With all that has been said about biomass it seems, literally, to be the answer to the energy crisis. Biomass presents the world with a self sustaining and replenishable energy resource in perpetuity. Among its other benefits are listed job creation, carbon neutrality and a capacity that all but replaces fossil fuels.
Biomass energy is the utilisation of energy stored in organic matter. These organic matters are sometimes burned directly to produce heat or refined to produce fuel like ethanol or other alcoholic fuels that can be converted to liquid transportation fuels, used readily by current-generation vehicles. The fuel cycles created by biomass processing would not have any greenhouse emissions, and this processing is already easily convertible and compatible to the existing infrastructure of energy in the world.
Plants and sun
Plants have several properties which make them ideal for biomass energy usage and processing. Using biomass energy is actually an indirect way of using energy from the sun. Because plants are solar collectors, they readily store energy as a fact of their biology. Plants are self regenerating as well, and they are totally and spontaneously recyclable.
The timber industry produces saw dust, timber slash and mill scrap which are all considered organic materials. In South Africa where some 18 million tons of timber per annum are harvested the output of forest biomass is estimated to be about 6.7 million tons. The available portion is approximately 60% of the total which translates to about 1.5 million tons of biomass annually. Viewed broadly this biomass could replace about one million tons of coal, making carbon neutral forest biomass a viable alternative to fossil fuels.
By no means exclusive to forestry, biomass is virtually everywhere. In the agricultural industry, residuals like bagasse (fibres) from sugarcane, straw from rice and nutshells as well as manure lagoons from cattle, poultry and hog farms are usable. Even in cities, paper and yard wastes are suitable for biomass processing.
Biomass generates electricity
These organic materials can be captured and converted in to fuels suitable for generating electricity. The planting of crops like fast growing trees and grasses specifically for energy generation, can also prevent soil erosion and reduce global warming.
According to a recent paper entitled ‘Carbon sequestration through biomass energy’,
Worldwide, biomass accounts for 15% of the energy supply. Much more significant as a power supply in developing nations than in industrial nations, Biomass supplies 70-90% of the energy needs of Africa, 32% in China, and in Brazil, 33%.
In contrast, the United States gets only four percent of its energy from biomass. But, in the US, investment and available technology could increase the feasibility and efficiency of growing biomass as an energy crop and converting biomass to a more carbon neutral energy supply.
Estimates of energy capacity in the US generated from biomass range from 7 000 to 10,000 MW. Increased competition in the energy industry and technological advances in biomass power generation are likely to increase the potential amounts of energy from biomass. If these increases in biomass capacity replace some of the energy supplied by fossil fuels, this will reduce the US CO2 emission rate by as much as one third.
In South Africa, one of the country’s biomass projects is at Mondi Business Paper’s Richards Bay Mill, about 180km away from Durban.
Coal fired boilers are presently used at Mondi Richards Bay to generate heat and electricity for the production of pulp and linerboard. If necessary, modifications will be done to existing precipitators in order to handle emissions from the additional biomass load in the boiler and to ensure that emissions levels comply with national legislation.
The project focuses on the collection and recovery of biomass waste, for use in the generation of renewable energy as an alternative fuel to coal for general purposes and specifically to generate steam from the power boiler on site.
The collections consists of fines, wood chips and logs presently being used as landfill at a Richards Bay Municipal Landfill site and some plantation waste currently left in the plantations to decay.
Mondi SilvaCel and other timber processors (chippers) in the area of Richards Bay presently transport and landfill their biomass waste at a local municipal landfill site. With the implementation of the project these operations will no longer use biomass waste as landfill. In addition, other potential sources of biomass waste from surrounding plantations (stumps, off-cuts and branches) normally left in the plantations could be recovered and processed into fuel.
A more high profile project is in the Coega Industrial Development Zone (IDZ). An investment of R70 million has been secured for a biomass fuel project which will supply 10 000 tons of the product per month to European markets.
The plant will be one of the largest among the 285 biomass operations globally. According to Eastern Cape Biomass Fuel Pellets CEO Willie Claassen, the project would create about 100 jobs during the construction of the plant, an additional 60 direct jobs and about 3000 indirect jobs in the Eastern Cape rural areas.
The Coega plant will use forest residue, sawmill waste and alien vegetation from the Eastern Cape and part of the southern Cape as well as some scrap wood from the government’s working for water programme.
Weighing it all up, energy biomass, as a carbon neutral source of energy, some say, is ideal for replacing fossil fuels. This has the added benefit of counteracting the impact of global warming and in so doing could qualify for the use of carbon credits under the Clean Development Mechanism (CDM).
Others say that Biomass can not fully replace the huge volumes of petroleum and other fossil fuels now in use but it can make a significant contribution to providing fuels and chemicals comparable to those derived from petroleum.