Descarte de grãos de milho: comparação das possíveis destinações e análise de custos para implantação de usina de produção de etanol

Abstract

Brazilian agribusiness is expanding yearly, and Brazil is already world's third largest corn producer country. Corn is Brazil’s second largest produced grain, losing only to soybean. Corn is used not only for human and animal feeding, but also in the industrial and energy segments. Increase in grains demand has brought seeds to play a key role in debates about productivity, related to industrial chemical treatment and plant breeding. As in all other industrial activities, seed production generates waste. Nonconforming grains are discarded along the process, from harvesting to processing. Finding an environmentally and economically viable destination to the discarded grains, as well as reducing risks from co-responsibility are important challenges faced by agribusiness. Chemically treated grains discarded from corn production can be sent to landfills, incineration, composting, co-processing in cement kilns and ethanol production. This paper analyses and compares the alternatives for chemically treated grains handling, focusing on sustainable development. Projects management methodologies were used to help guiding decisions towards finding the best destination for the grains. The alternatives were firstly compared on their environmental aspects, through the review of Life Cycle Assessment studies. By the end of this session, sending the grains do landfill and co-processing were considered inadequate due to its great negative potential impacts to the environment. Subsequently, the cost benefit for the seed manufacturer company was analyzed, considering the price of which alternative and the risk by co-responsibility. Composting and incineration were found not attractive to the seeds manufacturer. The best destination among the alternatives was sending the discarded grains to ethanol production. Finally, a preliminary cost analysis was carried out for the implementation of the corn ethanol production plant. The results pointed to a capital cost of R$ 409 million and yearly production cost of R$ 109 million. The payoff time calculated for the investment was 16 years. To increase economic attractiveness, the project must go through further analysis and data revision before being implemented.