Analysis of industrial oilseeds: production, conversion to biofuels, and engine performance from large to small scale

Abstract

Most of the biofuel produced in the U.S. as an alternative to petrodiesel is derived from soybean oil. Three major problems of using soy and other traditional biofuel feedstocks are: (1) the high commodity cost of the feedstock results in higher cost fuel than the petroleum equivalent, (2) land use requirements are too great to offset a significant portion of petroleum use, and (3) many traditional biofuel feedstocks also have food uses, which creates market competition and a “food versus fuel” debate. The problems above are addressed by exploring the feasibility of biofuel production from a new class of oilseeds known as industrial oilseeds, and industrial corn oil as a biofuel feedstock. Industrial oilseeds are alternative low-cost oilseeds also known in the literature as low-impact oilseeds or non-food oilseeds. Due to their non-food nature, they steer us clear of any food versus fuel debates. They have several advantages over conventional oilseeds, such as a short growing season, high oil yield and quality, ability to thrive on marginal lands, and low water and fertilizer inputs. These advantages can equate to lower oil costs. Since these oils can be optimized for fuel instead of food, plant scientists can maximize the erucic and other long chain fatty acids, which increase fuel conversion rates and fuel quality. For several of these plant species, little or no engine research has been done; some in the agronomic community still consider some of these plants weeds. This research includes compression ignition engine performance and emissions studies, measurement of important fuel properties, and investigation into the feasibility of several fuel pathways. Corn is not classified as an oilseed by the USDA; however, the corn kernel contains a small amount of oil (~3.5%) which can be extracted during the production of ethanol. Only the starch portion of a corn kernel is converted to ethanol; the remaining solids (including the oil) remain in the distillers grain coproduct. Recently, the ethanol industry has discovered economical methods to extract this corn oil from the meal stream. As corn oil extraction technology has matured and ethanol margins have tightened, the ethanol industry has started widely adapting this technology as an additional revenue-generating coproduct. Since most ethanol plants are non-food grade facilities, corn oil from an ethanol plant can also be categorized as an industrial oilseed. Corn oil represents a relatively new, abundant, and inexpensive source of biofuel feedstock. This research includes compression ignition engine performance and emissions of corn oil based fuels, feasibility of using corn oil as an on-farm biofuel feedstock, research into fuel production and processing methods, and measurement of important fuel properties.