History of Bioenergy
Humans through history used the plant and animal materials around them to provide energy for their heating, lighting and cooking needs. This is still the case to a greater or lesser degree for up to half the world’s present population. Wood, dry straw or grass is gathered and burned, plant or animal oils are used in lamps, animal dung is collected, dried and burned. This is known as the 'traditional' use of biomass.
The development of electricity and the internal combustion engine meant that fuels of high energy value- coal and petroleum products - were in increasing demand. Organic chemistry based on petroleum has meant that now a significant fraction of the crude oil extracted is utilised for production of fibres, dyes, plastics and other ‘synthetic’ products. Increasing pollution of land, sea and air has been one unintended consequence. One aspect of this is the increasing acceptance that the Greenhouse effect exists, is increasing and is to a significant degree responsible for Global Warming. The control of the largest sources of oil in the hands of very few countries has meant occasional volatility in pricing. The approach of the predicted ‘peak oil’ and the situaltion of demand exceeding supply will only see this volatility increase along with dramatic increases in cost of oil .
For many years there has been a knowledge of how to utilise biomass – the natural plant and animal materials around us – to produce similar chemicals and fuels to those produced from oil and coal. Wood and other ligno-cellulosic material have many similarities chemically to oil and coal. If biomass is heated in limited or no oxygen a range of carbon-and hydrogen-rich gases are given off that can be refined to produce a wide range of carbon-based chemicals and fuels. But while fossil fuels were available cheaply the high cost of this process meant that it was only used when there was no other alternative. Examples are during World War Two in many countries with use of wood charcoal gas producers for commercial vehicles, in Germany during World War Two in production of petrol from coal, or in South Africa to produce fuels during the international sanctions during the Apartheid era. South Africa continues to produce diesel fuel from coal by this process.
But in the many developed and developing countries new technology or materials have improved the economics of producing energy (including transport fuels) from biomass, making it possible to move away from our present near-total reliance on oil, gas and coal for heat, electricity and transport fuels. This research and development was triggered by the oil price shocks of the 1970’s, when cost of imported crude oil increased up to tenfold.
Sweden and Finland have now shown that it is possible to produce 70% of heat energy and 10-20% of electricity needs from woody biomass. Denmark has shown that straw can be utilised to replace oil and coal in large power plants, and it can be the base material for production of ethanol in industrial-scale processes. Denmark and Sweden have improved the economics of anaerobic digestion of putrescible (wet) waste to produce methane as a replacement for natural gas, including for use as a transport fuel.
Sweden has developed the economics of freighting woody biomass up to 4 hours by train to new larger bioenergy plants near cities. The pelleting of wood waste means that now it is economic to freight wood pellets to Europe from Australia and the west coast of Canada. Austria is demonstrating the potential for wood pellets and energy-efficient housing design to dramatically reduce fossil fuel needs.
The governments and industries of these countries that presently lead in the drive to be self reliant for energy and to reduce their national green house gas emissions all have far higher targets for utilisation of biomass. Sweden aims to be producing all its heat needs (50% of its energy requirements) from biomass by 2020, and all its fuel needs by 2030 (25% of its energy requirement) while lifting electricity production from the present 10%. China by the end of 2011 will be generating 1000 MW-e from over 40 straw fired power plants that will be fuelled by 10 million tonnes of straw annually. It has another 300 million tonnes of straw economically available, and is about to add vast volumes of wood chip to this biomass flow. The heat from these power plants will be able to be used for district heat in urban communities and for industries including straw to ethanol.
The World Bioenergy Association has analysed the mass of research papers on sustainable use of biomass and concluded that the biomass sustainably available world wide is adequate to supply much of the world's energy needs (www.worldbioenergy.org).