Emission Characteristics Of Volatile Organic Compounds Research Articles

Updating vehicle VOCs emissions characteristics under clean air actions in a tropical city of China

In the context of clean air actions in China, vehicle emission limits have been continuously tightened, which has facilitated the reduction of volatile organic compounds (VOCs) emissions. However, the characteristics of VOC emissions from vehicles with strict emission limits are poorly understood. This study investigated the VOC emission characteristics from vehicles under the latest standards based on tunnel measurements, and identified future control strategies for vehicle emissions. The results showed that the highest percentage of VOCs from vehicle consisted of alkanes (80.9 %), followed by aromatics (15.8 %) and alkenes (3.1 %). Alkanes had the most significant ozone formation potential due to their high concentrations, in contrast to the aromatics that have been dominant in previous studies. The measured fleet-average VOC emission factor was 71.3 mg·km−1, including tailpipe emissions of 39.6 mg·km−1 and evaporative emissions of 31.7 mg·km−1. The VOC emission factors of the subgroups were obtained. The emission of evaporated VOCs accounted for 44.5 % of the total vehicle VOC emissions, which have increased substantially from previous studies. In addition, the emission characteristics of vehicles that are under the latest emission threshold values have changed significantly, and the mixing ratio of toluene/benzene (T/B) has been updated to 3:1. This study updates the VOCs emission factors of vehicles under clean air actions and highlights the future mitigation policies should focus on reducing evaporative VOC emissions.

Novel approach for identifying VOC emission characteristics based on mobile monitoring platform data and deep learning: Application of source apportionment in a chemical industrial park

Refined volatile organic compound (VOC) emission characteristics are crucial for accurate source apportionment in chemical industrial parks. The data from mobile monitoring platforms in chemical industrial parks contain pollution information that is not intuitively displayed, requiring further excavation. A novel approach was proposed to identify VOC emission characteristics using the class activation map (CAM) technology of convolutional neural network (CNN), which was applied on the mobile monitoring platform data (MD) derived from a typical fine chemical industrial park. It converts a large amount of monitoring data with high spatiotemporal complexity into simple and interpretable characteristic maps, effectively improving the identification effect of VOC emission characteristics, supporting more accurate source apportionment of VOC pollution around the park. Using this method, the VOC emission characteristics of eight key factories were identified. VOC source apportionment in the park was conducted for one day using a positive matrix factorization (PMF) model and seven combined factor profiles (CFPs) were calculated. Based on the identified VOC emission characteristics, the main pollution sources and their contributions to surrounding schools and residential areas were determined, revealing that one pesticide factory (named LKA) had the highest contribution ratio. The source apportionment results indicated that the impact of the chemical industrial park on the surrounding areas varied from morning to afternoon, which to some extent reflected the intermittent production methods employed for fine chemicals.

How do the main components influence the VOCs emission characteristics and formation pathways during moso bamboo heat treatment?

Bamboo heat treatment will cause plenty of release of volatile organic compounds (VOCs) into the atmosphere which are important precursors for ozone (O3) formation. In this study, dewaxed bamboo was heat-treated at 180 °C for 2 h to investigate the emission characteristics and the formation pathways of VOCs during heat treatment by removing different main components. The results showed that aldehydes (22.61%–57.54%) and esters (14.64%–38.88%) are the primary VOCs released during heat treatment. These compounds mainly originate from the degradation of hemicellulose, lignin, cellulose, and the linkage bonds between them in bamboo. During the bamboo heat treatment, the degradation of CO, CH, and CO bonds in hemicellulose results in the release of 5-hydroxymethylfurfural, 3-furfural, and 1-(+)-ascorbic acid 2,6-dihexadecanoate. The breakage of benzene ring group and the CO and CH bonds of lignin leading to the emission of VOCs including m-Formylphenol, Vanillin, and Syringaldehyde. The degradation of aliphatic CH, CC, and CO bonds in the amorphous region of cellulose contributes to an enhanced release of alcohols, olefins, and alkanes. It is calculated that acids (28.92%–59.47%), esters (10.10%–22.03%) and aldehydes (17.88%–39.91%) released during heat treatment contributed more to Ozone Formation Potential (OFP).

Volatile organic compounds (VOCs) emissions from internal floating-roof tank in oil depots in Beijing: Influencing factors and emission reduction strategies analysis

The internal floating-roof tank is the main type of storage tank for refined oil products. The volatile organic compounds (VOCs) emission from the internal floating-roof tank plays a dominant role in the unorganized emission source of the oil depot. In this study, we selected six typical oil depots in Beijing to investigate VOC emission characteristics from the tank top vent hole using infrared imaging technology and flame ionization detector (FID). The results reveal that infrared thermal imager is efficient in quickly identifying the emission level of the tank discharge point. The ambient temperature and wind speed have a direct effect on sealing loss, the turnover can greatly influence the wall hanging loss, and the concentration of VOCs emitted from the tank top vent hole is negatively correlated with liquid height. Furthermore, the influence of accessories type of the internal floating-roof tank on the concentration of VOCs emission from the top vent hole is also studied when other parameters remain unchanged, and find the floating deck type and sealing mode have a significant influence on their VOCs emissions, of which the combination of pontoon type floating deck and secondary seal are effective in controlling the concentration of VOCs emitted from the tank top vent hole. Finally, based on our experimental results, several feasible emission reduction strategies are proposed in terms of source prevention and process control in order to achieve the fine management of the whole process. This paper provides important technical support and policy thoughts for VOCs emission control during oil storage.

Process-specific volatile organic compounds emission characteristics, environmental impact and health risk assessments of the petrochemical industry in the Beijing-Tianjin-Hebei region.

Volatile organic compounds (VOCs) concentration, source profiles, O3 and SOA formation, and health risks were investigated in the petrochemical industry in Beijing-Tianjin-Hebei. The results showed that total VOCs concentrations were 547.1-1956.5μg·m-3, and alkanes were the most abundant group in all processes (31.4%-54.6%), followed by alkenes (20.6%-29.2%) and aromatics (10.1%-25.1%). Moreover, ethylene (11.3%), iso-pentane (7.1%), n-hexane (5.1%), benzene (4.9%) and 2,2-dimethylbutae (4.8%) were identified as the top five species released for the whole petrochemical industry. The coefficient of divergence between the source profiles from different processes was 0.49-0.73, indicating that most source profiles must not be similar. Moreover, because of the different raw materials and technologies used, the source profiles in this study are significantly different from those of other regions. The ozone and secondary organic aerosol formation potentials (OFPs and SOAPs) were evaluated, suggesting that ethylene, propylene, 1-butene, m,p-xylene, and 1,3-butadiene should be preferentially controlled to reduce OFPs. That benzene, toluene, ethylbenzene, m,p-xylene, isopropylbenzene, o-ethyltoluene, and 1,3,5-trimethylbenzene should be priority control compounds for SOAPs. Additionally, the total hazard ratio for non-cancer risk ranged from 0.9 to 7.7, and only living area was unlikely to be related to adverse health effects. Cancer risks associated with organic chemicals, rubber synthesis, oil refining, and wastewater collection and treatment have definite risks, whereas other processes have probable risks. This study provides a scientific basis for VOCs emission control and management and guides human health in the petrochemical industry.

Performance and VOCs emission inhibition of high-content waste rubber powder modified asphalt and its mixture

ABSTRACT The high-content waste rubber powder (WRP)-modified asphalt (WRMA) has poor storage stability and tends to produce many volatile organic compounds (VOCs). This study aimed to research the influence of incorporating high-content WRP on the performance enhancement and VOCs emission of asphalt and its mixtures. The storage stability, rheological properties and cracking resistance of WRMA were tested. Further, the high and low-temperature properties of WRMA mixtures were evaluated. Additionally, the VOCs emission characteristics of WRMA mixtures were analysed . The results indicate that activated WRP has good compatibility with asphalt. The high-content of WRP can significantly enhance the high-temperature rheological properties and low temperature cracking resistance of asphalt binder, and the addition of nanometre calcium carbonate (B3) adsorbent can further enhance the physicochemical properties of asphalt binder. Moreover, compared with 70# asphalt mixture, the dynamic stability of WRMA mixture increases by about 50%, and the immersion residual stability and freeze–thaw splitting strength values increase by 6.34% and 5.98%, respectively. In addition, the B3 adsorbent can significantly reduce the VOCs emission from WRMA mixtures. The corresponding conclusions could provide guidance for the large-scale application of high-content WRMA mixtures and promote cleaner and greener products.

Emission characteristics of VOCs emitted from household stove combustion in the north of China

The emissions of volatile organic compounds (VOCs) arising from household stove combustion of different fuels common in North China were quantified. Using a dilution tunnel sampling system and gas chromatography-mass spectrometry analysis, 107 different C2–C12 VOCs were identified in flue gases of four household solid fuels (coal briquette, honeycomb briquette, wood, and cornstalk), whose emission factors were 670 ± 550, 1322 ± 686, 1200 ± 1923, 8670 ± 8380 mg kg−1, respectively. Alkenes and alkynes contributed the most to the VOC emitted from the combustion of honeycomb briquettes (50.1%), wood (46.3%), and cornstalks (56.9%). N-Alkanes were the dominant VOC (43.9%) from coal briquette combustion. Ethane and ethene were the most abundant individual species found in the flue gas of coal briquettes, wood, and cornstalks, accounting for 60.4%, 59.8%, and 67.9% of the emissions, respectively. The VOC emitted from coal briquettes, honeycomb briquettes, wood, and cornstalks exhibited significantly different chemical reactivities. The OH reactivity of the VOCs from cornstalk combustion was 9–270 times greater than that of the other fuels. The differences in the atmospheric reactivity of emissions would suggest that cornstalk combustion should be prioritised in any strategy to reduce ozone pollution.

Study on the emission characteristics of VOCs under the condition of biomass blending combustion

In order to understand the emission characteristics of volatile organic compounds (VOCs) in the flue gas under the mixed combustion of biomass, the study on the emission characteristics of VOCs in the flue gas was carried out on a 58 MW circulating fluidized bed (CFB) unit. The results show that the co-firing of biomass can significantly reduce the emissions of VOCs and NOx and SO2. Changes in blended fuel particle size and combustion temperature reduce VOCs emissions. The most obvious change in the emission reduction of VOCs is reflected in the increase of the biomass mixing ratio from 20 % to 30 %. Biomass contains less S and N elements is the reason for the reduction of NOx and SO2 emissions. The emission of pollutants such as VOCs was the lowest when the biomass blending ratio was 40 %. Based on the actual operation of the power plant, 30 % is the optimal mixing ratio. The analysis showed that the amount of VOCs components had a strong positive correlation with the proportion of biomass in the fuel. The emission of VOCs under the condition of biomass blending has different characteristics from coal-fired boilers and biomass boilers. Under the two different mixing ratios, benzene series accounted for the largest proportion of VOCs emissions, reaching 44.38 % (20 %) and 33.75 % (40 %), respectively. The emission of benzene series is dominated by benzene and toluene, the emission of alkanes is dominated by n-hexane, and the emission of esters is dominated by ethyl acetate. The ozone formation potential (OFP) was analyzed by the maximum incremental reactivity method. The contribution of ozone generation potential at 20 % and 40 % mixing ratios was mainly from benzene series, which contributed 69.88 % and 70.24 %, respectively, and alkanes. contribution can also account for 25.76 % and 17.75 %.

Effects of different inhibitors on emission characteristics, environmental impact and health risk of volatile organic compounds from asphalt binder

Volatile organic compounds (VOCs) of asphalt will cause adverse environmental impact and workers’ health risk, inhibitors can be used to reduce the emission of VOCs from asphalt. Three inhibitors, including activated carbon (AC), expanded graphite (EG) and hydrotalcite (MA), were used to modified asphalt in this work. The effects of inhibitors on the VOCs emission characteristics of asphalt were investigated at multiple levels of VOCs total concentration, groups distribution and components characteristics. 101 asphalt VOCs components were detected, among which alkane accounted for more than 50% of the total concentration, followed by aldehyde and benzene. AC with the largest specific surface area and pore capacity exhibited the best inhibitory effect on the emission of VOCs with total concentration inhibition rate of 45.58%, followed by MA, while excessive MA would have adverse effect. Over 90% of VOCs components emissions had been suppressed by AC and EG. And inhibitors had the best inhibitory effect on the emission of olefin and aldehyde in VOCs, followed by ketone, but had the worst inhibitory effect on alkane, which was due to the weak interactions between non-polar alkane and polar hydroxyl on the surface of inhibitors. Furthermore, the effects of different inhibitors on the environmental impact and health risk of VOCs from asphalt were also systematically studied. The highest total inhibition rate of OFP and SOAP from asphalt VOCs by AC was only 58.3% and 21.7%, which was ascribed to the limited suppression on OFP and SOAP generated by alkane and benzene. Meanwhile, the non-carcinogenic risk from asphalt VOCs was mainly caused by acrolein with a contribution rate of 80.0%, AC and EG can completely inhibit the emission of acrolein in asphalt VOCs, while MA showed the poor performance. The contribution rate of acetaldehyde to the carcinogenic risk of asphalt VOCs reached 93.7%, while inhibitors had limited inhibitory effects on its emissions. This study contributes to a deeper understanding of the correlation mechanism between inhibitors, emission reduction characteristics of asphalt VOCs and environmental-health benefits, which could provide theoretical support for the design of bituminous material with low environmental-health load.

Emission inventories, emission factors, and composition profiles of volatile organic compounds (VOCs) and heavy metals (HMs) from an e-waste dismantling park in southern China

Electronic waste (e-waste) dismantling is a significant source of atmospheric pollutants, including volatile organic compounds (VOCs) and heavy metals (HMs), which may have adverse effects on the surrounding environment and residents. However, the organized emission inventories and emission characteristics of VOCs and HMs from e-waste dismantling are not well documented. In this study, the concentrations and components of VOCs and HMs were monitored at the exhaust gas treatment facility from two process areas of a typical e-waste dismantling park in southern China in 2021. Emission inventories of VOCs and HMs were established, with total emissions of 8.85 t/a and 18.3 kg/a for VOCs and HMs in this park, respectively. The cutting & crushing (CC) area was the largest emissions source, accounting for 82.6% of VOCs and 79.9% of HMs, respectively, while the baking plate (BP) area had higher emission factors. Additionally, the concentration and composition of VOCs and HMs in the park were also analyzed. For VOCs, the concentrations of halogenated hydrocarbons and aromatic hydrocarbons were comparable in the park, while m/p-xylene, o-xylene, and chlorobenzene were the key VOC species. The HM concentrations followed the order of Pb > Cu > Mn > Ni > As > Cd > Hg, with Pb and Cu being the main heavy metals released. This is the first VOC and HM emission inventory for the e-waste dismantling park, and our data will lay a solid ground for pollution control and management for the e-waste dismantling industry.

Review on Source Profiles of Volatile Organic Compounds (VOCs) in Typical Industries in China

The source profile of volatile organic compounds (VOCs) is essential for establishing reactivity- and toxicity-based emission inventories and developing effective air pollution control strategies. In this paper, the establishment of VOC source profiles and the VOC emission characteristics are reviewed in the petrochemical, solvent use, and chemical industries, and the most up-to-date profiles of the three industries in China are compiled via necessary adjustment and reconstruction of the test data from the literature. Alkanes dominated and OVOCs were often neglected in the overall petrochemical industry and refined processes. They accounted for 60.6% and 3.2% in the merged profiles. Aromatics and OVOCs dominated in the industrial solvent use industry. OVOCs were the most prevalent in the printing and dyeing industries, furniture manufacturing industries, and automobile coating process, whereas aromatics were major contributors of the total VOCs in metal surface coating, shipping coating, and other surface coating industries in the merged profiles. A wide range of products and limited profile studies were obtained in chemical industry, and the compositions of VOCs varied significantly in the production of 30 products in the merged profile. The future research directions of VOC source profiles are discussed, mainly focusing on the sampling, establishment, and evaluation of VOC profiles.

Impact of Water-Based Coating Substitution on VOCs Emission Characteristics for the Surface-Coating Industries and Policy Effectiveness: A Case Study in Jiangsu Province, China

As solvent-based coatings are gradually phasing out in China, the volatile organic compounds (VOCs) emission characteristics of surface-coating industries have changed rapidly. Sector-based field measurements were conducted to build VOCs emission factors and source profiles of surface-coating industries in Jiangsu Province. A VOCs emission inventory was developed, and the projections for 2020 to 2030 were set. It was found that VOCs content in water-based coatings is 50.8% of solvent-based coatings on average. VOCs emission factors of solvent-based coatings ranged from 0.40 to 0.51 kg kg−1, while those of water-based coatings ranged from 0.14 to 0.24 kg kg−1. Compared to solvent-based coatings, the proportion of aromatics emitted from water-based coatings was 44.2% lower, while the proportion of oxygenated VOCs (OVOCs) was 11.6% higher. The results showed that VOCs emissions were about 134 Gg in Jiangsu Province in 2020, of which the solvent-based coating sources contributed 79.6% of the total. Aromatics were the main species contributing 52.9% of VOCs emissions and 85.9% of ozone formation potential (OFP). According to emission prediction results of four scenarios, the emission reduction of implementing low-content VOCs coating substitution is 8.7% higher than that of adopting the best available end-of-pipe treatment measures by 2030.

Evolution and Characteristics of Full-process Vehicular VOCs Emissions in Tianjin from 2000 to 2020

Vehicle emissions are an important source of anthropogenic volatile organic compound (VOCs) emissions in urban areas and are commonly quantified using vehicle emission inventories. However, most previous studies on vehicle emission inventories have incomplete emission factors and emission processes or insufficient consideration of meteorological parameters. Based on the localized full-process emission factors attained from tested data and previous studies, a method to develop a monthly vehicular VOC emission inventory of full process for the long-term was established, which covered exhaust and evaporative emissions (including running loss, diurnal breathing loss, hot soak loss, and refueling emission). Then, the method was used to develop a full-process vehicular VOC emission inventory in Tianjin from 2000 to 2020. The results showed that the total vehicular VOC emissions in Tianjin rose slowly and then gradually decreased. In 2020, the total emissions were 21400 tons. The light-duty passenger vehicles were the dominant contributors and covered 75.00% of the total emissions. Unlike the continuous decline in exhaust emissions, evaporative emissions showed an inverted U-shaped trend with an increasing contribution to total emissions yearly, accounting for 31.69% in 2020. Monthly emissions were affected by both vehicle activity and emission factors. VOC emissions were high in autumn and winter and low in spring and summer. During the COVID-19 epidemic in 2020, vehicle activity was limited by closure and control, making VOC emissions significantly lower than those during the same period in previous years. The method and data in this study can provide technical reference and a decision-making basis for air pollution prevention and control.

Characteristics and environmental and health impacts of volatile organic compounds in furniture manufacturing with different coating types in the Pearl River Delta

Volatile organic compounds (VOCs) are essential pollutants affecting ambient air quality. In the Pearl River Delta of China, furniture manufacturing contributes significantly to VOCs emissions, mainly from coatings. Therefore, the source substitution of coatings is the most effective way to reduce VOCs emissions. In this study, eight typical furniture enterprises with five different coatings types (traditional solvent coatings (solvent and solvent ultraviolet (UV) coatings) and low VOCs content coatings (waterborne, waterborne UV, and powder coatings)) were selected for field monitoring to reveal differences in VOCs emission characteristics, environmental impacts and health risks between traditional solvent coatings and low-VOCs coatings. The results showed that solvent coating VOCs have the highest concentration (143.32 mg/m3) and are much higher than that of solvent UV coating (45.96 mg/m3) and other coatings (≤11.81 mg/m3). The highest proportion of VOCs of solvent (UV) coating is aromatic hydrocarbons (50.73% (44.05%)). While oxygenated VOCs rank first in low-VOCs coatings (47.81%–59.20%). Compared with other coatings, the solvent coating has the greatest contribution to the formation potential of ozone and secondary organic aerosols. Meanwhile, the solvent coating has the highest carcinogenic risk of ethylbenzene in the spraying workshop (8.53 × 10−6), and only solvent coating in the spraying workshop has the non-carcinogenic risk of xylene (1.07). Finally, through scenario analysis, the environmental benefits of low-VOCs coatings substituting solvent coating were quantified. The study will help accelerate the process of source substitution of coatings and promote cleaner production in the furniture industry.

Study on the Fingerprint and Atmospheric Activity of Volatile Organic Compounds from Typical Industrial Emissions

China is prone to severe surface ozone pollution in summer, so it is very important to understand the source of volatile organic compounds (VOCs) to control ozone formation. In this work, the emission characteristics of 91 VOC components from the plastic products industry, packaging and printing industries, printing ink industry, furniture manufacturing and vehicle manufacturing industries were studied. The results show that there are significant differences between these sources, and for the plastic products industry, alkanes (48%) are the most abundant VOCs. The main emission species in the packaging and printing industry are OVOCs (36%) and alkanes (34%). The proportion of OVOCs in the printing ink (73%) and furniture manufacturing industries (49%) is dominated by VOC emissions; aromatic hydrocarbons (33%), alkanes (33%), and OVOCs (17%) are the main emission species in the vehicle manufacturing industry. At the same time, the ozone generation potential (OFP) and secondary organic aerosol formation potential (SOA) of anthropogenic VOC emissions were evaluated, and the top 10 contributors to OFP and SOA were identified. Toluene, o-xylene, and m-xylene had a significant tendency to form OFP or SOA. Then, a health risk assessment of VOC components was carried out. These data can supplement the existing VOC emission characteristics of anthropogenic emissions, thus enriching the research progress of VOC emission sources.

Sector-based volatile organic compound emission characteristics and reduction perspectives for coating materials manufacturing in China

Coating materials manufacturing, with heavy use of organic raw materials and excipients, has become an important industrial source of ambient volatile organic compounds (VOCs). Effective control measures must be developed which rely on a complete understanding of both the current emission characteristics and future emission projections. Thus, a comprehensive whole-process method was proposed and local investigations and measurements were conducted to acquire the material balance-based emission factors (EFs) and sector-based VOC emission characteristics in China. Then, its historical emission trends were evaluated and future reduction perspectives were also projected. The results indicate that: (1) the non-controlled VOC EFs for different coatings were 80 g/kg solvent-based paint, 11 g/kg water-based paint, 49 g/kg varnish, 9 g/kg others (pigment, dyestuff, auxiliary), and 70 g/kg ink, respectively. (2) The VOC emissions increased from 0.34 Gg in 1949 to 872.72 Gg in 2018, and solvent-based paint was always the largest contributor (69–83%). Guangdong attributed the highest emissions (24.1%) in 2018, followed by Jiangsu (10.7%) and Sichuan (10.5%) provinces. The most abundant species were aromatics. (3) Disposal facility efficiency and VOC collection rate together determined the total process treatment efficiency. The disposal efficiency of adapted facilities could reach 90–99%, but the unmaintained or unsuitable facilities are more general and greatly reduced in efficiency. The collection rate could be up to >90% but only averaged about 40%. (4) Improving the treatment efficiency and expanding the market for green paint are the main pathways to reducing VOC emissions, and three scenarios were hereby set with increasing intensities. Compared to the non-controlled scenario, if basic or stringent control measures were fully implemented in China in 2030, the VOC emissions would be reduced by 70% or 81%, respectively.

Emission factors and source profiles of volatile organic compounds from typical industrial sources in Guangzhou, China

Volatile organic compounds (VOCs) are important precursors of ozone (O3) and fine particulate matter (PM2.5). An accurate depiction of the emission characteristics of VOCs is the key to formulating VOC control strategies. In this study, the VOC emission factors and source profiles in five industrial sectors were developed using large-scale field measurements conducted in Guangzhou, China (100 samples for the emission factors and 434 samples for the source profile measurements). The emission factors based on the actual measurement method and the material balance method were 1.6–152.4 kg of VOCs per ton of raw materials (kg/t) and 3.1–242.2 kg/t, respectively. The similarities between the emission factors obtained using these two methods were examined, which showed a coefficient of divergence (CD) of 0.34–0.72. Among the 33 subdivided VOC source profiles developed in this study, sources including light guide plate (LGP), photoresist mask, and plastic products were the first time developed in China. Due to regional diversities in terms of production technologies, materials, and products, the emission characteristics of the VOCs varied, even in the same sector, thereby demonstrating the importance of developing localized source profiles of VOCs. The ozone formation potential (OFP) of the shipbuilding and repair sector from fugitive emissions was the highest value among all the industrial sectors. Controlling the emissions of aromatics and OVOCs was critical to reducing the O3 growth momentum in industrial sectors. In addition, 1,2-dibromoethane showed high carcinogenic risk potentials (CRPs) during most of the industrial sectors and should be prioritized for controlling.

VOC Emission Characteristics of the Glass Deep-Processing Industry in China

To understand the pollution characteristics of volatile organic compounds (VOCs) in the glass deep-processing industry, samples were collected using polyvinyl fluoride bags and quickly transferred to summa tanks for GC/MS/FID analysis. The emission characteristics of VOCs, the ozone formation potential and the secondary aerosol formation potential were studied. The results showed that the VOCs emitted by the six enterprises were mainly aromatics and OVOCs, accounting for 35% to 97% of the emissions, with high emission loads of alkanes and halocarbons from individual enterprises. The stack emissions from Enterprise 2 were as high as 38 mg/m3, while the emissions from the remaining five enterprises were all in the range of 1.7~4.1 mg/m3, probably because the terminal treatment facilities were not updated in a timely manner, resulting in excessive stack emissions from Enterprise 2. The characteristic pollutants, including OVOCs, aromatics and alkanes, which are mainly derived from spray painting and gluing, were screened in the six enterprises. Aromatics and OVOCs contributed the most to the ozone formation potential in the six enterprises, with some enterprises having a high contribution from alkanes and alkenes. On the basis of the secondary aerosol formation potential, toluene, benzene, ethylbenzene, o-xylene and m/p-xylene account for 98% of the six enterprises’ emissions. Glass enterprises should prioritise the control of benzene and OVOCs emissions. The glass processing industry mainly emits aromatics, OVOCs and alkanes. Through a preliminary study on the emission characteristics of VOCs in the glass deep-processing industry, we provided basic data for the reduction and control of VOCs in the glass deep-processing industry in China.

Emission characteristics of volatile organic compounds from regenerated PET fibers based on the headspace gas chromatograph

AbstractThe emission behaviors of volatile organic compounds (VOCs) can be characterized by the key parameters: the initial concentration (m0), partition coefficient (K) and the diffusion coefficient (D). The MHE‐GC method was validated to determine the emission characteristics of VOCs (Benzene, Toluene, Ethylbenzene, P‐xylene, M‐xylene, Styrene, and O‐xylene) in regenerated PET fibers. This work has studied the effects of fiber size, sample weight incubation time and incubation temperature on the detection of these VOCs. It showed finer fiber sample with less sample facilitated the emission of VOCs in fibers above detectable limit. The optimized headspace incubation time, fiber sample weight, and headspace incubation temperature were selected as 60 min, about 0.8 g and 110 °C, respectively. In addition, incubation temperature has a negative effect on the gas/fiber partition coefficient. The fibers with greater fineness showed higher activation energy, which revealed a positive release of VOCs from fibers. The relative standard deviation (RSD/%) of detection was 3%–10%. The present method is reliable and suitable for use in testing of the VOCs content in fiber‐related materials.

Characteristics and source profiles of atmospheric volatile organic compounds (VOCs) in the heavy industrial province of Northeast China with cruise monitoring

As key precursors of tropospheric ozone (O3) pollution, volatile organic compound (VOC) pollution and related studies in China are mainly concentrated in developed regions or metropolises, while there are few studies on VOC pollution in the heavy industrial base in Northeast China. This study conducted a systematic survey of VOCs’ information for the first time in Jilin Province, covering eight prefecture-level cities, ten major industries (e.g., petrochemical, chemical), and 130 major factories, based on cruise monitoring for 2 months. The concentrations and compositions (i.e., 65 species) of VOC were measured in real-time. The emission characteristics of VOC, local source profiles, and the ozone formation potential (OFP) were further analyzed to support O3 pollution control in Northeast China. On the provincial scale, the concentrations of total VOC during the monitoring period ranged from 0.03 to 18321.5 μg/m3, and averaged at 607.9 ± 2051.8 μg/m3. Among the prefecture-level cities, Jilin City had the highest concentration level (1938.0 ± 3811.3 μg/m3) given the largest numbers of petrochemical factories, and the lowest level (85.5 ± 48.9 μg/m3) was found in Liaoyuan City. At the industrial scale, the highest (1915.2 ± 1842.6 μg/m3) was detected in the petrochemical industry with a major species of 1,1,2,2-tetrachloroethane. The lowest VOC emission concentration levels were found in the textile industry (57.8 ± 44.6 μg/m3; major species: xylene/ethylbenzene). Local source profiles in various industries were established, and normalized OFP of corresponding species was calculated, which are important parameters to evaluate the contribution of different VOC sources to O3 pollution. Combined with provincial industrial structure and future planning, we suggest two major industries including the chemical industry and petrochemical industry in Changchun City and Jilin City are prior to being optimized to reduce O3 pollution. This study contributes to the knowledge of the characteristics and source profiles of VOC emissions, providing an important reference for the management or control of O3 pollution in Northeast China.