Co_(3)O_(4)as an efficient passive NO_(x) adsorber for emission control during cold-start of diesel engines

The Co_(3)O_(4)nanoparticles,dominated by a catalytically active(110)lattice plane,were synthesized as a low-temperature NO_(x) adsorbent to control the cold start emissions from vehicles.These nanoparticles boast a substantial quantity of active chemisorbed oxygen and lattice oxygen,which exhibited a NO_(x) uptake capacity commensurate with Pd/SSZ-13 at 100℃.The primary NO_(x) release temperature falls within a temperature range of 200-350℃,making it perfectly suitable for diesel engines.The characterization results demonstrate that chemisorbed oxygen facilitate nitro/nitrites intermediates formation,contributing to the NO_(x) storage at 100℃,while the nitrites begin to decompose within the 150-200℃range.Fortunately,lattice oxygen likely becomes involved in the activation of nitrites into more stable nitrate within this particular temperature range.The concurrent processes of nitrites decomposition and its conversion to nitrates results in a minimal NO_(x) release between the temperatures of 150-200℃.The nitrate formed via lattice oxygen mainly induces the NO_(x) to be released as NO_(2) within a temperature range of 200-350℃,which is advantageous in enhancing the NO_(x) activity of downstream NH_(3)-SCR catalysts,by boosting the fast SCR reaction pathway.Thanks to its low cost,considerable NO_(x) absorption capacity,and optimal release temperature,Co_(3)O_(4)demonstrates potential as an effective material for passive NO_(x) adsorber applications.

China's Total Emission Control Policy:a Critical Review

As part of a comprehensive environmental management system, many countries establish emission control targets for mass emissions of a pollutant. Such targets are often the key objective of an environmental policy, such as an emission trading program. In China, however, it is more than just an objective of one particular policy; it has become a concept that has influenced many national environmental policies and activities. The objective of this article is to review the implementation of the total emission control policy in the past 10 years and explore emerging issues in its implementation. The article has three sections: a summary of the implementation experience, issues with the design and implementation of the policy, and policy recommendations.

Novel Oxygen Storage Components Promoted Palladium Catalysts for Emission Control in Natural Gas Powered Engines

A three-way catalyst comprised novel oxygen storage components for emission control in natural gas powered engines was prepared. The addition of novel oxygen storage components to the Pd/γ-Al2O3 catalysts resulted in improved activities of the fresh and aged catalyst by lowering the light-off temperature for methane in natural gas engines exhaust.

Eureka Webair： Web-Based Air Quality Management, Real-Time Forecasting and Emission Control Optimization

For the assessment and management of regional to local air quality, an integrated environmental management information system was built within the multi national Eureka project 3266 Webair, http：//www.ess.co.at/WEBAIR. The system combines data bases and GIS and a range of coupled models and analytical tools that address a range of typical management problems and cover several levels of nesting from regional to city level and street canyons. The main functions are to support regulatory tasks, compliance monitoring, operational forecasting and reporting, impact assessment EIA （environmental impact assessment）, SEA （strategic environmental assessment） and public information within one consistent framework. A major objective is the improvement of air quality through emission control. The integrated model system together with its shared data bases provides a reliable, consistent basis for the non-linear techno-economic and multi-criteria optimization of emission control strategies （including greenhouse gases and energy efficiency）. A real-time expert system drives, supports and monitors the autonomous and interactive operations, and provides embedded QA/QC （quality assurance/quality control） functions for reliable operations and ease of use.

COMPOSITIVE EMISSION CONTROL SYSTEM OF GASOLINE VEHICLE

The working principle of a kind of compositive emission control system is inquired into, which includes exhaust heater, secondary air supplement, exhaust gas recirculation （EGR）, thermal reactor and catalytic converter, etc. The purification effect of CO, HC and NOx emission of the gasoline spark ignite （S.I.） engine is studied. The entire vehicle driving cycle tests based on the national emission standard and a series of the gasoline engine-testing bench tests including full load characteristic experiment, load characteristic experiment and idle speed experiment are done. The results show that the system has a very good emission control effect to CO, HC and NOx of gasoline engine. The construction of the system is very simple and can be mounted on the exhaust pipe conveniently without any alteration of the vehicle-use gasoline engine.

Sulfur Dioxide Emission Control,Blockade and Drainage

This paper presents the present status of sulfur dioxide emission from thermal plants in China, tells the main problems existing in its emission control and finally gives out suggestions to the problems, that is, to constitute complete standards and regulations and enhancesupervision accordingly.

The Future of Quasi Emission Control Enterprises in a Low-Carbon Economy

At 9:30 a.m.on July 16,2021,the national carbon emission trading market started operation at Shanghai Environment and Energy Exchange.On the first day,the carbon emission quota totaled 4.244 million tons,with a turnover of 210 million yuan and an average transaction price of 51.23 yuan/ton.The carbon trading price is on the rise.With the gradual maturity and improvement of conditions,there will be about 8,000 to 10,000 emission control enterprises under the eight major industries in the future,and China’s carbon market will become the largest market covering greenhouse gas emissions worldwide.It can be seen that carbon trading is a“big deal.”If enterprises participate well,they will form carbon assets,but if they do not participate well,they will form carbon liabilities.This paper analyzes the opportunities and challenges faced by quasi emission control enterprises under the background of low-carbon economy.This provides certain reference significance for these enterprises to actively participate in the national carbon trading market in the future.

Advances in emission control of diesel vehicles in China

Diesel vehicles have caused serious environmental problems in China.Hence,the Chinese government has launched serious actions against air pollution and imposed more stringent regulations on diesel vehicle emissions in the latest China VI standard.To fulfill this stringent legislation,two major technical routes,including the exhaust gas recirculation(EGR)and high-efficiency selective catalytic reduction(SCR)routes,have been developed for diesel engines.Moreover,complicated aftertreatment technologies have also been developed,including use of a diesel oxidation catalyst(DOC)for controlling carbon monoxide(CO)and hydrocarbon(HC)emissions,diesel particulate filter(DPF)for particle mass(PM)emission control,SCR for the control of NOx emission,and an ammonia slip catalyst(ASC)for the control of unreacted NH3.Due to the stringent requirements of the China VI standard,the aftertreatment system needs to be more deeply integrated with the engine system.In the future,aftertreatment technologies will need further upgrades to fulfill the requirements of the near-zero emission target for diesel vehicles.

A review and evaluation of nonroad diesel mobile machinery emission control in China

China’s emission control for nonroad diesel mobile machinery(NDMM)must deal with a fast increase in stock as well as regulations that are two decades behind those for on-road vehicles.This study provides the first large-scale review and evaluation of China’s NDMM policies,along with emission measurements and an investigation on diesel fuel quality.The sulfur contents of the investigated diesel declined from 430 ppm(median value)in 2011 to6-8 ppm during the 2017-2018 period.The emission control of NO_(x)and PM greatly improved with the shift from the China II to China IV standards,as demonstrated by engine tests and field NO_(x)measurements.However,the NO_(x)emission factors for non-type-approved engines were approximately twice the limits of the China II standards.Emission compliance based on bench tests was not sufficient to control actual emissions because the field-measured NO_(x)emission factors of all machinery ranged from 24%to 225%greater than the respective emission limits for the engines.These circumstances adversely affected the effectiveness of the regulations and policies for China’s emission control of NDMM.Nevertheless,the policies on new and in-use NDMM,as well as diesel fuel quality,prevented NO_(x)and PM emissions amounting to 4.4 Tg and 297.8 Gg during the period 2008-2017,respectively.The emission management strategy contributed to enhancing the international competitiveness of China’s NDMM industries by promoting advanced technologies.For effective NDMM emission control in the future,portable testing and noncontact remote supervision should be strengthened;also,the issue of noncompliant diesel should be addressed through rigorous control measures and financial penalties.

Sensitivity analysis of surface ozone to emission controls in Beijing and its neighboring area during the 2008 Olympic Games

The regional air quality modeling system RAMS （Regional Atmospheric Modeling System）-CMAQ （Community Multi-scale Air Quality modeling system） is applied to analyze temporal and spatial variations in surface ozone concentration over Beijing and its surrounding region from July to October 2008.Comparison of simulated and observed meteorological elements and concentration of nitrogen oxides （NOx） and ozone at one urban site and three rural sites during Olympic Games show that model can generally reproduce the main observed feature of wind,temperature and ozone,but NOx concentration is overestimated.Although ozone concentration decreased during Olympics,high ozone episodes occurred on 24 July and 24 August with concentration of 360 and 245 μg/m 3 at Aoyuncun site,respectively.The analysis of sensitive test,with and without emission controls,shows that emission controls could reduce ozone concentration in the afternoon when ozone concentration was highest but increase it at night and in the morning.The evolution of the weather system during the ozone episodes （24 July and 24 August） indicates that hot and dry air and a stable weak pressure field intensified the production of ozone and allowed it to accumulate.Process analysis at the urban site and rural site shows that under favorable weather condition on 24 August,horizontal transport was the main contributor of the rural place and the pollution from the higher layer would be transported to the surface layer.On 24 July,as the wind velocity was smaller,the impact of transport on the rural place was not obvious.

Aerosol characterization in a city in central China plain and implications for emission control

Extensive studies on aerosol chemistry have been carried out in megacities in China,however,aerosol characterization in Central China Plain(CCP)is limited.Here we conducted real-time measurements of fine particle composition with a time-of-flight aerosol chemical speciation monitor in Kaifeng,Henan province in October 2019.Our results showed that nitrate and organics constituted the major fraction of non-refractory PM_(2.5)for the entire study,on average accounting for 34%and 33%,respectively.However,aerosol composition was substantially different among four periods due to different meteorological conditions and chemical processing.For instance,nitrate presented the lowest contribution during the first period due to evaporative loss associated with high temperature(T),and then rapidly increased during polluted periods as a function of relative humidity(RH).Positive matrix factorization analysis showed the dominance of secondary organic aerosol(SOA)in OA,and also the changes in OA composition under different T and RH levels.In addition,this study is unique with two periods of local emission controls.Back trajectory and coefficient of divergence analysis showed that air pollution in CCP was overall homogeneously distributed.As a result,the effectiveness of local emission controls in this region was strongly affected by meteorological conditions and regional transport.We found that one of the periods with emission control even showed the highest concentrations for the entire study.Our results point towards the limited effect of local emission controls in mitigating air pollution in CCP,and highlight the importance of joint emission controls under unfavorable meteorological conditions.

Mercury mass flow in iron and steel production process and its implications for mercury emission control

The iron and steel production process is one of the predominant anthropogenic sources of atmospheric mercury emissions worldwide. In this study, field tests were conducted to study mercury emission characteristics and mass flows at two iron and steel plants in China. It was found that low-sulfur flue gas from sintering machines could contribute up to41% of the total atmospheric mercury emissions, and desulfurization devices could remarkably help reduce the emissions. Coal gas burning accounted for 17%–49% of the total mercury emissions, and therefore the mercury control of coal gas burning, specifically for the power plant burning coal gas to generate electricity, was significantly important. The emissions from limestone and dolomite production and electric furnaces can contribute29.3% and 4.2% of the total mercury emissions from iron and steel production. More attention should be paid to mercury emissions from these two processes. Blast furnace dust accounted for 27%–36% of the total mercury output for the whole iron and steel production process. The recycling of blast furnace dust could greatly increase the atmospheric mercury emissions and should not be conducted. The mercury emission factors for the coke oven,sintering machine and blast furnace were 0.039–0.047 g Hg/ton steel, and for the electric furnace it was 0.021 g Hg/ton steel. The predominant emission species was oxidized mercury, accounting for 59%–73% of total mercury emissions to air.

City-specific vehicle emission control strategies to achieve stringent emission reduction targets in China's Yangtze River Delta region

The Yangtze River Delta（YRD） region is one of the most prosperous and densely populated regions in China and is facing tremendous pressure to mitigate vehicle emissions and improve air quality.Our assessment has revealed that mitigating vehicle emissions of NOx would be more difficult than reducing the emissions of other major vehicular pollutants（e.g.,CO,HC and PM_（2.5）） in the YRD region.Even in Shanghai,where the emission control implemented are more stringent than in Jiangsu and Zhejiang,we observed little to no reduction in NOx emissions from 2000 to 2010.Emission-reduction targets for HC,NOx and PM_（2.5） are determined using a response surface modeling tool for better air quality.We design city-specific emission control strategies for three vehicle-populated cities in the YRD region：Shanghai and Nanjing and Wuxi in Jiangsu.Our results indicate that even if stringent emission control consisting of the Euro 6/VI standards,the limitation of vehicle population and usage,and the scrappage of older vehicles is applied,Nanjing and Wuxi will not be able to meet the NOx emissions target by 2020.Therefore,additional control measures are proposed for Nanjing and Wuxi to further mitigate NOx emissions from heavy-duty diesel vehicles.

Baosteel emission control significantly benefited air quality in Shanghai

As the largest iron and steel producer in China, a part of Baosteel moved out of Shanghai deserves close attention due to its environmental impact. To understand the effect of Baosteel emission control on air quality in Shanghai, daily PM10, PM2.5, SO2, NO2 and CO were measured from 2010 to 2016. Concentrations of pollutants in Baoshan District presented a decreased trend during 2010-2016, with a reduction rate of 28.6% for PM10, 67.3% for SO2, 8.6% for NO2 and 42.0% for CO. However, fine particle pollution in Baoshan District during 2012-2016 seems to become more prominent, with PM2.5 concentration of 47 ± 28, 45 ± 33, 38 ± 24, 54 ± 41 and 51 ± 34 μg/m^3, respectively, indicating a slight increase of 8.5% in PM2.5. Concentrations of PM10 and CO decreased by 12.5% and 33.8% in the second half year in 2016 （compared with that in 2015） probably due to closure of blast furnace of Baosteel. Baosteel was identified as the largest pollution source in Baoshan District. Emission from Baosteel accounted for 58.0% of SO2, 43.6% of NO2 and 79.3% of dust in total emission from Baoshan District during 2010-2015. Meanwhile, pollutant emission and coal consumption from Baosteel decreased by 52.0% for SO2, 40.1% for NO2, 15.7% for dust and 22% for coal consumption. Energy consumption in Baoshan District reduced by 31% from 2011 to 2015. Air quality improvement in Shanghai was attributed to local emission reduction, together with regional air quality improvement.

An efficient and innovative catalytic reactor for VOCs emission control

Efficient mixing and thermal control are important in the flow reactor for obtaining a high product yield and selectivity.Here,we report a heterogeneous chemical kinetic study of propene oxidation within a newly designed catalytic jet-stirred reactor(CJSR).To better understand the interplay between the catalytic performances and properties,the CuO thin films have been characterized and the adsorbed energies of propene on the adsorbed and lattice oxygen were calculated using density functional theory(DFT)method.Structure and morphology analyses revealed a monoclinic structure with nano-crystallite size and porous microstructure,which is responsible for holding an important quantity of adsorbed oxygen.The residence time inside the flow CJSR(1.12–7.84 s)makes it suitable for kinetic study and gives guidance for scale-up.The kinetic study revealed that using CJSR the reaction rate increases with O_2concentration that is commonly not achievable for catalytic flow tube reactor,whereas the reaction rate tends to increase slightly above 30%of O_2due to the catalyst surface saturation.Moreover,DFT calculations demonstrated that adsorbed oxygen is the most involved oxygen,and it has found that the pathway of producing propene oxide makes the reaction of C_3H_6over CuO surface more likely to proceed.Accordingly,these findings revealed that CJSR combined with theoretical calculation is suitable for kinetic study,which can pave the way to investigate the kinetic study of other exhaust gases.

The Study on Cost of Application of International Emission Control Areas for China

In order to control the air pollution caused by ships and improve ambient air quality,China set up three domestic emission control areas(DECAs)in 2015 in the Pearl River Delta,the Yangtze River Delta and Bohai Rim(Beijing-Tianjin-Hebei)waters.In order to meet the emission requirements established at the 70th meeting of the Marine Environmental Protection Committee(MEPC),China intends to apply for the establishment of three international Emission Control Area(ECA)in 2030 for these DECAs.This paper discusses existing technologies to reduce emissions of nitrogen oxides(NOx)and sulphur oxides(SOx),and examines the abatement costs for the shipping industry in the year 2030 to comply with this action.Based on an examination of the literature and data collected for this study,four traditional alternatives,low-sulphur fuel,sulphur scrubbers/exhaust gas cleaning systems(EGCS),selective catalytic reduction(SCR),and exhaust gas recirculation,are analyzed.The analysis finds that switching to low-sulphur fuel is the best technical solution for SOx emission reduction,and the installation of SCR is the best technology for reducing nitrogen.In addition to traditional emission reduction technologies,the use of shore power facilities and liquefied natural gas(LNG),two alternatives welcomed by China’s green shipping industry,are also considered in this paper.The expected average abatement cost of these alternatives in the year 2030 are USD 2.866 billion,0.324 billion,1.071 billion,0.402 billion,0.232 billion and 0.34 billion,respectively.

Modelling the effects of emission control areas on shipping company operations and environmental consequences

In this study,two integrated game models are developed to explore the possible economic and environmental consequences of Emission control areas(ECA)regulations.Moreover,the analytical solutions compared with a benchmark case are derived.We find that vessel speed and SO_(2)emissions will decrease under the ECA regulations.However,shipping company’s level of competition has no effect on the equivalent speed.The equivalent freight volume to be reduced or increased is determined by the additional operational cost per voyage due to ECA regulations.Numerical study and sensitivity analysis reveal that the vessel speed and SO_(2)emission reduction are very sensitive to the inventory costs of intransit cargo.Furthermore,if low-sulphur marine gas oil is used throughout the voyage,the SO_(2)emission reduction may be greater than 80%,with a low impact on the shipping company’s profit.Thus,considering the environmental effects,much stricter limits can be set in the future.

A Brief Account of Domestic Vehicle Diesel Engines and Their Emission Control

Ⅰ. Briefing domestic vehicle diesel engines Before the 1970s, domestic vehicle diesel engines were mainly applied to heavy vehicles, while medium and light vehicles were powered chiefly with gasoline engines.

Auto Emission Control in 9th FYP

The work plan of auto emission control during the period of 9th Five-Year Plan is released by AIB of MMI recently and its main contents are as follows:

Study on the Environmental Quality Guarantee Ratio on the Basis of Total Air Pollutant Emission Amount Control

The hourly and daily air quality concentration in the total air pollutant emission amount control zone is not sure to be continuously up to national ambient air quality standard, even though the total annual air pollutant emission is permitted under the total air pollutant emission amount control (TAPEAC) on the basis of A-value method. So the concept of the environmental quality guarantee ratio (EQGR) for TAPEAC is advanced in this paper and its quantitative formula is figured out for both hourly and daily EQGR. It is concluded that the EQGR is related with the yearly arrangement of A-value besides the pollutant type. According to the meteorological data in a lower area along Yangtze River in 2000, the yearly A-value trend is analyzed. Based on the data, the hourly EQGR of SO 2 and NO 2 is respectively 97.4% and 90.2%, and daily EQGR respectively 90.2% and 79.5%.