Technical and Economic Analyses for the Implementation of a Biohydrogen Production System Using Bioelectricity from Vinasse Biogas of the Sugarcane and Alcohol Industry

Abstract

This paper studies the implementation of a system consisting of an electrolyzer connected to a bioelectricity generator set that operates using vinasse biogas. Data on total ethanol production across all regions of Brazil were collected, and two ethanol plants in São Paulo state were selected for analysis (São Jose da Estiva and São Manoel). The feasibility of implementing this system at these facilities was evaluated using energy analysis for biohydrogen production. The process’s energy efficiency was assessed, allowing for the construction of a Sankey Diagram for both plants. Additionally, the costs of producing bioelectricity and biohydrogen via electrolysis using vinasse biogas from Brazil’s sugar/alcohol industry were determined, factoring in the payback period, equivalent utilization period, and annual interest rate. The study demonstrates the efficiency and cost-effectiveness of producing biohydrogen using vinasse biogas. The cost of producing bioelectricity at the two plants decreases significantly over the 25-year system implementation period, starting at around 0.09–0.08 USD/kWh in the first year and dropping to a minimum of 0.027–0.039 USD/kWh by the end of the period. The initial cost of producing biohydrogen ranges from 0.24 to 0.25 USD/kWh at São Jose da Estiva and from 0.30 to 0.32 USD/kWh at São Manoel in the first year. However, prices drop by nearly half in the second year, reaching 0.05 to 0.06 USD/kWh at São Jose da Estiva and 0.06 to 0.07 USD/kWh at São Manoel. The payback period for the biohydrogen and bioelectricity production system increases, with São Jose da Estiva generating income by 1st year for a 4% to 12% interest rate. For São Manoel, income is expected by the 1.5 year for a 4% to 12% interest rate. Both plants recover their investment within the first 2 years of operation. By the 10th year, São Jose da Estiva’s income is projected to be between 3,888,501.96 USD (4%) and 3,678,407.29 USD (12%), while São Manoel’s income is expected to range from 3,123,824.69 USD (4%) to 2,932,050.63 USD (12%), demonstrating that the system is viable for sugar and ethanol plants.