic. Accordingly, this study explores the relationship between the current COVID-19 pandemic on hydropower and energy sector in relation to Carbon dioxide (CO2) emission reduction. This paper employs a systematic review of secondary data grounded from document reports and existing literature to explore the trend of COVID-19 pandemic on hydropower and energy sector in relation to CO2 emission reduction. Findings from this article offer empirical evidence toward the impact of COVID-19 on hydropower and energy sector in relation to CO2 emission decrease during the pandemic. More importantly, findings from this study discuss the relationship of COVID-19 on energy sector, impact of COVID-19 on the hydropower sector in comparison to other renewables, impact of COVID-19 and oil demand, and connection of COVID-19 on CO2 emission reduction during the lockdown. Finally, implications are provided to guide policy makers in making decision toward sustainable energy production and CO2 emission reduction. [ABSTRACT FROM AUTHOR]

This paper presents two multi-objective models that integrate packaging size and production scheduling problems for a flexible flow shop system. The main objective is to find the packaging size of finished product per item and the production schedule that would minimise cost of lost units, unpacking cost, inventory cost, earliness/tardiness penalties and kilograms of carbon dioxide emitted by resources operation. Since the complexity of the proposed models, a Pareto-based hybrid genetic algorithm (HGA) is also developed. A case study was developed to analyse the performance of both models using different instances. Numerical results indicate that the outperformance of one model over the other depends on the demand and the packaging size. [ABSTRACT FROM AUTHOR]

Taking the Yangtze River Delta (YRD) of China as the research area, this paper studies the influence of freight structure adjustment and energy intensity on carbon dioxide (CO2) emission from the transportation industry. Sample data from 1990 to 2019 are selected, and co-integration analysis is performed using three independent variables: energy intensity, turnover ratio of railway to highway (R/H), and turnover ratio of railway to waterway (R/W). Then, an autoregressive distribution lag-error correction model (ARDL-ECM) is established to estimate the long-run and short-run relationships among the variables through unit root test, autoregressive distributed lag (ARDL) boundary test, and Granger test. The results show that in the long run, the growth of energy intensity leads to the long-term growth of CO2 emission in the transportation sector of the YRD, and R/W and R/H have a suppressive effect on CO2 emission. Granger causality indicates that there is a bidirectional causal relationship between energy intensity and CO2 emission. This work can be a reference for government departments to formulate policies related to carbon emissions in the transportation industry. [ABSTRACT FROM AUTHOR]

Energy generation and pollutant emissions are two faces of the same coin, as the current energy sources i.e., fossil energy, are still considered to be major sources of greenhouse gases (GHG). Therefore, shifting to cleaner energy sources imposes itself as an inevitable solution to reduce this environmental cost. In this paper, a hybrid system based on the multi-agent approach and Long Short-Term Memory (LSTM) neural networks to forecast the energy production and its carbon dioxide (CO2) emissions and simulate the potential emission reduction in case of switching to renewable energy sources is presented. The proposed system's architecture consists of combining LSTM models with the agent-based technology, where multiple LSTM forecasting models were trained to forecast the production of each type of the studied energies and then estimate the equivalent emitted CO2 and calculate the influence of the renewable energy inputs on the carbon emissions and the fossil fuels consumption. The simulation process consists of two phases: firstly, each forecasting agent uses a specific LSTM model to forecast short-term energy production. Secondly, these agents send the forecasted values to the coordination agent who is responsible for calculating the total CO2 emissions and the benefits of the renewable energy inputs. [ABSTRACT FROM AUTHOR]

Composting is a complex bioprocess, requiring a lot of empirical experiments to optimize the process. A dynamical mathematical model for the biodegradation of the organic matter during the composting process has been developed. The initial organic matter expressed by chemical oxygen demand (COD) is decomposed into rapidly and slowly degraded compartments and an inert one. The biodegradable COD is hydrolysed and consumed by microorganisms and produces metabolic water and carbon dioxide. This model links a biochemical characterization of the organic matter by Van Soest fractionating with COD. The comparison of experimental and simulation results for carbon dioxide emission, dry matter and carbon content balance showed good correlation. The initial sizes of the biodegradable COD compartments are explained by the soluble, hemicellulose-like and lignin fraction. Their sizes influence the amplitude of the carbon dioxide emission peak. The initial biomass is a sensitive variable too, influencing the time at which the emission peak occurs. [ABSTRACT FROM AUTHOR]

Generated electricity from renewable sources such as solar panels and wind turbines is considered, until now, as clean and nonpolluting energy. However, these systems are responsible and directly tied to greenhouse gases (GHG) emissions when considering their different steps of manufacturing, transportation, operation, maintenance, and decommissioning. This paper describes a new sizing optimization methodology of a stand-alone hybrid Photovoltaic/Wind/Battery system, minimizing the Levelized Cost of Energy (LCOE), the Loss of Power Supply Probability (LPSP), and the Equivalent Carbon Dioxide (CO2-eq) life cycle emission. An elitist Non-dominated Sorting Genetic Algorithm (NSGA-II) is used to solve this constrained nonlinear multi-objective optimization problem taking the expected photovoltaic peak power, wind turbine output power, batteries' energy capacity as decision variables and embodied carbon dioxide per unit of electricity consumed as a constraint. Different combinations of PV/Wind/Battery systems are optimized and compared to identify the cost-effective, reliable, and environmentally friendly optimal architecture. Finally, a sensitivity analysis is applied to the proposed algorithm; only the batteries' state of charge (SOC) setpoint is considered to examine its impact on the system sizing procedure. The proposed algorithm is used for optimal planning of a stand-alone hybrid renewable power system expected to be installed in Borj Cedria Science and Technology Park (latitude = 36.71ºN, longitude = 10.42ºE). Simulation results proved the effectiveness of the proposed method to achieve economic, energetic, and environmental objectives. [ABSTRACT FROM AUTHOR]

The experiments on microwave pyrolysis of soybean straw are studied to produce hydrogen-rich gas under CO2 atmosphere in this paper. The microwave power has an important effect on the temperature. The final temperature increases and the time to obtain the highest temperature is shortened with the power increasing. The gas yield, H2 yield and potential H2 yield increase rapidly with the power increasing, and the gaseous yield at CO2 atmosphere is up to 55.70% at 1000 W, and it is higher than N2 atmosphere. The main components of microwave pyrolysis gas product are H2 and CO, the content of syngas (H2+ CO) at CO2 atmosphere is 84.19% at 1000 W, which is more than N2 atmosphere. However, H2/CO ratio is about 0.80 at CO2 atmosphere, which is lower than N2 atmosphere, and H2/CO ratio at CO2 atmosphere is not suitable for the requirements of chemical synthesis. If it is used to synthesize liquid fuels, H2/CO ratio must be adjusted. [ABSTRACT FROM AUTHOR]

Supercritical carbon dioxide fracturing can effectively relieve the environmental pressure caused by in-situ production of oil shale. In order to study the process of fracture propagation during supercritical carbon dioxide fracturing, a fracture propagation model of supercritical carbon dioxide fracturing is established in this paper, and an unsteady temperature field model is introduced. Based on the discrete fracture model, the fluid temperature field in one-dimensional fracture is coupled with the temperature field of two-dimensional reservoir rock. The new model also takes into account the real-time variation of carbon dioxide physical parameters, which are calculated by Span-Wagner and Vesovic equations. Based on this model, the influencing factors of fracture propagation in supercritical carbon dioxide fracturing are analyzed. The results show that the leak-off coefficient has an obvious effect on fracture propagation, so an additive needs to be developed to reduce the leak-off. Since carbon dioxide is a compressible fluid, the reservoir temperature and the original in-situ stress also have a significant impact on the fracture propagation. The temperature of carbon dioxide at the bottom of the well has no significant effect on fracture propagation, because carbon dioxide will quickly reach reservoir temperature when it enters the formation. Comprehensive considering the fracture length, width, filtration, and potential effect on proppant transport during supercritical carbon dioxide fracturing, the injection rate should be as high as possible. [ABSTRACT FROM AUTHOR]

Satellites provide global long-time series of spatio-temporal continuous CO2 observations. However, it is difficult to be applied to the study of small-scale carbon cycle because of its low spatial resolution. In this paper, the Greenhouse Gases Observing SATellite (GOSAT) XCO2 data are super-resolution reconstructed using bicubic interpolation, which improved the spatial resolution from 2.5o to 0.5o. CO2 measurements from ten selected TCCON sites are used to compare with the reconstructed GOSAT. Further, the high accuracy Orbiting Carbon Observatory-2 (OCO-2) data analysed by the combination of geographical grid statistics and kriging is used to evaluate the reconstructed data. The results show that compared with the original GOSAT data, the reconstructed GOSAT data not only improves the spatial resolution but also has little loss of the average accuracy. The mean error of original data has significant seasonal fluctuations with a peak from February to March and a trough from June to July [ABSTRACT FROM AUTHOR]

This paper aims to address the problem of allocating the CO2 emissions quota set by government goal in Chinese manufacturing industries to different Chinese regions. The CO2 emission reduction is conducted in a three-stage phases. The first stage is to obtain the total amount CO2 emission reduction from the Chinese government goal as our total CO2 emission quota to reduce. The second stage is to allocate the reduction quota to different two-digit level manufacturing industries in China. The third stage is to further allocate the reduction quota for each industry into different provinces. A new inverse data envelopment analysis (InvDEA) model is developed to achieve our goal to allocate CO2 emission quota under several assumptions. At last, we obtain the empirical results based on the real data from Chinese manufacturing industries. [ABSTRACT FROM AUTHOR]

Carbon dioxide released from the burning of fossil fuels is a major concern of our times. There is now a political agreement that these emissions must decrease. So far one way forward has been to design and maintain carbon markets. As part of this process, trees in the tropics have been enrolled in peculiar transactions: actions such as reforesting a land of degraded savannah or preserving a piece of forest can produce tradable emission credits to offset against CO2 emissions in distant locations. Based on a multi-sited investigation of carbon offsetting, including fieldwork in the Congo, the paper presents a journey across different marketization sites where the enrolment of forest carbon into market exchanges can be seen to be at stake. Several operations are foregrounded, from United Nations negotiations and the measurement of carbon stocks, to business venture and legal work. The paper proposes a focus on the mundane that attends to details and frictions. This provides a deflationary story of the marketization of forest carbon, a story of contingencies and unexpected ramifications. [ABSTRACT FROM AUTHOR]

The CO2-containing natural gas is increasing, and there is an urgent need for green treatment of natural gas containing CO2 to realize the utilization of natural gas. Conventional natural gas decarbonization methods have drawbacks such as non-environmental friendliness, and the low-temperature condensation separation of carbon dioxide (snowing-separation) method as a green method of carbon capture is proposed in this paper. Aiming at the characteristics of CO2 condensation in the snowing-separation process, the growth process of CO2 crystals is obtained by simulation using the CA (Cellular Automata) method and finds that the effect of supersaturation on the growth of CO2 crystals is exponential. The snowing-separation process at .5 MPa is analyzed, and it is found that the condensation range is 158.51 K–173.86 K, the upper limit of CO2 mole fraction in natural gas is 10.1%, and the minimum separation time is 8.65 × 10−8s. Analyzing the influencing factors of CO2 separation efficiency, combining the simulation results with the experimental results, the maximum relative error is 13.93%, which can better predict the snowingseparation technology of CO2 in natural gas, and then promote the development of efficient low-temperature carbon capture process. [ABSTRACT FROM AUTHOR]

Instead, we'd be investing that wood fiber - that biomass - into wood products with a long shelf life, which leads to much bigger carbon emission reductions than what happens when you turn that fiber into wood pellets for bioenergy. Our trees had removed that carbon from the atmosphere and locked it up in the form of wood, but the actual accounting benefits will go to Drax, Britain, because they are the ones who are considered to have I replaced i the burning of fossil fuel with the burning of wood. Biomass, bioenergy, carbon dioxide, climate change, forestry, wood combustion, Drax, sustainable forestry. [Extracted from the article]

Recent advancement in enhanced oil recovery techniques has given petroleum industries the chance to find optimum solutions to recover remained oil from hydrocarbon reservoirs. This paper aims to experimentally investigate the profound impact of reservoir characteristics such as permeability and pressure drop and foams properties such as foam quality and foams resistance factor in enhanced oil recovery processes. Therefore, a hybrid recovery technique containing a thermal recovery method (carbon dioxide) and a chemical method (foam injection) with different brine concentrations was performed to enhance the oil recovery factor. Consequently, after brine injectivity, foam injection has provided the highest recovery factor among other scenarios in shale reservoirs. Permeability increase has caused to increase in the resistance factor as the fluid mobilization is increased in the porous media. Therefore, for 80% of foam quality, the resistance factor is about 7.5, while for 40%, foam quality is about 5 at the permeability of 10mD. [ABSTRACT FROM AUTHOR]

The effect of catalyst addition on thermal conversion characteristics and kinetics of waste biomass chars was investigated. The experiments were performed in a thermogravimetric analysis system, at non-isothermal heating conditions, under a carbon dioxide atmosphere. Reaction rates were determined by a power law model. The bulk of char gasification process occurred between 800 °C and 950 °C. Addition of alkali salts improved char conversion and increased the reactivity of the samples by lowering the reaction temperature. Peak values were reduced by 4 to 138 °C. The catalytic activity was enhanced when 10% Na2CO3, 10% CaCO3, and 10% Li2CO3 were used during the gasification of municipal solid wastes, sewage sludge, and waste paper, respectively. Alkali carbonates and especially binary mixtures of them increased the reactivity of the fuels by significantly reducing the activation energy. Activation energies ranged from 180 to 370 kJ/mol without catalysts, whereas from 82 to 353 kJ/mol with catalyst addition. [ABSTRACT FROM PUBLISHER]

The present paper endeavours to analyse and provide fresh insights from the dynamic association between tourist arrivals, transportation services, growth and carbon dioxide emanation in the United States. The analysis employs a unique Morlet's Wavelet method. Precisely, this paper implements Partial and Multiple Wavelet Coherence techniques to the monthly dataset spanning from 2001 to 2017. From the frequency perspective, this research finds remarkable wavelet coherence and vigorous lead and lag associations. The analysis discovers significant progress in variables over frequency and time. The variables display strong but inconsistent associations between them. There exist a strong co-movement among the variables considered, which is not equal across the time scales. The study may help the policymakers and regulars to devise strategies and formulate policies pertaining to tourism development, which can contribute towards environmentally sustainable economic growth. [ABSTRACT FROM AUTHOR]

This paper presents a theoretical study of CO2-based transcritical Rankine cycle (CTRC) for engine's waste heat recovery, involving comparison and selection of four CTRC configurations for two engine types, namely a gasoline engine and a diesel engine. The results of configuration comparison show that the CTRC configuration with both a preheater and a regenerator may be more suitable for both two type engines with water-cooling system. If only recovering the waste heat of exhaust gas, the regenerated CTRC configuration may be more appropriate. The results of engine type comparison show that engine load has slighter effect on the CTRC performance for the gasoline engine compared with that for the diesel engine. Particularly, this paper jointly considers the effect of CTRC weight to evaluate the final CTRC output, which is significant for the vehicle engine. A critical weight is found for the two engines based on 100% engine load, 215 kg for the gasoline engine and 998 kg for the diesel engine, which is the upper limitation of the CTRC weight design. When considering the weight effect, the diesel engine may be the more suitable recovery target compared with the gasoline engine, owing to the more stable reaction of output performance to the CTRC weight. [ABSTRACT FROM AUTHOR]

The reduction of CO2 into clean energy through electro catalytic technology provides a promising solution to alleviate energy shortages. In this paper, the graphitised material-supported metal dimer used for electro catalytic reduction of CO2 was proposed, and the reduction reaction mechanism was explored by density functional theory. The results indicate that the hydrogenation reduction of CO2 tends to occur preferentially, and it was found that improving the stability of catalyst structure can reduce the free energy of reaction and improve the adsorption effect of reactants, which significantly increase the conversion efficiency of CO2. The activation of CO2 on the catalyst surface is closely related to the binding of O atoms on the metal sites, the main reduction products and their reaction pathways were clarified. The reduction over potentials of CuCo-C, CuRh-C, CuZn-C and ZnCu-C were 0.915, 0.820, 0.774, and 0.354 V, respectively, thus ZnCu-C had a lower reduction over potential and higher catalytic efficiency. [ABSTRACT FROM AUTHOR]

Increasing population in many countries consumed natural resources and generates secondary product. These secondary products may be in the form of pollutants and liberated in the atmosphere. In this paper, an analysis was performed for green house gas (GHG) emission from municipal solid waste disposal for Faridabad city, India. Land filling and waste-to-energy methods were considered for GHG emission and analysis was performed based on Intergovernmental Panel on Climate Change (IPCC) model. GHG emission and linear pinch analysis (LPA) were performed based on the 50% collection efficiency in Faridabad city over a period of 10 years (2015–2025). Two scenarios of emission forecasting, such as land filling and waste to energy (incineration), were incorporated in this study. Hybrid analysis was presented for emission forecasting and emission reduction to develop a sustainable municipal solid waste management system for Faridabad. A target of 20% and 30% reduction in GHG emission was formulated with the help of LPA. The result shows that GHG in Faridabad city has been continuously changed from 2015 to 2025.The result represented here could be a decision support matrix for municipalities to develop integrated municipal solid waste management system for upcoming smart cities in India. Moreover, another novelty of this study reflects that cities having approximate same population, waste characteristics, and waste management technology could adopt this model for saving of GHG inventory and target-based reduction. [ABSTRACT FROM AUTHOR]

With the development of China's economy, more and more energy consumption has led to serious environmental problems. Faced with the enormous pressure of large amounts of carbon dioxide ( C O 2 ) emissions, China is now actively implementing the development strategy of low-carbon and emission reduction. Through the analysis of the influencing factors of C O 2 emissions in China, five key influencing factors are selected: urbanization level, gross domestic product (GDP) of secondary industry, thermal power generation, real GDP per capital and energy consumption per unit of GDP. This paper applies the Elman neural network optimized by the Firefly Algorithm (FA) to forecast the C O 2 emissions in China. And the results show that the performance of the FA–Elman is better than the Elman neural network and Back Propagation Neural Network (BPNN), verifying the effectiveness of the FA–Elman model for the C O 2 emissions prediction. Finally, we make some suggestions for low-carbon and emission reduction in China by analysing key influencing factors and forecasting C O 2 emissions using the FA–Elman model from 2017 to 2020. [ABSTRACT FROM AUTHOR]

This paper introduces the Fleet Size and Mix Vehicle Routing Problem with Synchronized Visits (FSM-VRPS), an extension of the Vehicle Routing Problem with Synchronization (VRPS), where a mixed fleet composed of electric and conventional bikes, and passenger cars having different acquisition costs are considered. The problem consists of planning a set of different vehicle routes to serve a set of clients who may require more than one visit by different healthcare specialists, and some of these visits should be synchronized. Moreover, each client must be visited within a specified time window. In addition, the problem uses bikes to reduce Carbon Dioxide (CO2) emission for environmentally cleaner routing operations. This problem has many real-life applications, such as the scheduling of visits for homecare givers in the healthcare sector. We present a mixed integer linear-programming formulation and develop a Multi-Start Adaptive Large Neighborhood Search with Threshold Accepting algorithm. The results showed that our algorithm is highly effective on the FSM-VRPS, as well as on the heterogeneous VRPS. We also demonstrate the advantage of adopting different types of vehicles in terms of reducing the number of vehicles and costs. The analysis of the results also indicated that the new components added to the standard Adaptive Large Neighborhood Search algorithm enhanced intensification and diversification mechanisms during the search process. [ABSTRACT FROM AUTHOR]

Ventilation plays an important role in mitigating the risk of airborne virus transmission in university classrooms. During the early phase of the COVID-19 pandemic, methods to assess classrooms for ventilation adequacy were needed. The aim of this paper was to compare the adequacy of classroom ventilation determined through an easily accessible, simple, quantitative measure of air changes per hour (ACH) to that determined through qualitative "expert judgment" and recommendations from the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), and the American Conference of Governmental Industrial Hygienists (ACGIH)®. Two experts, ventilation engineers from facilities maintenance, qualitatively ranked buildings with classrooms on campus with regard to having "acceptable classroom ventilation." Twelve lecture classrooms were selected for further testing, including a mix of perceived adequate/inadequate ventilation. Total air change per hour (ACH) was measured to quantitatively assess ventilation through the decay of carbon dioxide in the front and rear of these classrooms. The outdoor ACH was calculated by multiplying the total ACH by the outdoor air fraction. The classrooms in a building designed to the highest ASHRAE standards (62.1 2004) did not meet ACGIH COVID-19 recommendations. Four of the classrooms met the ASHRAE criteria. However, a classroom that was anticipated to fail based on expert knowledge met the ASHRAE and ACGIH criteria. Only two classrooms passed stringent ACGIH recommendations (outdoor ACH > 6). None of the classrooms that passed ACGIH criteria were originally expected to pass. There was no significant difference in ACH measured in the front and back of classrooms, suggesting that all classrooms were well mixed with no dead zones. From these results, schools should assess classroom ventilation considering a combination of classroom design criteria, expert knowledge, and ACH measurements. [ABSTRACT FROM AUTHOR]

The impact on the use of carbon dioxide (CO2) as a diluent in the fuel and oxidizer streams on the formation and evolution of precursor nanoparticles and soot in axisymmetric ethylene laminar coflow diffusion flames is experimentally explored using optical diagnostics in this paper. The optical diagnostics employed are based on temporally and spectrally resolved point measurements of laser-induced fluorescence, elastic scattering, and laser-induced incandescence. The measurements provide insight to indicative structure and concentration of precursor nanoparticles, and enable the determination of volume fraction and mean diameter of soot. Previous studies have indicated that the use of CO2 as a diluent compared to nitrogen can reduce soot formation through both chemical and thermal effects. However, the effect of CO2 addition on precursor nanoparticles' concentrations and structure is not well understood, hence exploring the impact of CO2 on precursor nanoparticles is one of the primary aims of this study. Flames with CO2 as a diluent in the jet only, coflow only, and both streams are identified and investigated. For the flames studied with respect to the replacement of N2 with CO2: i), the soot volume fraction and mean soot diameter is reduced, and ii) precursor nanoparticles concentration is reduced, and the structural transformation is delayed. [ABSTRACT FROM AUTHOR]

Rotary drying is one of the most common unit operations in industries. It is a complex nonlinear process, and it is difficult to control with conventional methods. In this paper, a fuzzy multivariable controller is designed for an industrial rotary drying system. This fuzzy controller is applied to a fertilizer production unit to save energy and improve its performance. Based on the dryer operating conditions, the proposed control system aims to keep the exhaust gas temperature at the dryer outlet as close as possible to the optimum value. Thus, a reduction in energy consumption is achieved without losing the quality of the final product. Practical aspects of the industrial reality, such as the plant lacking an online moisture measurement instrument, are considered. The results prove that the proposed fuzzy control is able to reduce biomass consumption by 9%, which represents an annual reduction of 648 tons of carbon dioxide (CO2) emissions to the atmosphere. [ABSTRACT FROM AUTHOR]

It is known that in-vehicle carbon dioxide (CO2) concentration tends to increase due to occupant exhalation when the HVAC (heating, ventilation, and air conditioning) air is in recirculation mode. Field experiments were conducted to measure CO2concentration during typical commute in Bangkok, Thailand. The measured concentrations agreed with the concentration predicted using first-order mass balance equation, in both recirculating and outside air modes. The long-term transient decay of the concentration when the vehicle was parked and the HVAC system was turned off was also studied. This decay was found to follow Fickian diffusion process. The paper also provides useful operational details of the automotive HVAC system and fresh air ventilation exchange between cabin interior and exterior. Implications: Drivers in tropical Asian countries typically use HVAC recirculation mode in their automobiles. This behavior leads to excessive buildup of cabin CO2concentration levels. The paper describes the CO2buildup in a typical commute in Bangkok, Thailand. Auto manufacturers can potentially take measures to alleviate such high concentration levels. The paper also discusses the diffusion of CO2through the vehicle envelope, an area that has never been investigated before. [ABSTRACT FROM AUTHOR]

This paper explores the metafrontier environmental efficiency and group frontier environmental efficiency of the governments of the countries in Asia, the Americas, and Europe, adopting the directional distance function along with metafrontier analysis. The paper develops a new approach to measure technology heterogeneity between the environmental efficiency of the metafrontier and that of the group frontiers, namely technology gap. The 65 countries selected for this study include not only the countries in Annex B of the Kyoto Protocol, but also countries in Asia, the Americas, and Europe. According to the average values for environmental efficiency, based on these geographical locations, the empirical results show that European countries are superior to Asian and American countries, regardless of the environmental efficiency of the metafrontier or group frontiers. Also, the technology heterogeneity of European countries is lower than that of the other countries. [ABSTRACT FROM PUBLISHER]

In recent years, China's air quality problem is very serious. Among them, carbon dioxide emissions have been high, which has caused a series of ecological and environmental problems. In order to deeply study the relevant problems, this paper selects the information priority damping gray model to study and predict the carbon emissions of thirty-one provinces and municipalities in China. The model can give priority to new information and adjust the prediction trend, the accuracy of the model is verified by several cases. Through the data collection and data analysis of relevant provinces and cities, it is concluded that a total of twenty-one provinces and municipalities can reach the carbon peak in 2030, of which the carbon dioxide emission of Beijing is expected to drop to 51.3774 million tons by 2030. Ten provinces will not be able to reach the carbon peak by 2030. Among them, by 2030 the carbon dioxide emission of Jiangsu Province is expected to increase to 84.4668 million tons, but the growth rate is declining. The research results can be used as a reference for relevant departments. [ABSTRACT FROM AUTHOR]

For a smart grid system operating with clustered generating units, the challenge usually lies in the optimal scheduling of energy resources. Thus, the improvement of a unit commitment problem gains importance in the present power network. In this paper, a novel probability algorithm is proposed for solving the unit commitment problem, in which five separate units from a four-cluster group are operated for one day. This is done with the aim of optimizing the characteristics such as optional units, generation, operating, and marginal cost. Being a multi-objective function, the other factors such as cost response, unit commitment of supply clustering units, clustering of combined operational units, and CO2 emissions are also included. For this study, an RLC load is mathematically modeled in the cluster system, whereas the Unit Control is provided by a Converter and Battery Management Unit. The clustering model developed along with the Unit demand aims to increase the optional units (from 20 to 100 units), decrease the average demand (from 99 to 93 percentage), and lower the generating and marginal costs (from Rs.23,881 to Rs.21,079, Rs.43,082 to Rs.42,111, Rs.71,162 to Rs.64,955, Rs.83,169 to Rs.81,694, Rs.104,104 to Rs.102,928). The suggested algorithm is simulated for a comprehensive smart grid system and the response for marginal cost, CO2 emissions are obtained. In comparison to conventional schemes, the results of the proposed optimization approach show a reduction in the Carbon dioxide emission (in the range of 100 to 400 kg) and in the losses after adding working units with cluster spans of 0.5 to 1.5 kW. [ABSTRACT FROM AUTHOR]

To reach the short-term targets of the carbon dioxide limit, measures such as carbon capture and storage are necessary. The objective of this paper is to assess some low-temperature post-combustion technologies for the capture of CO2 from combustion gases. Two methods for the liquefaction and separation of CO2 are discussed: The use of the low-temperature exergy of liquefied natural gas (LNG), while regasifying the LNG, and a refrigeration cycle with helium as the working fluid. Each of these methods is evaluated at three CO2 concentrations: 30%, 13%, and 4%. The results showed that an increase in the concentration of CO2 in the combustion gases causes a large increase in the overall exergetic efficiency and a large decrease in the cost of CO2 capture and energy penalty of the capture process. In addition, these advantages can be seen when the liquefaction method is changed from helium refrigeration cycle to LNG regasification. For a 30% CO2 concentration using LNG, the overall exergetic efficiency is 41.2%, and the cost of CO2 capture is 45.5 $/tCO2 with a CO2 capture rate of 96.3%. [ABSTRACT FROM AUTHOR]