Design, Construction and Production of Small Scale Energy Generation Plant using Indigenous Resources

Abstract

Developing countries like Pakistan are in serious energy crisis. Renewable energy resources are the best alternative for conventional energy sources. The use of indigenous resources to produce bioenergy is an excellent solution to meet the energy needs of developing countries. The aim of the study was to design, construct and production of bioenergy generation from indigenous resources to fulfil bioenergy requirement for electricity, cooking and heating. This research introduces the Best Available Technology (BAT) and bioenergy plant was constructed with local materials at minimum cost to avoid economic burden on bioenergy production cost. An underground bio-digester unit with a volume of 10 cubic meter (7 m3 bioenergy digester tank plus 3 m3 bioenergy gas cap/holder) has been installed. The daily feed was approximately 160 kilogram of cow slurry (80 kg cow dung plus 80 litres/kg water). The retention period was approximately 44 days and the reported seasonal temperature was approximately 24˚C - 32˚C. The unit was thermally insulated, so the fluctuation in temperature was slightly about ±2˚C. In experimental setup, indigenous biomass resources were mixed with water in a mixing chamber. Whole mixture enters into digester through the inlet pipe and regularly feed up to selected retention time. Anaerobic bacteria decompose the biomass in the digester and produce bioenergy. A simulation was performed to estimate relevant model parameters from experimental data. The proposed model can predict methane production behaviour from some key indicators (such as organic matter and VFAs) in the anaerobic digestion process. Results obtained from the experiment showed that the plant could generate average volume of 3.18 m3 of bioenergy biogas at average pressure of 170 mbar in a day. Results also revealed that the rate of bioenergy generation increase with respect to time from 33 to 44 days of retention time, the pressure of bioenergy generated increase from 35 mbar to 175 mbar. From the results, it was observable that the more the pressure in the chamber, the more the volume of bioenergy generated; thus, at 175 mbars, it produced maximum volume of 3.2 m3 of bioenergy.