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Fuelling Development
[top] [end]IntroductionFuelwood is a serious issue in many developing nations. Internationally, traditional forest resources are being reduced faster than they are being replanted. Substantial energy can be obtained from burning ordinary agricultural and commercial residues. This paper discusses a wet, low-pressure briquetting process, which may be more appropriate where infrastructure is weak, supply of raw materials is inconsistent, and market populations are widely dispersed over inaccessible areas.This process was initially developed in the mid 1980s by Dr Benjamin Bryant, at the University of Washington, US. The Legacy Foundation developed a field-based extension package for the technology, leading to briquette technology usage in South America, the Caribbean, West, East and Southern Africa and Asia (12 countries to date). The production process is located within (or adjacent to) the user community, in areas of high environmental and population pressure, where there are few fuel alternatives, as cost determines what people will buy. The process requires modest technical skills and low start-up costs. The results in an optimum production unit are increased income and environmental protection. [top] [end]Wet, low-pressure processFuel briquetting is not always the right solution. Easily-replicated affordable equipment and a localized market for the finished briquettes make the technology ideal for entrepreneurs in marginalized communities in rural or urban areas. The wet, low-pressure, manual briquette making requires good access to water (up to 300 litres per day), ample sunshine for drying and available human resources.[top] [end]ResourcesThese include fallen, browned, nutrient-leached leaves, grasses, stems roots stalks, nuisance aquatic plants such as water hyacinth and agro-processing by-products such as rice husks, bagasse, sawdust, choir, scrap paper, and cardboard.[top] [end]ProductionProduction comprises material gathering, preparation, pressing (Figure 1) and drying. The preparation process is the most critical: fibrous agricultural residues are chopped, the fibres are partially removed using either hammer mills, hand cranked devices or mortar and pestle. Once the materials are broken down sufficiently, these residues are blended in selected proportions with other residues or with commercial processing wastes to achieve the desired characteristics for the briquette.
The required pressure in the wet briquetting process is easily provided by an average artisan, for continuous production of briquettes measuring 10 cm diameter X 7.5cm height. At the basic level of the technology, the equipment comprises a relatively easily made wood hand-operated compound lever press. The press can be altered to fit local resources and skills and is usually made on site in a few days. In Haiti for example, hydraulic jacks and concrete beams are used because of a shortage of wood. In other areas a single long lever is used because of the cost of metal bolts. A production team of six trained and experienced entrepreneurs will typically produce between 750 and 1200 briquettes per working day, including material gathering and processing. Generally, it takes two to three months for a trained team to achieve this capacity. The briquettes are dried in the open air for several days before use. They can be stored indefinitely and used through the rainy season as long as they are kept reasonably dry. [top] [end]Use of agro-residuesIn rural areas, the raw residues required for these briquettes tend not to conflict with soil quality; the much preferred residues will be dry and brown and already leached of soil building nutrients. As a matter of convenience, these agro-residues tend to be collected not over the main fields but from depressions and up against natural windbreaks.Following combustion, some of the residue is returned to the ground as ash. In all areas, commercial processing residues such as rice husks, peanut shells, maize-milling residues, sawdust, coir dust or waste papers are highly favoured as they do not require any chopping, pounding or decomposition. These processed residues can constitute up to 50% of an agroresidue based briquette and thus can reduce considerably the processing labour. [top] [end]Heat outputHeat output varies with blend; a 45% charcoal fines and agro-residue blend briquette, weighing 130 gm, will nearly equal the heat output of charcoal of the same weight in an open fire. Water hyacinth and certain other blends will produce only slow heat for extended periods, while others, particularly with oils in the original material, will burn with an intensity equalling a wood fire.The briquette burns efficiently due to a hole in its centre which provides both a chimney and insulation around the combustion chamber. The advantage is relatively high efficiency with open/three-stone fires or standard uninsulated metal stoves where wood and charcoal burn at very low efficiencies. Conversely, stoves with higher efficiencies offer less of an advantage for the briquette than they do for wood or charcoal. [top] [end]CookingCooking with these briquettes is easy and efficient. As noted, with ample air supply and allowance for ash removal from beneath, fuel briquettes burn easily using either a traditional threestone or metal stove.Culturally, there appear to be no problems in making or using fuel briquettes made from agro-residues; food reportedly tastes the same as it does when cooked with wood. Other uses are also relevant: use of dried eucalyptus leaves creates special aromas which have long been popular for improved breathing; the leaves of the neem tree repel insects and pine or cedar fronds make a pleasant aroma. Burned briquettes leave only a wispy white ash by product, suggesting relatively good combustion.
[top] [end]Generating incomeTo the majority of producers and users, the prime advantage of these briquettes is the increase in daily income, so the economic viability must be evaluated before any training commences.
For the briquettes to be economically viable, the six daily wages divided by 75 families will give the cost of briquette fuel for one family for one day. This should be compared with how much the family spends on other fuels. In rural areas, where firewood is ‘free’ for the gathering, hauling and chopping, the production of the equivalent in fuel briquettes has proved far less time-consuming, safer and less back-breaking. Project figures indicate that where people have to walk more than three hours a week for the family wood fuel supply, they are better off making briquettes, other factors being equal. In many cases the producers are former wood and charcoal makers, thus employment is not adversely affected. The average fuelwood consumption is 1.2 kg per person per day, as quoted in FAO, the Swedish Beijer Institute, the World Bank, the French SEED organization and others. At this rate, one press team, in full production, reaching a market of 750 persons per day, is effectively reducing demand by over 300 tonnes of fuelwood per year, while giving employment to six persons. [top] [end]ExtensionThe aim is to establish small incomeproducing groups which are combating deforestation through non-subsidized fuel briquette making and sales. Business and marketing training of the producer groups is part of the project. Awareness-raising and public promotion is the other part. For those projects with higher budgets, Legacy Foundation works with local partners to incorporate demonstrations, posters, graphics of many forms, in combination with newspaper, radio and video. We are experiencing a unique and growing network of colleagues who often can supply equipment locally, who are either trainers or project managers with direct training and production experience or who are conducting technical research in the ‘briquette carrying capacities’ of various land uses and forms, assessing heat values and thermal performance of various mixtures and developing a unique briquette gasifier stove.To more effectively reach the growing demand for information about the technology, Legacy Foundation has recently compiled four manuals which address fuel briquette making, briquette press construction, extension training and group formation and advanced technology issues regarding alternative fuel technologies. These manuals are currently in print and are available on CD and as directly downloadable electronic versions. For detailed ordering information or information regarding extension training programmes please email info@.... We feel that with such skills and exposure, the producer and trainer can enter a whole new world in which they gain respect, enhance their local identity, preserve their environment for their children and feed themselves in the process. In this way the briquettes do more than provide a cooking fuel: they fuel development. [top] [end]Download the original article Fuelling development by Richard Stanley (105 KB)[top] [end]Contents: Boiling Point 49: Forests, fuel and food
Categories: Boiling Point 49| Briquettes | ||||||||||||
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28 June 2007; Last edited:
28 June 2007; Version: 0 | ||||||||||||
Pagename: FuellingDevelopment @HEDON: YFFA | ||||||||||||
