Modeling vehicle emissions in different types of Chinese cities: importance of vehicle fleet and local features

We propose a method to simulate vehicle emissions in Chinese cities of different sizes and development stages. Twenty two cities are examined in this study. The target year is 2007. Among the cities, the vehicle emission factors were remarkably different (the highest is 50-90% higher than the lowest) owing to their distinct local features and vehicle technology levels, and the major contributors to total vehicle emissions were also different. A substantial increase in vehicle emissions is foreseeable unless stronger measures are implemented because the benefit of current policies can be quickly offset by the vehicle growth. Major efforts should be focused on all cities, especially developing cities where the requirements are lenient. This work aims a better understanding of vehicle emissions in all types of Chinese cities. The proposed method could benefit national emission inventory studies in improving accuracy and help in designing national and local policies for vehicle emission control.     

Investigation of volatile organic compounds and phthalates present in the cabin air of used private cars

The presence of selected volatile organic compounds (VOCs) including aromatic, aliphatic compounds and low molecular weight carbonyls, and a target set of phthalates were investigated in the interior of 23 used private cars during the summer and winter. VOC concentrations often exceeded levels typically found in residential indoor air, e.g. benzene concentrations reached values of up to 149.1 µg m^− 3. Overall concentrations were 40% higher in summer, with temperatures inside the cars reaching up to 70 °C. The most frequently detected phthalates were di-n-butyl-phthalate and bis-(2-ethylhexyl) phthalate in concentrations ranging from 196 to 3656 ng m^− 3.     

Air pollutant emissions from rice straw open field burning in India, Thailand and the Philippines

Rice is a widely grown crop in Asia. China (30%) and India (21%) contribute to about half of the world's total rice production. In this study, three major rice-producing countries in Asia are considered, India, Thailand and the Philippines (the later two contributing 4% and 2% of the world's rice production). Rice straw is one of the main field based residues produced along with this commodity and its applications vary widely in the region. Although rice production practises vary from one country to another, open burning of straw is a common practice in these countries.In this study, an approach was followed aiming at (a) determining the quantity of rice straw being subject to open field burning in those countries, (b) congregating pollutant specific emissions factors for rice straw burning, and (c) quantifying the resulting air pollutant emissions. Uncertainties in the results obtained as compared to a global approach are also discussed.     

Reducing carbon emissions through improved household energy efficiency in the UK

A number of schemes to increase household energy efficiency have operated in the UK over the last 5–10 years. This paper evaluates their effectiveness in terms of reducing household energy use, carbon emissions and fuel poverty. It then draws on the quantitative results of these schemes, and published plans for their continuation, to model an extended and expanded Household Energy Efficiency Scenario to 2020, using an integrated economy–energy–environment model of the UK. The results suggest that while such schemes can play a significant role in reducing carbon emissions from households, much more ambitious schemes than those currently implemented will be necessary to offset the underlying growth in these emissions. Finally, the results are compared with the UK government's own estimates, in its Climate Change Programme, of carbon emission reductions from such schemes to 2010. The paper concludes that the government's estimates are somewhat optimistic, and that it will need substantial new policy measures beyond those already announced if its carbon reduction targets in this area are to be met. Copyright © 2002 John Wiley & Sons, Ltd.     

合芜蚌试验区排污权交易制度建立之构想

排污权交易的实践证明了排污权交易可以有效地保护环境,同时也提出了亟需对其适用条件和建设模式进行探索的现实命题。文章以合芜蚌自主创新试验区为例,在分析了合芜蚌试验区内推行排污权交易制度的可行性基础上,提出了区域性排污权交易的构建模式。     

Studies on the use of low-volatile non-edible oils in a thermal barrier-coated diesel engine

Owing to the ever-increasing vehicle population, the consumption of diesel fuel in the transportation, agricultural and industrial sectors has increased at an alarming rate. This has led to rapid fossil fuel depletion, ozone depletion and environmental degradation, which have become a serious concern. Search for alternative renewable and clean energy fuel sources to mitigate the emissions of greenhouse gases is continuing, and attempts to find different techniques for efficient utilization of these fuels are also undertaken. Biodiesel being an oxygenated fuel obtained from vegetable oils has received greater attention over the years as a promising alternative to diesel fuel. However, vegetable oils exhibit high viscosity, poor volatility and poor cold-flow characteristics. These characteristics can cause the following problems in the engine when run for a longer duration: injector coking, severe engine deposits, filter gumming, piston ring sticking and thickening of lubrication. These problems can be eliminated or minimized by adopting suitable fuel processing techniques to obtain biodiesels from vegetable oils. The fuel processing techniques vary widely, which include transesterification, supercritical methanolysis, ultrasonic and continuous microwave-assisted transesterification methods. In the present study, the transesterification method is effectively used to obtain biodiesels from non-edible oils of honne and cotton seed. The biodiesels obtained from these oils were used in the unmodified diesel engine to check their feasibility as diesel engine alternatives. Different thermal barrier coatings (TBCs) were applied on the piston, cylinder head, and inlet and exhaust valve surfaces of the diesel engine in order to make it a fully adiabatic engine. The engine with such TBCs is called a low heat rejection engine. For the present study, the TBC of partially stabilized zirconia (PSZ) and aluminium oxide (Al₂O₃) were selected. Finally, the performance of the diesel engine fuelled with different biodiesels in both conventional and thermal barrier-coated modes was compared. The thermal barrier-coated engine with the PSZ version showed better performance with increased nitric oxide emissions when compared with the Al₂O₃ coating.     

Effects of injection timing,injector opening pressure and nozzle geometry on the performance of cottonseed oil methyl ester-fuelled diesel engine

Increasing petroleum prices, increasing threat to the environment from exhaust emissions and global warming have generated intense international interest in developing renewable and alternative non-petroleum fuels for engines. Evolving technology and a recurring energy crisis necessitates a continuous investigation into the search for sustainable and clean-burning renewable fuels. In this paper, cottonseed oil methyl ester (COME) was used in a four-stroke, single-cylinder variable compression ratio diesel engine. Tests were carried out to study the effects of fuel injection timing, fuel injector opening pressure (IOP) and injector nozzle geometry on the performance and combustion of COME biodiesel fuel used in a compression ignition engine with a single fuel mode. Fuel injection timing varied from 19° to 27° before top dead centre (bTDC) in incremental steps of 4° bTDC; fuel IOP varied from 210 to 240 bar in incremental steps of 10 bar. Fuel nozzle injectors with three, four and five holes, each of 0.3 mm size, were selected for the study. The results suggested that with retarded injection timing of 19° bTDC, increased IOP of 230 bar and a four-hole nozzle injector of 0.3 mm size resulted in overall better engine performance with an increased brake thermal efficiency and reduced HC, CO and smoke emission levels.     

Production of renewable and sustainable fuel from Calliandra calothyrsus and its utilisation in compression ignition engines

Alternative fuels have several advantages compared to fossil fuels as they are renewable, biodegradable, provide energy security, foreign exchange saving as well as help in addressing environmental concerns and socio-economic issues. Therefore, renewable fuels can be used predominantly as a fuel for transportation and for applications in power generation. Shaft power application is a key factor for economic growth and prosperity and depends crucially on the long-term availability of energy from sources that are affordable, accessible and environmentally friendly. In this context, the main objective of the present study was to implement the production of bioethanol from Calliandra calothyrsus, a potential lignocellulosic raw material for the cellulose-to-bioethanol conversion process that can be used as an alternative resource to starch- or sugar-containing feedstock. This study addresses a new pretreatment method known as hydrothermal explosion using C. calothyrsus for ethanol production. The present study also involves experimental investigations on a single-cylinder, four-stroke, direct-injection diesel engine operated with Honge oil methyl ester (biodiesel) and ethanol and its comparison with a neat diesel fuel mode of operation. The results revealed that optimal parameters for bioethanol production from C. calothyrsus were 2% acid concentration (HCl), 100°C temperature and 80 min retention time. For a diesel engine operated with a HOME–bioethanol blend, the experimental results showed a 3–4% decrease in brake thermal efficiency with a 8–10% increase in hydrocarbon and carbon monoxide emission levels and a 15–18% decrease in nitric oxide emission levels when compared with a neat diesel fuel mode of operation.     

Portuguese inventory of dioxins and furans atmospheric emissions

This article presents the results of the most recent estimation of polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF) atmospheric emissions in Portugal, which has covered the period 2004–2009 and includes 27 emission sources types. The results are compared with previous emissions inventories published for Portugal. The main objective of this work is to provide relevant information about the amounts of the compounds that are released into the atmosphere in Portugal, and identify their major sources and trends.     

Toxic Environmental Releases from Medical Waste Incineration: A Review

Toxic releases from medical waste incineration comprising organic emissions such as polychlorinated dibenzo-dioxin/furan (PCDD/Fs) and polycyclic aromatic hydrocarbons (PAHs), inorganic emissions and ashes containing toxic metals have been reviewed. Attempts made by various investigators to reduce/eliminate emissions have also been included. Legislations concerning emission standards for medical waste incinerators have been discussed.