Techno-economic analysis of an enhanced anaerobic digester in the Andean area of Peru

Abstract

This paper aims to determine the economic and technical feasibility of developing a thermally enhanced digester in the Andean area using solar collectors. Communities in the rural area of the Andes lack access to electricity and other basic services which impact negatively on their everyday life and exposes them to harmful and inefficient fuels. Several experiences with anaerobic digestion prove that this technology could be applied in the Andean area, although its performance is limited due to low temperatures. To overcome this constraint, an enhanced digester was modelled and simulated using TRNSYS Software. The system consisted of two solar collectors, a storage tank and a digester with a wrapped-around heat exchanger. The average digester temperature in the simulation was 30.7 °C. The enhanced temperature was used in a model to calculate the daily biogas production. The Net Present Value and Internal Rate of Return were calculated and confirm the economic viability of the project. The biogas production fully covers the requirements of the system for household cooking and lighting, making a significant social impact. This simulation indicates that it is technically possible to develop an enhanced digester in the Andean area that is economically viable as well.