Biorrefinaria de macaúba em pequena escala : uma análise técnica, econômica, ambiental e geoespacial

Abstract

Portanto, as biorrefinarias de macaúba em pequena escala podem descentralizar o setor de biocombustíveis no Brasil, e a viabilidade da pequena escala depende de fatores relevantes: cadeia de consumo de coprodutos; aumento dos preços dos créditos de carbono; desenvolvimento de novos sistemas para produção escalonável e descentralizada de H2 para evitar a dependência do gás natural; e catalisadores que favorecem as rotas de baixa demanda de H2.[EN] Biofuel-driven bio-refineries in small-scale can use decentralized biomass sources, and insert small producers in the biobased economy, generating socioeconomic and environmental gains. Macauba outstands in this scenario for its high productivity, low cost and low land and water use. In this study, three bio-refinery scales: large, medium and small (400, 40 e 4 kt of processed oil per year) were evaluated in technical, economic, environmental and geospatial terms for green diesel production from macauba pulp oil via hydrotreatment. From large to small scale, the results show that the relative capital expenditure (CAPEX) is 4 times higher, from US$ 0.60 L -1 ∙yr-1 to US$ 2.35 L - 1 ∙yr-1 , and the hydrogen production via steam reforming demands half CAPEX in all tested scales. On the other hand, coproducts, tax deductions for family farming and carbon credits reduce the green diesel price produced on small scale from US$ 1.48 L -1 to US$ 0.69 L - 1 , which is close to the commercial diesel price (US$ 0.58 L - 1 ). The Lifecycle Assessment of the green diesel shows a carbon footprint of 11.23 gCO2eq∙MJ-1 , lower than commercial biofuels in Brazil, representing 87% reduction in CO2 emissions by comparing with fossil diesel. Finally, the geospatial analysis reveals that most of the areas suitable for macauba cultivation are located in the countryside, far from large consumer markets, so convenient to implement small-scale bio-refineries. Therefore, small-scale macauba bio-refineries can decentralize the biofuel sector in Brazil, and the feasibility of the small scale depends on relevant factors: coproducts consumption chain; increasing prices of carbon credits; development of new systems for scalable and decentralized hydrogen production to avoid natural gas dependence; and catalysts that favor lowhydrogen demand routes.