Biofuel co-products as livestock feed - Opportunities and challenges

288Biofuel co-products as livestock feed – Opportunities and challengesof funding of the project were also tested, with differentiatedparameters for small and large properties. Parametersestimated included the Net Present Value (NPV) and theInternal Rate of Return (IRR). The biorefinery as a cooperativemodel was found the best option, with or withoutexternal financing, as compared with the associative model,mainly due to a lower tax regime for the cooperatives.KNOWLEDGE GAPS AND FUTURE RESEARCHNEEDSThe use of co-products, by-products and effluents frombio-ethanol production as nutritional supplements in animalfeed has been receiving increased attention in recent years,and although information about the technology options fortreatment and use of these effluents is available, there arestill some areas where more information, knowledge andresearch is required.The huge volume of effluents generated in the biofuelsprocessing operation is a major challenge. There is anurgent need to develop processing technologies that couldreduce considerably the large volumes of effluents generated.In large-scale operations, with high capital investments,this problem could be reduced to a large extent byevaporation of the effluents.In operations at smaller scale, with poor farmer groupsand rural communities, this option is more difficult to implementbecause they generally lack the resources to invest inprocesses that demand high capital and energy costs, and along time scale. Composting is one example of these options.Substantial capital investments are required, large areas needto be allocated, and a good composting process usuallyrequires from 70 to 90 days. Therefore, it is very importantto work on developing technologies that help to reduce theamount of water used in the production of the biofuel and,consequently, the volume of vinasse that is generated.An area that needs to strengthened, one that could helpto improve the overall efficiency of the biofuel productionprocess, is the conversion of vinasse into biogas, throughan anaerobic fermentation process. The biogas generatedcould then be used in the distillery, helping to reduce energycosts. The residue could be used as fertilizer. Finding anddeveloping new bacterial strains that could perform underthe hard conditions and characteristics of the vinasse wouldbe a major breakthrough for this process.Another area, in which there is still a large gap in knowledgeand information, is in the identification and validationof products that can act as flocculants and agglomerantsof the organic load present in the vinasse. Up to now,the most common products in use are the biopolymers.CLAYUCA, UFRGS and SoilNet have had very good resultsusing biopolymers. This has been the basis for the technologiesdeveloped for the formulation of the nutritional supplementsdescribed in this chapter. Although the cost of thebiopolymers is low (only 1.5 grams is required to prepare1 kilogram of nutritional supplement, and only 2.4 percentof the costs of producing 1 ton of nutritional supplementsis due to the biopolymers), the primary constraint is that thebiopolymers are usually produced by multinational companies,and there could be some difficulties in importing anddistributing them, especially if they are intended for use bysmall-scale, resource-poor farmer groups. Thus, there is aneed to develop alternative products that would functionin the same manner as the biopolymers, but that could beproduced and distributed locally and thus be more easilypurchased by small farmer groups.Finally, there is a need to develop and refine technologyprotocols for the production of products with greater valueadded,with good economic potential for use in the animalfeed market. The use of biofuel co-products in the productionof single-cell protein is one example of an emergingtechnology. CLAYUCA and UFRGS have already obtainedpromising results in pilot activities in which sugar canebasedvinasse has been used as a substrate to grow yeast(Candida utilis), with acceptable performance parameters.The biomass harvested from this process is the basis for anexcellent yeast cream with high protein percentages, thatcould have multiple uses in animal feeding and industry.This is an exciting field that will probably grow very rapidlyin the coming years.CONCLUSIONSThe effluents and different products and co-products generatedduring the biofuel production process have verygood potential as nutritional supplements in animal feed,especially for cattle. Co-product use in this way is an activitythat helps to improve the overall economic efficiency ofthe biofuel production process and has positive impacts onthe environment. Different technology options exist andtheir application to biofuel production enterprises is veryeasy, especially in large-scale, commercial operations withenough economic resources available for implementation.Scenarios of biofuel production and use with small-scalefarmer groups and rural communities, in which the RUSBIapproach is applied, have been presented in this chapter.The technologies that are currently available for the managementof the effluents through transforming them intonutritional supplements for animal feed (such as flocculationwith biopolymers) need to take into account the specificcontext of the target groups, which usually have limitedfinancial resources for investing, and with low educationallevels so learning to handle and assimilate sophisticatedprocesses and technologies takes time. The technologiesoffered have to be simple, efficient and sustainable.The transformation of the effluents from biofuelprocessing into nutritional supplements for use in animalfeed, especially cattle, could be a very important strategy