Biodiesel Use In Engines
AE-1305Biodiesel UseIn EnginesVern Hofman, Extension agricultural engineerDennis Wiesenborn, professor, Agriculture andBiosystems Engineering DepartmentMichael Rosendahl and Jason Webster,agricultural engineering techniciansJANUARY 2006
Government ActionBiodiesel is an alternative fuel for dieselengines that is produced from renewableagriculural sources. Biodiesel is eithera methyl or ethyl ester derived fromvegetable oils, waste cooking oils oranimal fat through a process calledtransesterification. In the U.S., soybeanoil is the major vegetable oil used inproducing biodiesel, but oils from cropssuch as canola, sunflowers, safflowersand others can be used as well. Theseoils contain varying proportions of fattyacids that affect their characteristics,especially the ability to flow in colderclimates. Biodiesel can be used inany diesel engine with little or nomodifications.Biodiesel can be blended with dieselfuel in any proportion or used as a purefuel (B100). Blended biodiesel, such asB20, is a 20 percent mix of biodieselwith 80 percent diesel fuel. Using purebiodiesel or any blend above 20 percentis not recommended as most enginemanufacturers do not warranty enginesusing higher percentages of biodiesel.However, some engine manufacturersallow up to a 20 percent blend. Somestates are requiring biodiesel to bemixed in small proportions (B2 inMinnesota) withdiesel fuel for usein almost all dieselengines.2The American JOBS Act of 2004 will play a majorrole in the development of the biodiesel industry.Congress established a tax incentive on biodiesel Jan.1, 2005. The tax incentive provides distributors ofbiodiesel a 1-per-gallon subsidy for new oil (B100)or 1 cent for each 1 percent of biodiesel used in afuel mix. Recycled cooking oil receives 50 cents pergallon for pure oil or a half cent per 1 percent mix.These subsidies make B100 competitive in price todiesel fuel. Biodiesel usually is priced higher thanNo.2 diesel fuel, but the current subsidy allowsbiodiesel to be priced similarly to No. 2 diesel. Theincentive does not go directly to the consumer;instead the subsidy goes to the biodiesel distributor.However, for fuel suppliers to remain competitive,the consumer likely will see most of the tax discountin less expensive biodiesel.This tax incentive started at an excellent time.In 2005, the Environmental Protection Agencymandated a reduction of sulfur content in diesel fuelfrom 500 parts per million (ppm) to 15 ppm (MakingCents, 2004). Removing the sulfur from diesel fuelreduces the lubricity of the fuel, which could causeconcern for the operator of diesel engines. Biodieselis an excellent lubricant for the fuel injection system.The addition of as little as 1 percent to 2 percent(B1 or B2) would give diesel fuel more lubricationthan previously accomplished with higher sulfurcontent diesel fuel.
Vegetable Oil Conversion to BiodieselBiodiesel in Cold WeatherThe process of converting vegetable oil to biodieselis relatively easy. The process requires alcohol(methanol or ethanol) with a catalyst (sodium orpotassium hydroxide), which is added to vegetableoil and heated to slightly above 100 degreesFahrenheit (38 degrees Celsius) with agitation. Theconversion process occurs very quickly if an excessamount of alcohol is used. When the agitation isstopped, the glycerol settles to the bottom of thechamber and is drained off.In cold weather situations, biodiesel and No. 2diesel can be mixed with No. 1 diesel to reduce thetemperature at which gelling will occur. Gelling,or solidification of biodiesel and No. 2 diesel, isdetermined by the cloud point of the fluid. Thecloud point is defined as the temperature at which acloudy appearance is observed. However, biodieselmade from various vegetable oils (soybean, canolaand sunflower) have different cloud and pourpoints, which is due to various fatty acid contents.The cloud point and pour point temperatures forbiodiesel produced from oil crops grown in NorthDakota are shown in Table 1.The next step is to remove any excess alcohol andcatalyst from the biodiesel by washing with water.Most of the excess alcohol is evaporated duringprocessing and usually is collected and distilled tosufficient purity for reuse. The basic process seemssimple, but each step must be taken with great careto produce a high-quality fuel. Used cooking oiland animal fat also can be used, but with a slightlydifferent process. The basic process is shown inFigure 1.The cloud point is the start of crystal formation inthe oil. As the temperature is lowered, the crystalscontinue to grow until the oil is no longer a fluid buta solid. The temperature at which flow ceases plus4.5 F is defined as the pour point. Usually, when thefuel nears the cloud point temperature, changes willneed to be made to the fuel, such as the addition ofanti-gel additives or No. 1 diesel fuel. Otherwise,filters will clog and stop the engine. The additionof a fuel line heater is another excellent method toprevent gelling of biodesel fuel.Table 1. Cold flow properties of (B100) Biodiesel (Methyland Ethyl Esters). (The Biodiesel Handbook).OilFigure 1. Basic Process lowerSunflowerSunflowerRapeseedRapeseedMustard Seed*Potassium hydroxide (KOH) or sodium hydroxide (NaOH)can be used.No.1 DieselNo.2 Diesel*Alkyl groupCP (oF)PP le-45VariableCP - Cloud Point; PP - Pour Point*The cloud and pour point of the fuel varies based on theambient (outside) temperature of where the fuel is used. This isdetermined and specified by the fuel supplier.3
Biodiesel Potential In North DakotaCommercially available (soybean) biodiesel (B100)will gel at about 30 F. Biodiesel made from other oilcrops (such as canola-based biodiesel) will operateat lower temperatures.This is due to the differencein the degree of unsaturation of the fatty acids of theoil. Vegetable oils consist of numerous fatty acids.Some common examples are palmitic, stearic, oleic,linoleic and linolenic.Mixing No.1 diesel fuel with biodiesel will helpreduce most fuel gelling problems. Other measuresmay include the addition of fuel-line heaters orin-tank fuel heaters, along with the use of anti-geladditives. Insulating the fuel filters and fuel linesfrom the cold also will help. These measures shouldeliminate most cold-weather operational problemsassociated with biodiesel.Research shows that biodiesel will have a storagelife similar to diesel fuel, which usually is six monthsto one year. A two-year study completed at theUniversity of Idaho found that biodiesel had slightdeterioration and will store similarly to No.2 dieselfuel. Biodiesel mixtures of any blend should storeduring warm and cold months with little problemof separation of the biodiesel from the diesel fuel.Two types of ester fuels can be produced. Theyare either a methyl or ethyl ester, and which it isdepends on the alcohol that is used (either methanolor ethanol). At the current time, all commerciallyavailable biodiesel is methyl ester of soybean oil.This is because it is the most reasonably priced.Ethyl ester is made with ethanol, which is anextender for gasoline and will cost slightly morethan methyl ester.In 2004, about 96 million gallons of diesel fuelwere used to produce crops in North Dakota.Approximately an equal amount of fuel is used inother areas, such as transportation and heating.North Dakota currently plants more than 3 millionacres of soybeans, with a statewide average yield of29 bushels per acre (bu/ac). Soybeans contain about18 percent oil, and with a yield of 29 bu/ac, produceapproximately 43 gallons of oil per acre.Other oil crops grown in North Dakota includecanola and sunflowers. About 1 million acres areplanted annually with each of these crops. Canolaand sunflower crops produce an oil content between40 percent and 45 percent, which produces moreoil per acre than soybeans. Each of these crops willproduce between 75 and 85 gallons of oil per acre.If all the oil in North Dakota’s major oil crops wereused to produce biodiesel, about 275 million gallonsof biodiesel could be produced. Also, the meal fromthe oil extraction process is an excellent proteinsupplement for livestock feed. Table 2 shows thepotential fuel from North Dakota’s primary oil crops.North Dakota has the potential to produce severalmillion gallons of biodiesel if only part of the cropis converted into biodiesel. If a B20 blend wereused, about 19 million gallons of biodiesel would beneeded to be mixed with diesel fuel for agriculturaluse.Canola-based biodiesel is not available in the U.S.But several biodiesel plants are in the planningstages and plan to use canola oil. Some newprocessing plants also plan to process sunflowerseed.Table 2. Potential Biodiesel Fuel from the Major North Dakota Oil Crops.(North Dakota Agricultural Statistics, 2004)CropSoybeansSunflowersCanola4AcresOil content(%)Yield3,030,0001,020,000960,00018444329 bu/acre1,300 lbs/acre1,410 lbs/acreGallons Total potential(per acre)gallons437883130,290,00079,560,00079,680,000
Biodiesel Use In EnginesThe conversion process of vegetable oil into biodieselis very efficient. It is nearly a 1-to-1 ratio, whichmeans 1 gallon of vegetable oil will produce almost1 gallon of biodiesel.Biodiesel is a relatively efficient producer of energy.Biodiesel provides about 3.3 British thermal units(Btu) of energy for every Btu put into growing theoil crop and processing the crop to biodiesel. ABtu is defined as the energy required to raise thetemperature of 1 pound of water 1 degree Fahrenheit.During the 2005 growing season, North Dakota StateUniversity used canola-based biodiesel in tractorsat the North Central Research Extension Center inMinot without problems. For biodiesel to be usedsuccessfully in a diesel engine, its quality mustmeet American Society for Testing and Materials(ASTM) standards or fuel system problems likelywill occur. The biodiesel used at the North CentralResearch Extension Center was tested and met ASTMstandards.Some reports of diesel engine problems have shownup in North Dakota. They include plugged fuel filtersand residue in the fuel tank. These problems haveoccurred on older tractors and some relatively newtractors. No one knows whether biodiesel is the causeof the problem or it is due to some other cause. Mostreports indicate excellent results with biodiesel.Most engine manufacturers have added warrantystatements indicating if biodiesel can be used in theirengines. For example, John Deere and Caterpillaroffer engine warranties that allow small percentageblends of biodiesel (B2 or B5) to be used. However,the fuel must meet ASTM specifications. Biodieselis being used in, or being adopted for, most dieselengines.As stated earlier, blends of B20 or less require little orno modification of the engine. If blends greater thanB20 are being used, some modifications may needto be made for the engine to provide long life. Fuellines, gaskets and fuel pump seals may need to bereplaced on injection systems that were built before1993 because biodiesel has been shown to causedeterioration of seals. One common replacementmaterial for seals is Viton.Biodiesel has characteristics similar to a solvent. Itmay remove deposits in the fuel system, which mayplug fuel filters or cause deposits to accumulate inthe fuel tank. Plugged fuel filters usually show up asreduced power. Replacing the fuel filter usually willcorrect the problem.Issues on oil dilution also have raised questionson the use of biodiesel. Studies at the Universityof Idaho, University of Missouri and Iowa StateUniversity have shown that replacing diesel fuelwith biodiesel did notcause any unusual wearof aluminum, iron,chromium and leadcomponents. Biodieselappears to have anengine wear rate similarto diesel fuel.One hundred percent biodiesel(B100), center, and 100percent soybean oil, right,are similar in color but verydifferent in viscosity. Bothdiffer in color from No. 2diesel fuel, left.5
content, it will require about 1.1 gallons of fuel to dothe same work as 1 gallon of diesel fuel.Two other important properties of fuels for dieselengines is cetane number and fuel viscosity. Thecetane number is a method for determining theignition quality of a fuel. Most farm tractor enginemanufacturers recommend a minimum cetane ratingof 40. But most fuel suppliers provide diesel fuelwith a cetane rating of 45 to 50.Diesel engine operators should have the engine oilanalyzed to check for excessive wear when an oilchange is performed. Analyzing the oil after everyoil change may not be necessary, but it should bedone on an occasional basis so the operator can see ifexcessive wear is occurring in an engine. The oil testmust be sent to a laboratory for analysis. A samplekit usually is available through implement dealers.Engine oil analysis is recommended whether anengine operator is using pure diesel fuel or biodiesel.If excessive wear is occurring, corrective action oftencan be taken before a major failure occurs. Excessivewear often is caused by an air intake or antifreezeleak.Universities and managers of fleets of state and citybuses, pickups, large trucks and tractors have doneseveral studies on various mixes of biodiesel/dieselfuel. The results of these studies look promising.One difference with using biodiesel compared withregular diesel fuel is power output. Biodiesel has alower energy content than diesel fuel. No. 2 dieselfuel typically contains about 140,000 Btu/gallon,while biodiesel contains about 130,000 Btu/gallon.Fuels with a higher heat ofcombustion (Btu content) usuallywill produce more power perunit of fuel than lower-energyfuels. As a result, an engineusing a lower-energy fuel willrequire more fuel to produce thesame power as diesel fuel. Sincebiodiesel has a lower energy6In general, high-cetane fuels permit an engine to bestarted easily at low temperatures and provide fastengine warmup without producing white smoke ormisfiring. Also, a high-cetane fuel will help reducethe rate of varnish formation and carbon deposits,and eliminate combustion roughness or engineknock. The cetane value of biodiesel is similar todiesel fuel, which allows it to be used in dieselengines without major modifications.Fuel viscosity is another important fuel parameter.Diesel engine injection pumps perform mostefficiently when the fuel has the proper viscosity.Viscosity has an influence on the atomization of thefuel when it is injected. If the viscosity is too high,excessively high pressures can occur in the injectionsystem. This will cause poor atomization of thefuel in the combustion chamber, which may causedeposits in the engine and especially around thepiston rings. This is the case when raw or partiallyrefined vegetable oil is mixed with diesel fuel.Biodiesel has a viscosity close to No. 2 diesel fuel andwill eliminate this problem. Table 3 lists properties ofseveral bio-based fuels, as well as No. 2 diesel fuel.Table 3. Fuel Properties.No. 2 DieselB100B20B5Vegetable OilFuel WeightLbs/galHeat 4855504935-453.05.73.33.140-50
Engine Emissions and Environmental EffectsEmissions of greenhouse gases and other pollutantsinto the air may be harmful to the environment.Research has shown that the use of biodiesel willreduce most engine emissions, such as sulfates andhydrocarbons. Engine emissions will vary withengine design. Table 4 shows average reductions ofemissions with biodiesel.With the reduction in some air pollutants, biodieselcould provide significant improvements to airquality and be better for the enviroment, especiallyin industrial areas and cities that have significantpollution problems. Also, the growing of oil crops toproduce biodiesel will help recycle carbon dioxidein the atmosphere because plants use carbon dioxidefor growth and to produce seed.Biodiesel is nontoxic and much more biodegradablethan diesel fuel. Biodiesel is the first alternative fuelto pass the evaluations of the EPA’s health effectssection under the Clean Air Act.Table 4. Percent Change in Engine Emissions of Biodieselas Compared with Diesel Fuel. (Biodiesel Handling and UseGuidelines, 2001)EmissionCarbon MonoxideHydrocarbonsParticulatesNitrogen OxidesAir ToxinsMutagenicityCarbon DioxideB100B20-43.2%-56.3%-55.4%5.8%-60 to -90%-80 to -90%-78.3%-12.6%-11.0%-18.0%1.2%-12 to -20%-20%-15.7%7
ConclusionReferencesBiodiesel is an excellent alternative fuel for dieselengines. North Dakota agricultural producersgrow sufficient oil crops to supply the food market,plus extend diesel fuel supplies for agriculturalproduction.Hofman, V. (2003). Biodiesel Fuel. NDSU ExtensionService publication. Fargo, N.D. AE-1240Biodiesel is an environmentally sound choice andhas few drawbacks. The major problem is coldweather operation, but with proper precautions(mixing with No. 1 diesel fuel, installing a fuel lineheater and using anti-gel additives), few problemsshould occur. Biodiesel mixed at low percentageswith diesel (B5 or B10, 5 percent and 10 percentbiodiesel mixed with diesel fuel) should havefew operating problems and will help reduce thedependence on petroleum-based fuels.Before using biodiesel, check with your enginemanufacturer to be sure it allows the use of biodieselwithout voiding the warranty.Knothe, G., J. Krahl and J. Van Gerpen, eds. The BiodieselHandbook. Champaign, Ill., 2004North Dakota Agricultural Statistics Service (2004).North Dakota Agricultural Statistics 2004. August2004: No. 73. Fargo, N.D.North Dakota Soybean Council (2003). Biodiesel–TheClear Choice: Facts and Information About Biodiesel.February 2003. Fargo, N.D.Schumacher, L G., S. Borgelt and M.A. Russel,(1995). Fueling 5.9L and 7.3L Navistar Engines withBiodiesel-20. Proceedings of the American Society ofAgricultural Engineers Summer Meeting. Chicago,Ill. ASAE Paper N o. 956739.Schumacher, L G., S. Borgelt, M.A. Russell and J.G.Krahl, (1995). Project Update: Fueling 5.9L CumminsEngines with 100% Biodiesel. American Society ofAgricultural Engineers . ASAE Paper No. 956740,St. Joseph, Mo.Schumacher, L. G., C. Peterson, J. Von Gerpen. 2001.Engine Oil Analysis of Diesel Engines Fueled withBiodiesel Blends. American Society of Ag Engineers,ASAE Paper No. 016053, St. Joseph, Mo.Useful Web sitesWeb sites that have a considerable amountof information pertaining to biodiesel can befound at:www.missouri.edu/ pavt0689/index.htmlU.S. Department of Energy. National RenewableEnergy Laboratory. Biodiesel Handling and UseGuidelines. Tyson, K. Shaine. Oak Ridge, Tenn.: U.S.Department of Energy, September 2001. (NREL/TP-580-30004)Williams, Jessica. “Making Cents,” Biodiesel Magazine.October/November 2004: 16-20.www.biodiesel.org/www.ndsoybean.org/For more information on this and other topics, see: www.ag.ndsu.eduCounty commissions, North Dakota State University and U.S. Department of Agriculture cooperating. Duane Hauck, director, Fargo, N.D. Distributed in furtheranceof the acts of Congress of May 8 and June 30, 1914. We offer our programs and facilities to all people regardless of race, color, national origin, religion, gender,disability, age, veteran’s status or sexual orientation; and are an equal opportunity institution. This publication will be made available in alternative formats for peoplewith disabilities upon request, (701) 231-7881.4M-1-06
of separation of the biodiesel from the diesel fuel. Two types of ester fuels can be produced. They are either a methyl or ethyl ester, and which it is depends on the alcohol that is used (either methanol or ethanol). At the current time, all commercially available biodiesel is methyl ester of soybean oil.
2008 Biodiesel Handling and Use Guide (Fourth Edition) 5 This document is a guide for those who blend, store, distribute, and use biodiesel and biodiesel blends. It provides basic information on the proper and safe use of biodiesel and biodiesel blends in compression-ignition engines
source. Fourth, small-scale biodiesel production does not take more energy to create than it gives back. According to Biodiesel.Org, a leading organization in biodiesel research and marketing: Biodiesel has one of the highest "energy balance" of any liquid fuel. For every unit of fossil energy it takes to make biodiesel, 4.5 units of energy are
Describe the inputs & process of making biodiesel (transesterification) . and hydrogen) of the alcohol to form fatty acid alkyl esters (in our case, fatty acid methyl esters or FAMEs), which are biodiesel. To speed up the reaction, a base catalyst , . ethanol* to form biodiesel. Biodiesel is a methyl or ethyl ester (depending on whether
Production – U.S. production of biodiesel was 159 million gallons in December 2020. Biodiesel production during December 2020 was 8 million gallons higher than production in November 2020. Biodiesel production from the Midwest region (Petroleum Administration for Defense District 2) accounted for 72 percent of the United States total.
basic catalyst used in making biodiesel. Methanol (CH3OH) a volatile colourless alcohol, derived originally as wood alcohol, used as a racing fuel and as a solvent. Also called methyl alcohol, used to make methoxide in biodiesel production. Methoxide an organic salt, in pure form a white powder. In biodiesel production, "methoxide" is a product of
2) Biodiesel will clean your injectors and fuel lines. If you have an old diesel vehicle, there's a chance that your first few tanks of biodiesel could free up all the accumulated crud and clog your fuel filter. 3) It has a higher gel point. B100 (100% biodiesel) gets slushy a little under 32 F.
Life cycle environmental impacts Life cycle environmental impacts of biodiesel production from seven categories of feedstocks were calculated (Table 1). In order to produce 0.2 million tonnes of biodiesel, biodiesel production consumed about 214-268 thousand tonnes of fruits and about 204-234 thousand tonnes of biomass oil from life cycle .
Engines regulated by 40 CFR Part 86 typically include engines used in on-highway applications such as heavy-duty gasoline fueled engines (HDGEs), heavy-duty diesel fueled engines (HDDEs), and heavy-duty engines using alternate fuels (CNG, LPG and LNG). Engines regulated by 40 CFR Part 89 include compression-ignition engines used in nonroad .
