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

English. 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.

Spanish; Castilian. Objective: To analyze the profitability of biogas production from tequila vinasses in an anaerobic packed bed reactor (PBR) plant to use biogas as substitute of heavy fuel (fuel oil) in boilers of the tequila industry.Design/methodology/approach: Financial information for biogas production was gathered; the methodology with the approach of investment project evaluation was used for two reactor volumes, 7 m3 and 10 m3, and the profitability was determined through the following financial indicators: Net Present Value (NPV), Internal Rate of Return (IRR), Benefit-Cost Ratio (B/C R).Results: Biogas production is profitable starting from a reactor’s volume of 7 m3 and it is more favorable when the process is scaled to 10 m3. It was obtained for a volume of 7 m3 and 10 m3 at an updating rate of 12% (NPV $780 376.70 and $5 062 685.22), (B/C R $1.04 and $1.21), (IRR 14% and 26%).Limitations on study/implications: The results are based on values reached in a PBR plant at laboratory scale with a capacity of 445 L, assuming that the values of yield and removal of the chemical demand for oxygen (CDO) are not modified when scaling the process to 7 m3 and 10 m3.Findings/conclusions: Analysis of the results showed that the use of tequila vinasses to generate renewableenergy for auto-consumption in an anaerobic PBR plant is profitable.