Forecast of Sulfur Deposition in Japan for Various Energy Supply and Emission Control Scenarios

In order to contribute to the analysis and solution of regional scale environmental problems in East Asia, we developed a tool for the comprehensive assessment of alternative policy options to improve air quality. This tool projects the future regional energy supply, calculates the emission levels of sulfur dioxide and estimates the geographical pattern of sulfur deposition resulting from emissions. Sulfur deposition in Japan through 2030 was forecasted for various energy supply and emission control scenarios using the analysis tool. Future sulfur depositions were calculated from the source-receptor matrix for 1995 and the growth rate of emission for the source subregion. In the case of the current legislation scenario, anthropogenic SO₂ emissions in East Asia would grow by 34 percent and sulfur deposition in Japan would increase by approximately 20 percent between 1995 and 2030. This increase in sulfur deposition over these 35 years is sligthly less than the contribution from volcanic emission to sulfur deposition in Japan. In the case of the hypothetical dirty scenario for China, sulfur deposition in several grids which face the Sea of Japan would double by 2030.     

Development of a Multi-Resolution Emission Inventory and Its Impact on Sulfur Distribution for Northeast Asia

Emissions in East Asia for 1993 by administrative units and source types are estimated to support regional emission assessments and transport modeling studies. Total emission of SO_x, NO_x, soil NO_x, N₂O, and NH₃ are 24 150, 12 610, 1963, 908, and 8263 kton yr^-1, respectively.China's emission contribution is the highest for every species.The area sources are the most significant source type for SO_x and NO_x, but the fraction due to mobile source is highest for NO_x. Major LPSs are located from the middle to the east part of China, south and middle-west part of South Korea, and the east part of Japan. The area sources of SO_x show a pattern similar to population density, whereas NH₃ shows a strong landuse dependency. Detail emissions analysis reveals higher SO_x emission `cores' within each province. The estimated emissions are used to estimate sulfur deposition in the regions. The seasonal average sulfur distribution amounts are estimated from the ATMOS2 chemical transport model. The results showed anti-correlation with temperature for sulfur (SO₂ + SO₄ ^-2) concentrations and a positive correlation with rainfall for deposition.     

Studies on Atmospheric Pollution,Acid Rain and Emission Control for their Precursors in Chongqing,China

Chongqing City in China has suffered from serious air pollution and acid rain caused by low graded raw coal (sulfur=ca. 3≈5%, ash=ca. 30%) combustion. In this paper, the situation of atmospheric pollution and acid rain in Chongqing are discussed, the reduction efficiency for sulfur dioxide (SO₂) with the bio-briquetting of the raw coal that is one of countermeasures for emission control of air pollutants due to domestic consumes was determined. The research indicated that the frequency of acid rain was high, more than 50% at urban area, and its pH was low, about 4.5. Under our experimental conditions, the reducing efficiency of sulfur SO₂ emission from high sulfur coal-biomass briquette amounted to 87%. The field investigation indicated that SO₂ indoor concentrations in case of using bio-briquette dropped to 1/2≈1/3 of the raw coal.     

A gaussian-box modeling approach for urban air quality management in a Northern Chinese City—II. pollutant emission abatement

A modeling framework by linking air quality simulation with system optimization was presented in this paper to develop cost-effective urban air quality management strategies in Fengnan district of China. The relation between the total allowable emission and wind speed as well as the relation between the total allowable emission and air-quality-guideline satisfaction were quantified based on the simulation results of the Gaussian-box modeling system. The area-source emission reduction objective in each functional zone of the study city during the heating and non-heating seasons was calculated based on such relations. A linear programming model was then developed to optimize the emission abatement which was subject to a number of dust and SO₂ control measures. The economic objective of the air quality management strategy was to minimize the total emission control system cost while the environmental objective can still be satisfied. The environmental objective was reflected by the emission reduction objective of TSP, PM₁₀ and SO₂ corresponding to an air-quality-guideline satisfaction percentage of 80%. Consequently, the modeling system comprehensively took into account the information of emission reduction objectives, emission abatement alternatives, emission reduction cost, and related resources constraints. An optimal emission abatement strategy and the related cost were obtained for various pollution control measures. The results would provide sound bases for decision makers in terms of effective urban air quality management and ensuring healthy economic development in the study city.     

Rains-Asia Model Application to China: Policy Implications for Sulfur Control

China's continuing dependence on coal suggests a need for a cost-effective strategy to address SO₂ and acid rain impacts. Results of modeling studies show that although there are important transboundary aspects of acid rain in Asia, the majority of emissions and damages lie within China. This implies that intra-regional cooperation within China, and cost-effective sulfur control are paramount for limiting acid rain damages. This article discusses the costs and benefits of six primary and secondary control and policy options using the RAINS-ASIA and UR-BAT models. The local health benefits were estimated to be an order of magnitude larger than the ecosystem benefits at the regional level. All abatement options involve substantial costs, except intensive energy efficiency which is the most cost effective with the rate of return of almost 200 per dollar as compared to around 6 for the other options.     

中国农村户用沼气工程建设对减排CO2、SO2的贡献——分析与预测

农村户用沼气工程是中国可再生能源建设的重点项目，可为农村居民生活提供清洁的可再生能源，该工程的建设能减轻农村环境污染，有助于部分缓解全球气候变暖的趋势。该文根据国际通用的减排量计算方法，对中国农村户用沼气替代传统生物质能和煤炭所产生的CO₂和SO₂的减排量进行了计算分析，为制定农村能源发展战略和农村环境发展规划提供参考。研究结果表明，在1996～2003年间，每年可减少CO₂排放39.76～419.39万t，减少SO₂排放2.13～6.20万t。通过对2010、2020和2050年沼气替代农村传统能源减排CO₂和SO₂量的预测，证明农村户用沼气工程的建设可以有效减少CO₂和SO₂的排放。     

Critical Loads of SO2 Dry Deposition and Their Exceedance in South China

The critical loads of SO₂ dry deposition in South China,which is transferred from critical level, as well the excess ofcritical loads are computed and mapped. The areas with thelowest critical load and the highest excess are, respectively,identified. The research is complementary to the previousresearches on critical loads for soils, and expected to beintegrated with them to make efficient sulfur emission abatement strategy.     

Projections of SO2, NOx,NH3 and VOC Emissions in East Asia Up to 2030

Starting from an inventory of SO₂, NO_x, VOC and NH₃ emissions for the years 1990 and 1995 in East Asia (Japan, South and North Korea, China, Mongolia and Taiwan), the temporal development of the emissions of the four air pollutants is projected to the year 2030 based on scenarios of economic development. The projections are prepared at a regional level (prefectures or provinces of individual countries) and distinguish more than 100 source categories for each region. The emission estimates are presented with a spatial resolution of 1×1 degree longitude/latitude. First results suggest that, due to the emission control legislation taken in the region, SO₂ emissions would only grow by about 46 percent until 2030. Emissions of NO_x and VOC may increase by 95 and 65 percent, respectively, mainly driven by the expected increase in road traffic volume. Ammonia, mainly emitted from agriculture, is projected to double by 2030.     

Suitability of Extractants for Predicting Available Sulfur in Natural Grassland in the Inner Mongolia Steppe of China

Abstract

It was the objective of this study to compare the suitability of different extractants for predicting the availability of sulfur (S) in natural grassland in a sulfur response trial on three different soil types in the Inner Mongolia steppe of China. For soil analysis, seven different extractants have been employed. The inorganic SO₄–S concentration was determined by ion chromatography. Additionally, in the Ca(H₂PO₄)₂ extract the total soluble S was determined employing turbidimetry. Weak salt solutions (0.15% CaCl₂, Ca(H₂PO₄)₂, and KH₂PO₄) extracted similar amounts of SO₄–S. Extraction with 0.025 M KCl provided the lowest SO₄–S values. Deionized water dissolved significantly more SO₄–S in the control plots than most weak salt extractants. The concentration of soluble organic S decreased in the control plots after 100 days of plant growth, indicating that the organic S pool contributed significantly to the S nutrition of the forage crops. Significant relationships among the SO₄–S in the soil determined in different extracts and crop yield, sulfur content in the forage, and total sulfur uptake were only found for the Ca(H₂PO₄)₂ extract. In general, the correlation coefficients proved to be unsatisfactory for field experimentation.     

Ozone‐Aided Corn Steeping Process

The present research evaluated the feasibility of using ozone (O₃) to replace sulfur dioxide (SO₂) in corn steeping. Traditionally, steep water contains 0.1–0.2% sulfur dioxide to promote starch‐protein separation and high starch yields, and to control microbial growth. However, residual SO₂ in starch products affects product quality and jeopardizes the “organic products” claims. Also, SO₂ discharged to the environment pollutes water and air. Ozone is a strong oxidant and disinfectant with a capability to control the growth of putrefactive microorganisms in steeping systems, and to break down the endosperm protein matrix and, hence, improve starch release. This study demonstrates that an ozone‐aided steeping (OAS) process had starch yields as high as conventional SO₂ steeping. OAS processes can be conducted at a lower temperature (20°C vs. 50°C) and for shorter times (36 hr vs. 48 hr) than the conventional SO₂ processes, suggesting significant energy savings and increased productivity. We have found that the timing of ozone application is of great importance to the performance of the OAS process.     

Modeling studies on sulfur deposition and transport in East Asia

A three dimensional regional Eulerian model of sulfur deposition and tranport has been developed. It includes emission, transport, diffusion, gas-phase and aqeous-phase chemical process, dry depostion, rainout and washout process. A looking up table method is provided to deal with the gas-phase chemical process including sulfur transfer. Calculated values have reasonable agreement with observations. Distribution of sulfur deposition and transport in East Asia are also analyzed in the paper. Simulation shows that sulfate (SO ₄ ^2– ) is the main substance to transport in long range transport. Some amount of sulfur emission of different countries transport across boundaries, but the main origin of sulfur deposition in each country in East Asia is from herself. Furthermore, some transport paths on different layers and outlet or inlet zones are found.     

Sulfur Deposition in Asia: Seasonal Behavior and Contributions from Various Energy Sectors

Sulfur transport and deposition in Asia, on an annual andseasonal basis, is analyzed using the ATMOS model. Calculationsare performed for two complete years (1990 and 1995). Deposition amounts in excess of 0.5 g S m^-2 yr^-1 are estimated for large regions in Asia, with values as high as 10 g S m^-2 yr^-1 in southeastern China. Annual averaged SO₂ concentrations in excess of 20 μg SO₂ m^-3 are calculated for many urban and suburban areas ofeastern China and S. Korea, with an average of 5 μg SO₂ m^-3 over most of the emitter regions. Sulfur deposition by major source categories is also studied. Southeast Asia (Indonesia, Malaysia, Philippines, Singapore)receives ～25% of its sulfur deposition from shipping activities. Sulfur deposition from bio-fuel burning is significant for most of the underdeveloped regions in Asia. Volcanoes are a major source of sulfur emissions in the PacificOcean, Papua New Guinea, Philippines and Southern Japan. Sulfur deposition is shown to vary significantly throughout the year.The monsoons are found to be the largest factor controlling sulfur transport and deposition in the Indian sub-continent andSoutheast Asia. India receives over 35% of its total depositionduring the summer months. In East Asia, sulfur deposition isestimated to be 10% higher during summer and fall than winterand spring. Model results are compared with observations from a number of monitoring networks in Asia and are found to be generally consistent with the limited observations.     

Control techniques and strategies for regional air pollution control from energy and industrial sectors

The technological options currently available to reduce SO₂ and NO_x emissions including abatement technologies and high efficient energy conversion technologies are reviewed. The energy emission model EFOMENV (Energy Flow Optimization Model-Environment) which takes into account all relevant emission reduction measures is used to determine the cost optimized energy pathway, the ranking of reduction measures and the corresponding costs as a function of given reduction levels of SO₂ and/or NO_x emissions for different scenarios in selected Central and Eastern European countries. It is shown that restructuring of the energy system is a major emission reduction option in all countries but with a potential varying greatly from country to country depending mainly on the existing structure and the age of the plants and on the development of the energy demand. The emission reduction costs for SO₂ in Central and Eastern European countries are 50% to 70% lower than in Western countries due to high potential of fuel/technology switching and energy saving measures. Cost efficient measures to reduce CO₂ emissions also lead to a significant decrease of SO₂ and NO_x emissions.     

Plotting of Acid Rain and Sulfur Dioxide Pollution Control Zones and Integrated Control Planning in China

The distribution and characteristics of acid rain and SO₂ pollution were presented, indicating that the areas with sulfur deposition over critical loads reached 21.9% of the territory in 1995. In order to control the acid rain and SO₂ pollution effectively, the Acid Rain Control Zone and SO₂ Pollution Control Zone (Two Control Zones for short) were designated based on the analysis of sulfur deposition. The corresponding integrated pollution control planning was formulated based on the life cycle approach of sulfur in coal and the technical options for SO₂ mitigation were also recommended for different sources such as coal industry, power industry, industrial boilers and kilns, and household stoves. Based on the countermeasures suggested, the SO₂ would be reduced by about 4.92Mt/yr during 2001–2005 and by 4.16Mt/yr during 2006–2010.     

NMVOCs and CO Emission Inventory in East Asia

For analyzing acidification in East Asia, long range transportation models has been developed, which require emissions inventories of the precursors. SO₂ and NOx emissions inventories were reported previously; here emissions of NMVOCs (Non methane volatile organic compounds) and CO in East Asia; China, Republic Korea, Japan and Taiwan area, are estimated. For the years 1994–95, the total emissions of NMVOC and CO in East Asia are estimated at 17.7 and 94.1Tg/y respectively. Small coal boiler and biomass use for residences are dominant sources of NMVOCs in the area, especially in China. More than half of CO emission comes from biomass use in residences in China. Regionally at east costal area in China high density emission is seen in the 1×1 degree grid emission map.     

Stack Gas Desulfurization by Seawater in Shanghai

There are a series of advantages in use of seawater as absorbent to remove SO₂ in stack gas. Use of seawater for stack gas desulfurization is the first choice method for thermal power plant located on seaside. A study on the possibility of desulfurization by seawater of the East China Sea has be done by our institute. The qualities of seawaters have been investigated. These seawater samples were sampled from the East China Sea located Shanghai and Zhejiang province in China. The stack gas desulfurization of coal-fired power plant by seawater was conducted on 100 m³/h scale at Zhejiang. A pilot plant with 6000 m³/h scale has been completed and put into operation in Shanghai. It is found that the removal efficiency of SO₂ increase with ratio of seawater with stack gas. The removal rate of SO₂ in stack gas reached about 90≈95% when a plate tower was used. The waste seawater absorbed SO₂ can return to the sea after aeration and neutralization.     

A simple apparatus used for effective fume control during plant tissue digestion using a heating block

Abstract

Rapid digestion of plant tissue using sulfuric acid results in emission of large quantities of SO₃ fumes. These fumes are a serious hazard to personnel and cause corrosion of equipment and exhaust ducts. A simple apparatus was designed for effective fume control during plant tissue digestion with sulfuric acid using a heating block. The apparatus consists of a battery of reflux columns that can be installed as a unit on top of the digestion tubes after they have been placed in the heating block. The apparatus is very economical to construct.     

Sulfur diagnostic criteria for French prune trees

One year old Marianna 2624 (Prunus cerasifera X P. munsoniana) trees grafted with French prunes (P. domestica) were grown in the greenhouse in pots containing vermiculite and supplied with graded amounts of sulfate‐sulfur (SO₄‐S) to study the methods of evaluating sulfur (S). Tree fresh weight gain was recorded. Leaf samples were analyzed for different S fractions. Chlorophyll concentration of leaves was better than fresh weight gain as an indicator of tree S status. Sulfate in recently matured leaves is a better diagnostic index for prunes than total‐S, organic‐S, or N:S ratio which are not suitable for this purpose. Using chlorophyll as an indicator of growth potential, critical SO₄‐S level of recently matured leaves is 97 ppm. Sulfate‐sulfur as a percent of total‐S can also be used as a diagnostic tool. Critical level for this index in the recently matured leaves is 7.85%. External critical S level is 80 μM (8 ppm as SO₄).     

A Computational Approach Based on GIS Technology for the Development of an Anthropogenic Emission Inventory of Gaseous Pollutants in Greece

This paper describes a computational system developed for the compilation of an anthropogenic emission inventory of gaseous pollutants for Greece. The inventory was developed using a geographical information system integrated with SQL programming language to provide high temporal gridded emission fields for CO, NO₂, NO, SO₂, NH₃ and 23 non-methane volatile organic compounds (NMVOCs) species for the reference year 2003. Activity and statistical data from national sources were used for the quantification of emissions from the road transport, the other mobile sources and machinery sectors and from range activities using top-down or bottom-up methodologies. Annual emission data from existing national and European emission databases were also used. The emission data were spatially and temporally disaggregated using source-specific spatiotemporal indicators. On national scale, the road transport sector produces about 60% of the annual CO and NMVOC total emissions, with gasoline vehicles being the main CO and NMVOC emissions source. The road transport is responsible for approximately half of the higher alkanes and for more than half of the ethene and toluene emissions. The maritime sector accounts for about 40% of the annual total NO_x emissions, most of which are emitted by the international shipping subsector, whilst SO₂ is emitted mainly by the energy sector. The evaluation of the emissions inventory suggests that it provides a good representation of the amounts of gaseous pollutants emitted on national scale and a good characterisation of the relative composition of CO and NO_x emission in the large urban centres.     

Recent developments in technologies and policies in Germany to control acid deposition

In Germany, acidifying emissions have decreased since the mid-eighties, but are still at levels that cause environmentally harmful acid deposition and thus make further action necessary. The driving force behind such actions is the precautionary principle laid down in pollution control legislation. It is implemented as a requirement to minimize emissions and mandates the parties concerned to formulate and implement emission control requirements based on the state of the art, and to update them as technological advances are made. As the scope for restructuring energy supply and switching to environmentally friendlier sources is very limited in Germany, strategies for controlling inevitable NO_X and SO₂ emissions will continue to be directed at further improving the technical systems (besides necessary changes in lifestyle). Since the large-scale retrofit programmes were initiated in the eighties, technological advances have provided some scope for a further tightening of emission reduction requirements for SO₂ and NO_X. In addition, there is some potential for further reducing these emissions through more energy-efficient demand- and supply-side technology.