Category Archives: 1995 Special Issue

Biofuel: technical, economic and environmental impacts

The world’s primary energy demand has quadrupled since 1950. Great changes and destructions in the environment have been caused by the combustion of huge amounts of fossil fuels. A reduction of the combustion of fossil fuels can be achieved by saving energy as well as by using renewable energies. Vegetable oil is one representative of the renewable fuels. Today the use of vegetable oils is mainly limited to nutrition and the production of cosmetics and detergents. We are witnessing a renaissance of vegetable oils as lubricating and fuel oils, caused by the search for renewable energies as well as by the surplus on many agricultural markets. Pure vegetable oils cannot be used in most conventional diesel engines. They can be similar in their properties to diesel fuel by means of the esterification process.

Within the next years, several 100 000 tonnes per annum of rapeseed oil methyl ester is to be produced in the European Union. To be able to use raw vegetable oil a fuel in diesel engines, precautions have to be considered to prevent the deposition of oil coke. One of the methods to make the use of vegetable oil in direct-injected diesel engines possible is the “duotherm” method invented by Ludwig Elsbett. The author is convinced that the worldwide first car manufacturer to include vegetable oil engines in his series production will enjoy a great economic success. By using vegetable oil fuels, at least part of the energy supply can be provided in an approximate equilibrium between man and environment.

Production and evaluation of palm oil methyl esters as diesel substitute

The fast diminishing energy reserves, greater environmental awareness and increasing energy consumption have led to an intensified search for viable alternate sources of energy globally. In this respect PORIM/PETRONAS has patented an efficient process to produce methyl esters from palm oil with varying amounts of free fatty acid content. The process requires milder conditions ie. low temperature (80°C and lower pressure (atmospheric) than the existing commercial processes. The production technology has been successfully demonstrated at a pilot plant (3,000 tonnes/year) scale and the technology is now ready for commercial exploitation.

Over the past few years, palm oil methyl esters has been extensively evaluated as diesel substitute in a wide range of diesel engines including stationary engines, passenger cars, buses and trucks. The last phase of an exhaustive field trial involving 36 buses is near completion. The buses are running on three fuels i.e. 100% palm oil methyl esters, 100% petroleum diesel (as control) and, a 5O:50 blend of the two fuels. So far very promising results have been obtained as follows:

1. No modification of the diesel engine is required
2. Engine performance is very good
3. The exhaust emission is much cleaner with reduction in black smoke, NOx, CO and absence of SO2
4. No abnormal wear and fear in engine components and no nozzle deposits
5. No engine oil dilution
6. Fuel consumption is comparable

This paper describes the production technology and evaluation of the palm oil methyl esters as diesel substitute/diesel improver.

Integrated production of bio-diesel esters and glycerol: top grade gylcerol as key factor of economical success in the bio-diesel cycle

It has been noted that, beginning from early 1991 till now a substantial number of transesterification plants have been in operation all over the world. Continental Europe has been particularly active in this field, due to the interest of the bussiness itself but mainly due to the encouragement of Regional, National and EEC Authorities finally to search for a stable solution of the dramatic problems of pollution, a more rational use of city for fuels and a better performance of agricultural resources. The agreements of last GATT and consequence of new PAC has given a further impulse to this activity.

Modern serial engines operating with natural diesel fuel 50 – 200 kW (60 – 270 b.h.p.)

Natural diesel is a fuel produced from crude plant oil. To use this high boiling and thick flowing fuel, a modern diesel engine has to be developed. The conventional pre-chamber engines in general are able to operate with natural diesel fuel. Biodiesel is the synonym for thin-bodied made plant oil methyl ester (PME). Both conceptions complement each other positively.

PME is suitable to be used for such engines already in production. Crude palm oil is more suitable for specially developed engines. Natural diesel is rather easily produced hence plant oil engine fleets are independent from central fuel distribution networks.

Future trends of biofuels engines with Elsbett-technology

Both animals and plants create fatty deposits as an energy reserve – the former in their reproductive organs, the latter in their vegetative organs. The vehicles for the reproduction and dissemination of plants are seeds. In these seeds the energy deposit is frequently formed by fatty matter. The seeds can also be surrounded by fatty fruit pulp.

Plants which produce large amounts of oil are known as oleaginous. Of these only about ten are used for commercial purposes. Some others are used from region to region in a semi-extractive manner, while there are hundreds of little-known oleaginous plants, not yet used commercially, which can be excellent sources of fuel.

Even though the processing of vegetable oils to yield fuels similar to standard diesel is one of the dominating biofuel trends today, ELSBETT sees no future for it. It will disappear together with the ability of governments to heavily sponsor it, and together with the still existing problems of food overproduction in some countries.

Diesel engine operation with vegetable oil – alcohol emulsion

Results of single-cylinder, direct-injection diesel engine tests for a range of loads at two speeds for emulsions with 10 per cent (by volume) of ethyl alcohol of a commercial seed-based oil are presented. Values of ignition delay, specific fuel consumption, thermal efficiency and equivalence ratio and exhaust gas concentrations of carbon monoxide, carbon dioxide, oxides of nitrogen and smoke particulates are given.

Comparison is made between the magnitudes of the measured parameters for the emulsion of vegetable oil with alcohol and those for diesel fuel, vegetable oil and an emulsion of this with water.

The effect of emulsification with alcohol was, in general, to increase carbon monoxide and reduce oxides of nitrogen emissions. Effects on ignition delay and smoke were different at different engine speeds.

Vegetable oil engine

Fossil energy raw materials are limited and have a negative CO2 cycle balance. Its use will be reduced through renewable energy. The utilization of vegetable oil as a renewable raw material will improve the COcycle balance.  There are several advantages of using vegetable oils versus fossil energy carriers for the environment.

Preparation of palm oil esters-diesel fuel mix and its performance test on stationary engine

As the consumption and import of diesel fuel increase in Indonesia, palm oil esters are now being considered to gradually replace the petroleum based fuel. A study on the laboratory preparation of methyl esters from crude palm oil has been successfully carried out in LEMIGAS R & D Centre for Oil and Gas Technology, Jakarta. Preliminary evaluation of palm oil methyl esters as diesel fuel and as diesel fuel substitute was initiated based on performance test on stationary engine. The test showed that the torque and power are lower and specific fuel consumption is larger when using the ester.

The use of biofuel in modern diesel engines

It is known the best possibility of adapting vegetable oils to the demand of existing diesel engines is transesterification to vegetable oil fatty acid esters, usually with methanol to vegetable oil fatty acid methyl esters.The resulting vegetable oil methyl ester can basically be used in all existing diesel engines even though their use necessitates modifications to the engine or the vehicle, sometimes to the fuel tank or to some adjustment parameters. In the engine investigations, a test of alternative fuels in the commercial vehicle division has been done which comprise single-cylinder engine tests, multi-cylinder engine test and vehicle field test.

Investigation on palm oil diesel emulsion as fuel extender for diesel engine

Results of performance, exhaust emissions and lube oil analysis of diesel engine fuelled with Malaysian palm oil diesel (POD) and ordinary diesel (OD) emulsions containing 5% and 10% of water by volume are compared with those obtained when 100%o POD and OD fuel were used. Very promising results have been obtained. Neither the lower cetane number of palm oil diesel fuel nor its emulsification with water presented obstacle to the operation of diesel engine during steady state engine tests and the twenty-hour endurance tests. Polymerization and carbon deposits on fuel injector nozzles were monitored. Engine performance and fuel consumption for POD and its emulsions are comparable with those of OD fuel. Accumulations of wear metal debris in crank-case oil samples were lower with POD and emulsified fuels compared with baseline OD fuel, both OD and POD emulsions with 10% water by volume show promising tendency for wear resistance. The exhaust emissions for POD and the emulsified fuels are found to be much cleaner, containing less CO, CO2 and hydrocarbon (HC); the absence of black smoke from the exhaust is an advantage. Theoretical aspects of diesel combustion are used to aid the interpretation of the observed engine behaviour.

Preliminary observations of using palm oil as fuel for cars fitted with Elsbett engine

Automobiles consume a high proportion of fossil oil which is a significant contributor to major global problems such as oil supply and through the associated emission, to global warming, acidification and urban air pollution. Several approaches in dealing with these problems involving automobiles must include their fuel economy, emissions and choice of fuel. In 1983 a symposium on vegetable oils as diesel fuels revealed that vegetable oils have good potential as alternative fuels if the problems of high viscosity, low volatility and the reactivity (polymerization) of the unsaturated hydrocarbon chains can be overcome.

The Elsbett engine was first introduced to Malaysia in 1984. It started with a joint study between Elsbett Konstruktion Germany, Mitsui of Japan and PORIM. In that joint study, four units of Elsbett engines were brought in to undergo trials to determine suitability of neutralised palm oil and palm diesel as fuel. Two units were used as generator sets running on palm diesel and palm oil as fuel. The other two units were used on two cars, each running on either palm diesel or neutralised palm oil. The palm oil car covered nearly 65,000 km and the palm diesel car covered 75,000 km. The results of this trial seemed to be satisfactory.

Based on that trial, several developments had to be made which includes:

– providing heaters to the fuel lines from the tank to the fuel filters,
– providing starting fuel which filled the injectors before the engine is switched off,
– providing collar heaters to the casing of the fuel filters,
– automatic changing over from starting fuel to crude palm oil (CPO) supply when the CPO fuel is in liquid state.

Biofuel: impact on environment

The paper focuses on the issue of reducing tailpipe emissions through the use of biofuels. Considerations central to the selection of biofuel against other alternative fuels for automotive use are also highlighted. The paper briefly compares emissions data available on crude palm oil methyl ester from a study conducted at PRRS.

Emission of Elsbett engine using palm oil fuel

Recent monitoring of the emission from the exhaust had shown that operating the multifuel Elsbett engine with palm oil resulted in an improvement when compared with that when operating on diesel fuel under identical conditions.

There were reductions in 29.70% of hydrocarbons, 7.6% of nitrogen oxides, and 47.2% in particles. Similarly there was also significant reduction in the emission of benzene, toluene, ethyl-benzene and xylene when diesel was replaced by palm oil as fuel. There were however slight increases in carbon monoxide (by 2.4%), carbon dioxide (by 1.2%) and also fuel consumption (by 7.0%). In terms of smoke characteristics, there were distinct improvements in the BOSCH smoke number (by 29-61%) and opacity (by 45-86%) in the range of engine operating speeds from 1845 to 4100 rpm.

Exhaust emissions and engine performance from the use of soya methyl ester blended with ARB #2 diesel in a 6V92TA MUI engine

This project’s objective was to examine the viability of a soya bean oil derivative, soya methyl ester (methyl ester) and ARB diesel fuel blends as an interim emissions-reduction solution for California’s transit properties as they progressively convert to cleaner technologies and fuels. A Detroit Diesel 6V92TA MUI engine was operated on a blend of two fuels: #2 diesel, subject to October 1, 1993 California Air Resources Board standards (ARB diesel) and methyl ester. Fuel characterization was conducted on ARB diesel, methyl esters from various suppliers and methyl ester/ARB diesel blends. Fuel quality varied with methyl esters from different suppliers. Engine dynamometer tests identified significant trends in exhaust emissions. When compared to the ARB diesel baseline, higher blend percentages of methyl esters led to increased emissions of oxides of nitrogen (6%-10%), carbon dioxide (2%-3%) and soluble particulate matter (19%-35%). Also noted were reductions in total hydrocarbons (16%-32%), carbon monoxide (8%-22%) and insoluble particulate matter (10%-37%). Chassis dynamometer tests showed similar trends in exhaust emissions. Field tests consisted of daily refuelling (using 20/80 and 25/75 methyl ester/ARB fuel blends) and operation of a mass transit passenger vehicle within the Los Angeles basin. These tests were conducted to determine the blends’ effects on engine performance and wear. Drivers’ comments and periodic engine oil analyses indicated no adverse effects. This project demonstrated that 20% soya oil-based methyl esters/ARB diesel blends do not lower emissions to merit utilization by the heavily regulated California mass transit industry. However, the results do indicate that soya oil-derived methyl esters, coupled with known technologies that reduce the soluble fraction of particulate emissions, deserves further exploration as a possible transition fuel option for the Southern California mass transit sector. This project did not develop any new jobs within the Los Angeles basin.