Nitrated aromatic compounds, the ubiquitous nitrogen-containing organic pollutants, impact the environment and organisms adversely. As industrial raw materials and intermediates, nitrated aromatic ...compounds and their aromatic precursors are widely employed in the industrial production activities. Nevertheless, their emission from industrial waste gases has so far not been studied extensively. In this study, the concentrations of 12 nitrated aromatic compounds in the particle and gas phases downwind of 16 factories encompassing eight industries (i.e., pharmaceutical, weaving and dyeing, herbicide, explosive, painting, phenolic resin, paper pulp and polystyrene foam industries), were determined by ultra-high-performance liquid chromatography-mass spectrometry. Their concentrations in the particle and gas phases from different factories ranged from 114.7 ± 63.5 to 296.6 ± 62.5 ng m−3 and 148.7 ± 7.4 to 309.8 ± 26.2 ng m−3, respectively, thus, exhibiting significantly high concentrations as compared to the background sites. Among the 12 detected species, 4-nitrophenol, 5-nitrosalicylic acid, 3-nitrosalicylic acid and 4-methyl-2,6-dinitrophenol were observed to be the predominant species, with total fractions up to 47.9–72.3% and 63.1–70.3% in the particle and gas phases, respectively. Their emission profiles with respect to the industrial activities exhibited large discrepancies as compared to the combustion sources, thus, indicating different formation mechanisms. The emission ratios of particulate nitrated aromatic compounds owing to the industrial activities were estimated between 0.5 ± 0.2 and 4.3 ± 1.5 ng μg−1, which were higher than or comparable to those from various combustion sources. The findings from this study confirm the industrial emission to be an important source of nitrated aromatic compounds in the atmosphere. The substantial emissions of nitrated aromatic compounds from various industries reported in this study provide the fundamental basis for further emission estimation and pollution control.
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•Industries are important sources of nitrated aromatic compounds (NACs) in the atmosphere.•The 4NP, NSAs, 4M-2,6NDP were the dominant NACs from industrial sources.•The emission ratios of NACs from industries were comparable to combustion sources.
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•Utilisation of biohythane in solid oxide fuel cells investigated for first time.•Coproduction of energy and syngas has been demonstrated experimentally.•Extra presence of H2 in ...biohythane increases electrical efficiency by up to 21%.•Overall, biohythane gives up to 77% better energy yield than conventional biogas.•Fuel conversion mechanisms and wide product range for coproduction is shown.
Alleviation of greenhouse gas emissions and air pollutants will require innovative deployment of efficient and clean energy technologies combined with optimal management of waste and renewable resources. This paper describes a novel and highly efficient method of utilising renewable and industrial waste gases using state-of-the-art solid oxide fuel cell (SOFC) technology. Coproduction of energy and useful chemicals using SOFCs is demonstrated experimentally through investigations into the utilisation of biohythane, a gaseous mixture consisting of 60/30/10 vol% CH4/CO2/H2 that is produced from an optimised two-stage anaerobic digestion (AD) process. In this work, the gain in energy yield from two-stage AD is shown to be supplemented with additional gains in SOFC efficiency due to the presence of H2 in biohythane, giving up to 77% increased electrical energy yields from biomass overall compared with utilisation of biogas from single-stage AD in SOFCs. The results therefore show that biohythane production rather than biogas is a highly advantageous route to energy production from biomass. Electrochemical measurements and quadrupole mass spectrometry were combined to gain clear new insights into the fuel conversion mechanisms present. The wide range of products that can be obtained via coproduction has been demonstrated and the techniques reported could be used to dispose and add value to many problematic renewable and industrial waste gas streams.
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•Solid oxide electrolysis of simulated coke oven gas with steam investigated.•The hydrogen content was increased by 119% with a purity of 91.7% by volume.•Worldwide, this could ...achieve a hydrogen production of up to 87.6 million tonnes.•89% of hydrogen production was via catalysis; 16% was by steam reduction.•The high steam-to-carbon ratios used considerably alleviated carbon deposition.
Coke oven gas is a by-product of coke production for steelmaking and by volume typically consists of 55–60% hydrogen, 23–27% methane and impurities. An estimated 650 million tonnes of coke oven gas are produced worldwide, with up to 50% re-utilised within steelmaking. However, the rest is flared, contributing to carbon emissions and wasting valuable and useful gases. This study has investigated the co-electrolysis of simulated coke oven gas with steam using commercially available solid oxide electrolysis technology for the purposes of recovering hydrogen. The electrochemical performance of an anode supported button cell was characterised using open circuit potential measurements, current-voltage curves and electrochemical impedance spectroscopy. The product gas composition was analysed using quadrupole mass spectrometry. Co-electrolysis of simulated coke oven gas (30/70% methane/hydrogen) with 50% steam achieved a hydrogen amplification of 119% and a purity of 91.7% by volume, balanced mainly in carbon dioxide and carbon monoxide. Theoretically, this corresponds to a worldwide hydrogen production from coke oven gas of 87.6 million tonnes, which is in excess of the current global demand for hydrogen (70 million tonnes). Catalytic steam reforming of methane and the water-gas shift reaction increased the hydrogen content by 89% and a further 16% gain was due to electrochemical steam reduction. Co-electrolysing at high steam-to-carbon ratios was shown to increase hydrogen yield, improve cell performance, maximise methane and carbon monoxide conversion and inhibit carbon deposition. Studies into fuel variability effects show that greater methane contents gave higher hydrogen yields but decreased hydrogen purity and cell performance. Increasing the operating voltage increased the conversion of carbon dioxide into carbon monoxide via promotion of the reverse water-gas shift reaction. The work demonstrates the considerable potential to upgrade coke oven gas using solid oxide electrolysis technology, which could enable greater downstream recovery and purification of hydrogen from an under-utilised industrial waste resource.
Laboratory scale biofilters were supplied with an artificial waste gas containing ammonia and an ammonia/dimethyldisulfide mixture. 62 bacterial strains were isolated from the filter material, ...differentiated and identified by chemotaxonomic and physiological methods. The taxonomic groups were compared with known bacterial strains originating from biofilters which were supplied with an ammonia containing complex industrial waste gas. The different effects of a defined artificial waste gas and a complex multicomponent waste gas on the culturable population of biofilters are discussed.
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•The kerogen model is simulated under real reservoir temperature–pressure conditions.•CO2-rich industrial waste gas injection causes shale oil desorption in kerogen slit.•Shale ...reservoirs are promising site options for waste gas sequestration.•Gas flooding performance is compared between pure CO2 and waste gas as driving gas.•The effect of surfactant on the oil-waste gas system is analyzed.
Enhanced oil recovery (EOR) by injection of CO2-rich industrial waste gas has been proposed as an energy-efficient and environmentally friendly method for shale oil reservoirs, in which the waste gas can be utilized and sequestered to reduce greenhouse gas emissions. In this work, the adsorption behaviors of shale oil and waste gas components in kerogen slits and the effects of gas flooding on EOR were investigated using molecular dynamics (MD) method, which can provide technical guide for shale oil development. In terms of the adsorption behaviors, an intensity decrease of oil adsorption is observed in kerogen slits after the injection of the waste gas components. Desorption of shale oil during injection of SO2 and CO2 is more pronounced in shallow reservoirs, whereas it is more evident for NO and N2 in deep reservoirs. The desorption efficiency can be 10.91 % for pure CO2 injection and 9.09 % for NO injection at a depth of 1000 m, and the relative stability ratios of CO2 and NO sequestration are 77.09 % and 76.06 %, respectively. For gas flooding, the existence of pressure difference provides favorable conditions for gas molecules to pass through the oil zone, and waste gas can be more effective than pure CO2 as driving gas. For the waste gas injection, the percentage of CO2 retained in the kerogen nanopores is much higher than that of pure CO2 injection, suggesting that more CO2 molecules can enter into kerogen matrix to take part in the displacement process. Furthermore, the effect of surfactants on oil desorption and displacement was also investigated and the interaction energy of the surfactant/oil/gas system was calculated and analyzed, finding that addition of the oil-soluble surfactants can be beneficial to shale oil displacement. This work can provide a comprehensive evaluation of the feasibility of CO2-rich industrial waste gas application for EOR, which is of great significance in the effective production of shale oil and the sequestration of waste gas in shale reservoirs.
The front cover summarizes crucial roles of the surface, interface, and structure optimization of MOFs for performance enhancements towards reversible capture and catalytic conversion of industrial ...waste gases. See the Review by Y. Miao, S. Xiao, and co‐workers (DOI: 10.1002/tcr.202200211).
•Evaluating the TFWGTE from enterprise perspective based on four-stage SBM-DEA model.•The average TFWGTE of 65 CISEs showed an upward trend from 2005 to 2014.•The improvement of TFWGTE is mainly due ...to the external environmental factors.•The improvement of environmental awareness has a positive effect in TFWGTE.•Electric furnace steelmaking has significant environmental positive externalities.
Taking the four-stage SBM-DEA as the theoretical tool, this paper evaluates the total factor waste gas treatment efficiency (TFWGTE) of 65 Chinese iron and steel enterprises (CISEs) from 2005 to 2014. Then, after the influences of external environmental factors and statistical noise are eliminated, TFWGTE is decomposed into total factor waste gas managerial efficiency (TFWGME) and total factor waste gas environmental efficiency (TFWGEE), and the differences between TEWGTE, TEWGME and TEWGEE are systematically analysed from regional and enterprise perspectives. The results reveal that: (1) TFWGTE and TFWGEE showed an upward trend from 2005 to 2014, whereas TFWGME showed a downward trend from 2005 to 2014. The elimination of external environmental factors had provincial specific effects on TFWGTE; (2) By comparing the dynamic trends of TFWGTE in eastern, central and western regions, it is found that there are differences among different regions, which indicates that the external environmental factors in the region have an impact on TFWGTE; (3) In 4 provinces, TFWGME increased compared with TFWGTE, while in 23 provinces, TEWGME decreased compared with TFWGTE; (4) The Tobit regression results show that the command-and-control environmental regulation, environmental awareness and manufacturing process have significant effects on the input slacks of waste gas treatment, indicating that the strengthening of command-and-control environmental regulation, the improvement of environmental awareness, and the decline of the proportion of the short process can effectively reduce the input slacks of waste gas treatment.
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•CO2-rich industrial waste gas injection can displace unconventional gas.•Adsorption energy of waste gas components/CH4 on diverse reservoirs is compared.•Adsorption selectivity is ...calculated under reservoir temperature–pressure conditions.•The gas adsorption modes in different unconventional gas reservoirs are analyzed.
Direct injection of CO2-rich industrial waste gas to displace unconventional natural gas is proposed as an energy-saving and green development method. In this work, the Giant canonical Monte Carlo and molecular dynamics methods were employed to compare the adsorption mechanisms of this method in three typical unconventional gas reservoirs, which are coal seam, shale and tight sandstone. It is found in the adsorption configurations that the proportion of gas molecules in the free state is higher in tight sandstone than in shale and coal seam. The adsorption energy of CH4/waste gas components on all reservoirs is in the order of CH4/SO2 > CH4/CO2 > CH4/NO > CH4/N2, among which the absolute value of the CH4/SO2 adsorption energy on the coal seam reaches the highest 64.220 kJ/mol. The adsorption selectivity of SO2, CO2 and NO over CH4 is greater than 1.0 in all reservoirs at depths of 0.5–4.0 km, and the competitive adsorption phenomenon in the deep reservoirs has a severe negative effect on it. Gas adsorption mode in the tight sandstone is dominated by filling pore structures, while gas adsorption in the coal seam is highly correlated with adsorption sites. This study is instructive for enhanced unconventional natural gas recovery by CO2-rich industrial waste gas injection from the perspective of gas adsorption.
"Carbon peaking and carbon neutrality" is an essential national strategy, and the geological storage and utilization of CO2 is a hot issue today. However, due to the scarcity of pure CO2 gas sources ...in China and the high cost of CO2 capture, CO2-rich industrial waste gas (CO2-rich IWG) is gradually emerging into the public's gaze. CO2 has good adsorption properties on shale surfaces, but acidic gases can react with shale, so the mechanism of the CO2-rich IWG–water–shale reaction and the change in reservoir properties will determine the stability of geological storage. Therefore, based on the mineral composition of the Longmaxi Formation shale, this study constructs a thermodynamic equilibrium model of water–rock reactions and simulates the regularity of reactions between CO2-rich IWG and shale minerals. The results indicate that CO2 consumed 12% after reaction, and impurity gases in the CO2-rich IWG can be dissolved entirely, thus demonstrating the feasibility of treating IWG through water–rock reactions. Since IWG inhibits the dissolution of CO2, the optimal composition of CO2-rich IWG is 95% CO2 and 5% IWG when CO2 geological storage is the main goal. In contrast, when the main goal is the geological storage of total CO2-rich IWG or impurity gas, the optimal CO2-rich IWG composition is 50% CO2 and 50% IWG. In the CO2-rich IWG–water–shale reaction, temperature has less influence on the water–rock reaction, while pressure is the most important parameter. SO2 has the greatest impact on water–rock reaction in gas. For minerals, clay minerals such as illite and montmorillonite had a significant effect on water–rock reaction. The overall reaction is dominated by precipitation and the volume of the rock skeleton has increased by 0.74 cm3, resulting in a decrease in shale porosity, which enhances the stability of CO2 geological storage to some extent. During the reaction between CO2-rich IWG–water–shale at simulated temperatures and pressures, precipitation is the main reaction, and shale porosity decreases. However, as the reservoir water content increases, the reaction will first dissolve and then precipitate before dissolving again. When the water content is less than 0.0005 kg or greater than 0.4 kg, it will lead to an increase in reservoir porosity, which ultimately reduces the long-term geological storage stability of CO2-rich IWG.
Financial constraints have long existed in China's manufacturing sectors. The growth of the manufacturing sector has been slowing in recent years due to increasingly strict environmental regulations ...that force factories to cut production. In this study, we discussed whether financial constraints were essential in firms' decision to control pollution, and matched the Annual Surveys of Industrial Firms dataset with the Ministry of Environmental Protection survey data on firms' expenditures in industrial waste gas emission control. The relationship between calculated investment-cash flow sensitivity (ICFS) and the environmental investment ratio (the ratio of firms' expenditures on pollution control to total assets) was analyzed. We found that, overall, financial constraints had a significantly negative effect on firms' efforts to reduce waste gas emission. State-owned enterprises (SOE) relieved financial pressure mainly by seeking external financing sources to reduce emission. On the other hand, private-owned (POE) and foreign-owned enterprises (FOE), if efficiently financed internally, can reduce waste gas emission by increasing investment in waste gas treatment. This study provided a quantitative analysis on firms' financial constraints in environmental protection investment, contributing to the development of effective government policies on related issues in China.
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