By associating organic waste from combustion processes and coal gasification, a highly economical and low-pollutant fuel is obtained. This is an energy solution which fits in well with the concept of sustainable development. It is a European solution, the benefits of which will go far beyond the frontiers of the EU.
Given the current rate of consumption
of oil and natural gas, it is expected that the available stocks
of these two fossil fuels will no longer be able to cover the energy
requirements of an increasing world population by the middle of
the next century. The earth's coal stocks, on the other hand, are
still enormous. The major obstacle to using this fuel stems from
its high degree of harmfulness to the environment, particularly
from sulphur dioxides, nitrogen oxides and carbon dioxide (greenhouse
Two paths have been explored since the end of the 1980s with a view to improving the use and environmental impact of this traditional ore: gasification and pressurised coal combustion. These methods increase electrical output and industrial heat recovery, reduce polluting gases and provide solid subproducts which can be used by industry (as in the manufacture of cement, for example).
Since the beginning of the 1990s, a third path with promising
prospects has been opened up: a mixture of coal and organic waste
(biomass). This new fuel, which is particularly economical, should
also make it possible to solve the problem of the increasing management
of waste from timber for construction, sludge from purification
plants, paper, straw, manure, and other agricultural and forestry
waste products. When these are stored and allowed to decompose naturally,
they release two gases which have been implicated in the greenhouse
effect: carbon dioxide (CO2) and methane.
If incinerated in that state, they release various toxic emissions
and their use as an industrial energy source is generally of a totally
Two projects supported by the European Commission and carried out under the JOULE Programme were launched in 1993. One, coordinated by the CRE Group Ltd (United Kingdom) concerns the co-gasification of coal combined with biomass waste. The other, coordinated by the University of Stuttgart, studies coal combustion. This partnership brings together about 30 industrial firms, universities and research centres in 13 European countries.
Work done in the laboratory and then industrial trials, yielding up to 300 Mwe, have made it possible to obtain a new fuel, the energy from which may be efficiently recovered for electricity production, with a minimum of waste and harmful emissions, and which offers the great advantage of flexibility in that the nature of the waste can vary greatly and the relative mixture of the raw materials - coal and waste - can vary according to the quantities available.
Individually tailored solutions
The results were presented at an international congress for industrialists and decision-makers (Lisbon, 1994), all greatly interested in this innovation. This technique makes it possible for sites to exploit the available sources of biomass on the spot which are sometimes very specific from one region to another and subject to seasonal variations. This energy solution is particularly well adapted to the needs of central and eastern Europe(1) and developing countries, which still depend heavily on coal for their energy requirements. New research projects are currently being pursued with European support (through the JOULE and THERMIE programmes), in an attempt to improve this type of energy supply while reducing harmful emissions into the environment to the fullest extent possible.
(1) In the framework of international cooperation by the EU
on scientific and technological areas with the countries of central
and eastern Europe (the COPERNICUS Programme), a Czech industry
has been associated with the research work on coal/biomass coal