Avaliação tecno-econômica-ambiental-social de biorrefinarias modulares em Guiné-Bissau

Abstract

Modular biorefineries are promising industries for diversifying developing countries’ economies and reducing external dependence on productive inputs. This research aimed to evaluate the techno-economic, environmental, and social viability of modular biorefineries for the production of inputs with high added value for the pharmaceutical, cosmetic, or food industry in Guinea-Bissau, from the processing of Fresh Fruit Bunches of palm oil (FFB) and peeled castor bean seeds. The methodology employed to achieve the proposed objective relies on a multi-criteria multidimensional optimization model built to assess the sustainability of proposed biorefineries and support decision-making. The FFB products evaluated were crude oil, refined oil, palm kernel oil, and stearin; while those from castor oil were crude oil, refined oil, and stearin. In order to serve regional markets with these products, the installation of seven modular biorefineries in Guinea-Bissau was proposed. Data were obtained from secondary sources and compiled in the Python® programming language. Data uncertainty was evaluated from the Pedigree Matrix and its variability through Monte Carlo Simulations. Availability of 3.66 x 105 t year−1 of FFB and 1.8 x 104 t year−1 of castor bean seeds was estimated. The solution of the multidimensional model indicated the optimal quantity of each product to be produced in order to reach a gross profit of 5.03 x 108 US$ year-1 in the optimized scenario. GHG emissions from the processing of raw materials in the base scenario were 1.75 x 108 kg CO2eq year-1, while in the optimized scenario it was 2.40 x 108 kg CO2eq year-1. This difference, however, is within the uncertainty range of environmental assessment information. The generation of jobs in the base scenario is 1.24 x 105 jobs per year; in the optimized scenario, it is 1.80 x 105 jobs per year. There is a trade-off between maximizing profit and minimizing GHG emissions. By maximizing profit, GHG emissions increase by 148 %, and by minimizing GHG emissions, gross profit decreases by 82 %. Finally, different carbon credit compensation scenarios were simulated with excess GHG emissions by maximizing gross profit at a cost of 0.03 US$/(kg-1 CO2), 0.10 US$/(kg-1 CO2) and total compensation of all GHG emissions generated, which indicated an impact of 0.86 %, 2.86 % and 4.77 % of gross profit, respectively. The economic-financial feasibility analysis made it possible to verify that the project is viable since the Net Present Value is 5.68 x 107 US$, the Minimum annual Attractiveness Rate of 20 %, the Internal Rate of Return is equal to 39 %, and the deadline for return on the initial investment (Simple Payback and Discounted Payback), is 2.56 years and 3.95 years, respectively.