The unstable world political situation combined with the fact that a large amount of the world\u27s oil reserves is located in the Middle East means we must continue to search for an alternate fuel source for our agricultural machinery. It is well-known that there is a limited amount of fossil fuels and even with no world political problems the demand will exceed supply in the not-too-distant future. The United States currently imports fossil fuels because we use more than we produce. Vegetable oils are a renewable resource. They offer a means of keeping our agricultural equipment operating in an oil emergency

Holmes, E.

Taraba, Joseph L.

Turner, George M.

English

University of Kentucky

University of KentuckyUKnowledgeAgricultural Engineering Energy Series Biosystems and Agricultural Engineering11-1986Vegetable Oil as an Emergency FuelE. HolmesUniversity of KentuckyJoseph L. TarabaUniversity of KentuckyGeorge M. TurnerUniversity of KentuckyRight click to open a feedback form in a new tab to let us know how this document benefits you.Follow this and additional works at: https://uknowledge.uky.edu/aees_reportsPart of the Bioresource and Agricultural Engineering CommonsThis Report is brought to you for free and open access by the Biosystems and Agricultural Engineering at UKnowledge. It has been accepted forinclusion in Agricultural Engineering Energy Series by an authorized administrator of UKnowledge. For more information, please contactUKnowledge@lsv.uky.edu.Repository CitationHolmes, E.; Taraba, Joseph L.; and Turner, George M., "Vegetable Oil as an Emergency Fuel" (1986). Agricultural Engineering EnergySeries. 2.https://uknowledge.uky.edu/aees_reports/2Vegetable Oil as anEmergency FuelE. Holmes, J. L. Taraba and G. i\4" TumerAEE$37Oniversity of KentrckyCollege of AgricultureCooperative Extension ServiceDepartment of Agricultural EngineeringThe unstable world pol i t ical  s i tuat ioncombined with the fact that a large amount of theworld 's oi l  reserves is located in the Middle Eastmeans we must cont inue to search for an al ternatefuel source for our agricul tural  machinery. l t  iswel l -known that there is a l imited amount of fossi lfuels and even with no world pol i t ical  problems thedemand wi l l  exceed supply in the not-too-distantfuture. The United States current ly imports fossi lfuels because we use more than we produce.Vegetable oils are a renewable resource. Theyoffer a means of keeping our agricul turalequipment operat ing in an oi l  emergency.What are Vegetable Oils?Vegetable oils are extracted from corn,soybean, peanut,  sunf lower, rape and other lesscommon oi l  seed crops. The energy content ofthese oi ls var ies somewhat but is general lycomparable to that of  diesel fuel .  However,because of their  high viscosity,  vegetable oi ls wi l lnot f low as easi ly as diesel fuel ,  especial ly dur ingcold weather,  and this is a major problem.Vegetable oi ls are composed of longmolecular chains of carbon, hydrogen and oxygen.Technical ly they are cal led fat ty acids. These oi lsw i l l  burn  in  in te rna l  combust ion  eng ines  a t  a  muchslower rate than propane, gasol ine or diesel fuelbecause the vegetable oi l  molecules are largerthan those of these standard fuels.However,  vegetable oi l  molecules arefractured into smal ler ones when they react withalcohol,  forming glycerol  and esters. Onceextracted, the esters burn much l ike regular dieselfue l .Vegetable oi ls are widely used in food andindustr ial  product ion and many extract ing faci l i t iesare located throughout the country.  Thesefaci l i t ies are not always ut i l ized to their  maximumcapab i l i t y  and cou ld  p roduce more  o i l s  i f  the  o i lseeds were avai lable.Published by the Coopemtive Extension SeMce in cooperation with the Kentuc}<y Departnent of Energy as a part of the Kentucky EnergyConserrration Program.hoduction of Oil Seed CropsSoybeans, corn, rape and sunflower seeds areKentucky crops from which vegetable oil can beextracted for fuel production. Kentucky farmerscurrently have the technology and experience ofgrowing corn and soybeans. Rape and sunflowersare adaptable to the Kentucky climate but have notbeen grown on a large scale because of the lack ofa market. However, with some experience theycould be grown. Soybeans, sunflower seeds andrape seeds have a greater potential for oilproduction than corn because their oi l  yield can beas high as 20, 30 and 41 percent respectively, whilethe oi l  yield of corn is only 4.3 percent. Anotherconsideration i  growing these crops is the energyrequired to produce the crop compared to theenergy found in the oi l .  l l l inois researchers foundthat on non-irr igated land the energy units fromthe oil was 4.09 for soybeans, 3.5 for sunflowerseed and 4.18 for rape seed for each unit of energyexpended to grow the crop.Extncting the OilThe University of ldaho buil t  and tested asemi-automatic, on-farm extraction unit capable ofprocessing 88 pounds (44 ki lograms or ninegallons) of sunflower seeds per hour. The unitconsisted of a 220-pound hopper placed over aspecial ly buil t  preheating auger. On the waythrough the auger the seed was heated byconduction through the inner and outer walls ofthe special auger to a temperature of 85 to 130degrees F for 15 to 20 minutes. Heat was providedby four 750-watt, hermostatically controlled stripheaters in a closed, forced-air system.The seed passed over four magnets beforeentering the press hopper. The press hopper waskept ful l  with the use of a photo cell .  Pressure onthe seed was manually adjusted to maximize theoil  f low. The oi l  was pumped into a holding tankand allowed to settle for 48 hours. The oil was thenforced through a 3-stage filter unit consisting of arecleanable prefi l ter 20 microns thick, and thenthrough a 4- to 5-micron throw-away filter. Oil wasthen degummed by hydrating with steam or hotwater. Degumming was necessary on all seedexcept rape.The unit was 78 percent efficient for soybeanand more than 80 percent efficient for rape seed.They found no signif icant oi l  breakdown duringaerobic storage of 140 to 200 days.The unit  cost approximately $10,000 to bui ldin 1982. l t  required 0.6 ki lowatt  hours of electr ic i typer gallon of oil processed.Commercial plants that extract vegetable oilsfor food and industrial markets process moreeff ic ient ly than on-farm units.  These faci l i t iesremove about half  of  the oi l  f rom seeds with mi ldpressing and remaining oil is extracted withsolvents.Diesel Engine Test ResultsTests using vegetable oi ls as a subst i tute fordieselfuel  have been run in the United States andsome foreign countries. These tests have been runwith raw oi ls,  semi-ref ined oi ls,  blends (semi-ref ined oi l  mixed with diesel fuel)  and esters.For the purposes here, raw vegetable oils arethose in which the oi l  has been pressed out ofseeds with no further processing. Seml-reflnedvegetable olls are those that have undergone aprocess of preheating the seed, pressing, settling,f i l ter ing and degumming. Semi-ref ined oi ls wereused in practically'all of the tests reported.Short-Term Tests On Semi-Refined OilsEarly tests revealed that raw oils caused filter-plugging and injector- jamming problems and sotests with raw oils were abandoned in favor ofsemi-ref ined oi ls.Many short-term tests have been madeoperating farm-type diesel tractors with 100percent semi-ref ined oi ls in direct in ject ionengines. Many engines began to fai l  af ter about 50hours of operation with some failures at less than50, For this reason, test periods of 50 hours or lesshave been given the name short-term while tests ofmore than 50 hours are called long-term.Toward the end of the 50 hours all directinjection engines became hard to start. Theinternal carbon bui ld-up became so great that theengines had to be torn down and thoroughlycleaned. In al l  engines, the vegetable oi ls causedoi l  di lut ion in the crankcase at a faster rate thandiesel fuel .Other tests with farm tractors have shown thatvegetable oils can be used successfully with theabove l imitat ions as long as the oi l  is changedfrequently and the injectors are removed andcleaned regularly.Long-Term Tests On Semi-Refined OilsMany long-term tests with vegetable oils as adieselsubstitute have been conducted in theUnited States and foreign countries. The resultsare quite different making it  dif f icult to drawdefinite conclusions. In Europe, where there aremore indirect injection engines than in the UnitedStates, some tests indicate much longer and moresatisfactory engine performance when these typesof engines burn vegetable oi ls. l t  seems l ikely thatindirect injection systems could utilize vegetableoils better than direct injection engines.In general, direct injection engines becomeimpossible to start after 150 to 200 hours. Theyalso show a high percentage of power losses, andtear-down reveals coring of cyl inder walls, stucktop rings, high carbon build-up and otherdiff icult ies such as contamination of the injectornozzle.Yet in one test, a 2-cyl inder indirect injectionengine with regular oi l  changes operated on rawlinseed oil for 200 hours. No noticeable loss ofpower or decrease in cylinder pressure wasdetected. The engine was torn down and found tobe in excellent condit ion.Engineers conducting these tests put forth thefol lowing theories to explain the usual durabil i typroblems: 1) high viscosity results in pooratomization at the injectors giving incompletecombustion, 2) chemical structure of the oi lscontributes to incomplete burning and adhesion tointerior combustion chamber parts, and 3) aftersome build-up on the top ring, blow-by results incontamination of crankcase oi l  and build-up onvalve stems, leading to burning of the valvesurface.Short- and Long-Term Tests on Blendsand EstersMany tests have been run on blends ofdiesel fuel  and vegetable oi l .  In general  any mixabove 20 percent semi-refined vegetable and 80percent diesel oi l  eventual ly caused some kind ofdurability problem. Several tests of 400 to 600hours on 10-90 blends were consideredsatisfactory. Nearly all 50-50 blend tests had to bestopped after 10 to 40 hours of operation.Straight esters of vegetable oils appear to giveperformance nearly as good as regular diesel fuelwith crankcase oil changes twice as often as withdieselfuel. The big drawback is processing costs.ln one test, processing cost about $3.30 per gallon.Also, this process is highly technical requiring aperson knowledgeable in chemistry and highlysophist icated equipment.  At this t ime processingesters cannot be considered as an on-farmoperat ion.Engine ModificationsSome tests show that engines can usevegetable oi l  successful ly with no modif icat ions.However,  f rom a summary of al l test results i tappears that f requent oi l  changing is imperat iveand an attempt should be made to operate theengine at 75 percent power or less to reducecarbon deposits. Some method of heating the fuelin the fuel  tank and l ines leading to the injectorpump would reduce the viscosity problem.It  also appears that indirect in ject ion dieselengines offer superior performance and durabi l i tyin the burning of vegetable oi ls,  when compared todirect injection types. This, however, is a ratherdrast ic engine modif icat ion requir ing a new type ofhead instal lat ion and thus cannot be considered assimple modif icat ion.One test showed some power improvementwhen the timing was advanced a few degrees butmore proof is needed before recommendations inthis regard can be made.The No<t TimeAgriculture production will be severelyaffected the next time the United States is facedwith a shortage of petroleum. Some farms may belocated close enough to a vegetable oil processingplant to secure some vegetable oi l  for fuel  in anemergency. However, most farmers will need totransport  oi l  seed to a commercial  plant and totransport processed oil back to the farm.Another opt ion would be to organize acommunity press with equipment and capacitylarger than on-farm units.  This wi l l  involvepurchasing expensive quipment and trainingpersonnel to operate the facility. Owners of such afaci l i ty could afford sophist icated fract ioningequipment so that long-term operat ion in farm-type diesel engines would be safe and practical.The by-products of these facilities might be usedas animal feed or fert i l izer.  This would help reducethe cost of operation.I t  is obvious that on-farm units,  at  this t ime,are not practical. Research is badly needed tomake them efficient and easy to operate. In themeantime, farmers as well as policy-makers needto think now about food product ion during thenext, inevitable, fuel emergency.3|hacollegeo|AgriculturaisfEqua|oppo|tunityorganizationwithrspecttoedUcdtionandemploymentdndaUthorizationtoptovid6resoarh,educaservicesontytoi;dividualsandinstitutionsthatfunctionwithoutrgardtorce,colo\nationatorigTitlevllott-hecivi|RightActot1g64,Tit|etxo|theEduca|ionalAmendments,saction5o4ofthOffice, Cotlege ol Agticutturc, univarcity ot Kentucky, R@m S-105, Agricultunl Science Building-North, Lexington, Kentucky 10546.lssued in furtherance ot Coopgrative Extension work, Acts ol May 8 and June 30, 1914, in coopsration with the U.S. Departmsnl of Agriculture. Charles E. Barnhart, Director ofCooperative Extension Servico, Univ€rsity ot Kantucky College ol Agricultur€, Lexington, and Kentucky State University, Franktort.1 M-1 1-86

Vegetable Oil as an Emergency Fuel

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Vegetable Oil as an Emergency Fuel

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