Cereals bioethanol production

The perishable nature of potatoes limits the market of this raw material to the region of production what is produced in Europe is predominantly consumed in Europe. On the other side, cereals are commodities traded globally and therefore subject to the dynamics of a global market. A recent demonstration of these global dynamics was the temporary shortage of cereal on the market caused, among others, by an increased demand for food coming from China and India, bad weather conditions and the use of cereals as feedstock for bioethanol production. 

The cereal seeds, tubers, starch storage roots, and bean/pea seeds are directly consumed as food in human diet or animal feed and are used as a source of starch. Extracted starch can be used to produce starch derivates or hydrolyzed to produce soluble sugars, food additives, or glucose syrup. Also, extracted starch can be used for other applications in nonfood industries (Nghiem et al. 2011). For example, it is used as a thickener and as a source of renewable raw material for bioethanol production. The major source of starch for the world market is cornstarch holding more than 80 % of the market, but wheat, potato, cassava or tapioca, and to a lesser extent rice and sweet potato starches are also commercialized (Thomsen et al. 2008). 

Perez-CarriUo, E., Sema-Saldivar, S.O., Alvarez, M., and Cortes Calleja, M.L. 2008. Effect of sorghum decortication and use of protease before liquefaction with thermoresistant a-amylase on the efficiency of bioethanol production. Cereal Chem. 85(6) 792-798. 

Bioethanol is the largest biofuel today and is used in low 5%—10% blends with gasoline (E5, E10), but also as E85 in flexible-fuel vehicles. Conventional production is a well known process, based on the enzymatic conversion of starchy biomass (cereals) into sugars, and fermentation of 6-carbon sugars with final distillation of ethanol to fuel grade. 

Biofuels such as bioethanol and biodiesel originate from cereal crops such as plant oils, and sugar beets. Today the production cost of bioethanol cereal crops is still too high, which is the major reason why bioethanol has not made its breakthrough as a fuel source yet. When producing bioethanol from maize or sugar cane the raw material constitutes about 40-70% of the production cost. 

Fig. 2.5 Flow chart for the production bioethanol from cereal grain...

First generation bioethanol and biodiesel production, which mainly makes use of cereal grains and vegetable oils, represents a growing source of high quantities of protein as a valuable by-product. Sanders et al. (2007) estimated that a 10% substitution of fossil transportation fuels worldwide by first generation biofuels would result in an annual production of 100 million tonnes of protein - about four times the proteins requirement of the world s human population. A direct result of this would be the saturation of traditional protein markets. New opportunities would therefore emerge for chemical production from proteins. 

Proteins are found in wooden biomass (< 5 wt%), cereals ( 10 wt%), and herbs (up to 20 wt%) [13, 30]. They can accumulate in large-scale biomass processes like bioethanol or biodiesel production with approximately 1% of the deployed biomass [6],... 

According to Gustavsson et al. food commodities can be grouped into cereals roots and tubers fruits and vegetables meat, fish and seafood milk and egg. Examples for substantial products are products derived from paper, timber, particle boards, biobased plastics, biobased chemicals and for energy carriers steam, biogases, biodiesel, bioethanol. 

There are several markets for cereals, including milling for human consumption, animal feed, malting, seed, export and industrial uses including production of biofuel and bioethanol (Table 13.1). Grain quality requirements will be affected by the proposed market... 

Grain maize grows well in many southern countries in Europe, especially in France and Italy. Yields are very high averaging between 8 and 9t/ha of grain. With this yield, grain maize is the third most importatrt cereal in the EU after wheat and barley. Most of the maize crop is used for animal feed with a smaller amount milled for industrial use (starch) and for human consumption. There is an increasing market for maize for production of bioethanol. For crop husbandry see Chapter 18. 

Production of Bioethanol from Cereals Other Than Maize... 

Chuck-Hemandez, C., Perez-CarriUo, E., and Sema-Saldivar, S.O. 2009. Production of bioethanol from steam-flaked sorghum and maize. J. Cereal Sci. 50(1) 131-137. 

Approximately 98% of US bioethanol is based on com (Zea Mays), a raw starchy material produced in high quantities in that country (14,216 MkT in 2014). Total domestic use of corn in US was 11,883 MkT in the same year. From that amount, 5208 MkT of com were used for ethanol production, 5315 MkT for feed and residual use purposes, while the rest was transformed into high-fructose com symp, sugars (glucose and dextrose), starch, alcohol for beverages and manufacturing, seeds, cereals, and other products (Service, 2015). 

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