Biodiesel Quality, Standards And Properties
1Biodiesel Quality, Standards and PropertiesIstván Barabás and Ioan-Adrian TodoruţTechnical University of Cluj-NapocaRomania1. IntroductionQuality is a prerequisite for the long-term success (successful use, without technicalproblems) of a biofuel. Biodiesel quality depends on several factors that reflect its chemicaland physical characteristics. The quality of biodiesel can be influenced by a number offactors: the quality of the feedstock; the fatty acid composition of the parent vegetable oil oranimal fat; the production process and the other materials used in this process; the postproduction parameters; and the handling and storage. Given the fact that most currentdiesel engines are designed to be powered by diesel fuel, the physicochemical properties ofbiodiesel should be similar to those of diesel oil.This chapter presents the main standards on commercial biodiesel quality adopted indifferent regions of the world and the importance and significance of the main propertiesthat are regulated (cetane number, density, viscosity, low-temperature performances, flashpoint, water content, etc.) and unregulated (elemetal composition, fatty acid methyl andethyl esters composition, heating value, lubricity, etc.). Properties of fatty acid methyl andethyl esters obtained from different feedstocks1 are presented based mainly on datapublished in the specialized literature, but also on personal research.2. Biodiesel standardization world-wideThe main criterion of biodiesel quality is the inclusion of its physical and chemicalproperties into the requirements of the adequate standard. Quality standards for biodieselare continuously updated, due to the evolution of compression ignition engines, everstricter emission standards, reevaluation of the eligibility of feedstocks used for theproduction of biodiesel, etc. The current standards for regulating the quality of biodiesel onthe market are based on a variety of factors which vary from region to region, including1 ALME – algae methyl ester, CCEE – coconut oil ethyl ester; CCME – coconut oil methyl ester; CME –canola oil methyl ester; COME – corn oil methyl ester; CSOME – cottonseed oil methyl ester; FOEE –fish oil ethyl ester; FOME – fish oil methyl ester; JME – jatropha oil methyl ester; OEE – olive oil ethylester; OME – olive oil methyl ester; PEE – palm oil ethyl ester; PEEE – peanut oil ethyl ester; PEME –peanut oil methyl ester; PME – palm oil methyl ester; REE – rapeseed oil ethyl ester; RME – rapeseed oilmethyl ester; SAFEE – safflower oil ethyl ester; SAFME – safflower oil methyl ester; SEE - soybean oilethyl ester; SFEE – sunflower oil ethyl ester; SFME – sunflower oil methyl ester; SME – soybean oilmethyl ester; TEE – tallow ethyl ester; TME – tallow methyl ester; WCOEE – waste cooking oil ethylester; WCOME – waste cooking oil methyl ester; YGME – yellow grease methyl ester; YMEE – yellowmustard oil ethyl ester; YMME – yellow mustard oil methyl ester.www.intechopen.com
4Biodiesel – Quality, Emissions and By-Productscharacteristics of the existing diesel fuel standards, the predominance of the types of dieselengines most common in the region, the emissions regulations governing those engines, thedevelopment stage and the climatic properties of the region/country where it is producedand/or used, and not least, the purpose and motivation for the use of biodiesel (EuropeanCommission, 2007).In Europe the fleet of cars equipped with diesel engines is considerable, while in the UnitedStates of America and Brazil diesel engines are specifically used in trucks. The mostcommon feedstocks used are rapeseed and sunflower oil in Europe, soybean oil and wastevegetable oil in the USA and Canada, soybean oil in South America, palm, jatropha andcoconut oil in Asia, palm oil and soybean oil in Australia and waste vegetable oil and animalfat in New Zealand. It is therefore not surprising that there are some significant differencesamong the regional standards, a universal quality specification of biodiesel is, and will beimpossible. Table 1 presents a list of the most important biodiesel quality standards in theworld, while in Tables 2-9 specifications of the imposed limits for the main properties ofbiodiesel and the required test methods are presented.Country/Area SpecificationsTitleEUEN 14213Heating fuels - Fatty acid methyl esters (FAME) Requirements and test methodsEUEN 14214EN 14214 Automotive fuels - Fatty acid methyl esters (FAME)for diesel engines - Requirements and test methodsU.S.ASTM D 6751 ASTM D6751 - 11a Standard Specification for Biodiesel FuelBlend Stock (B100) for Middle Distillate FuelsAustraliaFuel Standard (Biodiesel) Determination 2003BrazilANP 42Brazilian Biodiesel Standard (Agência Nacional do Petróleo)IndiaIS 15607Bio-diesel (B 100) blend stock for diesel fuel - SpecificationJapanJASO M360 Automotive fuel - Fatty acid methyl ester (FAME) as blendstockSouth Africa SANS 1935Automotive biodiesel fuelTable 1. Biodiesel standardsThe biodiesel standards in Brazil and the U.S. are applicable for both fatty acid methyl esters(FAME) and fatty acid ethyl esters (FAEE), whereas the current European biodiesel standardis only applicable for fatty acid methyl esters (FAME). Also, the standards for biodiesel inAustralia, Brazil, India, Japan, South Africa and the U.S. are used to describe a product thatrepresents a blending component in conventional hydrocarbon based diesel fuel, while theEuropean biodiesel standard describes a product that can be used either as a stand-alonefuel for diesel engines or as a blending component in conventional diesel fuel. Somespecifications for biodiesel are feedstock neutral and some have been formulated around thelocally available feedstock. The diversity in these technical specifications is primarily relatedto the origin of the feedstock and the characteristics of the local markets (EuropeanCommission, 2007; NREL, 2009; Prankl, et al., 2004).The European standard EN 14214 is adopted by all 31 member states of the EuropeanCommittee for Standardization (CEN): Austria, Belgium, Bulgaria, Croatia, Cyprus, theCzech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland,Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, and the Unitedwww.intechopen.com
5Biodiesel Quality, Standards and PropertiesKingdom. Thus, there are no national regulations concerning biodiesel quality, but there is aseparate section (not presented in the table), which provides cold flow property regulations.The national standards organizations provide the specific requirements for some regulationsof CFPP (cold-filter plugging point, method EN 116), viscosity, density and distillationcharacteristics depending on the climate (6 stages for moderate climate and 5 for arcticclimate). The regular diesel quality standard EN 590 specifies that commercial diesel fuelcan contain 7% v/v biodiesel, compliant with the standard EN 14214. The standard ASTMD6751 describes the quality requirements and the methods of analysis used for biodieselblended with diesel oil, applying to methyl esters as well as for ethyl esters. As therequirements for low-temperature properties can vary greatly, the standard foresees theindication of the cloud point. The standard ASTM D975 allows mixing commercial diesel oilwith 5% biodiesel that meets the requirements of ASTM D6751, and ASTM D7467 specifiesthe quality requirements of mixtures with 5-20% of biodiesel.PropertyTest methodLimitsminmaxUnitsEster contentEN 1410396.5–% (m/m)Density at 15 CEN ISO 3675,EN ISO 12185860900kg/m3Viscosity at 40 CEN ISO 3104, ISO 31053.55.0mm2/sFlash pointEN ISO 3679120– CSulfur contentEN ISO 20846, EN ISO 20884–10.0mg/kgCarbon residue(in 10% dist. residue)EN ISO 10370–0.30% (m/m)Sulfated ash contentISO 3987–0.02% (m/m)Water contentEN ISO 12937–500mg/kgTotal contaminationEN 12662–24mg/kgOxidative stability, 110 CEN 141124.0–hoursAcid valueEN 14104–0.50mg KOH/gIodine valueEN 14111–130g I/100 g–1% (m/m)Polyunsaturated methyl esters( 4 double bonds)Monoglyceride contentEN 14105–0.80% (m/m)Diglyceride contentEN 14105–0.20% (m/m)Triglyceride contentEN 14105–0.20% (m/m)Free glycerineEN 14105, EN 14106–0.02% (m/m)Cold-filter plugging pointEN 116–– CPour pointISO 3016–0 CNet calorific value (calculated)DIN 51900, -1, -2, -335–MJ/kgTable 2. European standard EN 14213 for biodiesel as heating oilwww.intechopen.com
6Biodiesel – Quality, Emissions and By-ProductsPropertyTest methodLimitsminmaxUnitEster contentEN 1410396.5–% (m/m)Density at 15 CEN ISO 3675, EN ISO 12185860900kg/m3Viscosity at 40 CEN ISO 3104, ISO 31053.55.0mm2/sFlash pointEN ISO 3679120– CSulfur contentEN ISO 20846, EN ISO 20884–10.0mg/kgCarbon residue (in 10% dist.residue)EN ISO 10370–0.30% (m/m)Cetane numberEN ISO 516551––Sulfated ashISO 3987–0.02% (m/m)Water contentEN ISO 12937–500mg/kgTotal contaminationEN 12662–24mg/kg–1classCopper strip corrosion (3 hours,EN ISO 216050 C)Oxidative stability, 110 CEN 141126.0–hoursAcid valueEN 14104–0.50mg KOH/gIodine valueEN 14111–120g I/100 gLinolenic acid contentEN 14103–12% (m/m)–1% (m/m)Content of FAME with 4 doublebondsMethanol contentEN 14110–0.20% ( m/m)Monoglyceride contentEN 14105–0.80% (m/m)Diglyceride contentEN 14105–0.20% (m/m)Triglyceride contentEN 14105–0.20% (m/m)Free glycerineEN 14105; EN 14106–0.02% (m/m)Total glycerineEN 14105–0.25% (m/m)Alkali metals (Na K)EN 14108; EN 14109–5.0mg/kgEarth alkali metals (Ca Mg)EN 14538–5.0mg/kgPhosphorus contentEN 14107–10.0mg/kgTable 3. European biodiesel standard (EN 14214)www.intechopen.com
7Biodiesel Quality, Standards and PropertiesPropertyTest MethodLimitsminmaxUnitsCalcium & Magnesium, combinedEN 14538–5ppm(μg/g)Flash Point (closed cup)D 9393– C1. Methanol ContentEN 14110–0.2% (m/m)2. Flash PointD93130– CAlcohol Control (one to be met):Water & SedimentD 2709–0.05% (v/v)Kinematic Viscosity, at 40 CD 4451.96.0mm2/sec.Sulfated AshD 874–0.02% (m/m)Sulfur: S 15 GradeS 500 GradeD 5453D 5453––Copper Strip CorrosionD 130–3No.CetaneD 61347––Cloud PointD 2500Carbon Residue, 100% sampleD 4530–0.05% (m/m)Acid NumberD 664–0.05mgKOH/gFree GlycerinD 6584–0.020% (m/m)Total GlycerinD 6584–0.240% (m/m)Phosphorus ContentD 4951–0.001% (m/m)Distillation-Atmospheric equivalenttemperature 90% recoveryD 1160–360 CSodium/Potassium, combinedEN 14538–5ppm(μg/g)Oxidation StabilityEN 15751–3hoursCold Soak FiltrationFor use in temperatures below -12 CD7501D7501–360200secondssecondsTable 4. Biodiesel standard ASTM D6751 (United States)www.intechopen.com0.0015 % (m/m)0.05 % (m/m)report C
8Biodiesel – Quality, Emissions and By-ProductsPropertyTest methodLimitsminmax50UnitSulfurASTM D5453–Density at 15 CASTM D1298,EN ISO 3675860Distillation T90ASTM D1160–360 CSulfated ashASTM D 874–0.20% (m/m)Viscosity at 40 CASTM D4453.55.0mm2/sFlash pointASTM D93120– CCarbon residue10890mg/kgkg/m3–––– 10% dist. residueEN ISO 10370–0.30% (m/m)– 100% dist. sampleASTM D4530–0.05% (m/m)Water and sedimentASTM D2709–0.050% (v/v)Copper strip corrosion (3 hours at50 C) 10 mg/kg of sulfurEN ISO 2160 10 mg/kg of sulfurASTM D130Class 1Ester contentEN 14103PhosphorusASTM D4951–10mg/kgAcid valueASTM D664–0.80mgKOH/gTotal contaminationEN 12662, ASTM D5452–24mg/kgFree glycerolASTM D6584–0.02% (m/m)Total glycerolASTM D6584–0.25% (m/m)Cetane numberEN ISO 5165, ASTMD61351––report– C––hours–No. 396.5–% (m/m)ASTM D6890, IP 498/03Cold–filter plugging pointOxidation stability 6 hours at110 CEN 14112, ASTM D2274(as relevant forbiodiesel)Metals: Group I (Na, K)EN 14108, EN 14109(Group I)–5mg/kgMetals: Group II (Ca, Mg)EN 14538 (Group II)–5mg/kgTable 5. Australian biodiesel standardwww.intechopen.com
9Biodiesel Quality, Standards and PropertiesPropertyTest methodLimitsmin maxUnitsDensity at 15ºCISO 3675 /P 32860900kg/m3Kinematic viscosity at 40ºCISO 3104 / P252.56.0mm2/sFlash point (closed cup)P21120–ºCSulphurD5443/P83–50mg/kgCarbon resiue (Ramsbottom)D4530–0.05% (m/m)Sulfated ashISO 6245/P4–0.02% (m/m)Water contentD2709 / P40–500mg/kgTotal contaminationEN 12662–24mg/kgCopper corrosion 3 hr at 50ºCISO 2160 / P15–1–Cetane numberISO 5156/ P951––Acid valueP1–0.50mgKOH/gMethanolEN 14110–0.20% (m/m)–0.20% (m/m)EthanolEster contentEN 14103–96.5% (m/m)Free glycerol, maxD6584–0.02% (m/m)Total glycerol, maxD6584–0.25 % (m/m)mPhosphorous, maxD 4951–10.0Sodium and potassiumEN 14108To reportmg/kgCalcium and magnesium–To reportmg/kgIodine valueEN 14104To report–Oxidation stability at 110ºCEN 141126Table 6. Biodiesel standard in Indiawww.intechopen.com–mg/kghours
10Biodiesel – Quality, Emissions and By-ProductsPropertyTest methodLimitsmin maxUnitsEster contentEN 1410396.5–% (m/m)DensityJIS K 22490.860.90g/mlKinematic ViscosityJIS K 22833.55.0mm2/sFlash PointJIS K 2265120– CSulfurJIS K 2541–1, –2, –6, –7–10ppm10% Carbon ResidueJIS K 2270–0.3% (m/m)Cetane numberJIS K 228051––Sulfated AshJIS K 2272–0.02% (m/m)WaterJIS K 2275–500ppmTotal contaminationEN 12662–24ppmCopper strip corrosion (3 hours at 50 C)JIS K 2513–Class 1ratingTotal acid numberJIS K 2501, JIS K0070–0.5mgKOH/gIodine NumberJIS K 0070–120gI/100gMethyl linolenateEN 14103–12.0% (m/m)MethanolJIS K 2536, EN 14110–0.20% (m/m)MonoglycerideEN 14105–0.80% (m/m)DiglycerideEN 14105–0.20% (m/m)TriglycerideEN 14105–0.20% (m/m)Free glycerolEN 14105, EN 14106–0.02% (m/m)Total glycerolEN 14105–0.25% (m/m)Metals (Na K)EN 14108, EN 14109–5ppmMetals (Ca Mg)EN 14538–5ppmPhosphorousEN 14107–10ppmTable 7. Japanese Biodiesel Specificationwww.intechopen.com
11Biodiesel Quality, Standards and PropertiesPropertyTest methodLimitsmin maxUnitsEster contentEN 1410396.5–% (m/m)Density, at 15 CISO 3675, ISO 12185860900kg/m3Kinematic viscosity at 40 CISO 31043.55.0mm2/sFlash pointISO 3679120– CSulfur contentISO 20846, ISO 20884–10.0mg/kgCarbon residue (on 10% distillationresidue)ISO 10370–0.3% (m/m)Cetane numberISO 516551.0––Sulfated ash contentISO 3987–0.02% (m/m)Water contentISO 12937–0.05% (m/m)Total contaminationEN 12662–24mg/kgCopper strip corrosion (3 hours at50 C)ISO 2160–No.1ratingOxidation stability, at 110 CEN 141126–hoursAcid valueEN 14104–0.5mg KOHIodine valueEN 14111–140g I/100 gLinolenic acid methyl esterEN 14103–12% (m/m)–1% (m/m)Content of FAME with 4 doublebondsMethanol contentEN 14110–0.2% (m/m)Monoglyceride contentEN 14105–0.8% (m/m)Diglyceride contentEN 14105–0.2% (m/m)Triglyceride contentEN 14105–0.2% (m/m)Free glycerolEN 14105; EN 14106–0.02% (m/m)Total glycerolEN 14105–0.25% (m/m)Group I metals (Na K)EN 14108; EN 14109–5.0mg/kgGroup II metals (Ca Mg)EN 14538–5.0mg/kgPhosphorus contentEN 14107–10.0mg/kgCold Filter Plugging Point (CFPP)Winter/SummerEN 116––4/ 3 CTable 8. South African Biodiesel Standardwww.intechopen.com
12Biodiesel – Quality, Emissions and By-ProductsPropertyTest methodABNT NBR 14598,ASTM D93, EN ISO 3679Water and sedimentsASTM D2709ABNT NBR 10441,Kinematic viscosity at 40 CEN ISO 3104, ASTM D445ABNT NBR 9842,Sulfated ashASTM D874; ISO 3987SulfurASTM D5453; EN/ISO 14596ABNT NBR 14359,Copper corrosion 3 hours at 50 CASTM D130; EN/ISO 2160Ester contentEN 14103Distillation – atmosphericequivalent temperature 90%D 1160RecoveryCetane numberASTM D613; EN/ISO 5165Cloud pointASTM D6371Carbon Residue, 100% sampleASTM D4530; EN/ISO 10370Flash pointLimitsminmax100– C–0.05% (v/v)report0.02% (m/m)–0.001% (m/m)–No. 1–report% (m/m)–360 C45––––0.050.80– C% (m/m)mgKOH/gmg/kg% (m/m)% (m/m) Cmg/kgASTM D664; EN 14104–Total contaminationFree glycerinTotal glycerinDistillation recovery 95%PhosphorusEN 12662ASTM D6854; EN 14105–6ASTM D6854; EN 14105ASTM D1160ASTM D4951; EN 14107ABNT NBR 7148, 14065ASTM D1298/4052EN 14110EN 14111ASTM D6584; EN 14105ASTM D6584; EN 14105ASTM D6584; EN 14105EN 14108, EN 14109EN 14538—EN 14112report–0.02–0.38–360–10AlcoholIodine s: Group I (Na, K)Metals: Group II (Ca, Mg)AspectOxidation stability at 110 Cmm2/s–Acid numberSpecific 25–10reportclear6––% (m/m)gI/100g% (m/m)% (m/m)% (m/m)mg/kgmg/kg–hoursTable 9. Brazilian biodiesel standard3. Biodiesel fuel propertiesThe properties of biodiesel can be grouped by multiple criteria. The most important arethose that influence the processes taking place in the engine (ignition qualities, ease ofstarting, formation and burning of the fuel-air mixture, exhaust gas formation and qualitywww.intechopen.com
13Biodiesel Quality, Standards and Propertiesand the heating value, etc.), cold weather properties (cloud point, pour point and cold filterplugging point), transport and depositing (oxidative and hydrolytic stability, flash point,induction period, microbial contamination, filterability limit temperature, etc.), wear ofengine parts (lubricity, cleaning effect, viscosity, compatibility with materials used tomanufacture the fuel system, etc.).3.1 Chemical composition of biodieselThe elemental composition (carbon – C, hydrogen – H and oxygen – O), the C/H ratio andthe chemical formula of diesel and biodiesel produced from different feedstocks is shown inTable 10 (Barabás & Todoruţ, 2010; Chuepeng &Komintarachat, 2010). The elementalcomposition of biodiesel varies slightly depending on the feedstock it is produced from. Themost significant difference between biodiesel and diesel fuel composition is their oxygencontent, which is between 10 and 13%. Biodiesel is in essence free of sulfur.FuelCHOC/HEmpirical 98O2PME76.3511.2612.396.16C18.07H34.93O2Table 10. Elemental composition of diesel fuel and biodiesel, % (m/m)Unlike fuels of petroleum origin, which are composed of hundreds of hydrocarbons (puresubstances), biodiesel is composed solely of some fatty acid ethyl and methyl esters; theirnumber depends on the feedstock used to manufacture biodiesel and is between 6 and 17(Shannon & Wee, 2009). The fatty acid methyl and ethyl esters in the composition ofbiodiesel are made up of carbon, hydrogen and oxygen atoms that form linear chainmolecules with single and double carbon-carbon bonds. The molecules with double bondsare unsaturated. Thus, fatty acid esters take the form Cnc:nd (lipid numbers), where nc is thenumber of carbon atoms in the fatty acid and nd is the number of double bonds in the fattyacid (e.g., 18:1 indicates 18 carbon atoms and one double bond). The ester composition ofbiodiesel (methyl and ethyl esters) is shown in Table 11 (Bamgboye & Hansen, 2008; Barabás& Todoruţ, 2010; Chuepeng &Komintarachat, 2010). The highest concentrations are C18:1,C18:2, C18:3, followed by C18:0. A significant exception is biodiesel from coconut oil, in thecase of which the highest concentration is C12:0, C14:0 and C16:0, hence this biodiesel ismore volatile than the others. The physicochemical properties of biodiesel produced from agiven feedstock are determined by the properties of the esters contained.3.2 Cetane numberCetane number (CN) is a dimensionless indicator that characterizes ignition quality of fuelsfor compression ignition engines (CIE). Since in the CIE burning of the fuel-air mixture isinitiated by compression ignition of the fuel, the cetane number is a primary indicator offuel quality as it describes the ease of its self-ignition.Theoretically, the cetane number is defined in the range of 15-100; the limits are given by thetwo reference fuels used in the experimental determination of the cetane number:www.intechopen.com
14Biodiesel – Quality, Emissions and By-ProductsEster2ALMERMEREEC8:0 C10:0 C12:0 C14:0 C16:0 C18:0 C18:1 C18:2 C18:3 C20:0 C20:1 Others Obs.–––0.66.9375.2 12.4 1.20.4–0.3–––––3.81.9 63.9 199.70.6–1.1–22.2%––––4.91.6 33.0 20.4 7.9––22.2C22:1CME––––4.2257.4 21.3 11.2 1.22.10.60–SME––––9.44.122 55.3 8.9––0.3–SEE––––10.8326.5 47.39––3.40–SFME––––4.23.3 63.6 27.6 0.2––1.1–PME––0.20.5 43.4 4.6 41.9 8.60.30.3–0.2–COME–––12.1 1.8 27.2 56.2 1.30.4–1––AME––––11.6 4.4 49.6 33.7 0.7––––OEE––––11.6 3.1 74.9 7.80.6––2–TME––0.22.9 24.3 22.8 40.2 3.30.70.20.64.8–FOME25.1%––0.27.7 18.8 3.9154.60.30.21.447.9–C20:5JME––––12.7 5.5 39.1 41.6 0.20.2–0.7–JME––––12.5 30.9 34.4 20.4–––1.8–WCOME ––0.10.1 11.8 4.4 25.3 49.5 7.10.3–1.4–WCOEE ––2.0–15.7 3.1 29.6 41.5 1.0––7.1–SAFME––––7.31.9 13.6 77.2–––––CCME6.3649.2 18.5 9.12.76.51.7–––––CCEE7.5653.3 17.1 61.2 20.6 20.6 13.3 0.9 10.7 30.1–C20:1YGME––0.10.5 14.3835.6 3540.3–2.2-Table 11. Fatty acid composition of different biodiesels (methyl and ethyl esters), % (m/m)a linear-chain hydrocarbon, hexadecane (C16H34, also called n-cetane), very sensitive toignition, having a cetane number of 100, and a strongly branched-chain hydrocarbon,2,2,4,4,6,8,8-heptamethylnonane (HMN, also called isocetane), having the same chemicalformula C16H34, with high resistance to ignition, having a cetane number of 15. The cetanenumber is the percentage by volume of normal cetane in a mixture of normal cetane andHMN, which has the same ignition characteristics as the test fuel. Thus the cetane number isgiven by the formula: CN n-cetane [%, v/v] 0.15*HMN [%, v/v]. Determination of thecetane number on the monocylinder engine specially designed for this purpose (EN ISO5165, ASTM D613) is an expensive and lengthy operation. A cheaper and faster alternative isto determine the derived cetane number through ignition delay in a constant-volumecombustion chamber (ignition quality tester – IQT), a widely accepted method described inASTM D6890 and ASTM D7170, accepted by the biodiesel quality standard ASTM D6751.The cetane number indicates ignition delay, i.e. the time elapsed since the injection of fuelinto the combustion chamber and self-ignition of the fuel-air mixture. Thus, ignition time lag2 C8:0 – caprylate, C10:0 – caprate, C12:0 – laurate, C14:0 – myristate, C16:0 – palmitate, C18:0 – stearate,C18:1 – oleate, C18:2 – linoleate, C18:3 – linolenate, C20:0 – arachidate, C22:1 – erucate.www.intechopen.com
15Biodiesel Quality, Standards and Propertiesmeans a low cetane number and vice versa. The upper and lower limits of the cetanenumber ensure the proper functioning of the engine. If the cetane number is too low,starting the engine will be difficult, especially at low temperatures and the engine willfunction unevenly and noisily, with cycles without combustion, it will warm more slowly,combustion will be incomplete and engine pollution will increase, especially hydrocarbonemissions. In case of a fuel with a very high cetane number, ignition will be carried outbefore a proper mix with air, resulting in incomplete combustion and the increase of theamount of exhaust smoke. Also, if the cetane number is too high the fuel will ignite close tothe injector causing it to overheat, and unburned fuel particles can plug the injector nozzles.The optimal range of the CN (Fig. 1) is between 41 and 56, but must not be higher than 65(Băţaga et al., 2003). The minimum cetane number of biodiesel is 51 in the European Union,47 in the United States and 45 in Brazil. The minimum CN for diesel oil is 40 in the USA(ASTM D 975) and 51 in Europe (EN 590). The cetane numbers of the main pure methyl andethyl esters are shown in Table 12 (Bamgboye & Hansen, 2008; Barabás & Todoruţ, 2010).Acid (Cnc:nd)Caprylate (C8:0)Caprate (C10:0)Laurate (C12:0)Myristate (C14:0)Palmitate (C16:0)Palmitoleate (C16:1)Stearate (C18:0)Oleate (C18:1)Linoleate (C18:2)Linolenate (C18:3)Arachidate (C20:0)Erucate (C22:1)Cetane numberMethyl esterEthyl .00n.d.76.00n.d.Heat of combustion, kJ/kgMethyl esterEthyl d.n.d.n.d.n.d.Table 12. Cetane number and heat of combustion for fatty acid estersFig. 1. Brake specific fuel consumption and ignition delay vs. fuel cetane number.www.intechopen.com
16Biodiesel – Quality, Emissions and By-ProductsThe cetane number of a substance depends on its molecular structure. The cetane numberdecreases with the number of double bonds, nd, in fatty acid ester molecules (degree ofunsaturation, characterized by the iodine number) and increases with the number of carbonatoms, nc. Generally, the cetane number of ethyl esters is higher than that of methyl esters.Methyl- and ethyl palmitate as well as methyl- and ethyl stearate have a high cetanenumber, but methyl- and ethyl linoleate has a low cetane number. The cetane number ofbiodiesel depends on the cetane number and the concentration of the esters it is made up of.The cetane number of biodiesels is higher than that of the vegetable oils from which theyare produced (34.6 CN 42), and is between 39 and 67. The cetane number values ofbiodiesel produced from various feedstocks are presented in Table 13 (Anastopoulos etal., 2009; Barabás & Todoruţ, 2010; Chuepeng &Komintarachat, 2010; Shannon et al., 2009;Fan et al., EWCOMEYMEECNn.d.67.457.4n.d.6545.5 – 51.2n.d.5148n.d.6156.2n.d.59.7 – 67.456 – 61.862.249.848.250.9n.d.45.5 – 5837 – 51.5n.d.58 – 61.8n.d.n.d.54.9Qg, d.390703983738300 – 961-4020037800 – 405004011040679Qn, 287n.d.375003782037300 – n.d.n.d. , mm2/s4.523.08n.d.4,34 – 4.844.18 – 4.524.063.984.96 – 5.764.8 – 5.564.04.70n.d.3.704.84 – 6.174.83 – 5.654.314.034.40 – 5.034.84.434.033.97 – 4.275.204.1 – 4.995.815.78 – 6.05.66 , kg/m3879n.d.n.d.883 – 888884874 – 884887850870 – 880.3881.5n.d.n.d.864.4 – 870876 – 881.2880.2n.d.880833n.d.882.7878 – 884872 – 885n.d.876 – 887888.5920n.d.Table 13. Cetane number, gross and net heat of combustion, viscosity and density ofbiodiesels from different feedstokswww.intechopen.com
Biodiesel Quality, Standards and Properties173.3 Heat of combustionThe heat of combustion (heating value) at constant volume of a fuel containing only theelements carbon, hydrogen, oxygen, nitrogen, and sulfur is the quantity of heat liberatedwhen a unit quantity of the fuel is burned in oxygen in an enclosure of constant volume, theproducts of combustion being gaseous carbon dioxide, nitrogen, sulfur dioxide, and water,with the initial temperature of the fuel and the oxygen and the final temperature of theproducts at 25 C. The unit quantity can be mol, kilogram or normal square meter. Thus theunits of measurement of the heating value are kJ/kmol, kJ/kg. The volumetric heat ofcombustion, i.e. the heat of combustion per unit volume of fuel, can be calculated bymultiplying the mass heat of combustion by the density of the fuel (mass per unit volume).The volumetric heat of combustion, rather than the mass heat of combustion is important tovolume-dosed fueling systems, such as diesel engines.The gross (or high, upper) heating value (Qg) is obtained when all products of thecombustion are cooled down to the temperature before the combustion and the water vaporformed during combustion is condensed. The net or lower heating value (Qn) is obtained bysubtracting the latent heat of vaporization of the water vapor formed by the combustionfrom the gross or higher heating value. The net heat of combustion is related to the grossheat of combustion: Qn Qg – 0.2122 H, where H is the mass percentage of hydrogen in thefuel. As in internal combustion engines the temperature of exhaust gases is higher than theboiling temperature of water (water vapor is discharged), for assessing the heating value ofthe fuel, the lower heating value of the biodiesel is more relevant. The heating value of fattyacid esters (Table 12) increases with molecular chain length (with the number of carbonatoms, nc) and decreases with their degree of unsaturation (the number of double bonds,nd). The mass heating value of unsaturated esters is lower than that of saturated esters, butdue to their higher density, the volume heating value of unsaturated esters is higher thanthat of saturated esters. For example, methyl stearate (nd 0) has a mass heating value of40099 kJ/kg, and methyl oleate (nd 1) has 40092 kJ/kg. Reported to the volume unit, theheating value of methyl stearate is 34070 kJ/L, while the volume heating value of methyloleate is 34320 kJ/L. The presence of oxygen in the esters molecules (Table 1) decreases theheating value of biodiesel by 10.13% compared to the heating value of diesel fuel (see Table13). Due to the fact that fuel dispensing in CIE is volumetric, the energy content of theinjected dose will be more reduced in the case of biodiesel, therefore, the specific fuelconsumption for biodiesel will be higher. This is partially compensated by the fact that thedensity of biodiesel is higher than that of diesel fuel.3.4 Density of biodieselFuel density ( ) is the mass of unit volume, measured in a vacuum. Since density is stronglyinfluenced by temperature, the quality standards state the determination of density at 15 C.Fuel density directly affects fuel performance, as some of the engine properties, such ascetane number, heating value and viscosity are strongly connected to density. The density ofthe fuel also affects the quality of atomization and combustion. As diesel engine fuelsystems (the pump and the injectors) meter the fuel by volume, modification of the densityaffects the fuel mass that reaches the combustion chamber, and thus the energy content ofthe fuel dose, altering the fuel/air ratio and the engine’s power. Knowing the density is alsonecessary in the manufacturing, storage, transportation and distribution process of biodieselas it is an important parameter to be taken into account in the design of these processes. Thedensity of esters depends on the molar mass, the free fatty acid content, the water
Biodiesel Quality, Standards and Properties 5 Kingdom. Thus, there are no national regulation s concerning biodiesel quality, but there is a separate section (not presented in the table), wh ich
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
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.
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
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 .
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.
Each reference should include everything you need to identify the item. You need to identify the source type (e.g. book, journal article) and use the correct referencing format from this guide to create the reference. If you include items that are not specifically cited but are relevant to the text or of potential interest to the reader, then that is a bibliography. Generally speaking, the key .
