Advanced exhaust gas aftertreatment systems for gasoline and diesel fuelled vehicles

In this article, the main reasons for the intensive development work being done on automotive emission control catalysts are discussed and the most important features of these technologies are described. Special attention is paid to the development of improved three-way catalysts for gasoline engines, that have to fulfil the more stringent future emission standards. Diesel fuelled vehicles and lean burn gasoline engines show completely different exhaust gas emission characteristics, which lead to dissimilar demands for the aftertreatment systems.     

Effect of HHO gas on combustion emissions in gasoline engines

Reducing the emission pollution associated with oil combustion is gaining an increasing interest worldwide. Recently, Brown’s gas (HHO gas) has been introduced as an alternative clean source of energy. A system to generate HHO gas has been built and integrated with Honda G 200 (197 cc single cylinder engine). The results show that a mixture of HHO, air, and gasoline cause a reduction in the concentration of emission pollutant constituents and an enhancement in engine efficiency. The emission tests have been done with varying the engine speed. The results show that nitrogen monoxide (NO) and nitrogen oxides (NO_X) have been reduced to about 50% when a mixture of HHO, air, and fuel was used. Moreover, the carbon monoxide concentration has been reduced to about 20%. Also a reduction in fuel consumption has been noticed and it ranges between 20% and 30%.     

Preventive knock protection technique for stationary SI engines fuelled by natural gas

In a combined heat and power (CHP) plant, spark ignition engines must operate at their maximum power to reduce the pay back time. Because of environmental and economic concerns, engines are set with high compression ratios. Consequently, optimal operating conditions are generally very close to those of knock occurrence and heavy knock can severely damage the engine piston.There are two main protection techniques: the curative one commonly used by engine manufacturers and well documented in the literature and the preventive one based on a knock prediction according to the quality of the supplied gas. The indicator used to describe gas quality is the methane number (MN). The methane number requirement (MNR) of the engine is defined, for an engine set (spark advance, air-fuel ratio, and load), as the minimum value of MN above which knock free operation is ensured. To prevent knock occurrence, it is necessary to adapt the engine tuning according to variable gas composition. The objective of the present work is to validate the concept of knock preventive protection. First, a prediction of MNR according to engine settings (ES) is computed through a combustion simulator composed of a thermodynamic 2-zone model. Predicted MNR are compared to experimental results performed on a single-cylinder SI gas engine and show good agreement with numerical results (uncertainty below 1 point). Then, the combustion simulator is used to generate a protection mapping. At last, the knock preventive protection was successfully tested.     

Preparation, evaluation and characterization of copper catalysts for ethanol fuelled diesel engines

Copper-based monolithic honeycomb catalysts for ethanol fuelled diesel engines have been prepared and evaluated. The washcoat consisted either of alumina or titania. Two different methods to apply the active material were used; incipient wetness impregnation and deposition precipitation. The catalysts have been evaluated in a laboratory reactor and have been characterised using SEM, XRPD, TEM, TPR, XPS, BET surface area and pore-size distribution measurements. Both the choice of washcoat material as well as the preparation method is of importance. Titania as washcoat gave a better performing catalyst than alumina in this case. Deposition precipitation gave a better catalyst than incipient wetness impregnation when alumina was used as washcoat, as well as at low temperatures for titania catalysts.     

汽油发动机积炭的形成、清除机理及汽油清净剂的研究进展

发动机经过长期运转以后,在燃烧室、燃油喷嘴、进气阀等部位会形成大量的碳质沉积物,严重影响发动机的效率、操作性能和尾气排放。为解决发动机的积炭以及尾气排放问题,汽油清净添加剂成为现代清洁汽油不可或缺的组成部分。本文综述了积炭的形成机理：积炭的形成过程分为引发和生长两个阶段,同时积炭的形成受到金属表面温度、燃油组成、喷射速率等众多因素的影响。指出利用某种特殊结构的有机胺类物质对金属表面的吸附作用及其对胶质的分散作用可以清除金属表面已经形成的积炭。此外,对汽油清净剂的组成、发展以及性能评价方法作了详细介绍。     

木质素制备生物液体燃料进展

木质素中含有丰富的芳环结构,可以作为可持续再生的原料用于生产高值能源及化工品。但由于木质素结构复杂,现阶段用于制备生物液体燃料仍处于探索阶段。本文首先介绍了木质素通过催化热解、催化氢解、催化氧化3种解聚方式制备生物液体燃料的进展,分析了当前解聚产物存在低碳原子数、高氧含量的不足而导致其难以投入生产使用的现状,指出应通过C—C偶联方法（包括羟醛缩合、烷基化反应、寡聚反应以及Diels-Alder 反应）增加产物碳原子数、使用加氢脱氧（hydrodeoxygenation, HDO）工艺以降低产物氧含量,从而实现由木质素制备高密度生物液体燃料。最后对当前木质素制备高密度燃料所面临的挑战以及未来研究趋势进行了总结与展望,指出构建高效催化体系,耦合解聚、C—C偶联和HDO过程,将是该领域未来研究重点。     

Specific features of combustion in gasoline-driven internal combustion engines

Physical and chemical processes of gasoline combustion in internal combustion engines are considered. A model of combustion evolution in gasoline-driven engines, which explains some specific features of the processes in internal combustion engines, is proposed.     

离子液体脱除汽油中含硫化合物的研究

Brφnsted酸性吡咯烷酮离子液体N-甲基-2-吡咯烷酮氟硼酸盐([Hnmp]BF4)为萃取剂和催化剂,质量分数30%双氧水为氧化剂,将萃取脱硫和氧化脱硫相结合,对含有噻吩的模型油和FCC汽油进行萃取氧化脱硫研究。考察了氧与硫摩尔比、温度等对脱硫率的影响。结果表明:[Hnmp]BF4既是萃取剂又是催化剂,与H2O2作用产生的羟基自由基能将模型油中的噻吩和FCC汽油中的含硫化合物氧化,离子液体再生4次后脱硫性能开始下降,汽油的脱硫率达到82.7%。     

Fuelling of aircraft radial piston engines by ES95 and 100LL gasoline

The cost of maintaining aeroplanes is still considerable. It concerns especially operation cost where fuel is a substantial part. At the moment the special 100LL gasoline is used to fuel aircraft piston engines. It is about 20% more expensive than ES95 gasoline featuring comparable properties.The article shows the results of test-bed research conducted on the radial piston aircraft engine fuelled by aircraft 100LL gasoline and automotive ES95 gasoline. The object of research was ASz-62IR engine by WSK PZL-Kalisz that was equipped with an experimental fuel injection system. Power, fuel consumption, head temperatures and indicated pressure in cylinders were analysed in the selected typical operating points. The testing was carried out in steady state. It was proved that it is possible to exchange fuels with no engine power loss and merely an insignificant increase of fuel consumption but with significant increase of IMEP cycle-to-cycle variation.     

Impact of altitude on fuel consumption of a gasoline passenger car

Engines of new passenger cars are tuned at the sea level. However, in several countries, a significant part of the engine operation is performed at higher altitudes than that of the sea level. The different air density can have a significant impact on fuel consumption. In the case of gasoline engines, the higher altitude theoretically leads to lower fuel consumption due to lower throttle frictions due to the wider throttle opening. From the other side, as the air is less dense at higher altitudes, the vehicle aerodynamic is changed and this also leads to lower fuel consumption. This work studies, on three regulated driving cycles, the impact of high altitude on the fuel consumption of a gasoline passenger car. The impact of changed vehicle aerodynamics of higher altitudes, through the change of deceleration times, on fuel consumption is also analyzed.     

Molecule sieving catalysts for NO reduction with hydrocarbons in exhaust of lean burn gasoline and diesel engines

NO oxidation catalysts with small pores and low hydrocarbon oxidation activity owing to molecular sieving were prepared by dispersing platinum in the pores of ferrierite and chabazite zeolites. These small pore platinum zeolite crystals were physically mixed with large pore silver mordenite zeolite crystals and evaluated as HC-SCR catalysts for selective catalytic reduction of NO in a synthetic gas mixture doped with octane or isooctane, mimicking exhaust from lean burning engines with unburned hydrocarbons. A synergetic effect on N₂ formation and hydrocarbon efficiency was obtained in these physical zeolite mixtures. In the pores of the small pore zeolite where the diffusion of NO, O₂ and NO₂ molecules with small kinetic diameters was rapid, NO was effectively oxidized by the platinum into NO₂, while the small window apertures suppressed the diffusion and reaction of the hydrocarbon. The silver plated large pore zeolite catalyzed the reaction between the NO₂ formed in the small pore zeolite and the hydrocarbon. The importance of molecular sieving was demonstrated in experiments with permutation of pore sizes and catalytic functions.     

Specific energy consumption in electrochemical treatment of food industry wastewaters

BACKGROUND: Specific energy consumption (SEC) is an important factor in electrochemical treatment of wastewaters. SEC during electrochemical treatment of food industry wastewaters, specifically deproteinated whey wastewater (DWW), simulated sugar beet factory wastewater (SFW) and fruit juice factory wastewater (FJW), were investigated in this study. The effects of operational parameters applied voltage, and electrolyte and wastewater concentrations on SEC were assessed and optimized. RESULTS: SEC values were found in the range of 0.27–148.65, 0.94–375.76 and 0.20–636.40 kWh (kg COD)^?1 for DWW, SFW and FJW, respectively, after 8 h of reaction. Operational parameters were optimized at 25 °C through response surface methodology (RSM) where applied voltage was kept in the range (2–12 V), wastewater concentration and COD removal percent were maximized electrolyte concentration and SEC were minimized. Optimum conditions were estimated as 7.73 V applied voltage and 100% wastewater concentration in the presence of 27.11 g L^?1 supporting electrolyte concentration to achieve 25.02, 67.74 and 43.10% COD removal for DWW, SFW and FJW with corresponding SEC values of 17.85, 22.79 and 80.47 kWh (kg COD)^?1, respectively. CONCLUSIONS: Providing further research on the reduction of SEC values, application of electrochemical treatment to food industry wastewaters with non‐biodegradable components may become an alternative to conventional methods. Copyright © 2012 Society of Chemical Industry     

Fuel consumption and emissions from a diesel power generator fuelled with castor oil and soybean biodiesel

This work investigates the impacts on fuel consumption and exhaust emissions of a diesel power generator operating with biodiesel. Fuel blends with 5%, 20%, 35%, 50%, and 85% of soybean biodiesel in diesel oil, and fuel blends containing 5%, 20%, and 35% of castor oil biodiesel in diesel oil were tested, varying engine load from 9.6 to 35.7 kW. Specific fuel consumption (SFC) and the exhaust concentrations of carbon dioxide (CO₂), carbon monoxide (CO), and hydrocarbons (HC) were evaluated. The engine was kept with its original settings for diesel oil operation. The results showed increased fuel consumption with higher biodiesel concentration in the fuel. Soybean biodiesel blends showed lower fuel consumption than castor biodiesel blends at a given concentration. At low and moderate loads, CO emission was increased by nearly 40% and over 80% when fuel blends containing 35% of castor oil biodiesel or soybean biodiesel were used, respectively, in comparison with diesel oil. With the load power of 9.6 kW, the use of fuel blends containing 20% of castor oil biodiesel or soybean biodiesel increased HC emissions by 16% and 18%, respectively, in comparison with diesel oil. Exhaust CO₂ concentration did not change significantly, showing differences lower than ±3% of the values recorded for diesel oil operation, irrespective of biodiesel type, concentration and the load applied. The results demonstrate that optimization of fuel injection system is required for proper engine operation with biodiesel.     

Control of exhaust emission from gasoline engines: the state of the art and pointers to the future

The work to date on emission control and its penalties is reviewed in the light of the overriding future importance of fuel economy compared with power output.     

中国洗衣液市场状况及消费群特点

目前中国洗涤剂市场上洗衣粉仍然占据主导地位,但随着社会经济的发展和消费者需求的提高和逐渐细分,洗衣液近几年发展迅速.本文通过对专业调查公司的市场调查数据进行分析,总结了洗衣液的使用状况及相应的消费群特点.     

亚洲生物燃料的开发

由于石化能源的日益耗竭和不可再生,生物燃料作为一种新的替代能源逐渐成为人们研究的热点.主要介绍了亚洲一些国家在生物燃料开发方面的最新进展,并对生物燃料的普及应用进行了展望.     

Novel antioxidants from cashew nut shell liquid applied to gasoline stabilization

This study developed a methodology for converting hydrogenated cardanol, a compound extracted from cashew nut shell liquid into compounds with structural characteristics of antioxidants similar to the ones used in products derived from petroleum. The intended changes were carried out through exhaustive alkylation with tert-butyl chloride. The performance of the products was estimated in terms of oxidative stabilization during storage of cracked naphtha samples collected from the outlet of an industrial unit. The compound 2,4,6-tri-t-butyl-pentadecylphenol (new antioxidant) has presented a better efficiency in the storage assays as compared to the commercial additive used as reference in the refinery at the moment of sampling.     

Cold start and fuel consumption of a vehicle fuelled with blends of diesel oil–soybean biodiesel–ethanol

Fuel consumption and cold start characteristics of a production vehicle fuelled with blends of N. 2 diesel oil (500 ppm sulfur content), soybean biodiesel (3%, 5%, 10%, and 20%) and hydrous ethanol (2% and 5%) were compared. A wagon-type vehicle equipped with a four-cylinder, 1.3-l, 63 kW diesel engine was tested in a cold chamber at the temperature of −5 °C for the cold start tests. Fuel consumption tests were performed following the 1975 US Federal Test Procedure (FTP-75). The results showed that the cold start time was satisfactory for all fuel blends tested, but it was longer for the blend containing 20% of soybean biodiesel (B20) in comparison with the blends with lower biodiesel concentration. The cold start time also increased with increasing with increasing ethanol content in the fuel blend. Specific fuel consumption was not affected by increasing biodiesel concentration in the blend or by the use of 2% of ethanol as an additive. However, the use of 5% of ethanol concentration in the B20 blend resulted in increased specific fuel consumption.     

正构生物烷烃在Pt/ZSM-5催化剂上选择性加氢裂化制备液体生物燃料

开发了一种通过正构生物烷烃在Pt/ZSM-5催化剂上的选择性加氢裂化来制备高品质液体生物燃料的新方法.生产得到的液体生物燃料包含了煤油、汽油和柴油,分离后可直接作为航空燃料或车用燃料使用.以商业ZSM-5分子筛为载体,制备和表征了不同组成的Pt/ZSM-5催化剂.采用转化率、煤汽比和异构率为指标,考察了温度、压力和空速等条件对反应的影响,比较了不同组成时催化剂的催化性能.结果表明:对于同一催化剂,裂化产物异构率随转化率增加而增加;除转化率外,异构率还与酸性位的烯烃被覆度相关;当采用0.7%Pt/ZSM-5(硅铝比50)为催化剂时,在4MPa、320℃、1h^-1、氢油体积比1500:1的反应条件下,原料转化率即可达到82%,产物中煤油含量为43.6%,异构率为1.29,汽油含量为38.0%.