Reduction Of SO2 Research Articles

Resource utilization of high-concentration SO2 for sulfur production over La-Ce-Ox composite oxide catalyst.

Sulfur dioxide is one of the main causes of air pollution such as acid rain and photochemical smog, and its pollution control and resource utilization have become important research directions. La2O3 was incorporated into CeO2 to enhance the surface basicity of La-Ce-Ox catalyst and increase the concentration of chemisorbed oxygen, thereby promoting the improvement of catalytic performance of SO2 reduction by CO. Results have showed that the incorporation of La2O3 would not only increase the concentration of chemisorbed oxygen and hydroxyl on the catalyst surface, but also increase the basicity of the catalyst, thereby facilitating the adsorption of SO2 on the catalyst surface. The 12%La-Ce-Ox was the optimal catalyst, and its SO2 conversion at 350-400 ℃ reached close to 100%, and the sulfur yield at this temperature range was higher than 93%. Finally, according to the in situ infrared diffuse reflectance spectrum, it was found that the main reaction intermediates of 12%La-Ce-Ox in the catalytic reduction of SO2 were weakly adsorbed sulfate, SO32-, non-coordinating CO32-, monodentate carbonate, and CO, so the catalytic reaction followed the L-H and E-R mechanisms simultaneously.

Insight into carbon corrosion of different carbon supports for Pt-based electrocatalysts using accelerated stress tests in polymer electrolyte fuel cells

Carbon-based catalyst support and Pt catalysts are commonly used in polymer electrolyte fuel cells (PEFCs). During cell start-up and shutdown processes, carbon support oxidation occurs, which leads to losses of electrochemical performance. In this work, carbon corrosion accelerated stress tests (ASTs) were performed and lifetimes of high surface area carbon (HSAC) and graphitized carbon (GrC) supports were investigated. 1000 AST cycles were conducted on Pt/HSAC while 10000 AST cycles were conducted on Pt/GrC due to different carbon corrosion rates, and both Pt/HSAC and Pt/GrC showed rapid decrease of performance at end of life (EOL). Detailed comparisons of electrochemical characterizations were also conducted between Pt/HSAC and Pt/GrC. Electrochemical surface area (ECSA) loss in different levels was found for both Pt/HSAC and Pt/GrC due to Pt loss, Pt detachment and particles coalescence, which also resulted in reduction of SO3− group coverage and more tortuous H+ transportation, leading to decreased catalyst layer ionic conductivity. For Pt/HSAC after 1000 AST cycles, more than 2 times higher ECSA loss but with only 50% greater particle size growth and similar Pt loss strongly suggested that a greater Pt detachment occurred on HSAC support during the AST cycles. Apart from that, it was found that after 1000 AST cycles, graphitized carbon support was much more robust compared to HSAC support, and it showed 2 times less ECSA reduction, 2.5 times less catalyst layer ionic conductivity reduction and 4 times less SO3− group coverage reduction. Double layer capacitances increased for both carbon supports after AST at their EOLs, as more disordered carbon contacts were formed, which created more contacts between solid and ionic materials. This study shows a possibility of Pt/GrC catalysts to meet the Department of Energy (DOE) target of 5000 AST carbon cycles, as the Pt/GrC cell met the target of ≤ 40% ECSA loss of initial area.

Transformation of sedimentary and colloidal phosphorus across the land‒sea margin received effluents from agricultural and municipal activities

The transformation, transport, and release of phosphorus (P) are highly subject to anthropogenic activities and complex biochemical interactions. Its bioavailability and recalcitrance are generally regulated by P forms, arousing imposition for the accurate identification of chemical speciation. Here, P K-edge X-ray absorption near edge structure spectroscopy was exploited to determine the molecular P species on colloids, canal sludge, and coastal sediments collected in the area receiving mixed effluents from agricultural and municipal activities. Although Fe(III)-bonded P [Fe(III)–P] dominated the P inventory for colloids and sludge collected near the agricultural area, its proportion on colloids was approximately half of that on the sludge, suggesting the emerging contribution of other P species such as Al–P, Fe(II)–P, and organic-P (org-P) to carry colloidal P. Proportions of Fe(III)–P on colloids and sludge both declined seaward, yet the maximum P loss from colloids was derived from the org-P. The organic matter degradation plausibly drove the reduction of SO4 and Fe(III), leading to the prominent increase in FeS and the conversion of org-P to authigenic P. While Al–P accounted for a comparable proportion of colloidal P inventory to that of Fe(III)–P in adjacent coastal wetlands, the proportion of Fe(II)–P showed the greatest increase on colloids in the transition from fresh-to saltwater. Collective results attest to the significance of Fe(II) and Al in partitioning colloidal and sedimentary P, which should be taken into account to improve the assessment of the P dynamics and eutrophication risk.

Reducing the Effect of High Sulfur Content in Diesel Fuel on NO x Emissions and PM Characteristics Using a PPCI Mode Engine and Gasoline-Diesel Blends.

Recently, high sulfur content in diesel fuel is one of the main problems that have an effect on combustion and emission characteristics. Iraq is one of many countries in the world that use diesel fuel with high sulfur content. Therefore, the partially premixed combustion ignition (PPCI) concept and different blend ratios of gasoline–diesel (GD30, GD40, and GD50) were suggested in this study to reduce the sulfur content in the fuel, improve the engine performance, and reduce the exhaust emissions. The combined effect of adding gasoline to the diesel fuel and manipulating the fuel injection timings can lead to better and clean combustion. For the same engine operating conditions, it is found that the brake thermal efficiency (BTE) decreases during the combustion of GD blends in comparison with diesel fuel. Furthermore, the results of using GD blends showed a small reduction in brake-specific fuel consumption (BSFC) compared to the conventional diesel fuel. The exhaust gas temperature reduces from the combination effect of PPCI mode and GD blends, which in turn decreases the NOx emission concentration under variable conditions of engine loads and speeds. It is indicated that the NOx emissions significantly decreased during the combustion of GD30, GD40, and GD50 blends by 25.94, 50.9, and 84%, respectively, in comparison with diesel fuel. In addition, higher reduction in CO and HC formation was obtained during the combustion of conventional fuel in comparison with the combustion of GD blends. The results showed that the number and concentration of PM reduced more when using GD blends and PPCI mode. The average particle diameter (dp) decreased from the combustion of GD blends in comparison with diesel fuel. The particle diameter of the GD blend was varied from 25 to 26 nm compared to those of diesel fuel of 35 and 36 nm under the same engine operating conditions. Reducing the sulfur content in GD blends contributed to a clear reduction in SO2 and H2S emissions by 57.85 and 50.12%, respectively.

Monitoring and inverse modelling of hydrogeochemical processes during managed aquifer recharge in Southwestern Bangladesh

Managed Aquifer Recharge (MAR) has been applied as Aquifer Storage, Transfer, and Recovery (ASTR) to provide fresh drinking water for local communities at 99 locations in southwest Bangladesh since 2009. Aerobic freshwater from ponds is filtered and subsequently infiltrated into anaerobic shallow brackish aquifers. At approximately 45% of these sites, relatively higher levels of Fe and As were observed in recovered water, which requires a better understanding of the hydrogeochemical processes that govern the Fe, Mn, and As levels in these MAR systems. Therefore, two representative sites with As above (74 ± 11 μg/L at site GMF11) and below (19 ± 6 μg/L at site JJS91), the Bangladesh drinking water standard of 50 μg/L were weekly monitored on hydrochemical changes from Dec 2017 to Dec 2018. Hydrogeochemical processes occurring during storage were quantified with inverse and forward geochemical mass balance models developed with PHREEQC. The following processes explained the changes in water quality: 1) mixing of infiltration water with native groundwater (∼90%:∼10%); 2) consumption of O2 by a) dissolved Fe2+ that subsequently precipitated as Fe(OH)3 at GMF11 and by b) dissolved and sedimentary organic matter (OM) at site JJS91; 3) reduction of SO4 coupled to the oxidation of OM at both sites; and 4) mixing corrosion and freshening induced cation-exchange (Ca sorption; Na desorption) triggering calcite and siderite dissolution at GMF11. Dissolution of these carbonate minerals occurred to a lesser extent at JJS91, while cation exchange (Na sorption; Ca desorption) suggested that the freshwater was displaced by brackish groundwater because of inadequate infiltration at JJS91. Distinct pH values in recovered water reflected the dominance of Fe2+ versus OM oxidation. Siderite dissolution led to 4.3 ± 3.1 and 1.0 ± 0.5 mg/L Fe in recovered water at GMF11 and JJS91, respectively. Elevated As and Mn levels in recovered water were caused for max. 20% by mixing with native groundwater and for min. 80% by mobilization processes, mainly by desorption of As from Fe-oxides and by the dissolution of Mn-bearing siderite. Recommendations are provided to improve recovered water quality.

Environmental and health impacts of heating fuel transition: Evidence from Northern China

The heating season in the Northern China usually consumes massive high-polluted coal, severely threatening the ambient air pollution and human health. Therefore, the Chinese government set forth the clean heating policy in 2017, aiming to fulfill the heating fuel transition in terms of “coal to gas” or “coal to electricity”. To clarify the current progress and guide future action on clean heating, a comprehensive evaluation is indispensable. Hence, the policy effects on air quality from temporal and spatial perspectives are evaluated through a difference-in-difference model. Furthermore, the health benefits obtained from implementing a clean heating policy are estimated via an exposure-response model, the value of statistical life, and the cost of illness. The empirical results indicate that the “2 + 26” cities, defined as BTH air pollution transmission channel cities, have witnessed a significant improvement in mitigating PM2.5 pollution. For the cities in the Fenwei Plain, a larger reduction in SO2 and CO emissions is realized. Moreover, Tianjin and Hebei inhibit PM2.5 pollution efficiently. In terms of the three batches of pilot cities, the policy effects on decreasing air pollutants concentrate on the first batch of pilot cities, and weaker in the second and third batches. In addition, an event study is conducted for the first batch of pilot cities to trace out the year-by-year impacts of clean heating on air pollutants, demonstrating temporal variations in the policy effects. During 2017–2019, the total health benefits induced by improved air quality have been accumulated to 7.69 billion yuan, 7.96 billion yuan, and 10 billion yuan in four provincial capital cities, including Shijiazhuang, Zhengzhou, Taiyuan, and Jinan. The multidimensional exploration of the clean heating effects on air pollution and public health supports evidence-based policymaking in China and inspires developing countries to adopt household energy transition initiatives similar to clean heating.

Effect of Replacing Coke with Biomass Fuel on Sinter Properties and Pollutant Emissions

In the iron-ore-sintering process, the use of biomass charcoal instead of coke breeze can reduce the emission of flue gas pollutants and alleviate the energy crisis of fossil fuels. However, the direct application of biomass charcoal to iron ore sintering is bound to affect the sinter properties. The effects of biomass charcoal addition on the sintering ore properties and flue gas pollutants emission were studied through sintering cup and related performance test experiments. Meanwhile, the influence mechanism of biomass charcoal instead of coke breeze on iron ore sintering was expounded. The experimental results show that with an increase in biomass charcoal, the vertical sintering rate increased, the internal pore structure developed rapidly, and the pollutant emission decreased gradually. When the biomass charcoal content was less than 40%, the sinter strength and yield were stable and slightly improved with the increase in biomass charcoal. When the biomass charcoal content was higher than 40%, the metallurgical properties of sinter degraded sharply, making it difficult to meet the production requirements. The comprehensive effect of biomass charcoal on the sinter suggests that the suitable biomass charcoal addition was 40%; under this condition, the reduction in SO2 and NOx was 28.2% and 25.7%, respectively.

Selected Techniques for Cutting SOx Emissions in Maritime Industry

Burning fuels with high sulfur content leads to SOx emissions, especially SO2, which leads to various environmental and health problems. The maritime sector is responsible for 13% of the global anthropogenic emissions of SO2. Thus, the International Maritime Organization (IMO) has issued a protocol, known as MARPOL Annex VI, which aims to further limit SO2 emissions derived from ships along with NOx, particulate matter and volatile organic compound emissions. This has led ship owners and operators to choose between more expensive fuels with low sulfur content or to apply a DeSOx solution, which still allows them to use the cheapest heavy fuel oil. The current work reviews the state-of-the-art DeSOx solutions both for the maritime and land-based sector. Next, it proposes an alternative cheaper and environmentally friendly DeSOx solution based on the selective reduction of SO2 to elemental sulfur by utilizing a catalytic converter based on metal oxides, similar to the ones used in the automotive industry. Finally, it reviews the most promising metal oxide catalysts reported in the literature for the selective reduction of SO2 towards elemental sulfur.

Glycerol amendment enhances biosulfidogenesis in acid mine drainage-affected areas: An incubation column experiment.

Microbial sulfate (SO4 2−) reduction in Acid Mine Drainage (AMD) environments can ameliorate the acidity and extreme metal concentrations by consumption of protons via the reduction of SO4 2− to hydrogen sulfide (H2S) and the concomitant precipitation of metals as metal sulfides. The activity of sulfate-reducing bacteria can be stimulated by the amendment of suitable organic carbon sources in these generally oligotrophic environments. Here, we used incubation columns (IC) as model systems to investigate the effect of glycerol amendment on the microbial community composition and its effect on the geochemistry of sediment and waters in AMD environments. The ICs were built with natural water and sediments from four distinct AMD-affected sites with different nutrient regimes: the oligotrophic Filón Centro and Guadiana acidic pit lakes, the Tintillo river (Huelva, Spain) and the eutrophic Brunita pit lake (Murcia, Spain). Physicochemical parameters were monitored during 18 months, and the microbial community composition was determined at the end of incubation through 16S rRNA gene amplicon sequencing. SEM-EDX analysis of sediments and suspended particulate matter was performed to investigate the microbially-induced mineral (neo)formation. Glycerol amendment strongly triggered biosulfidogenesis in all ICs, with pH increase and metal sulfide formation, but the effect was much more pronounced in the ICs from oligotrophic systems. Analysis of the microbial community composition at the end of the incubations showed that the SRB Desulfosporosinus was among the dominant taxa observed in all sulfidogenic columns, whereas the SRB Desulfurispora, Desulfovibrio and Acididesulfobacillus appeared to be more site-specific. Formation of Fe3+ and Al3+ (oxy)hydroxysulfates was observed during the initial phase of incubation together with increasing pH while formation of metal sulfides (predominantly, Zn, Fe and Cu sulfides) was observed after 1–5 months of incubation. Chemical analysis of the aqueous phase at the end of incubation showed almost complete removal of dissolved metals (Cu, Zn, Cd) in the amended ICs, while Fe and SO4 2− increased towards the water-sediment interface, likely as a result of the reductive dissolution of Fe(III) minerals enhanced by Fe-reducing bacteria. The combined geochemical and microbiological analyses further establish the link between biosulfidogenesis and natural attenuation through metal sulfide formation and proton consumption.

A novel synthetic method of porous and nanoflower-like Al2O3/MoS2 catalyst for reduction of SO2 to elemental sulfur

A novel synthetic method of porous and nanoflower-like Al2O3/MoS2 catalyst for reduction of SO2 to elemental sulfur

Managing Methane Emissions in Abandoned Coal Mines: Comparison of Different Recovery Technologies by Integrating Techno-Economic Analysis and Life-Cycle Assessment.

Methane emissions from worldwide increasing abandoned coal mines have posed multiple challenges of global warming, energy waste, and explosion risk. This study first profiles the dynamic patterns of coal mine methane emissions in different recovery technologies, methane extraction with drainage (MEWD, mine-water concurrently extracted and treated) and direct methane extraction (DME, noncontrol on mine-water), in two abandoned mines from Ningxia and Inner Mongolia as China's leading coal provinces. Then, we conducted a techno-economic analysis and life-cycle assessment to quantify their comprehensive benefits. The key findings are as follows: (1) MEWD can long recover methane, although the economic profits decrease with declining methane extraction volume. DME can only work for ∼5 years, after which the mine is flooded, where methane is sealed underground and not recoverable. (2) MEWD drains and further treats the mine-water with an additional 29.4-35.9 million CNY cost compared with DME, while MEWD can achieve greater life-cycle environmental benefits with more cumulative methane recovery, whose CO2-eq (GWP-100) and SO2 reductions are 64.4 and 53.4% higher than those of DME. (3) MEWD is more promising for large-scale implementation, where feed-in tariffs and carbon market measures can improve the economics for sustainable management of incremental abandoned mine methane.

A Stackelberg game model with tax for regional air pollution control

The command-and-control regulation is likely inefficient and costly. This study investigates a regional pollution control scheme with tax (RPCST) under which the central government sets the tax rate under a given pollutant reduction quota and local governments determine their pollution removal rates based on the central government’s policy. First, a one-leader-multi-follower (OLMF) Stackelberg game model is formulated, in which the central government is the leader and the local governments are the followers. Then, a procedure based on bilevel programming and relaxation method is applied to solve the OLMF model. Finally, a case study analyzing the SO2 reduction of the Yangtze River Delta in China is conducted to demonstrate the effectiveness of the RPCST. The results show that RPCST works better than the current command-and-control scheme. Our analysis provides a guideline for governments to design optimal tax schemes to effectively solve the regional air pollution crisis.

A picture of Delhi’s regional air quality during diminished anthropogenic activities in the COVID-19 era

COVID-19 pandemic lockdown was imposed in 2020 and 2021 globally and in India, which created a temporary switch off for various anthropogenic activities, which helped in improving Delhi’s air quality drastically. The present study discusses air pollution reduction during that lockdown period compared to the previous year. The study tries to establish a comparison between various parameters like particulate matter (PM10, PM2.5), gaseous pollutants (SO2, NO2, CO, O3), and meteorological data (WS, WD, RH, AT, SR) during the year 2019 to 2021. The whole monitoring period is divided into four phases (P-I, P-II, P-III, and P-IV) based on stage-wise lockdown implementation. The data are analyzed using the R Studio version 1.3.1093. The PM10 concentration falls to 46.6% and 19.2% in 2020 and 2021, compared to 2019, and 69% increase in 2021 from 2020. PM2.5 reduced to 35% and 8.1% in 2020 and 2021, compared to 2019, and a 48% increase in 2021 from 2020. The O3 concentration shows an increment of about 10% in 2020 and a reduction of 5% in 2021, compared to 2019, and 12%, compared to 2020. The SO2 and CO reductions lie in between 20 and 35% in 2020 and 2021, compared to 2019. The NO2 shows around 56% and 32% reduction during 2020 and 2021 compared to 2019 and a 62% increment in 2021 compared to 2020. An absolute lockdown was imposed in 2020, whereas minimal activity or certain restrictions were only imposed in 2021. Such changes in concentration show that anthropogenic sources played a significant role in determining regional air quality in urban areas. The outcomes of the study show the changes that occurred during that period due to phase-wise implementation of lockdown and other unlocking conditions, which may be helpful for policymakers in implementing certain restrictions based on emissions in a planned manner in the future.Supplementary InformationThe online version contains supplementary material available at 10.1007/s12517-022-10567-8.

Can China's Carbon Emissions Trading System Achieve the Synergistic Effect of Carbon Reduction and Pollution Control?

Achieving synergistic governance of air pollution treatment and greenhouse gas emission reduction is the way for the Chinese government to achieve green transformational development. Against this background, this paper takes the implementation of the carbon emissions trading system (ETS) as the breakthrough point, using the time-varying difference-in-differences (DID) model to explore the synergistic emission reduction effect of ETS on air pollution and carbon emissions and its mechanism. The results indicate that the implementation of ETS not only significantly reduces CO2 emissions but also synergistically achieves the reduction of air pollutants, and the synergistic emission reduction effect is mainly achieved through the synergistic reduction of SO2. Moreover, the emission reduction effect of ETS has economic and regional heterogeneity. On the one hand, the ETS has a more prominent carbon reduction effect in less developed provinces and cities and has a significant synergistic emission reduction effect on SO2 and PM2.5; on the other hand, the carbon emission reduction effect of ETS is more potent in Beijing, Hubei, and Shanghai, followed by Tianjin and Chongqing, and the weakest in Guangdong. In addition, through the analysis of the mediating effect, this paper finds that reducing energy consumption, optimizing the energy structure, and improving energy efficiency are effective ways for ETS to achieve synergistic emission reduction. This study provides valuable policy enlightenment for promoting the synergistic governance of pollution and carbon reduction.

Thermodynamic study of regenerative barium-based materials towards barium sulfide for catalytic sulfur dioxide reduction

Flue gas with high SO2 content presents a series of human health and environmental problems, which prompted Flue Gas Desulfurization (FGD) technologies widely utilised in industries. However, the conventional FGD using absorbents or adsorbents could generate secondary sulfur-containing pollutants. Thus, a regenerative FGD reaction system that eliminates secondary pollutants while recovering valuable S has been researched. Ba-based materials, viz. Ba(OH)2, BaCO3 and BaO as the precursors, are involved in a regenerative BaS/BaSO4 reaction system of this research. Current thermodynamic study via minimization of Gibbs free energy explored the feasibility of BaS production from these Ba-based materials and reviewed its potential in SO2 reduction to S. Formation of BaS from Ba-based materials was feasible but the yield depends strongly on the temperature and sulfidizing agent used. Compared to BaCO3-systems, Ba(OH)2- and BaO-systems showed better performance in BaS synthesis due to their high equilibrium conversion, even at temperatures< 773 K. Besides, H2S is a better sulfidizing agent for BaS synthesis due to higher BaS yield (maximum 99%). Synthesis routes of different Ba-systems were confirmed by their respective Keq profiles. The feasibility of BaS catalyst in SO2 reduction to S was proven by the excellent SO2 reducing activity and high S yield (100%) at 273 – 1173 K with S8 and S2 as major products. BaS regeneration via H2 was also validated by high BaS yield (100%) at 473 – 1273 K.

Evaluating the effects of air pollution control policies in China using a difference-in-differences approach

Air pollution has caused wide concern in China, and many governance policies and plans have been implemented in recent years. Based on counterfactual quasi-natural experiments, we analyzed the implementation effects of autumn and winter air pollution control policies in the Jing-Jin-Ji region and surrounding areas using a difference-in-differences (DID) model. The control group was selected based on geographical and meteorological factors, and we analyzed the impact of the policies on six pollutants. The results show that the policies reduced air pollution overall, but not every pollutant. Due to the policy contribution, the concentrations of PM2.5 and PM10 in autumn and winter from 2017 to 2018 decreased by 6.9 % and 8.5 %, respectively. The numerical value of PM2.5, PM10, CO, and AQI in 2018–2019 decreased by 18.2 %, 7.2 %, 13.9 %, and 8.8 %, respectively. The role in the reduction of O3, SO2, and NO2 was not obvious. This work provides a research paradigm for evaluating the effects of atmospheric environment policy which can be applied to other studies and provide references for formulating additional policies.

Performance and reaction mechanism of pyrite(FeS2)-based catalysts for CO reduction of SO2 to sulfur

In this study, an iron sulfide catalyst (PAC) was prepared to catalyze the reaction of CO reducing SO2 to sulfur to satisfy the high activity and stability of the catalyst, simplify the preparation process, and remove the sulfurization process. The physicochemical properties, reduction activity of the iron sulfide catalyst, and reaction mechanism of PAC-catalyzed CO reduction of SO2 were then systematically investigated. The results indicated that the optimum reaction conditions were a FeS2 proportion of 6 wt%, a reaction temperature of 550 °C, an airspeed of 5000 h−1, and a CO/SO2 molar ratio of 2.6:1. Under these conditions, the SO2 conversion of PAC was stabilized at over 99.5% with a sulfur yield of up to 95.5% within 850 min without deactivating the active component or deteriorating the sulfate. This proves that PAC has very high catalytic activity and stability. The XRD and in situ XRD characterization showed that the reduced PAC contained primarily Fe7S8 in the sulfur phase, while no sulfate and sulfite were found. The reaction mechanism of the PAC-catalyzed CO reduction of SO2 can be divided into the FeS2 thermal decomposition mechanism and the COS intermediate product mechanism.

Development Scenarios and Environmental Benefits Analysis of Future Power Generation Industry Under Two Modes in China

In order to study the impact of the "carbon peak and neutrality" mode on future power generation and the environment in China, a Verhulst gray model was established to predict the development of the power generation industry from 2021 to 2060 under the non-"carbon peak and neutrality" mode. In addition, based on the "China 2030 Energy and Power Development Planning Research and 2060 Outlook Report," the development of the power generation industry from 2021 to 2060 under the "carbon peak and neutrality" mode was obtained, and the development scenarios of the future power generation industry in China under two models were compared and studied. The emission factors and emission reduction factors of CO2, SO2, NOx, PM, PM10, and PM2.5 were constructed through the conservation of elements and the generating performance standard, and then four environmental benefits A1-A4 were defined. The results showed that the installed capacity of thermal power will reach the carbon peak in 2026 under the "carbon peak and neutrality" mode. To achieve the carbon neutralization, the installed capacity of thermal power will be reduced by an average of 28 million kilowatts per year after 2026, and the installed capacity of renewable energy generated is required to increase by 154 million kilowatts per year after 2020. Compared with that in the non-"carbon peak and neutrality" mode, the installed capacity of thermal power generation will be greatly reduced, and the installed capacity of renewable energy power generation will be greatly increased under the "carbon peak and neutrality" mode, resulting in huge A1 and A2 environmental benefits. In the next four decades, the cumulative emission reductions in CO2, SO2, NOx, PM, PM10, and PM2.5 thermal power generation A1 are predicted to be 6.64×1010 tons, 1.54×107 tons, 1.55×107 tons, 3.18×106 tons, 1.71×106tons, and 2.23×105 tons, respectively. The cumulative emission reductions of renewable energy power generation A2 will be 5.77×1010 tons, 1.64×107 tons, 1.42×107 tons, 2.86×106 tons, 1.54×106 tons, and 2×105 t tons, respectively. Under the "carbon peak and neutrality" mode, compared with those from coal-fired power generation, the environmental benefits A3 and A4 produced by the relative cleanliness of renewable energy and nuclear power indicated that the cumulative emission reductions (A3+A4) in clean energy power generation of CO2, SO2, NOx, PM, PM10, and PM2.5 in the next four decades will be 3.014×1011 tons, 7.292×107 tons, 7.119×107 tons, 1.454×107 tons, 7.827×106tons, and 1.018×106 tons, respectively.

Effect of Replacing the Hearth Layer Used in the Sintering Process on the Reduction of NO and SO2

Effect of Replacing the Hearth Layer Used in the Sintering Process on the Reduction of NO and SO2

Non-Invasive-Monitoring Methodology for the Evaluation of Environmental Impacts on Istrian Stone Surfaces in Venice

This work proposes a non-invasive, affordable, and easily reproducible methodology for monitoring limestone surfaces vulnerability. The proposed methodology integrates the study of environmental factors impacting limestone surfaces with physical–chemical and morphological observations of historical Istria stone surfaces in Venice. Pollutant trends of particulate matters (PPM), NO2, SO2, O3, and the meteorological forcing were considered over a 20-year period. To collect information on the conservation state of stone surfaces, visual, optical microscopy observation, chemical analysis via FT-IR-ATR spectroscopy, and the evaluation of morphological and profilometric parameters by digitalizing the surface of silicone molds were carried out. The surfaces of Ca’ Foscari, Ca’ Dolfin, and Garzoni Palace were monitored in 2015 and five years after. Indicators, such as site, sheltered or exposed position, and location of the stone surfaces, were taken into consideration for data interpretation. A relationship between surface conservation state and the proposed environmental indicators has been evaluated. Deposits and crusts were found only in the courtyard façade and in sheltered points, reflecting SO2 reduction; large, eroded areas were found on exposed surfaces related to rain runoff and possibly related to the locally high NOx levels.