A biomass powered Ringbom-Stirling engine for developing countries: a low-budget solution for distributed electricity generation.

Abstract

In   many   isolated   settings   electricity   is   not available or is supplied by fossil fuels, while biomass is used for cooking purposes, not exploiting all of its potential. We are building a prototype of a biomass powered 1kWel  Ringbom-Stirling   engine   that   doesn't   require   high   technology,   but nevertheless brings relevant innovations. This solution aims to generate electricity using the same source used for cooking. It is meant to be used and to be producible in developing countries, where distributed electricity generation, using locally available primary   sources,   can   help   reducing   the   dependence   from foreign   aids   or   suppliers.   The   system   we   are   building   is composed of a down-draft gasifier which supplies the syngas that is then burned to heat the Ringbom-Stirling engine, which produces electricity, while the remaining heat is available for cooking. We discuss here the general scheme of this solution with particular regard for some new applications that greatly simplify the operation of traditional Stirling engines, such as metal   bellows,   used   instead   of   the   typical   cylinder-piston arrangement,  to totally eliminate the friction due to sealing needs between moving parts.