Biofuel co-products as livestock feed - Opportunities and challenges

An outlook on world biofuel production and its implications for the animal feed industry 5process and technology used to convert sugar beet intoethanol is quite similar to the sugar cane ethanol process.However, the fibrous component of the sugar beet thatremains after sugars are extracted (known as “beet pulp”)is most often dried and marketed as an animal feedingredient. Currently, the use of sugar beet for ethanoloccurs mainly in the European Union. An estimated6.9 million tonne of sugar beet was used for ethanol in2010 ( F.O. Licht, 2011).Sugar cane and beet molassesMolasses is a by-product of raw sugar production fromsugar cane and beets. It contains minerals regarded asimpurities in the raw sugar, but also retains some fermentablesugars. Molasses has generally been used as ananimal feed ingredient, but is also used as a feedstock forethanol production in facilities that have integrated sugarand ethanol production capabilities. Fermentation of thesugars found in molasses is conducted in a manner similarto fermenting sugars from other feedstocks. An estimated18.4 million tonne of molasses was processed into fuel ethanolin 2010, with Brazil representing 74 percent of totaluse, followed by Thailand (7 percent) and India (5 percent)(F.O. Licht, 2011).CassavaCassava, also known as tapioca, is an annual crop that iscultivated in tropical regions. The cassava root has relativelyhigh starch content, making it a suitable feedstock forethanol fermentation. It is typically available in two formsfor ethanol production: fresh root (high moisture, availableseasonally) and dried chips (low moisture content, availablethroughout the year). When processing fresh root, thefeedstock is washed to remove soil and debris, followedby peeling. The peeled root is then subjected to a processknown as rasping, which breaks down cell walls to releasestarch granules. The starch is then steeped and separatedfrom the fibrous residue and concentrated. Next, the starchis fed into the fermentation process, followed by distillationand dehydration, similar to the process for grain-basedethanol. The co-product of the cassava-to-ethanol processis root fibre, which is used as a boiler fuel source, similar tobagasse in the sugar cane ethanol process. Root fibre is notcurrently used as animal feed.In 2010, the equivalent of nearly 1.3 million dry tonneof fresh cassava root was processed into ethanol. Thailandwas the leading producer (50 percent), followed by China(44 percent) (F.O. Licht, 2011).Small amounts of other feedstocks, such as cheesewhey, potato and beverage waste, were probably usedin 2010, but they are not discussed here because of theirinsignificant volumes and hence impact on global feedmarkets.Biodiesel feedstocks and processesBiodiesel is a petroleum diesel fuel replacement producedfrom renewable fats and oils sources such as vegetable oils,animal fats and recycled cooking oils. Chemically, biodieselis a mono-alkyl ester of long chain fatty acids. It is producedfrom a diverse set of feedstocks, reflecting the natural fatsor oils indigenous to specific geographical regions. Thus,European biodiesel producers rely upon rapeseed as a primaryfeedstock for biodiesel production. In Southeast Asia,crude palm oil or its derivatives are the primary feedstocksutilized. Meanwhile, in the United States, soybean oil isthe predominant feedstock, although a host of other feedstocks,such as animal fats, yellow grease, and vegetable oilrecovered from dry mill ethanol plants, contribute suppliesas well.It is estimated that global production of biodiesel in2010 was 17.9 million tonnes (5.34 billion gallons) (OilWorld, 2011). Production is expected to increase 17 percentin 2011 to 21 million tonne (6.3 billion gallons). TheEuropean Union was the global leader in biodiesel productionin 2010, accounting for an estimated 52 percent ofproduction. Almost 80 percent of the anticipated productionin 2011 will be generated by the EU, United States,Argentina and Brazil.OilseedsOilseeds such as rapeseed or canola and soybeans representthe most common source of vegetable oil feedstocksfor biodiesel production. The biodiesel production processutilized for these feedstocks is similar. In 2010, an estimated5.8 million tonne of rapeseed or canola oil and 5.7 milliontonne of soybean oil were used globally in the productionof biodiesel, representing 69 percent of the total feedstocksused in global biodiesel production (Figure 3).PalmGlobally, palm oil is an important vegetable oil source. Aunique feature of the palm tree is that it produces twotypes of oil; crude palm oil from the flesh (mesocarp) of thefruit, and palm kernel oil from the seed or kernel. The crudepalm oil may be further refined to get a wide range of palmproducts of specified quality. For example, palm oil maybe fractionated to obtain solid (stearin) and liquid (olein)fractions with various melting characteristics. The differentproperties of the fractions make them suitable for a varietyof food and non-food uses.In 2010, an estimated 2.4 million tonne of palm oilwere used globally in the production of biodiesel (F.O. Licht,2011), representing 15 percent of the total feedstocks usedin global biodiesel production. Indonesia, Thailand, the EUand Colombia were the top users of palm oil for biodieselproduction in 2010. Together, they represented 78 percentof global use of palm oil for biodiesel.