Profitability of biogas production as a source of energy for tequila distilleries from the anaerobic treatment of tequila vinasses

Abstract

Objective: To analyze the financial profitability of biogas production from tequila vinasse in an anaerobic packed-bed (AP) plant for the use of biogas as a substitute fuel for heavy fuel (fuel oil) in boilers of the tequila industry.

Design/methodology/approach: First, financial information was collected for biogas production. Next, a traditional approach was utilized to evaluate investment projects for two reactor volumes, 7 m³ and 10 m³. Finally, profitability was determined by the following financial indicators: Net Present Value (NPV), Internal Rate of Return (IRR), and Benefit-Cost Ratio (BCR).

Results: The study results indicate that biogas production is cost-effective from a reactor volume of 7 m³ and is more favorable when scaling up the process to 10 m³. These results were obtained for a volume of 7 m³ and 10 m³ at an update rate of 12% (NPV $780 376.70 and $5 062 685.22), (BCR $1.04 and $1.21), (IRR 14% and 26%), respectively.

Study limitations /implications: The results are based on values achieved in a laboratory-scale AP plant with a capacity of 445 L, assuming that the yield and removal values of chemical oxygen demand (COD) are not modified by scaling the process to 7 m³ and 10 m³.

Findings/conclusions: The findings demonstrate that using tequila vinasse to generate renewable energy for self-consumption in an AP anaerobic plant is profitable.