AUSTRALIAN BROWN COAL/OIL MIXTURES AS A FUEL FOR DIESEL ENGINES; ENGINE PERFORMANCE AND ECONOMIC VIABILITY

ABSTRACT

CSIRO Division of Energy Technology has used mixtures of finely ground, chemically beneficiated, Australian brown coal (up to 30% by weight, maximum particle size less than 13 microns) and automotive diesel oil (ADO) to fuel an essentially unmodified single cylinder diesel engine operating at 800, 1200 and 1500 r/min. Engine performance tests indicate that brown coal can be used as a fuel extender to reduce consumption of the conventional liquid diesel fuel (ADO). Partially burnt coal agglomerates were identified in the engine exhaust and there were indications of late burning at the higher engine speeds and coal concentrations. Engine brake thermal efficiency ratio is identified as an important parameter when evaluating the thermal performance and economic viability of new fuels for internal combustion engines. A simple economic model based on ‘payback period’ is developed and used to assess the viability of converting an existing diesel engine powered plant to operate on the coal/oil mixture fuels (COM). The simple economic analysis technique can also be applied to other fuel formulations and fuel extenders. Conversion of large, slow speed stationary diesel engines to operate on brown COM fuels is shown to be uneconomical, given a projected brown coal cost of 215 $A/t (including processing).     

IGNITION DELAY CHARACTERISTICS OF SOME TURKISH VEGETABLE OIL-DIESEL FUEL BLENDS

Vegetable oils have chances to be used in Diesel engines as alternative fuels contributing to the solution of some agricultural, environmental and economical problems. Direct use of them has some technical problem yet but as blended fuels with diesel fuel or esters they have places on the application area. In this paper the effect of the compression ratio on ignition delay is investigated in an ASTM-CER engine working with four different types of vegetable oil of Turkish origin (sunflower, corn, soybean, and olive oil) blended with grade No.2-D diesel fuel at a ratio of 20/80 (v/v) and the results are compared with baseline diesel fuel. Longer ignition delay periods have generally been obtained for blend fuels ranking from olive oil to sunflower oil as compared to diesel fuel.     

IGNITION DELAY CHARACTERISTICS OF SOME TURKISH VEGETABLE OIL-DIESEL FUEL BLENDS

ABSTRACT

Vegetable oils have chances to be used in Diesel engines as alternative fuels contributing to the solution of some agricultural, environmental and economical problems. Direct use of them has some technical problem yet but as blended fuels with diesel fuel or esters they have places on the application area. In this paper the effect of the compression ratio on ignition delay is investigated in an ASTM-CER engine working with four different types of vegetable oil of Turkish origin (sunflower, corn, soybean, and olive oil) blended with grade No.2-D diesel fuel at a ratio of 20/80 (v/v) and the results are compared with baseline diesel fuel. Longer ignition delay periods have generally been obtained for blend fuels ranking from olive oil to sunflower oil as compared to diesel fuel.     

国外石油钻机柴油机的技术进展

世界石油钻机的机械驱动型式,经历了蒸汽机、柴油机、燃气轮机、液压马达、柴油机液力传动和柴油机动力换挡变速箱等６个发展阶段,在国外应用较多的是后两种型式。从美国Ｃａｔｅｒｐｉｌａｒ公司、Ｗａｕｋｅｓｈａ公司、Ｃｕｍｍｉｎｓ公司、ＥＭＤ公司、Ｄｅｔｒｏｉｔ公司以及俄罗斯、罗马尼亚和德国生产的石油钻机柴油机系列的结构设计、输出功率及工作转速、燃油消耗,使用寿命等方面可以看到,现代柴油机具有适应性强、经济性好、可靠性高等特点。为了使国内柴油机的各项技术经济指标达到国际先进水平,应改进１９０系列柴油机、研制１９０系列长冲程柴油机、高速柴油机,开发烧原油、渣油、页岩油、天然气、油井伴生气、液化石油气、柴油和天然气双燃料、沼气和煤气等发动机,改进沙漠柴油机。     

Biodiesel production by direct esterification of fatty acids with propyl and butyl alcohols

The expected depletion of natural petroleum resources in the near future and pollution of the environment due to excessive carbon dioxide emissions by fossil fuel and its adverse effect on global warming constitute two major problems facing the whole world. In view of these problems, much research work is now directed worldwide to find fuels alternative to those derived from petroleum which should be renewable and more environmentally friendly fuels. Biodiesel fuel which is a blend of fatty acid esters with alcohols is considered the most suitable alternative fuel for diesel engines. In this scope of research work, a previous study (Soliman et al., 2013) has been made to explore the opportunity of utilizing the fatty acids that can be obtained from the waste of edible oil industry in Egypt to produce biodiesel fuel by direct esterification with methanol as well as ethanol in the presence of sulfuric acid as a catalyst. This paper is a continuation of that work where two other alcohols of a chain length longer than ethanol have been used being propanol and butanol. The performance of a diesel engine running using a 50% blend of regular diesel fuel and each of the two biodiesels prepared was compared to that using regular diesel fuel. The results have shown that the brake specific fuel consumption (BSFC) and the brake thermal efficiency at full engine loading were almost the same in all cases. This indicates that the produced fuel could be used as an efficient fuel substitute for diesel engines. By comparing the results of the present work to those reported in our previous work, it appeared that methanol which has the shortest carbon chain length is the most recommended in view of the brake thermal efficiency of a diesel engine at full loading.     

IGNITION DELAY AND SOOT EMISSION CHARACTERISTICS OF METHANOL-DIESEL FUEL BLENDS

Alcohols, as alternative fuels, may contribute to the solution of environmental and economical problems to a certain extend. But, they seem to have little chances to be directly used in Diesel engines because of their low cetane number. However, as blended fuels with diesel fuel they have places on the application area. In this study, the effect of the compression ratio on ignition delay and soot emission for methanol-diesel fuel blends with various blending ratios is investigated on an ASTM-CFR engine and the results are compared with baseline diesel fuel. Longer ignition delays and less soot emissions have been obtained for blend fuels as compared to diesel fuel.     

高原地区柴油发动机燃用混合燃料的研究

针对高原地区低温、低压、低氧特点,考虑油料与车辆发动机适应性,并综合考虑混合燃料代用效益最大化,考察了分别添加不同体积分数4种油品的0#车用柴油混合燃料的理化性能和SRV摩擦磨损性能,同时进行了发动机台架试验。结果表明,与0#车用柴油相比,各混合燃料的凝点和十六烷值均降低;添加93#车用汽油者的馏程和运动黏度(40℃)均降低,而添加10#航空液压油、HM32液压油和SF15W/40内燃机油者的则均升高。25℃时,随着载荷的增加,加入体积分数20%的93#车用汽油者的平均摩擦系数增大,而添加10#航空液压油、SF15W/40内燃机的柴油混合燃料的平均摩擦系数均减小;70℃时,这3种柴油混合燃料的平均摩擦系数均未随载荷的增加而增大。除添加15% SF15W/40内燃机油者外,分别添加20% 93#车用汽油、20% HM32液压油和30% 10#航空液压油者的磨斑直径均未随温度或载荷的变化而减小,且这4种柴油混合燃料均能满足高原地区柴油发动机使用要求。与0#车用柴油相比,此4种柴油混合燃料的燃油消耗率均增大;除添加30% 10#航空液压油者外,其他三者的功率和扭矩均减小。     

Performance and emission characteristics of a stationary diesel engine fuelled by Schleichera Oleosa Oil Methyl Ester (SOME) produced through hydrodynamic cavitation process

In this study, the performance and emission characteristics of biodiesel blends of 10, 20, 30 and 50% from Schleichera Oleosa oil based on hydrodynamic cavitation were compared to diesel fuel, and found to be acceptable according to the EN 14214 and ASTM D 6751 standards. The tests have been performed using a single cylinder four stroke diesel engine at different loading condition with the blended fuel at the rated speed of 1500 rpm. SOME (Schleichera Oleosa Oil Methyl Ester) blended with diesel in proportions of 10%, 20%, 30% and 50% by volume and pure diesel was used as fuel. Engine performance (specific fuel consumption and brake thermal efficiency) and exhaust emission (CO, CO₂ and NOx) were measured to evaluate the behaviour of the diesel engine running on biodiesel. The results show that the brake thermal efficiency of diesel is higher and brake specific fuel consumption is lower at all loads followed by blends of SOME and diesel. The performance parameter for B10, B20, B30 and B50 were also closer to diesel and the CO emission was found to be lesser than diesel while there was a slight increase in the CO₂ and NOx. SOME produced by using hydrodynamic cavitation seems to be efficient, time saving and industrially viable. The experimental results revel that SOME-diesel blends up to 50% (v/v) can be used in a diesel engine without modifications.     

Effect of biodiesel fuels on diesel engine emissions

Energy production is heavily dependent on fossil fuels that are not only diminishing, but also are considered the main cause of harmful emissions and global warming. Therefore using vegetable oils such as Jatropha, palm, algae and waste cooking oils as alternative fuels in diesel engines has drawn a great attention. Biodiesel from Jatropha, palm, algae and waste cooking oils has been produced using the transesterification process. Biodiesel from different feedstock is mixed with diesel oil in different proportions e.g. B10 and B20. Biodiesel physical and chemical properties are measured according to ASTM standards. A “single cylinder diesel engine” is employed as the test engine in the present work. Exhaust emissions such as CO, CO₂, NO_x, HC, and smoke are measured and compared with diesel oil. CO, HC, CO₂ and smoke emissions are lower for biodiesel mixtures B10 and B20 (Jatropha, algae and palm) compared “to diesel fuel”. CO₂ emissions from biodiesel blends B10 and B20 produced from waste cooking oil are higher compared to diesel fuel. NO_X emissions from all biodiesel mixtures B10 and B20 increases than diesel fuel for all biodiesel blend B10 and B20.     

Study on the characteristics of palm oil–biodiesel–diesel fuel blend

Palm oil/palm oil methyl esters are blends with diesel fuel, the blends were characterized as an alternative fuels for diesel engines. Density, kinematic viscosity, and flash point were estimated according to ASTM as key fuel properties. Palm oil and palm oil biodiesel were blended with diesel. The properties of both blends were estimated. The results showed that the fuel properties of the blends were very close to that of diesel till 30% unless other characteristics are within the limits. The experimental data were correlated as a function of the volume fraction of oil/biodiesel in the blend. Different correlations were developed to predict the properties of the oil/bio-oil-diesel blends based on our experimental results. The developed correlations were validated by comparing the correlation prediction with experimental data in literature. A good agreement was found between modeled equations prediction and experimental data in literature. The developed equations can be used as a guide for determining the best blending mixture to be used for diesel engines.     

THE IMPORTANCE OF PYROLYSIS IN DIESEL IGNITION OF RESIDUAL FUEL OILS

Recent attempts to increase yields of distillate fuels from crude oil have resulted in a decline in the ignition quality of residual fuel oils and claims of ignition problems in large marine Diesel engines. This has revived an interest in fundamental studies of the ignition of liquid fuels and in new ways of defining and measuring ignition quality.

As part of an extensive study of the ignition of a range of residual fuels oils and during the development of novel teats of ignition quality it became obvious that thermal cracking of the fuel could play an important part in the pre-ignition chemistry. This paper reports kinetic data from simple experiments performed on the pyrolyses of residual fuel oils. Small samples and high heating rates were used to try to match the conditions inside a Blow-speed Diesel engine. This data has been used to assess the contribution that thermal cracking makes to ignition processes.

Pyrolyses were carried out on a small silica-coated platinum coil in the inlet of a gas chromatograph. Light hydrocarbon pyrolysis products were formed, and the extent and rate of cracking determined at four temperatures.

Assuming that reaction took place on a surface surrounding the oil and that a constant supply of reactants were available, pseudo zero order rate constants for the initial part of the reaction were evaluated. They showed an Arrhenius relationship with temperature giving an overall apparent activation energy of 110 kJ mol^-1. Extrapolating rate constants to temperatures expected in Diesel engines, and assuming typical droplet sizes end ignition delays, it was shown that thermal cracking of fuels was possible before ignition and that it is likely that these reactions will have a strong influence on the processes leading to ignition. It was also shown that the presence of oxygen greatly increases the rate of thermal cracking.     

IGNITION DELAY AND SOOT EMISSION CHARACTERISTICS OF METHANOL-DIESEL FUEL BLENDS

ABSTRACT

Alcohols, as alternative fuels, may contribute to the solution of environmental and economical problems to a certain extend. But, they seem to have little chances to be directly used in Diesel engines because of their low cetane number. However, as blended fuels with diesel fuel they have places on the application area. In this study, the effect of the compression ratio on ignition delay and soot emission for methanol-diesel fuel blends with various blending ratios is investigated on an ASTM-CFR engine and the results are compared with baseline diesel fuel. Longer ignition delays and less soot emissions have been obtained for blend fuels as compared to diesel fuel.     

Performance and emissions characteristics of C.I. engine fueled with palm oil/palm oil methyl ester blended with diesel fuel

The rapid increasing worldwide demand for energy, continuous increasing of fuel consumption and the progressive depletion of fossil fuels led to an intensive search for biodiesel as alternative fuel for diesel engine. Performance and emissions characteristics of C.I. engine fueled with palm oil/palm oil methyl ester blended with diesel fuel is investigated experimentally. Biodiesel was prepared from palm oil by transesterification process. Diesel, biodiesel and palm oil blends were prepared in volume percentages of 20 and 100% as B20, B100 and PO20. Physical and chemical properties of biodiesel blends were near to diesel fuel. The experimental study is conducted on a diesel engine at different engine loading from zero to full loads using palm oil and palm biodiesel and its blends with diesel fuel. Thermal efficiency of biodiesel and oil blends with diesel fuel was lower than diesel fuel. Specific fuel consumptions for biodiesel and oil blends were found to be higher than diesel oil. Unburned hydrocarbons and carbon monoxide emissions have been decreased for biodiesel blends but it increased for oil blends compared to diesel fuel. Nitrogen oxide emissions have slightly been increased for biodiesel and oil blends compared to diesel fuel. Blends of diesel – biodiesel up to 20% biodiesel percentage by volume are recommended because of the improvement in performance and emissions as compared to diesel fuel.     

柴油清净剂改善柴油机有害排放的研究

有关柴油中添加具有清净分散作用的添加剂的研究已成为降低柴油机排放的重要课题。在同一台TY1100柴油机上分别使用试验用空白柴油、加0.15％长城牌LCD级润滑油的柴油样品和加0.15％石油磺酸钙清净分散剂的柴油样品，测定了柴油发动机排放气中各种有害组分的含量、发动机性能和燃烧特性。结果表明，在柴油中添加石油磺酸钙清净分散剂，可以降低柴油机的排放烟度和CO含量，特别是烟度的降低幅度较大。柴油机在高输出功率区域运转时，随着功率的增大，烟度的下降幅度增大。     

Effect of waste cooking-oil biodiesel on performance and exhaust emissions of a diesel engine

The ever increase in global energy demand, consumption of depletable fossil fuels, exhaust emissions and global warming, all these led to search about alternative fuels. Biodiesel was produced from waste cooking-oil by transesterification process. Blends of waste cooking-oil biodiesel and diesel oil were prepared in volume percentages of 10, 20 and 30% as B10, B20 and B30. Biodiesel blends have ASTM standards of physical and chemical characterization near to diesel fuel. Diesel engine performance and exhaust emissions were studied experimentally for burning waste cooking-oil blend with diesel fuel. This experimental was applied on a diesel engine at different engine loads from zero to full load. Thermal efficiencies for waste cooking-oil biodiesel blends were lower than diesel oil. Specific fuel consumptions of biodieselblends were higher than diesel fuel. Higher exhaust gas temperatures were recorded for biodiesel blends compared to diesel oil. CO₂ emissions for waste cooking-oil biodiesel blends were higher than diesel oil. CO, smoke opacity and HC emissions for biodiesel blends were lower than diesel fuel. NO_x emissions for biodiesel blends were higher than diesel fuel.     

PERFORMANCE OF AUTOMOTIVE RECIPROCATING ENGINES WITH DIFFERENT FUELS

A single cylinder reciprocating engine test rig was used to measure power output, specific fuel consumption, exhaust gas temperature and energy balance for different speeds, air-fuel ratios and compression ratios with gasoline and diesel oil as fuels. Comparison of the results for the same compression ratios and range of running speeds shows that gasoline produces higher power and exhaust temperatures than diesel oil. However, it produced less thermal efficiency up to 2000 rpm speed. The energy balance shows slightly higher percentage in power and exhaust energy but markedly less radiation energy to the atmosphere with diesel oil.     

汽油与柴油掺兑用作柴油机应急燃料的试验研究

将不同比例的车用汽油掺入柴油中，进行实验室理化性能分析和发动机台架外特性试验分析。结果表明，柴油中掺入车用汽油后，对发动机功率、扭矩、平均爆发压力影响较大，使动力性能下降，燃料消耗率升高，排气烟度降低。对于柴油机来说，汽油与柴油混合油只能作为应急燃料使用，不能长期使用。应急燃料对于提高战时油料保障能力具有重要意义。     

低排放、长寿命柴油机对燃料和润滑油的需求

降低环境污染是世界共同关注的目标，重负荷柴油车作为氮氧化物和颗粒物排放的贡献者，清洁型柴油机是达到排放要求的关键因素，柴油机后处理系统对燃料和润滑油提出更高要求，带有尾气后处理发动机必须使用低硫燃料和低硫、低磷、低硫酸盐灰分（低SAPS）柴油机油。     

轻负荷柴油发动机润滑特点及其润滑油规格发展

介绍了轻负荷柴油发动机的润滑特点：机油箱体积小，每升润滑油负载功率大，润滑油循环量大，热负荷和机械负荷都很高。分析了ACEA轻负荷柴油发动机油的规格发展以及评价体系：自1983年开始出现轻负荷柴油发动机油规格，至今已进行多次修改；评价柴油机油性能有3方面内容，高温清净性和环粘结台架试验、中温分散性台架试验以及磨损和粘度增长台架试验。最后介绍了我国发展柴油轿车的可行性和目前的生产现状，中国石油在轻负荷发动机油评价体系建立方面所做的研究工作。     

把柴油机改装成天然气柴油机

为了充分利用油田的天然气资源,并尽量节约柴油,可将柴油机改装成天然气(主要)和柴油(少量)为燃料的双燃料发动机,简称天然气柴油机。本文分别介绍了自然进气四冲程柴油机和四冲程增压柴油机的改装方案。改装成的天然气柴油机,在天然气不能正常供应时,通过一个天然气-柴油自动切换装置,仍可完全用柴油为燃料运行。