Embodied Energy Calculation of Small-Scale Biogas Plants in Rural Areas of Bangladesh

Abstract

Installation of a biogas plant consumes a considerable amount of energy especially in transportation and manufacturing of various biogas plant construction materials. Energy conservation has become one of the important issues of today’s world for reducing greenhouse gases emission into the atmosphere and for reducing the costs of materials. This paper is focused on some issues relating to embodied energy in a biogas plant, particularly in the Bangladeshi context. Energy consumption in the production and transportation of basic biogas plant materials (such as brick, cement, sand etc.) and other materials used for construction has been discussed. Data has been collected from 20 small-scale biogas plants (2.4 m 3 , 3.2 m 3 , 4.8 m 3 ) located in different rural areas of Rajshahi, Bangladesh. It is found that the embodied energy of 2.4, 3.2 and 4.8 m 3 biogas plants are 9.4 GJ, 11.4 GJ, and 22.7 GJ respectively. Around 59-63% of total energy is costs by bricks, 29-33% by cement, 1.5% by sand, 3-5% by PVC pipe, 1% by HDPE pipe and 0.5% by steel used to install the plants. It is also found that the energy required for the production of the construction materials was 83-85% of total energy required while transportation energy was 16-17%. However, a complete analysis of energy input for the installation of a small scale biogas plant in Bangladesh has been described in this paper which will hopefully be helpful for further research in this sector.