It may be useful to try to compile the reports from studies done over the past few decades on compatability of vegoil fuel in diesle engines.

When I became re-involved with vegoil fuels several years ago I began scouring the web for information and found quite a bit. When my computer crashed hard last winter the cd drives were fried but the "computer guy" said the hard drive may be OK. So I saved it and am finally inspired to piggyback it on my existng computers hard drive.

Until then I have some related stuff I saved on CDR and will post it here. I invite anyone else that has saved info from the vegetable oil fuel studies done in the past decades to share it here as well.

The first paper I am posting is an overview of the studies and papers on this subject. I encourage all interested to scroll down to the bibliography to get leads for searching for papers and reports on vegoil fuel substitution.

If anyone want to discuss info in these papers/reports lets start a separate discussion for that.

Using Unmodified Vegetable Oils as a Diesel Fuel Extender –
A Literature Review

By
Sam Jones and Charles L. Peterson
Graduate Research Assistant and Professor and Interim Head
Department of Biological and Agricultural Engineering
University of Idaho, Moscow, Idaho 83843


Abstract
This paper is a review of literature concerning using vegetable oils as a replacement for diesel fuel. The term vegetable oils as used in this paper refers to vegetable oils which have not been modified by transesterification or similar processes to form what is called biodiesel. The oils studied include virgin and used oils of various types including soy, rapeseed, canola, sunflower, cottonseed and similar oils. In general, raw vegetable oils can be used successfully in short term performance tests in nearly any percentage as a replacement for diesel fuel. When tested in long term tests blends above 20 percent nearly always result in engine damage or maintenance problems. Some authors report success in using vegetable oils as diesel fuel extenders in blends less than 20 percent even in long term durability studies. Degumming is suggested by one author as a way to improve use of raw oils in low level blends. It is apparent that few, if any, engine studies using low-level blends of unmodified vegetable oils, < 20%, have been conducted.


Introduction
Many studies have been done at the University of Idaho and elsewhere involving vegetable oils as a primary source of energy. Particularly, during the early 1980's, studies were completed that tested the possibility of using unmodified vegetable oils as a replacement for diesel fuel.
There is no question that vegetable oil can be placed in the tank of a diesel powered vehicle and the engine will continue to run and deliver acceptable performance. Some vegetable oils, such as rapeseed oil, have very high viscosity and thus may starve the engine for fuel when operated at 100 percent. Most studies show that power and fuel economy, when compared to operation on diesel, are proportional to the reduced heat of combustion of the vegetable oil fuel.
Despite the success when diesel engines are operated on vegetable oil for short term performance tests, the real measure of success when using vegetable oil as a diesel fuel extender or replacement depends primarily on the performance of vegetable oils in engines over a long period of time. Thus many researchers have been involved in testing programs designed to evaluate long term performance characteristics. Results of these studies indicated that potential hazards such as stuck piston rings, carbon buildup on injectors, fuel system failure, and lubricating oil contamination (Pratt, 1980) existed when vegetable oils were used as alternative fuels. This effect diminishes as the blend of vegetable oil in diesel is decreased. The question of this literature review is to determine if there is a blend level at which vegetable oil in the unmodified form can be used as a diesel fuel extender. Throughout this paper when the term vegetable oil or the name of a particular vegetable oils is used, such as canola, it refers to the unmodified form.

100 Per Cent Vegetable Oil as Potential Fuel Sources
During World War II, Seddon (1942) experimented with using several different vegetable oils in a Perkins P 6 diesel engine with great success. The results of this experiment showed that vegetable oils could be used to power a vehicle under normal operating conditions. However, it was noted that much more work was needed before vegetable oils could be used as a reliable substitute for diesel fuel.
The Southwest Research Institute, Reid et al. (1982), evaluated the chemical and physical properties of 14 vegetable oils. These injection studies pointed out that the oils behave very differently from petroleum-based fuels. This change in behavior was attributed to the vegetable oils’ high viscosity. Engine tests showed that carbon deposits in the engine were reduced if the oil was heated prior to combustion. It was also noted that carbon deposit levels differed for oils with similar viscosities, indicating that oil composition was also an important factor.
Goering et al. (1981) studied the characteristic properties of eleven vegetable oils to determine which oils would be best suited for use as an alternative fuel source. Of the eleven oils tested, corn, rapeseed, sesame, cottonseed, and soybean oils had the most favorable fuel properties.
Bruwer et al. (1980) studied the use of sunflower seed oil as a renewable energy source. When operating tractors with 100% sunflower oil instead of diesel fuel, an 8% power loss occurred after 1000 hours of operation. The power loss was corrected by replacing the fuel injectors and injector pump. After 1300 hours of operation, the carbon deposits in the engine were reported to be equivalent to an engine fueled with 100% diesel except for the injector tips, which exhibited excessive carbon build-up.
Tahir et al. (1982) tested sunflower oil as a replacement for diesel fuel in agricultural tractors. Sunflower oil viscosity was 14% higher than diesel fuel at 37°C. Engine performance using the sunflower oil was similar to that of diesel fuel, but with a slight decrease in fuel economy. Oxidation of the sunflower oil left heavy gum and wax deposits on test equipment, which could lead to engine failure.
Bacon et al. (1981) evaluated the use of several vegetable oils as potential fuel sources. Initial engine performance tests using vegetable oils were found to be acceptable, while noting that the use of these oils caused carbon build up in the combustion chamber. Continuous running of a diesel engine at part-load and mid-speeds was found to cause rapid carbon deposition rates on the injector tips. Short 2-hour tests were used to visually compare the effects of using different vegetable oils in place of diesel fuel. Although short-term engine test results were promising, Bacon recommended long-term engine testing to determine the overall effects of using vegetables oils as a fuel in diesel engines.
Schoedder (1981) used rapeseed oils as a diesel fuel replacement in Germany with mixed results. Short-term engine tests indicated rapeseed oil had similar energy outputs when compared to diesel fuel. Initial long-term engine tests showed that difficulties arose in engine operation after 100 hours due to deposits on piston rings, valves, and injectors. The investigators indicated that further long-term testing was needed to determine if these difficulties could be adverted.
Auld et al. (1982) used rapeseed oil to study the effects of using an alternative fuel in diesel engines. An analysis of the rapeseed oil showed a relationship between viscosity and fatty acid chain length. Engine power and torque results using rapeseed oil were similar to that of diesel fuel. Results of the short-term tests indicated further long-term testing was needed to evaluate engine durability when rapeseed oil was used.

Bettis et al. (1982) evaluated sunflower, safflower, and rapeseed oils were evaluated as possible sources for liquid fuels. The vegetable oils were found to contain 94% to 95% of the energy content of diesel fuel, and to be approximately 15 times as viscous. Short-term engine tests indicated that for the vegetable oils power output was nearly equivalent to that of diesel fuel, but long-term durability tests indicated severe problems due to carbonization of the combustion chamber.
Engler et al. (1983) found that engine performance tests using raw sunflower and cottonseed vegetable oils as alternative fuels gave poor results. Engine performance tests for processed vegetable oils produced results slightly better than similar tests for diesel fuel. However, carbon deposits and lubricating oil contamination problems were noted, indicating that these oils are acceptable only for short-term use as a fuel source.
Pryor et al. (1983) conducted short and long-term engine performance tests using 100% soybean oil in a small diesel engine. Short-term test results indicated the soybean performance was equivalent to that of diesel fuel. However, long-term engine testing was aborted due to power loss and carbon buildup on the injectors.
Yarbrough et al. (1981) experienced similar results when testing six sunflower oils as diesel fuel replacements. Raw sunflower oils were found to be unsuitable fuels, while refined sunflower oil was found to be satisfactory. Degumming and dewaxing the vegetable oils were required to prevent engine failure even if the vegetable oils were blended with diesel fuel.
Over 30 different vegetable oils have been used to operate compression engines since the 1900’s (Quick, 1980). Initial engine performance suggests that these oil-based fuels have great potential as fuel substitutes. Extended operation indicated that carbonization of critical engine components resulted from the use of raw vegetable oil fuels, which can lead to premature engine failure. Blending vegetable oil with diesel fuel was found to be a method to reduce coking and extend engine life.
Pryde (1982) reviewed the reported successes and shortcomings for alternative fuel research. This article stated that short-term engine tests using vegetable oils as a fuel source was very promising. However, long-term engine test results showed that durability problems were encountered with vegetable oils because of carbon buildup and lubricating oil contamination. Thus, it was concluded that vegetable oils must either be chemically altered or blended with diesel fuel to prevent premature engine failure.
Studies involving the use of raw vegetable oils as a replacement fuel for diesel fuel indicate that a diesel engine can be successfully fuel with 100% vegetable oil on a short-term basis. However, long-term engine durability studies show that fueling diesel engines with 100% vegetable oil causes engine failure due to engine oil contamination, stuck piston rings, and excessive carbon build-up on internal engine components. Therefore 100% unmodified vegetable oils are not reasonable diesel fuel replacements.

Vegetable Oil, Diesel Blends as Potential Fuel Sources
Engelman et al. (1978) presented data for 10% to 50% soybean oil fuel blends used in diesel engines. The initial results were encouraging. They reported at the conclusion of a 50-hour test that carbon build-up in the combustion chamber was minimal. For the fuel blends studied, it was generally observed that vegetable oils could be used as a fuel source in low concentrations. The BSFC and power measurements for the fuel blends only differed slightly from 100% diesel fuel. Fuel blends containing 60% or higher concentrations of vegetable oil caused the engine to sputter. Engine sputtering was attributed to fuel filter plugging. They concluded that waste soybean oil could be used as a diesel fuel extender with no engine modifications.
Studies in New Zealand by Sims et al. (1981) indicated that vegetable oils, particularly rapeseed oil, could be used as a replacement for diesel fuel. Their initial short-term engine tests showed that a 50% vegetable oil fuel blend had no adverse effects. While in long-term tests they encountered injector pump failure and cold starting problems. Carbon deposits on combustion chamber components was found to be approximately the same as that found in engines operated on 100% diesel fuel. These researchers concluded that rapeseed oil had great potential as a fuel substitute, but that further testing was required.
Caterpillar (Bartholomew, 1981) reported that vegetable oils mixed with diesel fuel in small amounts did not cause engine failure. Short-term research showed that blends using 50/50 were successful, but that 20% vegetable oil fuel blends were better.
Deere and Company (Barsic and Humke, 1981) studied the effects of mixing peanut oil and sunflower oil with Number 2 diesel fuel in a single cylinder engine. The vegetable oil blends were observed to increase the amount of carbon deposits on the combustion side of the injector tip when compared with 100% diesel fuel. The vegetable oil fuel blends were found to have a lower mass-based heating value than that of diesel fuel. Fuel filter plugging was noted to be a problem when using crude vegetable oils as diesel fuel extenders.
International Harvester Company (Fort et al. 1982) reported that cottonseed oil, diesel fuel blends behaved like petroleum-based fuels in short-term performance and emissions tests. The experimental fuels performed reasonably well when standards of judgment were power, fuel consumption, emissions, etc. However engine durability was an issue during extended use of these fuel blends because of carbon deposits and fueling system problems.
Other research at International Harvest Company (Baranescu and Lusco, 1982) was done using three blends of sunflower oil and diesel fuel. Results indicated that the sunflower oil caused premature engine failure due to carbon buildup. It was noted that cold weather operation caused fuel system malfunctions.
Worgetter (1981) analyzed the effects of using rapeseed oil as a fuel in a 43-kW tractor. The goal of running the tractor for 1000 hours on a blend of 50% rapeseed oil and 50% diesel was never achieved as the test was aborted at about 400-hours due to unfavorable operating conditions. The use of rapeseed oil in the fuel resulted in heavy carbon deposits on the injector tips and pistons, which would have caused catastrophic engine failure if the tests had not been aborted. Upon engine tear down, it was found that the heavy carbon deposits on the pistons was the cause of the noted power loss and not the fuel injectors.
Wagner and Peterson (1982) reported mixed results when using rapeseed oil as a substitute fuel. Attempts to heat the oil fuel mixture prior to combustion exhibited no measurable improvement in fuel injection. Severe engine damage was noted during short-term engine testing due to the use of rapeseed oil. A long-term test using a 70% rapeseed, diesel fuel blend was successful for 850 hours with no apparent signs of wear, contamination of lubricating oil, or loss of power.
Van der Walt and Hugo (1981) examined the long-term effects of using sunflower oil as a diesel fuel replacement in direct and indirect injected diesel engines. Indirect injected diesel engines were run for over 2000 hours using de-gummed, filtered sunflower oil with no adverse effects. The direct injected engines were not able to complete even 400 hours of operation on the 20% sunflower oil, 80% diesel fuel mixture without a power loss. Further analysis of the direct injected engines showed that the power loss was due to severely coked injectors, carbon buildup in the combustion chamber, and stuck piston rings. Lubricating oil analysis also showed high piston, liner, and bearing wear.

Engine Testing by Ziejewski and Kaufman (1982) at Allis Chalmers using a 50/50 blend of sunflower oil and diesel was unsuccessful. Carbon buildup on the injectors, intake ports, and piston rings caused engine operating difficulties and eventual catastrophic failure.
Fuls (1983) reported similar findings for indirect and direct injection engines using 20% sunflower oil, diesel fuel blends. Fuls Emphasized that injector coking was the problem with using sunflower oil in direct injected diesel engines.
Caterpillar Tractor Co. (McCutchen, 1981) compared engine performance of direct injection engines to indirect injection engines when fueled with 30% soybean oil, 70% diesel fuel. The results showed that indirect injection could be operated on this fuel blend while the direct injection engine could not without catastrophic engine failure occurring. The direct injection engines showed injector coking and piston ring sticking as a result of using sunflower oil.
An on-farm study using six John Deere and Case tractors by German et al. (1985) averaged 1300-hours of operation. Carbon deposits on the internal engine components were greater for the tractors fueled with 50/50 sunflower oil/diesel than for those fueled with a 25/75 sunflower oil/diesel fuel blend. All the test engines had more carbon build-up than normally seen in an engine fueled with diesel fuel. The results of this study indicated that neither of the fuel blends could be use as a replacement for petroleum based fuels on a permanent basis without shortening engine life.
Peterson et al. (1982) used rapeseed oil as a diesel fuel extender to study the long-term effects of using vegetable oils as a fuel source. Fuel composed of 70% rapeseed oil and 30% Number 1 diesel fuel was successfully used to operate a small single cylinder engine for 850 hours. No adverse operating conditions were reported at the conclusion of this engine study. A short-term performance test using a 100% sunflower oil caused severe piston ring gumming and catastrophic engine failure. This study highlighted the need for significant long-term engine testing before recommendations of using vegetable oil as a fuel could be made.
Nag et al. (1995) did studies involving the use of seed oils grown natively in India. Performance tests using fuel blends as great as 50-50 seed oil from the Indian Amulate plant and diesel fuel exhibited no loss of power. Knock free performance with no observable carbon deposits on the functional parts of the combustion chamber were also observed during these tests. Although this seed oil was not yet commercially available at the time of this study, it was hoped that it soon would be.
Sapaun et al. (1996) reported that studies in Malaysia, with palm oils as diesel fuel substitutes, exhibited encouraging results. Performance tests indicated that power outputs were nearly the same for palm oil, blends of palm oil and diesel fuel, and 100% diesel fuel. Short-term tests using palm oil fuels showed no signs of adverse combustion chamber wear, increase in carbon deposits, or lubricating oil contamination.
Ryan et al. (1984) characterized injection and combustion properties of several vegetable oils. The atomization and injection characteristics of vegetable oils were significantly different from that of diesel fuel due to the higher viscosity of the vegetable oils. Engine performance tests showed that power output slightly decreased when using vegetable oil fuel blends. Injector coking and lubricating oil contamination appeared to be a more dominate problem for oil-based fuels having higher viscosities.
Pestes and Stanislao (1984) used a one to one blend of vegetable oil and diesel fuel to study piston ring deposits. Premature piston ring sticking and carbon build-up due to the use of the one to one fuel blend caused engine failure. The severest carbon deposits were located on the major thrust face of the first piston ring. These investigators suggested that to reduce piston ring deposits a fuel additive or a fuel blend with less vegetable oil was needed.

Other studies by Hofman et al. (1981) and Peterson et al. (1981) indicated that while vegetable oil fuel blends had encouraging results in short term testing, problems occurred in long-term durability tests. They indicated that carbon build-up, ring sticking, and lubricating oil contamination was the cause of engine failure when vegetable oils were used in high percentages (50% or more) as diesel fuel substitutes.
Due to engine durability problems encountered using raw vegetable oils as a fuel in the early 1980's, most researchers opted to use chemically modified vegetable fuels more commonly known as biodiesel in place of unrefined vegetable oils. Thus, in recent years there has been little literature concerning the feasibility of using raw vegetable oils as a fuel additive.
McDonnell et al. (2000) studied the use of a semi-refined rapeseed oil as a diesel fuel extender. Test results indicated that the rapeseed oil could serve as a fuel extender at inclusion rates up to 25%. As a result of using rapeseed oil as a fuel, injector life was shortened due to carbon buildup. However, no signs of internal engine wear or lubricating oil contamination were reported.

Conclusions
Many studies involving use of un-modifed vegetable oils in blend ratios with diesel fuel exceeding 20 percent were conducted in the early 1980’s. Short-term engine testing indicates that vegetable oils can readily be used as a fuel source when the vegetable oils are used alone or are blended with diesel fuel. Long-term engine research shows that engine durability is questionable when fuel blends contain more than 20% vegetable oil by volume. More work is needed to determine if fuel blends containing less than 20% vegetable oil can be used successfully as diesel fuel extenders.


References
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Wagner, G. L., and C. L. Peterson. 1982. Performance of winter rape (Brassica Napus) based fuel mixtures in diesel engines. Vegetable Oil Fuels: Proceedings of the International Conference on Plant and Vegetable Oils Fuels. St. Joseph, MI: ASAE.
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Results of engine and vehicle testing of semi-refined rapeseed oil

Kevin P. McDonnell, Shane M. Ward & Paul B. McNulty

University College Dublin, Dept of Agricultural & Food Engineering, Earlsfort Terrace.
Dublin 2, Ireland.

ABSTRACT

The renewed interest in environmentally compatible fuels has led to the choice of rapeseed oil as the main alternative to diesel fuel in Europe. The objective of this research was to produce and test an economic and high quality non-esterified rapeseed oil suitable for use as a diesel fuel extender. This was achieved by acidified hot water degumming combined with filtration to five microns. This rapeseed oil, designated as a Semi Refined Oil (SRO), has a high viscosity in comparison with diesel. Hence SRO fuel can only be used as a diesel fuel extender, with inclusion rates of up to 25 %.

SRO proved to be a suitable diesel fuel extender, at inclusion rates up to 25 %, when used with direct injection combustion systems (viz. tractor type engines). Power output (at 540 rev/min at the power take off shaft) was reduced by c. 0.06% for every 1% increase in SRO inclusion rate, and brake specific fuel consumption (BSFC) increased by c. 0.14% per 1% increase in SRO inclusion rate (viz. a 25% SRO/diesel blend had a 1.5% decrease in power and a 3.5% increase in BSFC compared with diesel). These values are in accordance with the lower energy density of rapeseed oil fuels compared with diesel. Chemical and viscosity analysis of engine lubrication oil (after c. 170 hours per fuel tested), including metal contamination as an indicator of engine wear occurring, showed that there was no measurable effect on engine lubricating oil due to SRO inclusion in diesel oil. When SRO was used to fuel IDI engines (viz. light duty commercial vehicles), power was considerably reduced mainly due to inadequate air/fuel mixing.

KEYWORDS: Biodiesel, SRO, Injector Fouling, Engine Tests

INTRODUCTION
In 1900 at the Paris Exposition, Dr. Rudolf Diesel ran a prototype of his engine on groundnut oil (Lowry, 1990). In 1911 he was quoted as saying: "The diesel engine can be fed with vegetable oils and would help considerably in the development of agriculture of the countries which will use it". From the very beginning the diesel engine concept has been associated with vegetable oils as well as the original liquid coal-tar and later the petroleum derivatives (Seddon, 1942 and Wiebe et al., 1949). Initially, diesel engines were designed and developed to be of a dual-fuel nature, indeed it is believed that KHD Deutz engine manufacturers, Germany, warranted their original engines for operation with vegetable oils (Harwood, 1984). The practice of developing dual-fuelled engines continued up until the 1940's when two events caused a change in the development of the compression ignition engine. Firstly an abundance of petroleum supplies at a low cost tipped the fuel supply balance in favour of diesel fuel. Secondly, the effects of atmospheric pollution from automobiles were being felt in the Los Angeles basin and so that initiated the development of Clean Air legislation. This began to tighten the levels of emissions allowable from automobiles. The overall result of the two issues was to promote engine manufacturers to develop engines dedicated to run on diesel fuel oil and to tune the engine in order to decrease emissions thereby decreasing the ability of the engine to operate as a dual fuelled engine. Since the 1970's there has been a renewed interest in using vegetable oils in diesel engines for various reasons including: Political considerations, Environmental concerns, Economic aspects and European Union proposals.

The renewed interest in environmentally compatible fuels has led to the choice of rapeseed oil as the main alternative to diesel fuel in Europe. Esterified rapeseed oil (viz. rape methyl ester) has been the predominant vegetable oil fuel used because its characteristics are quite similar to diesel. It is, however, an expensive product (due to high processing costs) leading to renewed interest in an economic and high quality, non-esterified rapeseed oil. It has been demonstrated that the use of crude (gum content c. 2%) or degummed crude (gum content of 1.4%, this study) rapeseed oil leads to performance problems including filter blockages and engine coking. Gums are a major precursor of gel formation which becomes particularly problematic at temperatures below 2 °C. These problems can be ameliorated by using rapeseed oil which has been degummed to food grade standard (gum content < 0.2 %).

Methods and materials
The objective of this research was to produce an economic and high quality non-esterified rapeseed oil suitable for use as a diesel fuel extender. This was achieved by acidified hot water degumming combined with filtration to five microns. The resultant degummed and filtered oil, had a gum content, as determined by the Differential Scanning Calorimetry (DSC), of 0.13 %(w/w) compared with c. 1.4% for unfiltered degummed rapeseed oil, 0.4% for non winterised rape methyl ester and c. 2 % for crude rapeseed oil (manufacturers specifications). This rapeseed oil, designated as a Semi Refined Oil (SRO), has a high viscosity in comparison with diesel (589 mPa.s v. 22 mPa.s at -12 °C). Tests on fuel pumping systems have shown that, in order to support adequate fuel flow and atomisation, the maximum acceptable viscosity for a fuel, in order to prevent fuel starvation, is c. 55 mPa.s at - 12 °C. Hence SRO fuel can only be used as a diesel fuel extender, with inclusion rates of up to 25 % as the resultant blend has a viscosity of 55 mPa.s at -12°C. The 25% SRO/diesel blend has a slightly lower energy content than diesel (41 v. 43 MJ/kg) while its density is slightly higher (0.87 v. 0.85 kg/l).

The problems associated with the use of crude vegetable oils in diesel engines have been discussed elsewhere (Barsic and Humke, 1981, Ziejewski and Kaufman, 1983 Goering and Fry, 1984 and Kaufman et al., 1985). The main conclusion from these researchers is that coking is a potentially serious problem with unmodified vegetable oil fuels. A unique method (based on reduced injector needle opening pressure Virk et al., (1991) was used to accelerate fouling combined with 2-dimensional image analysis) for assessing injector fouling was developed which has the advantage of enabling a very rapid engine test cycle to be used. Current methods can require up to a five hour test cycle whereas this new procedure is based on a twenty minute engine cycle, shown to be equivalent to approximately 2 500 hours of normal engine operation. The method used fibre optics and a 2-dimensional image analysis package to assess the extent of injector coking. A Fouling Index (FI) based on the ratio between the fouled injector orifice area compared with a clean injector orifice area was developed which enabled the fouling propensity of various fuel blends to be correlated. This showed that injector orifice blocking increases with increasing SRO inclusion rates. For example, a 25% SRO /diesel blend gave a Fouling Index (FI) of 0.67 compared with 0.40 for diesel. This means that injector fouling would be expected to occur considerably faster when operating on a 25% SRO/diesel blend. Hence injector service intervals would need to be reduced accordingly (viz. an injector with a service interval of c. 1 000 hours would need to be serviced at c. 600 hours, i.e. 1 000 (0.4/0.67)). Further work is required to confirm these preliminary observations.

Results
In the Pennsylvania State University (Braun & Stephenson, 1982), short term tests were carried out on blends of degummed soyabean oil, ethanol and diesel in respective ratios of: 40: 20: 40, and 40: 30: 30. The engine was run for 25 hours on each blend. No problems were reported and no irregularities in the injector spray pattern was observed, however, the engine used for these tests was a 6 cylinder energy cell engine which utilises major and minor combustion chambers as in an indirect injection engine to aid turbulence and hence mixing of the air and fuel charge. This decreases the validity of comparing these results to standard agricultural diesel engines.

International Harvester Science and Technology Laboratory (Fort & Blumberg, 1982) conducted trials using blends of cottonseed oil and diesel oil. The cottonseed oil was refined almost to food grade in order to reduce its "particle content" to as low a value as possible by an inexpensive commercial treatment. The cottonseed oil was mixed with diesel in blends of: 30%, 50%, 65%, and 80% cottonseed oil. The tests consisted of 4 engine cycles at 15 hours per cycle. A 50% cottonseed oil: 50% diesel oil blend was chosen for a two hundred-hour endurance test. The short-term tests showed no significant differences between the fuels. After the endurance test the engine showed scoring on two of the cylinders, the corresponding pistons were also deeply scored with the surfaces torn. All the engines' top rings were heavily filled with a very hard carbonaceous deposit, which was obstructing the rings functions.

Barsic et al., (1981 a and b) evaluated crude soyabean oil, a 50: 50 mixture of crude soyabean oil and diesel, and degummed soyabean oil in a direct injection engine. The vegetable oils were evaluated in short-term tests i.e. 25 hours. Comparison of the engines performance and emissions for diesel versus the vegetable oils resulted in 1-2 g/l kWh lower thermal efficiency, 1-2 g/l kWh lower NOx, 2-20 g/l kWh more carbon monoxide, 1-2 g/l kWh more hydrocarbons and 1-2 g/l kWh more particulates for the vegetable oil. Comparing crude soyabean oil and degummed soyabean oil resulted in a 6% lower thermal efficiency for the crude oil versus a 1% lower thermal efficiency for the degummed oil. The coking of nozzles in both cases increased the emissions, with the crude soyabean giving a greater increase in total emissions than the degummed oil after 25 hours.

Jori and Hanzely (1993) experimented with rapeseed oil and rape methyl ester mixtures i.e. using rape methyl ester instead of diesel to lower the viscosity of the rapeseed oil. This was compared with both diesel and rape methyl ester. The performance of three tractors tested with a power take-off dynamometer was evaluated and concluded that there were no limitations with the use of rape oil fuels. The different fuels decreased the engine power by between 2-4% with a slightly improved energy consumption and combustion efficiencies. The rapeseed oil fuels had lower oxides of nitrogen, hydrocarbons and smoke emissions but slightly higher carbon monoxide emissions compared to diesel.

Worgetter (1981) carried out a series of tests using a research college tractor, which was fuelled with a blend of 50% (v/v) rapeseed oil and diesel. The rapeseed oil used was of food grade quality. These tests showed a power loss after 100 hours. At 350 hours the injector nozzles were visually inspected and although there were carbon residues, the manufacturer deemed that the injectors were suitable for continued use. The tests were stopped due to power losses and to prevent carbon deposits on the upper piston area.

King (1995) examined degummed and filtered rapeseed oil as a diesel fuel extender for direct injection engines. In that research a 15/85 (%v/v) blend of degummed and filtered rapeseed oil/ diesel was used to power a conventional agricultural tractor for c. 400 hours. Dynamometer testing showed that the outputs of power and torque were on average 2.5% lower on the test fuel compared with diesel. Brake specific fuel consumption was 1.5% higher with the test fuel also. An analysis of the engine lubricating oil for both diesel and the test blend showed no abnormal wear or elemental composition changes in the lubricating oil for the test fuel as compared to the diesel lubricating oil sample.

Semi Refined rapeseed Oil (SRO) proved to be a suitable diesel fuel extender, at inclusion rates up to 25 %, when used with direct injection combustion systems (viz. tractor type engines). Power output (at 540 rev/min at the power take off shaft) was reduced by c. 0.06% for every 1% increase in SRO inclusion rate, and brake specific fuel consumption (BSFC) increased by c. 0.14% per 1% increase in SRO inclusion rate (viz. a 25% SRO/diesel blend had a 1.5% decrease in power and a 3.5% increase in BSFC compared with diesel). These values are in accordance with the lower energy density of rapeseed oil fuels compared with diesel. Chemical and viscosity analysis of engine lubrication oil (after c. 170 hours per fuel tested), including metal contamination as an indicator of engine wear occurring, showed that there was no measurable effect on engine lubricating oil due to SRO inclusion in diesel oil. When SRO was used to fuel indirect injection combustion systems (viz. light duty commercial vehicles), power was considerably reduced mainly due to inadequate air/fuel mixing.

Conclusion
It was concluded that SRO can be used as a diesel fuel extender in unmodified direct injection diesel engines. The only practical difference observed in this study is that the injectors require more frequent servicing compared with diesel operation. The technology for producing SRO is relatively simple and hence offers the possibility of small, locally based production units as well as economic mass production units. Rape methyl ester requires major investment in industrial plant. For example, a rape methyl ester plant with a throughput of 36 000 tonnes per annum has an estimated capital cost of $18 million compared with approximately $3 million for an equivalent SRO rapeseed oil plant. Thus at road side diesel station, a 25% SRO/diesel blend would cost approximately $ 0.68/litre as compared to $0.73/litre for a 25% rape methyl ester/ diesel blend. Further work is required to determine if this cost advantage (7%) for a 25% SRO/diesel blend is sufficient to contravene any negative aspects of engine performance.

References:
Lowery J.P.A. 1990. Alternative fuels for automotive and stationary engines in developing countries. Institution of Mechanical Engineers Seminar, U.K., November 19-20, pp31-35.
Seddon R.H., 1942. Vegetable oils in commercial vehicles. Gas Oil Power, August, pp 136-146.
Wiebe R. & Nawakawska J. 1949. USDA Bibliographical US Government printing office, Bulletin no. 10.
Harwood H.J. 1984. Oleochemicals as a fuel; Mechanical and economic feasibility. Journal of the American Oil Chemists Society, 61 (2) pp 315-324.
Barsic N.J. & Humke A.L. 1981a. Performance and emission characteristics of a naturally aspirated diesel engine with vegetable oil fuels. Society of Automotive Engineers 810262 pp95-109.
Ziejewski M. & Kaufmann K.R. 1983. Laboratory endurance test of a sunflower oil blend in a diesel engine. Journal of the American Oil Chemists Society 60 (8) pp1567-1573.
Goering C.E. & Fry B. 1984. Engine durability screening test of a diesel oil/soy oil/ alcohol micro emulsion fuel oil. Journal of the American Oil Chemists Society 61 (10) pp. 1627-1632.
Kaufmann K.R., Ziejewski M., Pratt G.L. & Goettler H.J. 1985. Fuel injection anomalies observed during long term engine performance tests on alternative fuels. Society of Automotive Engineers 852089 pp 591-600.
Virk K., Herbstmann S. & Rawdon R. 1991. Development of direct injection diesel engine injector keep clean and clean up tests. Society of Automotive Engineers 912329 pp 820-830.
Braun D.E. & Stephenson K.O. 1982. Alternative fuel blends and diesel engine tests. Proceedings of the International Conference on Plant and Vegetable Oils as Fuels. American Society of Agricultural Engineers, August, pp294-299.
Fort E.F. & Blumberg P.N. 1982 Performance and durability of a turbocharged diesel engine fuelled with cottonseed oil blends. Proceedings of the International Conference on Plant and Vegetable Oils as Fuels. American Society of Agricultural Engineers, August, pp374-383.
Barsic N.J. & Humke A.L. 1981b. Performance and emission characteristics of a naturally aspirated diesel engine with vegetable oil fuels. Society of Automotive Engineers 810955 pp2925-2935.
Jori I.J. & Hanzely G. 1994. Biodiesel research in Hungry. Research Status Report, Institute of Agricultural Engineering, Godollo, Hungry.
Worgetter M. 1981. Results of a long term engine test based on rapeseed oil fuel. Contribution to ICEUM III, October, Berlin, Germany, Pergamon Press.
King A. 1995. Rapeseed oil as a diesel fuel extender. M.Eng.Sc. Thesis, National University of Ireland.

Dear Dana,
Congratulations on your extensive and informative posting.
Tests carried out in Malaysia has shown that Palm Oil is a far better oil in terms of production per hectare or per acre. The properties of palm oil also surpass that of other oils as a food product and pharmaceutical uses. Please go to: www.mpob.gov.my for more information.
I am not a staff member, just an interested party in biodiesel.
Thank you.

BK
Kuala Lumpur
Malaysia.

Hi,
I'm interested in converting a diesel van to run on vegetable oil. I read that it is only good for short term use. How long is short term use?
Shirel

Well, many people have run in excess of 100,000 miles on a 2 tank setup. I would consider that long term reliable. If you do your conversion right, you can use WVO for the life of the car.

Can I use wvo in the winter? I live in toronto. What would I have to do to run it in the winter? And what is the difference between running on wvo and running on biodiesel?
Shirel

quote:

Originally posted by shirel:
Can I use wvo in the winter? I live in toronto. What would I have to do to run it in the winter? And what is the difference between running on wvo and running on biodiesel?
Shirel

Shirel,

Welcome to the forum.
You'll find it very helpful to read the first two threads on the main page:
http://biodiesel.infopop.cc/eve/forums/a/frm/f/159605551

Titles:
-If you are new to this forum please read this first! Helpful info is HERE!
-10 steps to converting to wvo...the basic process

Then, if you have specific questions about your vehicle, or about conversions in general, you should try searching. Most aspects of conversions have been discussed at leangth, and you will find LOTS of helpful information here.

quote:

Thus at road side diesel station, a 25% SRO/diesel blend would cost approximately $ 0.68/litre as compared to $0.73/litre for a 25% rape methyl ester/ diesel blend.

I wish I could get ANY fuel at this price right now!

But seriously, I think it's a great idea to compile these research papers. Can we get them in a sort of library file format rather than just posts in a thread? I'm not sure if the infopop forums let you have a file section like that where we could have PDF files and maybe just have each abstract as a seperate post linked to the full PDF.

Using Unmodified Vegetable Oils as a Diesel Fuel Extender –
Results of engine and vehicle testing of semi-refined rapeseed oil

Most Food Grade oils are degummed, deacidified, and winterized.A far cry from the oils used in the above papers.