Potenciales y Viabilidad del Uso de Bioetanol y Biodiesel para el ...

Potenciales y Viabilidad del Uso de Bioetanol y Biodiesel para el Transporte en México (SENER-BID-GTZ)Task C: Biodiesel production and end-use in Mexico; Task D: Potentials in relation to sustainability criteriaTask E: Rationales, drivers and barriers for biodiesel market introduction; Task F: Synthesis and recommendationsTab. 3-2 Average crops and oil yield for mechanical and solvent extractionFeedstockPalmaafricanaJatropha Sunflower Rape seed Safflower Soy beansCrops yield [t/ha] 14.8 2.0 1.7 1.53 1.12 1.63Total oil content [%] 22 35 37.5 38 35 17Oil extraction efficiencymechanical extraction [%] 80 70 74 80 67 67Solvent extraction [%] 96 96 96 98 96 96Oil yieldmechanical extractionSolvent extraction[kg Input /l] 5.2 4.1 3.0 3.0 3.6 8.1[l/ha] 2,825 533 513 506 315 202[kg Input /l] 4.4 2.7 2.6 2.5 2.7 5.6[l/ha] 3,390 730 665 619 409 289Based on this, although rape seeds dispose of the highest oil content, in terms of oil yield perhectare cultivated land oil extraction of palma africana leads to the highest amount of about3,400 l/ha due to the comparably high crops yield. Despite of this, oil based on soy beans isless attractive in terms of oil productivity since both crops and oil yield are very low.However, as mentioned soy beans oil is produced as by-product of soy bean fodder (cf.section 3.1.2).3.2.2.2 Animal fats or fish oils and waste oilsAnimal fats and waste oils are recycled into useable products through a process calledrendering. Rendering processes may be categorized as either edible or inedible processes.Although edible and inedible rendering processes are generally similar, they differ in theirfeedstocks, end products and the applied equipment. In “edible” rendering processes, carcassby-products such as fat trimmings are ground into small pieces, melted and disintegrated bycooking processes to release moisture and “edible” tallow or fat. Plants that employ “inedible”rendering processes convert the protein, fat, and keratin (i.e. hoof and horn) materials found incarcasses into tallow and carcass meal (used in e.g. livestock feed, soap, production of fattyacids and fertilizer). The main rendering processes include size reduction followed by cookingand separation of fat, water and protein materials using techniques such as screening, pressing,sequential centrifugation, solvent extraction and drying (Gerpen et al., 2004a).3.2.3 Biodiesel productionAs mentioned in section 3.1.1 commercial biodiesel plants can be grouped in dependency onwhich maximum FFA level they can handle. The two main biodiesel technology models are25