Control Of Volatile Organic Compounds Emissions Research Articles

Analysis of the source of abnormal odor components in medium-density fiberboard (MDF)

ABSTRACT To investigate the cause of the abnormal odor emitted by medium-density fiberboard (MDF) when formaldehyde-free diphenylmethane diisocyanate (MDI) adhesive is used, a comparative study of three types of MDF was conducted: MDF made with masson pine wood and MDI adhesive (PW-MDI), MDF made with masson pine wood and urea-formaldehyde resin (PW-UF), and MDF made with mixed hardwoods and MDI adhesive (HW-MDI). Volatile organic compounds (VOCs) emitted were collected and analyzed using gas chromatography-mass spectrometry (GC-MS), identifying 86 VOCs. Results reveal that the PW-MDI specimen contains a higher concentration of acid substances, comprising 56% of the specimen. These acid mainly octanoic and nonanoic acids, were the primary contributors to its abnormal odor. In contrast, the PW-UF and HW-MDI specimens were predominantly composed of alcohol substances, accounting for 33% and 36% respectively. Gas chromatography-ion mobility spectrometry (GC-IMS) was used to obtain VOC fingerprints. Analysis revealed that acids and aldehydes are the primary contributors to the relative odor activity value (ROAV). These compounds are known for their abnormal odor that impact the indoor air quality. This research successfully identified the source of the abnormal odor and provided technical support for the effective control of low abnormal odor VOC emissions from MDF.

The Structures and Compositions Design of the Hollow Micro-Nano-Structured Metal Oxides for Environmental Catalysis.

In recent decades, with the rapid development of the inorganic synthesis and the increasing discharge of pollutants in the process of industrialization, hollow-structured metal oxides (HSMOs) have taken on a striking role in the field of environmental catalysis. This is all due to their unique structural characteristics compared to solid nanoparticles, such as high loading capacity, superior pore permeability, high specific surface area, abundant inner void space, and low density. Although the HSMOs with different morphologies have been reviewed and prospected in the aspect of synthesis strategies and potential applications, there has been no systematic review focusing on the structures and compositions design of HSMOs in the field of environmental catalysis so far. Therefore, this review will mainly focus on the component dependence and controllable structure of HSMOs in the catalytic elimination of different environmental pollutants, including the automobile and stationary source emissions, volatile organic compounds, greenhouse gases, ozone-depleting substances, and other potential pollutants. Moreover, we comprehensively reviewed the applications of the catalysts with hollow structure that are mainly composed of metal oxides such as CeO2, MnOx, CuOx, Co3O4, ZrO2, ZnO, Al3O4, In2O3, NiO, and Fe3O4 in automobile and stationary source emission control, volatile organic compounds emission control, and the conversion of greenhouse gases and ozone-depleting substances. The structure-activity relationship is also briefly discussed. Finally, further challenges and development trends of HSMO catalysts in environmental catalysis are also prospected.

Emissions of volatile organic compounds from Chinese coal-fired power plants: Characteristics, source profile, inventories, and impacts

Volatile organic compounds (VOCs) are key precursors for secondary organic aerosols (SOA) and ozone, imposing severe impacts on human health and environment. Considering the massive coal consumption, coal fired power plants (CFPPs) in China are non-negligible VOCs contributors, whose emission characteristics remain inadequately understood. Here, we investigated emission characteristics of 117 VOCs by field tests in four typical CFPPs, and a latest localized CFPPs source profile was compiled by integrating literature reviews. Then speciated-VOCs emission inventories for 2018–2022 were established based on dynamic emission factors and unit-level activity data. The results suggested that oxygenated VOCs (OVOCs) constituted the dominant group (76.5 %), with propionaldehyde (32.0 %) and formaldehyde (24.5 %) being the predominant species. OVOCs (93.2 %) and aromatics (77.4 %) were identified as the primary contributors to ozone and SOA, respectively. Driven by both the rise in coal consumption and technological advancements, nationwide VOCs emissions decreased from 83,393 t in 2018 to 53,251 t in 2022. Regional disparities and varying rates of decline in provincial emissions were evident, with VOCs emissions predominantly concentrated in northern and eastern provinces. Neimenggu, Shandong, Shanxi, Jiangsu, and Guangdong were identified as the top five provinces with the highest emissions. We believe this study would be conducive to a more comprehensive understanding and effective control of VOCs emissions from CFPPs in China.

Ozone Pollution in Suzhou During Early Summertime: Formation Mechanism and Interannual Variation

This study investigated the concentrations of atmospheric pollutants in the urban area of Suzhou from May to June, 2017-2021. The variation characteristics and annual changes of ozone (O3), nitrogen oxide (NOx), total oxidant (Ox), carbon monoxide (CO), and volatile organic compounds (VOCs) were analyzed. The O3 formation mechanism and its annual changes were studied using an Observation-Based Model (OBM), and VOCs source apportionments and their trends were discussed. The results indicated that ① The volume fractions of Ox and the concentrations of NOx and CO have decreased in the urban area of Suzhou in recent years, while the volume fractions of VOCs have increased, and sufficient photochemical conditions for O3 formation still existed during polluted days. ② The O3-NOx-VOCs sensitivity in Suzhou was in the VOCs-limited regime. The long-term reduction ratio between VOCs and NOx should not be less than 5:1, and aromatics and alkenes were the critical VOCs for mitigating O3 pollution. ③ The results of VOCs source apportionment revealed that industrial emissions, gasoline vehicle exhaust, and diesel engine exhaust were the major sources of VOC emissions in Suzhou. Industrial emissions and solvent usage declined from 2017 to 2021; however, gasoline vehicle exhaust and gasoline evaporation, which possess higher O3 formation potential(OFP), increased significantly. ④ The OFP source apportionments results indicated that controlling VOC emissions from solvent usage and gasoline vehicle exhaust is crucial for O3 pollution control in Suzhou.

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.

Catalytic Oxidation Mechanism of Toluene on the Ce0.875Zr0.125O2 (110) Surface

Aromatic volatile organic compounds (VOCs) are toxic to public health and contribute to global air pollution; thus, it is urgent to control VOC emissions. Catalytic oxidation technology has been widely investigated to eliminate aromatic VOCs; this technology exhibits high catalytic efficiency even at low temperatures. However, the reaction mechanism of aromatic VOCs’ total oxidation over metal-oxide-based catalysts, which is of great significance in the design of catalysts, is not yet clear. In this study, we systemically calculated the catalytic oxidation mechanism of toluene over the Ce0.875Zr0.125O2 catalyst using density functional theory (DFT). The results show that toluene first loses hydrogen from the methyl group via oxy-dehydrogenation and is gradually oxidized by lattice or adsorbed oxygen to benzyl alcohol, benzaldehyde, and benzoic acid following the Mars-van Krevelen (MVK) mechanism. Afterwards, there is a decarboxylation step to produce phenyl, which is further oxidized to benzoquinone. The rate-determining step then proceeds via the ring-opening reaction, leading to the formation of small molecule intermediates, which are finally oxidized to CO2 and H2O. This work may provide atomic-scale insight into the role of lattice and adsorbed oxygen in catalytic oxidation reactions.

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.

Inhibition effect of three types of biochar on volatile organic compounds from asphalt: Revealing chemical adsorption as the primary mechanism

For advancing sustainable and eco-friendly road materials, addressing the emissions of volatile organic compounds (VOCs) from asphalt binders is paramount. As an environment-friendly adsorbent, biochar is highly promising for mitigating such VOCs emissions. Herein, the feasibility and mechanism of using biochar to control VOCs emissions from asphalt were investigated. Biochar was derived from rice husk, straw and coffee grounds. The VOCs composition was analysed using thermal desorption–gas chromatography–mass spectrometry. Differential scanning calorimetry was employed to simulate asphalt VOCs release, while temperature-programmed desorption spectroscopy was employed to investigate biochar inhibition. Rice husk–derived biochar exhibited the highest inhibition effect on asphalt VOCs. The inhibitory effects of the three biochar samples were weakened with increasing number of carbon atoms in organic compounds, with less ideal inhibition efficiency for aromatic compounds. Chemical adsorption was the primary mechanism for the inhibition of VOCs emissions by biochar at high temperatures.

Benchmark of plant-based VOCs control effect for indoor air quality: Green wall case in smith campus at Harvard University

The emission of volatile organic compounds (VOCs) from interior materials can significantly impact people's health and daily activities, necessitating effective management. In the construction of the interior built environment, plants serve as a suitable means to enhance air quality. They not only function as ecological living materials for air purification and VOCs removal but are also valued for their aesthetic appeal. However, often the emphasis in designing green infrastructure is placed more on the aesthetics of planting design rather than considering plants' ecological properties. This research examines the ability of 12 plant species used in the interior green wall design at Harvard University's Smith Center as a case study to decompose and absorb VOCs through experimental studies. By integrating ecological properties and key factors such as spatial and budget constraints into the design process, this research explores the potential of using an algorithmic model to select plant species capable of reducing interior VOC pollution in green wall design. The significance of this study lies in its contribution to indoor environmental health and environmental management practices through providing a potential plant selection model and suggesting a relevant workflow for interior planting design with the goal of controlling VOC emissions. By leveraging the knowledge gained from experiments on the VOC removal abilities of selected plant species, this study offers a valuable resource for practitioners seeking to create innovative indoor air cleaning and decontamination technologies.

Volatile organic compounds conversion pathways and odor gas emission characteristics in chicken manure composting process

IntroductionComposting is a highly effective method for managing the growing quantity of agricultural waste, promoting nutrient recycling, and advancing sustainable agriculture. However, the significant amounts of volatile inorganic compounds (VICs) and volatile organic compounds (VOCs) generated during the composting process cannot be ignored due to their serious ecological environmental hazards and detrimental impact on human health. The types and pathways of VICs and VOCs produced during the composting process remain not well understood.MethodsIn this study, we investigated the VOCs produced during chicken manure and straw composting using gas chromatography–mass spectrometry (GC/MS). We performed qualitative and quantitative analyses of VOCs in composting emissions gases and their correlation with odor.ResultsOur results showed that 44 VOCs were detected during composting, including 4 oxidation-containing compounds, 2 sulfur-containing organics, 5 alkanes, 19 halogenated compounds, and 14 aromatic compounds. Aromatic compounds were found to be the main component of VOCs, accounting for 59.14% of the total content. The highest VOC content was found in the pre-composting period, and the highest emitting VOC was p-Isopropyl Toluene, which reached 7870.50 μg/m3. We identified eight substances that were highly correlated with odor concentration (p < 0.01) and are the main odor-causing substances that need to be monitored and controlled.DiscussionOur study provides important insights into the transformation of volatile gases during the composting process. It highlights the need for proper management practices to control VOCs emissions and reduce their environmental impact.

The volatile organic compounds emission mechanism of pretreated bamboo during heat treatment

Heat treatment can be used to improve bamboo product quality. Pretreatment of the bamboo material can reduce the energy consumption of heat treatment. However, large quantities of volatile organic compounds (VOCs) are released during the bamboo heat treatment process, causing potential problems for the environment and human health. In this study, the effects of pretreatment with sodium hydroxide and zinc chloride solutions on VOCs emissions during heat treatment were investigated. We also explored chemical and structural changes of heat-treated bamboo. The VOCs released by untreated bamboo during heat treatment were mainly aldehydes, alcohols, alkanes, and esters. Alcohol and alkane contents decreased as treatment temperature increased, accompanying the emergence of more complex chemicals. Compared with untreated bamboo, sodium hydroxide pretreatment destroyed the hemicellulose structure, released stable VOCs under heat treatment, and did not produce acidic compounds; ether compounds increased significantly with increase in temperature. The catalysis of zinc chloride pretreatment degraded hemicellulose during heat treatment. The relative contents of aldehydes and esters released from zinc chloride pretreated bamboo during heat treatment increased significantly with temperature. Up to 69.76 % of aldehyde compounds were released at 160 °C, among which the relative proportion of furfural reached 37.23 %. These results may provide theoretical support for controlling VOCs emissions from different pretreated bamboo materials during heat treatment, which is also conducive to the subsequent recycling of VOCs.

Chemical Composition of VOCs from Service Stations Vapor Processing Device and Associated Contributions to Secondary Pollution

Vapor processing device is a device that can control the headspace pressure in the underground storage tanks and recover the vapor. By analyzing the chemical composition of volatile organic compounds (VOCs) at the inlet and outlet of the vapor processing device, the ozone formation potential (OFP) and secondary organic aerosol formation potential (SOAP) were estimated by maximum incremental reaction (MIR) and fractional aerosol coefficients (FAC), and the secondary pollution formation contribution of VOCs were quantitatively evaluated. The results showed that:① the ρ(total volatile organic compounds, TVOC) at the inlet and outlet of the vapor processing device were 436-706 g·m-3 and 4.98-10.04 g·m-3, respectively. Alkanes (72%±4%), oxygenated organics (14%±2%), and olefins (11%±5%) were the dominant components of VOCs emissions. There were little differences in VOCs emissions from the different vapor processing devices; the key species were i-pentane (approximately 25%), followed by n-butane, i-butane, and n-pentane. ② The ozone source reactivity (SR) of VOCs emissions from the outlet of the vapor processing device was 2.6-3.3 g·g-1, and the OFP was 3.5-25.6 g·m-3. Olefins contributed the most (43%-69%), followed by alkanes (20%-35%) and oxygenated organics (10%-22%). Butene, cis-2-butene, trans-2-butene, i-pentane, and propionaldehyde were the species that highly contributed to OFP. ③ Aromatics in VOCs emissions contributed the most to SOAP (80%-92%), and the main active species were toluene, 1, 2, 4-trimethylbenzene, 1, 3, 5-trimethylbenzene, and p-diethylbenzene. The research showed that different VOCs species emitted by the vapor processing device contributed obvious differences to the secondary atmospheric pollution, and butene species and aromatics such as toluene were the focus of VOCs emission control of vehicle gasoline and vapor processing device.

Characteristics, chemical transformation and source apportionment of volatile organic compounds (VOCs) during wintertime at a suburban site in a provincial capital city, east China

Based on the continuous online measurements of volatile organic compounds (VOCs) at a suburban site in Jinan, Shandong province in the wintertime of 2021, characteristics, chemical transformations and sources of VOCs were analyzed. The total mixing ratio of VOCs was 30.35 ± 19.9 ppbv, with alkanes being the most abundant species. Alkenes and aromatics were the major contributors to the hydroxyl radical loss rate (LOH) and the ozone formation potential (OFP), accounting for 44.9% and 32.7% to LOH, and 43.2% and 33.4% to OFP, respectively. Aromatics had the primary contribution (98.1%) to the secondary organic aerosol potential (SOAP), and the high correlation between SOAP and PM2.5 concentrations (R = 0.70) suggested that VOCs were critical precursors of PM2.5. Coal/biomass burning and motor vehicle emissions were the main sources of VOCs (24.6% and 23.8%, respectively), followed by petrochemical and fuel evaporation (19.9%), industrial sources (16.9%), and liquefied petroleum gas/natural gas use (14.8%). Backward trajectories and the potential source contribution function (PSCF) analysis results suggested that short-range transport from the southeast was the primary potential source of VOC concentrations in suburban Jinan. The results can provide theoretical support for local governments to develop VOC emission control strategies in suburban areas.

Regulation and impact of VOC and CO2 emissions on low‐carbon energy systems resilient to climate change: A case study on an environmental issue in the oil and gas industry

AbstractThe impact of emissions from the fuel and energy sectors adversely affects the environment on the economies of countries. One of these pollutants is volatile organic compounds (VOCs), which contribute to the formation of tropospheric ozone. Emissions of hydrocarbon formation in the form of VOCs occur in four stages of the fuel and energy industry sector: (1) production, (2) processing, (3) transportation, and (4) storage. The oil and gas industry ranks among the top polluting industries in terms of VOC emissions. Research on the negative impact of VOCs, as well as CO2 emissions from the consequences of the extraction, processing, transport, and storage of oil and gas on the ecosystem of the planet and the population, has begun to be studied by science recently. Typically, these studies were conducted using laboratory and field analyses, as well as using data on anthropogenic emissions in the development of regulatory documents and requirements governing the control of VOC and CO2 emissions in the oil and gas industry. This paper presents a critical analysis of the literature on research on the negative effects of VOC emissions on the ecosystem and human health because of such factors as production, processing, transportation, and storage of hydrocarbons. This analysis shows the global magnitude of VOC emissions. Data from human‐made emissions from the oil and gas industry and direct emissions from transportation and energy processing were used to figure out how VOCs affect the environment around the world and how far they spread. In conclusion, this study found patterns of VOC emissions that show how important it is to control VOCs during the production, processing, transportation, and storage of oil and gas, as well as how important it is to create a single research base on emissions for each industry sector and on sources of greenhouse gas absorption.

Thermal-Driven Optimization of the Strong Metal-Support Interaction of a Platinum-Manganese Oxide Octahedral Molecular Sieve to Promote Toluene Oxidation: Effect of the Interface Pt2+-Ov-Mnδ.

Strong metal-support interactions (SMSIs) have a significant effect on the performance of supported noble-metal catalysts for volatile organic compound (VOC) elimination. Herein, the strength of the SMSI of Pt/OMS-2 between Pt and the OMS-2 support is regulated by simply changing calcination temperatures, and the catalyst calcined at 300 °C (Pt/OMS-2-300) performs the best in the catalytic combustion of toluene. Through systematic structural characterizations, it is revealed that much more Pt2+-Ov-Mnδ+ species are formed in Pt/OMS-2-300, which can help facilitate the generation of more reactive oxygen species and promote lattice oxygen mobility. Moreover, the results of in situ DRIFTS experiments further confirm that abundant Pt2+-Ov-Mnδ+ species at the Pt-MnO2 interface on Pt/OMS-2-300 can better enhance the adsorption and activation of toluene, thus boosting the catalytic performance in toluene combustion. This newly developed strategy of thermal-driven regulation of the SMSI provides a novel perspective for constructing highly efficient catalysts for VOC emission control.

Environmental impact assessment of VOC emissions from biomass gasification power generation system based on life cycle analysis

The control of volatile organic compounds (VOC) is one of the key challenges in biomass combustion. This study aims to establish a process-based model to assess the life cycle VOC emissions of a biomass gasification power plant in China. In this study, the life cycle assessment (LCA) method was used for the first time to evaluate the direct VOC emissions and indirect VOC emissions from biomass gasification power generation. The whole system consists of three parts: biomass waste feedstock system, gasification power generation system and waste treating system. And waste treatment mainly includes waste water treatment and waste gas treatment. Results show that the life cycle VOC emissions intensity from the biomass gasification power generation process as a whole are calculated as 57.05 g/MWh, without considering the influence of air pollution control devices’ (APCDs). With the implementation of APCDs, this value will be reduced to 7.08 to 22.83 g/MWh, reducing by 12.41 to 40.02 %. In the scenario analysis, APCDs with different combinations of installations are evaluated by applying the practical engineering applications. The scenario of selective catalytic reduction (SCR) and wet electrostatic precipitation (WESP) can achieve the best removal effect, under which VOC emissions intensity can achieve 34.22 g/MWh, and the indirect emissions account for 46.15 % of life cycle VOC emissions, which are mainly from wastewater treatment process. The photochemical ozone generation potential and ozone layer depletion potential from emitted VOC are the two largest in this scenario, accounting for 17.71 % and 8.59 % respectively. If all open burning and indoor combustion of biomass in China can be replaced by the biomass gasification power generation technology, the relevant national VOC emissions reduction potential could reach up to 1.95 Mt/year. Among all the provinces, Heilongjiang, Anhui, Henan, Shandong and Jilin are the five provinces with the highest VOC emissions reduction potential. The influence of key input variables on overall VOC emission is also analyzed in this study. Based on the results, the optimal direction and possible measures to reduce VOC emission are put forward. This study is of great significance for the accurate control of VOC emissions in biomass gasification power generation technology.

In Situ Fabrication of Highly Dispersed Co-Fe-Doped-δ-MnO2 Catalyst by a Facile Redox-Driving MOFs-Derived Method for Low-Temperature Oxidation of Toluene.

Cost-efficient and durable manganese-based catalysts are in great demand for the catalytic elimination of volatile organic compounds (VOCs), which are dominated not only by the nanostructures but also by the oxygen vacancies and Mn-O bond in the catalysts. Herein, a series of nanostructured Co-Fe-doped-δ-MnO2 catalysts (Co-Fe-δ-MnO2) with high dispersion were in situ fabricated by employing metal-organic-frameworks (MOFs) as reducing agents, dopants, and templates all at the same time. The as-obtained Co-Fe-δ-MnO2-20% catalyst exhibited robust durability and high catalytic activity (225 °C) for toluene combustion even in the presence of 5 vol % water vapor, which is 50 °C lower than that of pristine δ-MnO2. Various characterizations revealed that the homogeneously dispersed codoping of Co and Fe ions into δ-MnO2 promotes the generation of oxygen vacancies and weakens the strength of the Mn-O bond, thus increasing the amount of adsorbed oxygen (Oads) and improving the mobility of lattice oxygen (Olatt). Meanwhile, due to successfully inheriting the framework structures of MOFs, the obtained catalyst exhibited a high surface area and three-dimensional mesoporous structure, which contributes to diffusion and increases the number of active sites. Moreover, in situ DRIFTS results confirmed that the toluene degradation mechanism on the Co-Fe-δ-MnO2-20% follows the MVK mechanism and revealed that more Oads and high-mobility Olatt induced by this novel method contribute to accumulating and mineralizing key intermediates (benzoate) and thus promote toluene oxidation. In conclusion, this work stimulates the opportunities to develop Co-Fe-δ-MnO2 as a class of nonprecious-metal-based catalysts for controlling VOC emissions.

Estimation of Anthropogenic VOCs Emission Based on Volatile Chemical Products: A Canadian Perspective.

Volatile organic compounds (VOCs) in urban areas are of great interest due to their significant role in forming ground-level ozone and adverse public health effects. Emission inventories usually compile the outdoor VOCs emission sources (e.g., traffic and industrial emissions). However, considering emissions from volatile chemical products (e.g., solvents, printing ink, personal care products) is challenging because of scattered data and the lack of an effective method to estimate the VOCs emission rate from these chemical products. This paper aims to systematically analyse potential sources of VOCs emission in Canada's built environment, including volatile chemical products. Also, spatial variation of VOCs level in the ambient atmosphere is examined to understand the VOC relationship with ozone and secondary organic aerosol formation. The study shows that VOCs level may vary among everyday microenvironments (e.g., residential areas, offices, and retail stores) depending on the frequency of product consumption, building age, ventilation condition, and background ambient concentration in the atmosphere. However, it is very difficult to establish VOC speciation and apportionment to different volatile chemical products that contribute most significantly to exposure and target subpopulations with elevated levels. Thus, tracer compounds can be used to identify inventory sources at the consumer end. A critical overview highlights the limitations of existing VOC estimation methods and possible approaches to control VOC emissions. The findings provide crucial information to establish an emission inventory framework for volatile chemical products at a national scale and enable policymakers to limit VOCs emission from various volatile chemical products.

VOC emission caps constrained by air quality targets based on response surface model: A case study in the Pearl River Delta Region, China

Because of the recent growth in ground-level ozone and increased emission of volatile organic compounds (VOCs), VOC emission control has become a major concern in China. In response, emission caps to control VOC have been stipulated in recent policies, but few of them were constrained by the co-control target of PM2.5 and ozone, and discussed the factor that influence the emission cap formulation. Herein, we proposed a framework for quantification of VOC emission caps constrained by targets for PM2.5 and ozone via a new response surface modeling (RSM) technique, achieving 50% computational cost savings of the quantification. In the Pearl River Delta (PRD) region, the VOC emission caps constrained by air quality targets varied greatly with the NOx emission reduction level. If control measures in the surrounding areas of the PRD region were not considered, there could be two feasible strategies for VOC emission caps to meet air quality targets (160 µg/m3 for the maximum 8-hr-average 90th-percentile (MDA8-90%) ozone and 25 µg/m3 for the annual average of PM2.5): a moderate VOC emission cap with <20% NOx emission reductions or a notable VOC emission cap with >60% NOx emission reductions. If the ozone concentration target were reduced to 155 µg/m3, deep NOx emission reductions is the only feasible ozone control measure in PRD. Optimization of seasonal VOC emission caps based on the Monte Carlo simulation could allow us to gain higher ozone benefits or greater VOC emission reductions. If VOC emissions were further reduced in autumn, MDA8-90% ozone could be lowered by 0.3-1.5 µg/m3, equaling the ozone benefits of 10% VOC emission reduction measures. The method for VOC emission cap quantification and optimization proposed in this study could provide scientific guidance for coordinated control of regional PM2.5 and O3 pollution in China.

Study on Volatile Organic Compound (VOC) Emission Control and Reduction Potential in the Pesticide Industry in China

The pesticide industry is one of the primary industries with large and complex VOC emissions. The present study examined the emission characteristics and whole-process control of VOCs in the pesticide industry in China by reviewing pollutant discharge permits, questionnaires, and site investigations. After evaluating the effectiveness of current treatment technologies, the potential of VOC emission reduction in China was analyzed. The results indicate that there are 41 key VOC substances in the pesticide industry that should be given considerable attention. Among treatment facilities, incineration was found to be the most efficient technology, with a removal rate of 53–98% and coverage rate of 23.3%. Multistage absorption–adsorption is a universal technology that had a removal rate of 35–95% and coverage rate of 64.14%. Multistage absorption was used most frequently, with a coverage rate of 71.99%, but its removal rate was between 16 and 85%. Pesticide factories were divided into three levels according to their pollution control capability; the comprehensive removal rates of benchmark, moderate, and poor factories were 81%, 46%, and 8%, respectively, and the emission reduction ratios for high, moderate, and low targets were 41.55%, 32.12%, and 24.32% with corresponding emission reduction costs of $0.653, $0.505, and $0.038 billion/year. The results and prospects from this study will provide support for policy development in industrial VOC emission control in China during the “14th Five-Year Plan” period.