Volatile Organic Compounds Emissions In China Research Articles

Advances in Adsorption, Absorption, and Catalytic Materials for VOCs Generated in Typical Industries

In recent years, atmospheric composite pollution has become increasingly serious, and accelerating VOC governance has become the focus of and difficulty in atmospheric governance. Volatile organic compounds (VOCs) come from a wide range of sources, and industrial sources are the main source of anthropogenic VOC emissions in China. Chemicals, oil refining, and solvents are three typical VOC-emitting industries, and their control is an important part of accelerating and optimizing VOC governance. It can be controlled by source control, process control, and pipe end treatment; among these, pipe end treatment is divided into recovery technology and destruction technology. In pipeline end treatment, with the key materials of adsorption, absorption, catalytic oxidation, and catalytic combustion, the research and development of adsorbents, absorbents and catalysts has become a hot spot in recent years. This paper summarizes the chemical materials used in typical VOC pipe end-treatment technology (including adsorbents used in the adsorption method, absorbents used in the adsorption method, and catalysts used in the catalytic oxidation and catalytic combustion methods), summarizes the advantages and disadvantages of various materials and their application range, and looks forward to the direction of future developments.

Emission factors and source profiles of VOCs emitted from coke production in Shanxi, China

Coking plants in China generate a substantial amount of volatile organic compounds (VOCs). The emission factors (EFs) of VOCs from coking plants are not well known, and thus, this study characterized the VOCs in the emissions from four coking plants in Shanxi, China. The EFs of VOCs from different stages of the coking process were calculated, and coal charging exhibited the highest EFs of VOCs, followed by the flue gases from combustion of coke oven gas, wastewater treatment, coke pushing and chemical byproduct recycling. The VOCs in emissions differed by coking process. Alkanes, aromatics and alkenes were the main VOCs emitted during the coking, wastewater treatment and chemical byproduct recycling processes, respectively. To effectively control the contribution of VOCs from coking processes to secondary organic aerosols and ozone formation, attention should be given to wastewater treatment and coal loading processes. The mean annual weight of VOCs emitted from coking plants in China from 2019 to 2021 was estimated to be 32.91 Gg with coking, chemical byproduct recycling, and wastewater treatment processes accounting for 91.34%, 7.85%, and 0.80% of total VOCs, respectively. An uneven spatial distribution of VOCs emissions in China was identified, with Shanxi, Shaanxi, Hebei, Inner Mongolia and Shandong being the largest contributors.

Analysis of Spatio-Temporal Characteristics and Trend Forecast of Building Industry VOCs Emissions in China

Emissions of volatile organic compounds (VOCs) from the building industry in China are increasing. Predicting future trends in China’s building industry VOCs will help the implementation of China’s construction VOCs emission reduction policy. The aim of this study is to combine Granger causality analysis, Ridge regression, GM(1,N), and categorical boosting (CatBoost) methods for the analysis of factors influencing and trend prediction of VOCs emissions from building industry in China. Firstly, the spatial and temporal characteristics of building industry VOCs emissions in China were calculated, based on building industry VOCs emissions data from 2006 to 2020 for each province and city in China. Secondly, Granger causality tests and STIRPAT models were used to examine the influencing factors of construction VOCs, combined with ridge regression to estimate the elasticity coefficients of the influencing factors and feature screening, which were used as input features for prediction. Finally, a combination of the improved GM(1,N) model and the CatBoost model was used to predict and compare the results with those of the GM(1,N) model, the support vector regression model (SVR), the random forest (RF), and the CatBoost model. The results show that the combined model with improved GM(1,N) and CatBoost has better prediction accuracy than the other models. China’s building industry VOCs emissions are increasing year on year and are not expected to reach their peak by 2030. The size of the population, the number of people employed in the building industry, and the area of housing floor space under construction are important influencing factors that affect VOCs emissions from building industry in China. Based on the predicted results for the different scenario settings, building industry VOCs emissions are lower in the short term for the baseline scenario and in the long term for the high-speed scenario.

Carbonyls from commercial, canteen and residential cooking activities as crucial components of VOC emissions in China

Cooking in China supply the large population with nutrition and, as a commercial activity, it also promotes the economic growth of Chinese society. The specific cooking styles in China can produce complex volatile organic compound (VOC) emissions. The resulting adverse effects on the environment and human health of carbonyls from cooking should not be ignored. We quantitatively evaluated the contribution of carbonyls to common VOCs (carbonyl/VOC ratio) from cooking activities in China through the establishment and comparison of the source profiles, emission factors (EFs), emission amount and ozone formation potential (OFP). It was found that carbonyls are crucial components of VOCs from commercial, canteen and residential cooking activities (COC, CAC and REC, respectively). The carbonyl/VOC ratio from cooking activities in China had EFs, emissions, and a total OFP of 22–65 %, 23–34 %, and 49–104 %, respectively. The high OFP was due to the high OFP emissions intensity (OFPEI) and maximum incremental reactivity (MIR) values of carbonyls. This indicates that to alleviate O3 pollution, OFP-based control measures that target carbonyls might be more efficient than measures that target common VOCs. Priority should be given to emission controlling COC emissions, specifically those from medium- and large-scale catering. Formaldehyde, acetaldehyde, and hexanal were the key carbonyl species that form O3 in the environment. Our findings imply that cooking-emitted carbonyls should not be overlooked in investigations of O3 formation and that these compounds should be subject to strict regulations.

Research progresses on VOCs emission investigations via surface and satellite observations in China.

Volatile organic compounds (VOCs) are important precursors of severe pollution of ozone (O3) and secondary organic aerosols in China. Fully understanding the VOCs emission is crucial for making regulations to improve air quality. This study reviews the published studies on atmospheric VOCs concentration observations in China and observation-based estimation of China's VOCs emission strengths and emission source structures. The results reveal that direct sampling and stainless-steel-tank sampling are the most commonly used methods for online and offline observations in China, respectively. The GC-MS/FID is the most commonly used VOCs measuring instrument in China (in 60.8% of the studies we summarized). Numerous studies conducted observation campaigns in urban areas (76.2%) than in suburban (17.1%), rural (18.1%), and background areas (14.3%) in China. Moreover, observation sites are largely set in eastern China (83.8%). Though there are published studies reporting observation-based China's VOCs emission investigation, these kinds of studies are still limited, and gaps are found between the results of top-down investigation and bottom-up inventories of VOCs emissions in China. In order to enhance the observation-based VOCs emission investigations in China, this study suggests future improvements including: (1) development of VOCs detection techniques, (2) strengthening of atmospheric VOCs observations, (3) improvement of the accuracy of observation-based VOCs emission estimations, and (4) facilitation of better VOCs emission inventories in China.

A comprehensive review on anthropogenic volatile organic compounds (VOCs) emission estimates in China: Comparison and outlook.

Accurate measurement and estimation on the trends and spatial distributions of VOCs emissions in China are critical to establishing efficient local or regional pollution control measures, while less is known about the discrepancies on VOCs emissions estimated by previous studies. In this study, two of the estimation approaches including the bottom-up and top-down methods have been reviewed with the data collected from many studies. The approaches demonstrated that the total anthropogenic VOCs emissions in China have been increasing since 1949. The contributions of industrial and solvent use to total VOCs emissions have been increasing since 2000, whereas the contributions of transportation sector have shown a decreasing trend since 2000. The contributions of fuel combustion have also been decreasing since 1950. The gaps of emission estimates for the industry and solvent use were 99.3±22.7% and 81.5±41.8%, respectively, which distributed in much wider ranges than other sources (e.g. 28.9±16.7% for fuel combustion). In comparison to the top-down method, larger variations on the annual VOCs emission estimates were seen using the bottom-up method that comprised different data sources. For the view of spatial pattern, most hot emission estimate spots were concentrated in the eastern China, consistent to their relatively stronger strengths in the industrialization and urbanization. Although the total VOCs emission in China has been continuously increasing during 2008-2016, the VOCs emissions per gross domestic production (GDP) showed a decreasing trend. As for individual compounds, large discrepancy was seen on formaldehyde, with the coefficient of variation (CV) ranged from 37% to 128% over the years. In overall of view, the importance of industrial process and solvent use is increasing. More focuses must be made to these two sources. Emissions of individual compound, particularly those of oxygenated VOCs, were not completely determined and should be better quantified.

Accounting Methods of VOCs Emission Associated with Production Processes in a Fine Chemical Industrial Park

Volatile organic compounds (VOCs) are one of the key atmospheric pollutants associated with great impact on air quality. Industrial sources have become the most important source of VOCs emissions in China, of which the chemical industry accounts for a large part. At present, more than half of chemical manufacturers are clustered in chemical industrial parks (CIPs), thus the control of VOCs in CIPs is crucial. This study analyzed the production processes of the fine chemical industry and the principle of VOCs production, and then proposed an accounting model of VOCs emissions associated with production processes, based on a typical fine chemical industrial park:Hangzhou Bay Shangyu Economic and Technological Development Area (HSEDA). The quantity of VOCs generation in the main production processes, such as feeding, heating, chemical reaction gas take-off, cleaning, vacuum pumping, pressure release, and evaporating, were calculated. Meanwhile, the chemical process simulation software Aspen was also employed to simulate the VOCs generation in these processes. The methods were applied to 14 representative products in HSEDA and the feature of VOCs generation in the chemical processes mentioned above, and components were revealed. The results of the two methods were compared, and the difference between the two methods was within±22% except for the pressure release process. The model and accounting methods proposed in this study will have sound applicability in accounting for VOCs emissions in fine chemical industrial parks underpinned by quantitative chemical industry production parameters.

Quantitative assessment of industrial VOC emissions in China: Historical trend, spatial distribution, uncertainties, and projection

The temporal trends of industrial volatile organic compound (VOC) emissions was comprehensively summarized for the 2011 to 2013 period, and the projections for 2020 to 2050 for China were set. The results demonstrate that industrial VOC emissions in China increased from 15.3 Tg in 2011 to 29.4 Tg in 2013 at an annual average growth rate of 38.3%. Guangdong (3.45 Tg), Shandong (2.85 Tg), and Jiangsu (2.62 Tg) were the three largest contributors collectively accounting for 30.4% of the national total emissions in 2013. The top three average industrial VOC emissions per square kilometer were Shanghai (247.2 ton/km2), Tianjin (62.8 ton/km2), and Beijing (38.4 ton/km2), which were 12–80 times of the average level in China. The data from the inventory indicate that the use of VOC-containing products, as well as the production and use of VOCs as raw materials, as well as for storage and transportation contributed 75.4%, 10.3%, 9.1%, and 5.2% of the total emissions, respectively. ArcGIS was used to display the remarkable spatial distribution variation by allocating the emission into 1 km × 1 km grid cells with a population as surrogate indexes. Combined with future economic development and population change, as well as implementation of policy and upgrade of control technologies, three scenarios (scenarios A, B, and C) were set to project industrial VOC emissions for the years 2020, 2030, and 2050, which present the industrial VOC emissions in different scenarios and the potential of reducing emissions. Finally, the result shows that the collaborative control policies considerably influenced industrial VOC emissions.

Ozone and secondary organic aerosol formation potential from anthropogenic volatile organic compounds emissions in China

Volatile organic compounds (VOCs) are major precursors for ozone and secondary organic aerosol (SOA), both of which greatly harm human health and significantly affect the Earth's climate. We simultaneously estimated ozone and SOA formation from anthropogenic VOCs emissions in China by employing photochemical ozone creation potential (POCP) values and SOA yields. We gave special attention to large molecular species and adopted the SOA yield curves from latest smog chamber experiments. The estimation shows that alkylbenzenes are greatest contributors to both ozone and SOA formation (36.0% and 51.6%, respectively), while toluene and xylenes are largest contributing individual VOCs. Industry solvent use, industry process and domestic combustion are three sectors with the largest contributions to both ozone (24.7%, 23.0% and 17.8%, respectively) and SOA (22.9%, 34.6% and 19.6%, respectively) formation. In terms of the formation potential per unit VOCs emission, ozone is sensitive to open biomass burning, transportation, and domestic solvent use, and SOA is sensitive to industry process, domestic solvent use, and domestic combustion. Biomass stoves, paint application in industrial protection and buildings, adhesives application are key individual sources to ozone and SOA formation, whether measured by total contribution or contribution per unit VOCs emission. The results imply that current VOCs control policies should be extended to cover most important industrial sources, and the control measures for biomass stoves should be tightened. Finally, discrepant VOCs control policies should be implemented in different regions based on their ozone/aerosol concentration levels and dominant emission sources for ozone and SOA formation potential.

Exploring the spatiotemporal characteristics and control strategies for volatile organic compound emissions in Jiangsu, China

China being a large developing country, with rapid economic growth over the last three decades, has a great challenge to control volatile organic compound (VOC) emissions and mitigate their related environmental issues and health problems. Moreover, China has great disparity in characteristics of VOC emissions and economic development among its 31 provincial regions. Local governments should suit their control measures to local conditions. To address this issue, we selected Jiangsu Province, one of the largest contributors of VOC emissions in China, having the second largest economy among the 31 Chinese provinces, as our example. Then we built a VOC emission inventory for the period 2000–2013 and set up a scenario analysis for the reduction of VOC emissions for Jiangsu Province. Results show that total VOC emissions in Jiangsu have risen from 0.98 Tg in 2000 to 2.15 Tg in 2013, and emissions related to solvent utilization and industrial processes account for 49.0% and 42.9% of the 1.17 Tg increase. Overall, VOC emissions were concentrated in Jiangsu's southern and coastal areas for the study period. Although per-gross-domestic-product VOC emission intensity is decoupled from urbanization ratio, Jiangsu's VOC emissions are strongly correlated with gross domestic product and urbanization ratio. In scenario analysis, only enhanced control measures involving cleaner production processes and more stringent end-of-pipe approaches can achieve the two controlled sources', i.e., industrial process' and solvent utilization's, total reduction rate of 24.6% by 2020, compared with 2013, which means such measures will realize the emission reduction goal, 24.3%, assumed for China's thirteenth five-year-plan period of national development.

Vehicular volatile organic compounds losses due to refueling and diurnal process in China: 2010–2050

Volatile organic compounds (VOCs) are crucial to control air pollution in major Chinese cities since VOCs are the dominant factor influencing ambient ozone level, and also an important precursor of secondary organic aerosols. Vehicular evaporative emissions have become a major and growing source of VOC emissions in China. This study consists of lab tests, technology evaluation, emissions modeling, policy projections and cost-benefit analysis to draw a roadmap for China for controlling vehicular evaporative emissions. The analysis suggests that evaporative VOC emissions from China's light-duty gasoline vehicles were approximately 185,000ton in 2010 and would peak at 1,200,000ton in 2040 without control. The current control strategy implemented in China, as shown in business as usual (BAU) scenario, will barely reduce the long-term growth in emissions. Even if Stage II gasoline station vapor control policies were extended national wide (BAU+extended Stage II), there would still be over 400,000ton fuel loss in 2050. In contrast, the implementation of on-board refueling vapor recovery (ORVR) on new cars could reduce 97.5% of evaporative VOCs by 2050 (BAU+ORVR/BAU+delayed ORVR). According to the results, a combined Stage II and ORVR program is a comprehensive solution that provides both short-term and long-term benefits. The net cost to achieve the optimal total evaporative VOC control is approximately 62 billion CNY in 2025 and 149 billion CNY in 2050.

Characteristics and Uncertainty of Industrial VOCs Emissions in China

An industrial sector-based source volatile organic compounds (VOCs) emission inventory was developed for the year 2011 in China with the use of ‘emission factor method’. Based on the concept of source-tracing and a ‘bottom-up’ approach, it is estimated that the total emissions of industrial VOCs were 15.8 Tg for the year 2011, 17.7% of which came from production of VOCs, 8.4% came from storage and transport, 14.2% came from industrial processes using VOCs as raw materials, and 59.7% came from use of VOCs-containing products. Industrial VOCs emissions in East China were the largest contributors, comprising 40% of total. Four kinds of sources including furniture manufacturing, petroleum refining, machinery equipment manufacturing and printing industry took up 53.8% of total emissions. Therefore, more efficient VOCs control equipment should be paid attention to and promoted. A quantitative approach, the bootstrap simulation and Monte Carlo sampling, was used to analyze uncertainties, there is relatively medium uncertainty with an error of –42% to +71%, ranging from 9.2 to 27.2 Tg on the 95% confidence interval. To reduce VOCs emission inventory uncertainties requires giving priority to research on conducting more measurements of key sources. It’s imperative to establish domestic emission factor database.

Photochemical roles of rapid economic growth and potential abatement strategies on tropospheric ozone over South and East Asia in 2030

Abstract. A regional air quality simulation framework including the Weather Research and Forecasting modeling system (WRF), the Community Multi-scale Air Quality modeling system (CMAQ), and precursor emissions to simulate tropospheric ozone over South and East Asia is introduced. Concentrations of tropospheric ozone and related species simulated by the framework are validated by comparing with observation data of surface monitoring, ozonesondes, and satellites obtained in 2010. The simulation demonstrates acceptable performance on tropospheric ozone over South and East Asia at regional scale. Future energy consumption, carbon dioxide (CO2), nitrogen oxides (NOx), and volatile organic compound (VOC) emissions in 2030 under three future scenarios are estimated. One of the scenarios assumes a business-as-usual (BAU) pathway, and other two scenarios consider implementation of additional energy and environmental strategies to reduce energy consumption, CO2, NOx, and VOC emissions in China and India. Future surface ozone under these three scenarios is predicted by the simulation. The simulation indicates future surface ozone significantly increases around India for a whole year and around northeastern China in summer. NOx is a main driver on significant seasonal increase of surface ozone, whereas VOC as well as increasing background ozone and methane is also an important factor on annual average of surface ozone in East Asia. Warmer weather around India is also preferable for significant increase of surface ozone. Additional energy and environmental strategies assumed in future scenarios are expected to be effective to reduce future surface ozone over South and East Asia.

An Estimate of Biogenic Emissions of Volatile Organic Compounds during Summertime in China (7 pp)

and Aim. An accurate estimation of biogenic emissions of VOC (volatile organic compounds) is necessary for better understanding a series of current environmental problems such as summertime smog and global climate change. However, very limited studies have been reported on such emissions in China. The aim of this paper is to present an estimate of biogenic VOC emissions during summertime in China, and discuss its uncertainties and potential areas for further investigations. This study was mainly based on field data and related research available so far in China and abroad, including distributions of land use and vegetations, biomass densities and emission potentials. VOC were grouped into isoprene, monoterpenes and other VOC (OVOC). Emission potentials of forests were determined for 22 genera or species, and then assigned to 33 forest ecosystems. The NCEP/NCAR reanalysis database was used as standard environmental conditions. A typical summertime of July 1999 was chosen for detailed calculations. The biogenic VOC emissions in China in July were estimated to be 2.3×1012gC, with 42% as isoprene, 19% as monoterpenes and 39% as OVOC. About 77.3% of the emissions are generated from forests and woodlands. The averaged emission intensity was 4.11 mgC m-2 hr-1 for forests and 1.12 mgC m-2 hr-1 for all types of vegetations in China during the summertime. The uncertainty in the results arose from both the data and the assumptions used in the extrapolations. Generally, uncertainty in the field measurements is relatively small. A large part of the uncertainty mainly comes from the taxonomic method to assign emission potentials to unmeasured species, while the ARGR method serves to estimate leaf biomass and the emission algorithms to describe light and temperature dependence. This study describes a picture of the biogenic VOC emissions during summertime in China. Due to the uneven spatial and temporal distributions, biogenic VOC emissions may play an important role in the tropospheric chemistry during summertime. . Further investigations are needed to reduce uncertainties involved in the related factors such as emission potentials, leaf biomass, species distribution as well as the mechanisms of the emission activities. Besides ground measurements, attention should also be placed on other techniques such as remote-sensing and dynamic modeling. These new approaches, combined with ground measurements as basic database for calibration and evaluation, can hopefully provide more comprehensive information in the research of this field.