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close this book Boiling Point No. 15 - April 1991
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Biomass Briquetting?

Abridged translation from "Bois de Feu et Energie"

Biomass briquetting seems to be going through one of its quiet spells in Asia and East and South Africa. R Louvel reports in "Bois de Feu et Energie" No. 26, June 1990, on the continuing lack of success of several attempts to produce cheap briquettes in francophone West Africa. The following "Boiling Point" summary translation gives more details of the situation in the Soudano- Sahelian countries.

Availability of Residues

The energy potential of the residues is very large - in Niger 6.4 m tons of millet and sorghum husks represent 1.6 m TEP (tons equivalent petroleum), enough to supply all the country's energy needs. In more practical terms the biomass residues in the region are of two types, firstly ground nuts, rice, cotton and sugar cane which are found unmixed and localized at agro-industry sites. Industry has the capacity to install industrial type briquetting machinery with high power presses but also has the choice of other options to valorize the residues. Secondly, garden or small farm crops such as millet or sorghum which are widely dispersed, mixed and in small quantities, difficult to collect and again with alternative and perhaps more pressing uses ea. roofing thatch or cattle food or directly as unprocessed fuel. A large majority of the total residues are in this category, however, a survey in Burkina Faso showed that there are, in fact, no surpluses of this type of residue available for briquetting, for sale in Niamacy.

Briquetting Experience

All the industrial presses installed over the last dozen years have experienced serious problems. In Niger, at a groundnut oil mill installed in 1979, 2 presses, total capacity of 2,800 T/year of shells, have never produced 400 T/Y. In the Gambia in 1982, as a result of technical problems, the sale of briquettes is still not successful and has now stopped, despite the Government ban on charcoal. In North Cameroun, the rice husk presses have ceased operation and in the Ivory cost, the presses were not satisfactory and the coffee husks are now used as a powder fuel.

In Niger, the main problems are as follows:

1. Technical problems of effective operation of the plant resulting from the European manufacturers testing with temperate climate residues rather than those of the country of operation.

2. The price of the briquettes (22 F CFA/kg) is not competitive with those of conventional fuels which have not risen as anticipated (10-20 F CFA/kg). The production costs of the briquettes is estimated at 37 F CFA/kg excluding investment cost.

3. Sustained acceptability of the ground nut shell briquettes, as a substitute for both wood and charcoal ea. lighting difficulties, smoke, slower cooking, storage difficulties. Distribution needs to be door to door rather than a trip to the factory.

Recent Developments

The industrial presses have improved and are now viable but still cannot compete with the low prices of traditional fuels for the domestic market ea. Belgamil in the Gambia. In Niger and Burkina Faso the Rassaut small scale, manually operated presses (capacity 10-20kg/h) are unpopular because they need a man to operate them whereas fuel collection is normally done by women and children. The briquettes are unlikely to be marketable as long as wood is available for collection free.

Briquettes or Substitute Fuels

In an unmonitorized fuel situation, the costs of buying and using a manual press and marketing the briquettes locally are very difficult to recoup.

In the urban economy it seems likely that more modern fuels such as gas or kerosene will be preferred if charcoal prices rise. Institutional or small- scale industry users will be interested in briquettes if a reliable supply of suitable quality can be relied upon. The continued supply of suitable and low cost residues is the essential condition for the use of briquettes.