BTC PTEC Biodiesel Workshop August 7 – 8, 2006 Session 7 – Feed stock and biodiesel quality

Agenda for session Feedstocks for biodiesel US and WA feedstocks Oil yields for different sources Comparison of feedstocks Feedstock preparation Feedstock quality issues and tests Comparison of biodiesel from different feedstocks Evaluation of biodiesel quality

Feedstocks for biodiesel Vegetable oils (most volume) –Soybean –Rapeseed –Palm Animal fats (lower cost) –Rendering plants Spent oils (lowest cost, so far) –Yellow and grey grease

Some US feedstocks FeedstockBillion lb/yr% of total Soybean oil Corn oil Cottonseed oil Edible tallow Inedible tallow Lard and grease Yellow grease Poultry fat Total

Vegetable oil production in WA (Armstrong, 2005) WA crops (millions of planted acres) –2.3 in wheat –0.337 in barley – in canola 100,000 acres needed for a 5 million gallons/year canola/mustard biodiesel plant Not promising due to –Closest crushing facility is in Montana –Low current market prices –Little experience with oil crops

Vegetable oil yields Feedstocklb oil/acregal/acre Oil palm Rapeseed Mustard seed43061 Soybean33548 Corn12918

Vegetable oil yeilds US –Soybean oil (0.4 T oil/ha, 20% yield from seeds) –Canola and mustard oil (40% yield from seeds) Europe –Rapeseed oil (0.5 T/ha, 40% yield from seeds) –Sunflower oil (0.5 T/ha) Tropics –Palm oil (4 T/ha)

Comparison of feedstocks Vegetable oil –Unrefined (high phospholipid content) un-degummed oils have separation problems in the process –Refined (better product) Animal fats –Lower cost –Higher concentrations of saturated FA –Biodiesel products may have higher freezing points –Higher cetane numbers

Comparison of feedstocks Spent oils –Trap grease (odor, moisture and color problems for this low cost feedstock) –Brown grease (FFA > 15%) –Yellow grease (FFA < 15%) –Cheaper

Prices SubstancePrice, 6/037/06 Grain$8.72/bu Soymeal$0.13/lb Soy oil$2.23/gal$2/gal Diesel$1.44/gal$3/gal Biodiesel$3/gal Glycerine$5.25/gal Methanol Ethanol$1.32/gal

Feedstock preparation Harvesting Crushing and pressing to separate the oil Filtration Removal of gums (phosphatides – 1.5 to 2.5% and unsaponifiable matter – 1.6%) Removal of free fatty acids (0.3 – 0.7%, soybean oil) Bleaching and deodorizing

Feedstock quality issues Free fatty acids (variable) Phosphorus (may be 600 – 900 ppm in soybean oil Sulfur (usually low, < 3 – 5 ppm in vegetable oil but may be higher in animal fats, 40 – 50 ppm) Iodine value (level of saturation) Water (variable) Solids (should be filtered, 100 micron)

Feedstock quality tests Fatty acids Specific gravity Refractive index Iodine number Saponification number Color

Free fatty acid concentrations Refined vegetable oil < 0.05% Crude soybean oil0.3 – 0.7% Yellow grease2 – 7% Animal fat5 – 30% Trap grease75 – 100%

Comparison of feedstocks Fatty Acid Profile (major FA) Oil or fat16:018:018:118:218:3 Soybean Cottonseed Rapeseed (hi oleic) Lard Tallow

Problems in feedstocks due to Free fatty acids (can react with catalyst to make it ineffective) Phosphorus (ASTM fuel limitation of 10 ppm) Sulfur (ASTM fuel limitation of 15 ppm) Water (can deactivate the catalyst interfere with the reaction and methanol recovery)

Processing High FFA Feedstocks High FFA from animal stock and spent grease Mainly acid catalyst to form esters (forms water) so that FFA <0.5%, followed by normal base catalyst transesterification Or just do normal transesterification and live with results (loss of FFA and possible emulsion formation) for low FFA levels

Comparison of B100 from different feedstocks feedstockCloud Point, deg C Iodine value Cetane number Diesel Rapeseed Canola Tallow Soybean

Product quality tests ASTM D6751 tests BQ-9000 tests Others –Physical properties –Iodine number

ASTM D6751 Biodiesel Standard PropertyTestLimitsUnit Flash PointD93130 minDeg C Water and sedimentD max% volume Kinematic 40 deg CD – 6.0mm 2 /sec Sulfated ashD max% mass SulfurD or 0.05 max% mass Copper strip corrosionD130No. 3 max Cetane numberD61347 min Cloud pointD2500reportDeg C Carbon residue (100% sample)D max% mass Acid numberD maxmg KOH/g Free/total glycerineD /0.24 max% mass PhosphorusD max% mass Distil temperature (90% recovered) D maxDeg C

Product quality issues Quality of the feedstock –Fatty acid composition –Contaminants (solids, moisture) Processing –Chemicals used (nature and purity) –Completeness of reaction Tri, di, mon glyceride products for incomplete reaction –Contaminants –Clean up steps (Water wash or Magnesol) Post production –Filtration (5 micron)

Product quality Glycerols (easily removed by washing) –Total glycerol < 0.24% –Free glycerol < 0.02% –Monoglycerols have low solubility in product Alcohol –Biodiesel may have 4 – 5% alcohol –< 0.1% indirectly due to flash point limit –Small amounts will not affect engine Catalyst –sulfated ash < 0.02% limit –Mostly removed with glycerin phase