Biomass energy: Sustainable solution for greenhouse gas emission

Abstract

Biomass is part of the carbon cycle. Carbon dioxide is produced after combustion of biomass. Over a relatively short timescale, carbon dioxide is renewed from atmosphere during next generation of new growth of green vegetation. Contribution of renewable energy including hydropower, solar, biomass and biofuel in total primary energy consumption in world is about 19%. Traditional biomass alone contributes about 13% of total primary energy consumption in the world. The number of traditional biomass energy users expected to rise from 2.5 billion in 2004 to 2.6 billion in 2015 and to 2.7 billion in 2030 for cooking in developing countries. Residential biomass demand in developing countries is projected to rise from 771 Mtoe in 2004 to 818 Mtoe in 2030. The main sources of biomass are wood residues, bagasse, rice husk, agro-residues, animal manure, municipal and industrial waste etc. Dedicated energy crops such as short-rotation coppice, grasses, sugar crops, starch crops and oil crops are gaining importance and market share as source of biomass energy. Global trade in biomass feedstocks and processed bioenergy carriers are growing rapidly. There are some drawbacks of biomass energy utilization compared to fossil fuels viz: heterogeneous and uneven composition, lower calorific value and quality deterioration due to uncontrolled biodegradation. Loose biomass also is not viable for transportation. Pelletization, briquetting, liquefaction and gasification of biomass energy are some options to solve these problems. Wood fuel production is very much steady and little bit increase in trend, however, the forest land is decreasing, means the deforestation is progressive. There is a big challenge for sustainability of biomass resource and environment. Biomass energy can be used to reduce greenhouse emissions. Woody biomass such as briquette and pellet from un-organized biomass waste and residues could be used for alternative to wood fuel, as a result, forest will be saved and sustainable carbon sink will be developed. Clean energy production from biomass (such as ethanol, biodiesel, producer gas, bio-methane) could be viable option to reduce fossil fuel consumption. Electricity generation from biomass is increasing throughout the world. Co-firing of biomass with coal and biomass combustion in power plant and CHP would be a viable option for clean energy development. Biomass can produce less emission in the range of 14% to 90% compared to emission from fossil for electricity generation. Therefore, biomass could play a vital role for generation of clean energy by reducing fossil energy to reduce greenhouse gas emissions. The main barriers to expansion of power generation from biomass are cost, low conversion efficiency and availability of feedstock. Internationalization of external cost in power generation and effective policies to improve energy security and carbon dioxide reduction is important to boost up the bio-power. In the long run, bio-power will depend on technological development and on competition for feedstock with food production and arable land use.