|Low Cost Charcoal Gasifiers for Rural Energy Supply (GTZ, 1994, 49 p.)|
|10. Concepts of future dissemination of small gasifier-engine systems|
For an assessment of the part which gasifier technology can play in the energy scenario of the near future, the potential of an increased energetic use of biomass has to be seen in a broader context.
Agriculture and forestry, especially that of the so-called developing countries, will increasingly be confronted with the following problems:
- On the one hand only a small amount of harvested plant material is really being used.
A far larger part of biomass remains as waste (wood cuttings, shavings, saw dust, straw, cotton stalks, coffee pulp, bagasse, rice husks and so on), and thus poses a local disposal problem, which most of the time is "solved" by burning.
- On the other hand primary manufacturing processes need energy, which is usually provided by consuming fossil fuels. For countries with a weak economy this means an additional strain on their balance on foreign exchange payments by importing mineral oil, respectively a loss of income by fewer exports. In addition the consumption of fossil fuels always implies a strain on the atmosphere by increasing the CO2 content (introducing carbon stored in fossils into the atmosphere).
- Furthermore, developing countries have an enormous demand for biomass, needed for domestic firing processes as well as for drying processes in industry or crafts. This demand is usually covered by firing wood and charcoal from forest stands. The devastating consequences for the natural resources are well-known.
Facing these problems the tasks of agriculture and forestry have to be reconsidered. In addition to the classic demand for a sustainability of production-which is not at all realized at all times - the protection of environment and resources has to be increasingly taken into account. This requires
- protecting the still existing forest stands
- securing the sustainability of forestry by afforestation
- growing energy plantations appropriate to the according site
- efficient use of biomass by integration of waste and residues of agriculture and forestry as a source of energy and for substitution of firewood.
By making energetic use of residues and waste material the ruthless exploitation of resources could be limited and a rational, environmentally adequate use of energy could be promoted. In this context the following technical procedures are of special interest:
(1) Gasification of residual biomass materials for generation of heat and power
(2) Substitution of firewood by other plant material
(3) Production of biocoal briquettes for use as cooking fuel and/or gasifier fuel.