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| − | =Technical Brief= | + | ==Processing== |
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| − | ==Short Description==
| + | The Green pulp exterior is removed. One method is to bury the fruit in the ground so that the pulp ferments and falls off. This takes 12 days or more. The nuts are parboiled or sun dried and then smoked for 3 to 4 days. The dried nuts can then be stored for long periods without significant losses. Decortication is done by crushing the outer shell to remove kernels. Shea nuts are mainly exported as smoked kernels'''.''' The kernels will be further dried before any additional processing is carried out. |
| − | *'''Problem:'''categorizing of different cooling procedures
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| − | *'''Idea:'''
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| − | *'''Difficulty:'''high
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| − | *'''Price Range:'''middle to high
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| − | *'''Material Needeed:'''
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| − | *'''Geographic Area:'''
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| − | *'''Competencies:'''
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| − | *'''How Many people?'''
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| − | *'''How Long does it take?'''
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| − | ==Introduction== | + | ==Shea nut butter== |
| | + | Traditionally wet processing by hand is a slow and laborious process that uses large quantities of wood for roasting. The kernels are roasted in a pot over a fire to approximately 100°C and then pounded in a mortar to produce a course paste. This is then ground between two stones to produce a smooth paste. The paste and water are mixed in a pot where the butter rises to the top. The butter can then be removed and washed repeatedly with warm water until clean. The remaining water is remove by heating. Impurities settle out and the butter can be left to cool and solidify. With the traditional technique, the fat obtained is between 25 and 40% of the dry kernel weight. |
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| − | <div class="booktext">
| + | The introduction of equipment can improve upon traditional methods of production by reducing the effort and time involved and by increasing the yield. Instead of pounding by hand a mill can be used, Oil can be extracted using a mechanical or hydraulic press. Manually turned roasters can be used rather than a traditional pot. A very important consideration is the minimum throughput required to run the equipment profitably, including the initial cost, management of the equipment and maintenance. |
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| − | Refrigeration plays an important role in developing countries, primarily for the preservation of food, medicine, and for air conditioning. Examples of these applications are:<br />
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| − | <blockquote>
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| − | ''• In agriculture and dairies:''<br />
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| − | </blockquote><blockquote><blockquote>
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| − | removal of field heat immediately after harvesting of crops, storage of fruit, flowers, vegetables, milk, meat, and cooling during transport.
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| − | </blockquote></blockquote><blockquote>
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| − | <br />''• In retail trades:''<br />
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| − | </blockquote><blockquote><blockquote>
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| − | sale of fresh foods, fish and cold drinks.
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| − | </blockquote></blockquote><blockquote>
| + | ==Shea butter press== |
| | + | The fat is squeezed out of the heated shea-powder under high pressure. For a high amount of fat, a press capable of at 125bar pressure is required. The fat must then be cleared of all residues by bringing it to the boil together with okra, lemon juice and water. To increase the output, the process can be repeated. The resulting press cake is excellent for use as fuel for ovens and reduces the fuelwood demand. The amount of fat derived is determined by the condition of the shea nut. The yield will be greater if the harvest carefully stored and preserved. Complete inactivation of enzymes will prevent the formation of free fat acids. The heating of the powder to between 100° and 120° Centigrade is not difficult but the unassisted use of the press needs longer to learn. In order to get a maximum pressure of 125 bar a lot of force is required by the user. |
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| − | <br />''• Buildings, computer installations:''<br />
| + | ==Food== |
| | + | Used as baking fat and to substitute cocoa butter to make chocolate and other products. |
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| − | </blockquote><blockquote><blockquote>
| + | ==Cosmetics== |
| | + | Shea butter is used as a base for cosmetics, skincare products moisturising cream anti ageing treatments. It also has anti inflammation properties. |
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| − | air conditioning and temperature regulation.
| + | ==Soapmaking from Shea== |
| − | | + | The cake left after the second pressing can be burned to produce potash for soapmaking or for fertiliser'''.''' |
| − | </blockquote></blockquote><blockquote>
| + | ==References and further reading== |
| − | | |
| − | <br />''• Domestic:''<br />
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| − | </blockquote><blockquote><blockquote>
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| − | food and drink storage.
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| − | </blockquote></blockquote><blockquote>
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| − | <br />''• Health clinics:''<br />
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| − | </blockquote><blockquote><blockquote>
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| − | storage of blood, vaccines and medicine.
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| − | </blockquote></blockquote></div>
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| − | ==Choice of technology== | |
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| | <div class="booktext"> | | <div class="booktext"> |
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| − | Cooling can be provided in different ways.
| + | • ''Soapmaking'', Practical Action Technical Brief |
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| − | The method adopted in industrialized countries depends heavily on grid electricity, supplied continuously and reliably to every part of the country. In contrast, refrigeration is required in developing countries to stimulate agriculture and commerce, in vast areas without a reliable electricity supply. Alternative methods are therefore necessary. A number of approaches can be considered. Three kinds of cooling technology are contrasted in Figure 1 a-c, these are:<br />
| + | • ''Oil Extraction'', Practical Action Technical Brief |
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| − | <blockquote>
| + | • ''Shea Butter Extraction in Mali, Appropriate Technology Bulletin No 6,'' Appropriate Technology International, 1985 |
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| − | • Passive (Figure 1a)<br /> • Sorption heat driven (Figure 1b)<br /> • Mechanical compression (Figure 1c) | + | • ''Oil Extraction, Food Cycle Source Book 1,'' UNIFEM and IT Publications, 1987 |
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| − | </blockquote><center>
| + | • ''Appropriate technology for shea-butter production: A women’s technology in Mali'' GTZ/GATE |
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| − | [[Image:Preservebyrefrigeration01.gif ]]<br /> Figure 1a'''<nowiki>:</nowiki>''' Passive coolers
| + | • ''Appropriate Technology Products of Ghana,'' DAPIT Project Secretariat, Ministry of Environmental, Science & Technology, 1995, ISBN 9988-7615-0-3 |
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| − | </center><center>
| + | • ''Minor Oil Crops,'' Intermediate Technology Consultants, 1991 |
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| − | [[Image:Preservebyrefrigeration02.gif ]]<br /> Figure 1b: Sorption refrigerator
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| − | </center><center>
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| − | [[Image:Preservebyrefrigeration03.gif ]]<br /> Figure 1c: Compression refrigerator
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| − | </center>
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| − | The third method, mechanical compression, is usually dependent on a reliable and continuous supply of grid or diesel generated electricity. The other two methods are therefore more suitable in non-industrialized areas. They require further development on the basis of requests from users in rural locations. Several approaches, which can be considered, are:<br />
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| − | <blockquote>
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| − | • Production of ice using electricity in regional centres; transport of this ice to agricultural areas; packing of produce to be cooled with ice in insulated containers. Electricity is either grid or diesel generated. Refrigerators, which are electrically driven, use mechanical compression technology. | |
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| − | • In some cases refrigerators can be driven directly by mechanical shaft power, for instance where water turbines can be readily installed.
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| − | • Production of ice using heat driven coolers ('HDCs') on a local level at agricultural production points. Packing of produce with ice for transport. The heat sources for HDCs are varied; it can be from wood, charcoal or agro-waste burnt in open stoves, from fossil fuel in conventional burners, or it can be from thermal solar collectors. HDCs use sorption technology.
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| − | • Provision of cold storage chambers using either passive, sorption, or mechanical compression technology. If passive cooling is used, temperatures less than 10°C can rarely be achieved.
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| − | • Provision of cold storage at the point of use using mechanical compression coolers drawing electricity from photovoltaic cells. This is referred to as photovoltaic cooling technology.
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| − | </blockquote>
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| − | <br /> The most suitable method of cooling chosen will depend upon various factors; the application, the degree of reliablity required, the supply of power, the level of skill needed to operate and maintain, training facilities, and available finance. The different technologies should be considered with these factors in mind. As with any technology, sufficient training is especially important; it must be planned as an integral part of an implementation programme and remains a constant concern during the years following installation. This will increase reliablity of the system and reduce life cycle costs dramatically.
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| | </div> | | </div> |
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| − | ==Temperatures and ventilation== | + | ==Useful contacts== |
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| − | <div class="booktext">
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| − | Different applications have different requirements for temperature control and ventilation. Figure 2 shows the temperatures needed for the storage of butter, meat, fresh fish and milk. Very often storage of vegetables is complicated by the need for careful ventilation to remove unwanted gases, and to avoid humidity conditions, which would spoil the produce. Relative humidity requirements vary depending on the moisture content of the produce. A simple method of increasing humidity is to sprinkle water on the floor. In vaccine and blood storage very careful temperature control is required.
| + | '''Raise''' <br />Website:<u>http://www.raise.org/natural/shea/shea.stm</u> |
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| − | <center> | + | '''GRATIS''' (Ghana Regional Appropriate Technology Industrial Service)<br /> P.O. Box 151, Tema, Ghana<br /> Tel: 010 233 221 4243, Fax: 010 233 221 6251 |
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| − | [[Image:Preservebyrefrigeration04.gif ]]<br /> Figure 2: Temperatures for safe storage
| + | '''COVOL''' (The Cooperative Office for Voluntary Organizations)<br /> 4680 Portola Drive, Santa Cruz CA 95062, USA<br /> Tel: 831 462.2182<br /> Web site: <u>http://www.covol.org/shea.html</u><br /> COVOL have a shea project working primarily with women's farming groups across northern Uganda |
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| − | </center></div> | + | '''International Centre for Underutilised Crops'''<br /> Institute of Irrigation and Development Studies<br /> University of Southampton<br /> Southampton SO17 1BJ<br /> United Kingdom<br /> Telephone: +44 (0)2380 594229<br /> Fax: +44 (0)2380 677519<br /> E-mail: <u></u><br /> Website: <u>http://www.soton.ac.uk/~icuc/</u> |
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| − | ==Passive==
| + | '''Post Harvest Programme'''<br /> NR International<br /> PO Box 258<br /> Chatham Maritime<br /> Kent ME4 4PU, UK<br /> |
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| − | <div class="booktext"> | + | '''CEPAZE''' (Centre d'Exchages et Promotion des Artisans en Zons a Equiper)<br /> 18 rue de Varenne<br /> 75007 Paris<br /> France<br /> CEPACE began developing equipment for shea butter production in 1980 |
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| − | In applications where temperatures between 10-25°C are needed, passive methods can be used. These include traditional methods such as the use of porous jars or wet sack coverings, where the evaporative heat of the liquid, usually water, is drawn into the atmosphere. This method is effective where the atmosphere is naturally dry. Domestic storage devices have been designed along these lines, particularly with the use of charcoal beds, drip-fed with water.
| + | '''DFID Crop Post-harvest Programme''', Improved processing of Shea nuts in northern Ghana (R6631). A bridge type screw press was developed for the extraction of shea butter, local construction of the press was carried out by the Intermediate Technology Transfer Unit in Tamale |
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| − | Nocturnal cooling in areas where clear night skies are common, can be effective. In airconditioning applications, the use of shade has been developed effectively in traditional architecture, together with evaporative cooling by fountains and roof ponds.
| + | '''KIT - Royal Tropical Institute''' (Koninklijk Instituut voor de Tropen)<br /> Postbus 95001<br /> 1090 HA Amsterdam<br /> The Netherlands<br /> Tel: +31 (0)20 568 8711<br /> Fax: +31 (0)20 6684 579<br /> </u><br /> Web site: <u>http://www.kit.nl/</u> |
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| − | Wherever possible passive methods should be used both in agriculture and architecture, since they can be sustained locally and are economic. Only when cooling below 10°C is needed, is it justifiable to look at active cooling technology, requiring complex machinery, and technical maintenance programmes.
| + | ==Equipment suppliers== |
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| − | </div>
| + | Note: This is a selective list of suppliers and does not imply endorsement by Practical Action. |
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| − | ==Sorption Heat driven coolers (HDCs)==
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| − | <div class="booktext">
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| − | The principle of sorption refrigeration is shown in Figure 3 which illustrates the simplest type of sorption cooler and which has an intermittent cycle consisting of two phases. Continuous cycles are also possible - the Electrolux uses a continuous cycle. The general term sorption covers both liquid absorption and solid adsorption variants of this technology. Sorption units have some very important advantages. They can be designed to contain no moving parts, so that skilled maintenance personnel and replacements of components are less likely to be needed. Secondly, they are simple to manufacture; local manufacture increases local knowledge of the technology, which improves operation, maintenance and faultfinding. Thirdly, they are readily adaptable to locally available fuels, including biomass and solar energy. Finally, the refrigeration circuit does not use CFCs, which damage the environment. Sorption units are referred to as HDCs (heat-driven coolers).
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| − | </div>
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| − | ==Conventional gas and kerosene-driven sorption units==
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| − | <div class="booktext">
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| − | The heat source in conventional sorption refrigerators is usually gas or kerosene flame. Units powered from gas bottles are used on caravans or boats. A domestic unit, often used in remote locations in developing countries is the kerosene-driven Electrolux. It has been calculated that the cost of purchasing and running one of these units is around £1000 for 10 years use. The refrigeration circuits of these devices operate reliably for many years. Maintenance of the burner assembly is required and a constant supply of wicks, burners and lamp glasses are essential. Lastly, the fuel tank must be replenished with kerosene of suitable quality. These units involve the use of hydrogen as a working fluid and cannot be designed as efficient icemakers, although they have some ice-making capacity.
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| − | <center>
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| − | [[Image:Preservebyrefrigeration05.gif]]<br /> Figure 3: Sorption cooler
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| − | </center></div>
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| − | ==Novel sorption units==
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| − | <div class="booktext">
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| − | Novel sorption units are being developed at present for greater efficiency in ice making and cold storage. They do not involve hydrogen as a working fluid. A great deal of emphasis is being placed on design for reliable operation in remote environments where technical maintenance services are not available. Emphasis is also placed, in some cases, on design for local manufacture.
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| − | Costs and performance figures are not easily available since many units are still on trial. Projected retail prices for biomass driven units are in the order of £2000 for a 100-kg per day icemaker. Taking fuel and operation costs into account, as well as capital repayment, this represents a production cost of ice of around £0.02 per kg.
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| − | </div>
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| − | ==Solar-powered sorption units==
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| − | <div class="booktext">
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| − | The heat source for sorption units of the kind shown in Figure 3 can be the sun. In a simple version the heating phase ends at sunset, and the refrigeration phase occurs during the night. If the sun fails to shine for a few days, the ice made on previous days acts as a store of cold, keeping the cold box at a low temperature while it gradually melts. It is expected that a unit producing 100 kg of ice per day can be produced for £4,000 (including the cost of highly efficient solar thermal panels), giving an ice cost of £0.03 per kg.
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| − | </div>
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| − | ==Mechanical Compression==
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| − | <div class="booktext">
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| − | '''Grid electricity'''
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| − | Where a reliable electricity supply exists, the most economic option is to install a standard compressor driven unit. Conventional refrigerators of this kind are sold commercially. As an example, a unit making about 100 kg of flaked ice, for fisheries use, each day in tropical conditions will cost £7000, not including the cost of storage containers for the ice, or delivery. The power consumption would be in the order of 4 kW continuously. There will be extra costs in the form of replacement parts, maintenance and ancillary equipment.
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| − | '''Water turbine driven coolers'''
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| − | Costs can be reduced if shaft power is used directly to drive the compressor, for example from a water turbine. An auxiliary electricity supply is useful to provide control and protection functions, and for instance to drive ventilation fans. It is nevertheless feasible to design wholly mechanical cold storage and ice-making systems.
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| − | '''Diesel generating sets'''
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| − | The cost of operating a generator in rural areas is dependent on local conditions and must be assessed in the light of local experience. Quite often the cost can be very much higher than expected because of the need for maintenance personnel and the difficulties encountered in obtaining fuel and spare parts. If the generated electricity is not available continuously then the refrigerator should be designed as an ice-maker, allowing cold to be stored in the form of ice. Experience has shown that systems involving the storage of electricity in batteries have very high costs and are unreliable.
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| − | '''Solar photovoltaic systems'''
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| − | Solar energy is an intermittent power source, usually available for 12 hours every day. The intensity of insolation is very variable. It can be converted by photovoltaic cells into electricity, which is then stored in batteries, so that a continuous smooth electrical supply can be provided to power a mechanical compression refrigerator.
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| − | The advantage of using solar power is that it is a source that can be relied upon, never to fail for more than a few days. This reliability is very important in some cases, such as vaccine storage, where loss of temperature control can spoil the vaccines completely. The battery is designed to continue to provide electricity at night and on days when no sunshine is available. In this application, the high cost of photovoltaic cells, batteries and control equipment is justified. The size of the photovoltaic array and the battery capacity must be carefully calculated to provide an economic system.
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| − | Solar refrigeration units of this kind, especially designed for vaccine preservation, are commercially available. A system providing 60-80 watts of cooling is typically priced in the range of £3000-5500. Replacement parts will tend to cost £500-1000 in the course of four years of operation. Most of this cost will be in the replacement of batteries which are designed to have a four year life but can fail in a shorter period if maintained poorly. Replacement costs are considerably reduced if skilled, technical maintenance personnel are available.
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| − | '''Combined heating/drying/cooling system'''
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| − | Because a refrigerator releases heat it can be used to raise temperatures in agricultural processes like crop or spice drying. The cooling effect can be used to dehumidify the air passing over the crop and the heating effect can be used to warm the air. In this, very high efficiencies can be obtained (for instance up to 7 times as much useful energy produced as required to drive the device). Such efficiencies are commonly met in timber drying plants using these principles. Practical Action is developing low cost methods of utilizing this effect, with respect to drives from small hydro turbines or from steam or diesel engines.
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| − | A second example is the use of heat from a refrigerator (also known as a heat pump, exactly the same machine) to help sterilize milk, while the same refrigerator cools the milk to preserve it.
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| − | </div>
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| − | ==Choosing the system==
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| − | <div class="booktext">
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| − | In order to decide which refrigeration system to adopt for a particular purpose, it is necessary to consider the ongoing inputs required by each system. Table 1 lists the various systems and the inputs required for each. The choice of system is based on the foreknowledge that all the necessary inputs will continue to be available in the locality of the fridge. The mistake is often made of installing a unit with a relatively low purchase cost which later ceases to function through lack of necessary inputs.
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| − | Table 1: Choosing a system
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| | <div align="left"> | | <div align="left"> |
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| − | {| border="1" cellpadding="5" | + | {| cellpadding="5" |
| − | |- valign="top" | + | |- valign="top"| |
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| − | '''COMMENT'''
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| − | '''ENERGY SOURCE'''
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| − | '''PERSONNEL'''
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| − | '''SPARE PARTS'''
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| − | '''10 YEAR TOTAL COST'''
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| − | MECHANICAL COMPRESSION
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| − | Grid
| + | Farmers' Technical Service and Technological Training Centre<br /> P. O. Box 9899<br /> Accra<br /> Ghana<br /> Manufacture batch toasters, a vertical Hand Press and motorised oil expellers. |
| | | valign="top" | | | | valign="top" | |
| − | Electricity available for other purposes, e.g. lighting, flaking of ice.
| + | S.I.S Engineering Ltd.<br /> P.O. Box 45<br /> U.S.T Kumasi<br /> Ghana<br /> Produced a churning and washing machine and a manual screw press. |
| | + | |- valign="top"| |
| | + | |- valign="top"| |
| | | valign="top" | | | | valign="top" | |
| − | Grid electricity. Cost of connecting/ transforming can be high.
| + | UNATA (Union for Appropriate Technology Assistance)<br /> G. Van den Heuvelstraat 131<br /> 3140 Ramsel<br /> Belgium<br /> Spindle press oil expeller |
| | | valign="top" | | | | valign="top" | |
| − | Maintenance: skilled personnel.
| + | IITU (Intermediate Technology Transfer Unit) -<br /> GRATIS<br /> P.O. Box 951, Northern Region<br /> Tamale<br /> Ghana<br /> Produce a shea nut grinder/mill<br /> 10 hp electric & 8hp diesel |
| − | | valign="top" |
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| − | Source of parts may be distant. Supply may be uncertain.
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| − | | valign="top" |
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| − | Purchase cost, electricity, personnel, replacement parts.
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| − | |- valign="top"
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| − | | valign="top" |
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| − | Diesel
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| − | | valign="top" |
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| − | Electricity available for other purposes, e.g. lighting, flaking of ice.
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| − | | valign="top" |
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| − | Diesel generator
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| − | | valign="top" |
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| − | Maintenance: skilled personnel permanently on-site.
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| − | | valign="top" |
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| − | Source of parts may be distant. Supply may be uncertain.
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| − | | valign="top" |
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| − | Purchase cost, diesel, replacement parts.
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| − | |- valign="top"
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| − | | valign="top" |
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| − | Solar photovoltaic
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| − | | valign="top" |
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| − | Expensive. Electricity available for lighting, communications, temperature control.
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| − | | valign="top" |
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| − | Irradiation of 10-20MJ/daym<sup>2</sup>. Long cloudy periods problematic.
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| − | | valign="top" |
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| − | Skilled personnel permanently available.
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| − | | valign="top" |
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| − | Battery life 2-4 years. Control electronics can fail.
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| − | | valign="top" |
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| − | £3500-6500 for 60-80W cooling, includes replacement costs.
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| − | |- valign="top"
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| − | SORPTION (HDCs)
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| − | Conventional
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| − | Well known in the field.
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| − | | valign="top" |
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| − | Gas/kerosene quality must be adequate.
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| − | | valign="top" |
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| − | Burner parts, wick adjustment, etc.
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| − | | valign="top" |
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| − | Replacement of burner parts routine.
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| − | | valign="top" |
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| − | £1000-2000 for 60-100W cooling and small maintenance cost.
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| − | |- valign="top"
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| − | | valign="top" |
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| − | Novel (biomass driven)
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| − | | valign="top" |
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| − | Local manufacture possible. Under development, relatively low cost.
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| − | | valign="top" |
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| − | Any locally available heat source suitable, eg charcoal, coal, agro wastes, cow dung fossil fuels.
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| − | | valign="top" |
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| − | Maintenance of open burner, brine tank, cooling water. Local skills sufficient.
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| − | | valign="top" |
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| − | Locally available spare parts.
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| − | | valign="top" |
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| − | Purchase cost projected at £2000 for 100kg ice/day. Fuel cost £50-100 per year.
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| − | |- valign="top"
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| − | | valign="top" |
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| − | Solar
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| − | | valign="top" |
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| − | Very new on market. Performance not yet evaluated. Low night temperatures can be advantageous in some cases. Presence of cooling water advantageous. Provincial manufacture possible.
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| − | | valign="top" |
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| − | Solar irradiation 10-120MJ/daym<sup>2</sup>. Long periods of cloud problematic.
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| − | | valign="top" |
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| − | Local skills sufficient, few moving parts.
| |
| − | | valign="top" |
| |
| − | Solar panels may require import of spare parts.
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| − | | valign="top" |
| |
| − | Current purchase cost £1500-2500 for 10kg ice/day. Projected cost £4000 for 100kg ice/day (including solar panel).
| |
| − | |}
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| − | | |
| − | </div></div>
| |
| − | | |
| − | ==Further information==
| |
| − | | |
| − | <div class="booktext">
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| − | | |
| − | Further information on refrigeration in developing countries is available from:
| |
| − | | |
| − | '''Literature'''
| |
| − | | |
| − | ASHRAE Handbooks:<br />
| |
| − | | |
| − | <blockquote>
| |
| − | | |
| − | • 1997 - Fundamentals<br /> • 1998 - Refrigeration<br /> • 1999 - HVAC Applications<br /> • 2000 - HVAC Systems and Equipment
| |
| − | | |
| − | </blockquote>
| |
| − | | |
| − | <br /> American Society of Heating, Refrigeration & Air Conditioning Engineers (ASHRAE)<br /> 1791 Tullie Circle<br /> North East Atlanta<br /> GA 30329,USA<br /> Tel: +1 (404) 636-8400<br /> Fax: +1 (404) 321-5478<br /> Website: http://www.ashrae.org
| |
| − | | |
| − | P D Dunn: Energy for Developing Countries. | |
| − | | |
| − | R J Dossat: Principles of Refrigeration. Prentice Hall, 1997, 4th ed.
| |
| − | | |
| − | Ray Tomkins: Prospects for Solar Refrigeration, 1985<br /> Ray Tomkins Management School<br /> Imperial College, 53 Princes Gate<br /> Exhibition Road, London, SW7 2PG, U.K.<br /> Tel: +44 (0)20 7594 9137<br /> Fax: +44 (0)20 7823 7685<br /> Website: http://www.ms.ic.ac.uk
| |
| − | | |
| − | B. McNelis, A. Derrick & M. Starr: Solar Powered Electricity: A survey of Photovoltaic Power in Developing Countries. ITDG Publishing, 1988.
| |
| − | | |
| − | Solar Power for Development UK ISES Conference Proceedings 1988
| |
| − | | |
| − | ==Organisations==
| |
| − | | |
| − | '''Practical Action'''
| |
| − | The Schumacher Centre for Technology & Development, Bourton on Dunsmore, RUGBY, CV23 9QZ, United Kingdom.<br />
| |
| − | '''Tel.:''' +44 (0) 1926 634400, '''Fax:''' +44 (0) 1926 634401
| |
| − | '''e-mail:'''[mailto:practicalaction@practicalaction.org.uk practicalaction@practicalaction.org.uk]
| |
| − | '''web:'''[http://www.practicalaction.org www.practicalaction.org]
| |
| − | <center>[[Image:Pa-logo-200x103.gif]]</center>
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| − | | |
| − | Institute of Food Research,<br /> Norwich Research Park, Colney,<br /> Norwich NR4 7UA, U.K.<br /> Tel +44 (0)1603 255 000<br /> Fax +44 (0)1603 507 723<br /> Website: http://www.ifrn.bbsrc.ac.uk
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| − | | |
| − | EPI (Expanded Programme on Immunisation),<br /> World Health Organisation,<br /> Attn Director EPI,<br /> Avenue Appia 20, 1211 Geneva 27,<br /> Switzerland.<br /> Tel: +41 (0)22 791 4517<br /> Fax: +41 (0)22 791 4193<br /> WHO Website Addresses:<br /> Home Page: http://www.who.int,<br /> Solar Energy and Rural Health Care: Fact Sheet N132: http://www.who.int/inffs/ en/fact132.html,<br /> Solar Energy Applications (with links to product information sheet): http://www.who.int/vaccinesaccess/<br /> Vaccines/Vaccine_Cold_Chain/solaren ergy.htm
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| − | | |
| − | Health Link Worldwide,<br /> Cityside House, 40 Adler Street,<br /> London E1 1EE, U.K.<br /> Tel: +44 (0)20 7539 1570<br /> Fax: +44 (0)20 7539 1580<br /> Website: http://www.healthlink.org.uk
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| − | | |
| − | Institute of Refrigeration,<br /> Kelvin House, 76 Mill Lane,<br /> Carshalton, Surrey, SM5 2JR, U.K.,<br /> Tel: +44 (0)20 8647 7033,<br /> Fax: +44 (0)20 8773 0165,<br /> Website: http://www.ior.org.uk
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| − | | |
| − | International Institute of Refrigeration,<br /> 177 Boulevard Malesherbes,<br /> 75017 Paris, France.<br /> Tel: +33 (0)1 4227 3235,<br /> Fax: +33 (0)1 4763 1798,<br /> Website: http://www.iifiir.org/
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| − | | |
| − | NR International<br /> Park House<br /> Bradbourne Lane<br /> Aylesford<br /> Kent<br /> ME20 6SN<br /> Tel: +44 (0)1732 878 686/7<br /> Fax: +44 (0)1732 220 498<br /> Website: http://www.nrinternational.co.uk/
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| − | | |
| − | </div>
| |
| − | | |
| − | ==Manufacturers==
| |
| − | | |
| − | <div class="booktext">
| |
| − | | |
| − | Note: This is a selective list of suppliers and does not imply endorsement by Practical Action.
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| − | | |
| − | '''Ice making machines'''
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| − | | |
| − | Total Refrigeration Ltd.,<br /> Dunkirk Lane, Hyde,<br /> Cheshire SK14 4PW, U.K.<br /> Tel: +44 (0)161 366 2535<br /> Fax: +44 (0)161 366 0342<br /> E-mail: [mailto:total@totalrefrigeration.co.uk total@totalrefrigeration.co.uk]<br /> Website: http://www.totalrefrigeration.co.uk,<br /> Icemakers, cabinets, chiller & freezer cold rooms.
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| − | | |
| − | Trembath Refrigeration and Air Conditioning Ltd.,<br /> Felstead Road, Longmead Industrial Estate,<br /> Epsom, Surrey, KT19 9XS, U.K.<br /> Tel: +44 (0)1372 215010<br /> Fax: +44 (0)1372 215011<br /> Ice-makers, refrigeration, air conditioning, dehumidifiers, heat pumps, design, manufacture, installation and maintenance.
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| − | | |
| − | Ziegra Ice Machines (UK) Ltd.,<br /> Unit 14, Enterprise Centre 2,<br /> Chestergate, Stockport, Cheshire, SK3 0BR,<br /> U.K.<br /> Tel: +44 (0)161 429 0525<br /> Fax: +44 (0)161 480 7927<br /> Website: http://www.ziegra.co.uk<br /> Specialists in ice machines and ice storage systems.
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| − | | |
| − | '''Sorption machines'''
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| − | | |
| − | Electrolux Leisure Appliances AB<br /> SE-105 45 Stockholm<br /> Sweden<br /> Tel: +46 (8) 738 64 26<br /> Fax: +46 (8) 738 75 38<br /> Website: http://www.electrolux.com/worldfridge
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| − | | |
| − | Sibir International AB<br /> S-105 45 Stockholm<br /> Tel: +46 (8) 738 61 18<br /> Fax: +46 (8) 738 75 38<br /> Website: http://www.sibir.com<br />
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| − | | |
| − | </div>
| |
| − | | |
| − | ==Categories:==
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| − | [[category:Example]]
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| − | [[Category:Difficult]] [[Category:High Technology]]
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| − | [[Category:Between 50 and 200 US$]]
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| − | [[Category:Up to 5 Persons]]
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| − | [[Category:Global Technology]]
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| − | [[Category:Energy]] [[Category:Food Processing]] [[Category:Health]] [[Category:Products]] [[Category:Mecanics]]
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Processing
The Green pulp exterior is removed. One method is to bury the fruit in the ground so that the pulp ferments and falls off. This takes 12 days or more. The nuts are parboiled or sun dried and then smoked for 3 to 4 days. The dried nuts can then be stored for long periods without significant losses. Decortication is done by crushing the outer shell to remove kernels. Shea nuts are mainly exported as smoked kernels. The kernels will be further dried before any additional processing is carried out.
Shea nut butter
Traditionally wet processing by hand is a slow and laborious process that uses large quantities of wood for roasting. The kernels are roasted in a pot over a fire to approximately 100°C and then pounded in a mortar to produce a course paste. This is then ground between two stones to produce a smooth paste. The paste and water are mixed in a pot where the butter rises to the top. The butter can then be removed and washed repeatedly with warm water until clean. The remaining water is remove by heating. Impurities settle out and the butter can be left to cool and solidify. With the traditional technique, the fat obtained is between 25 and 40% of the dry kernel weight.
The introduction of equipment can improve upon traditional methods of production by reducing the effort and time involved and by increasing the yield. Instead of pounding by hand a mill can be used, Oil can be extracted using a mechanical or hydraulic press. Manually turned roasters can be used rather than a traditional pot. A very important consideration is the minimum throughput required to run the equipment profitably, including the initial cost, management of the equipment and maintenance.
Shea butter press
The fat is squeezed out of the heated shea-powder under high pressure. For a high amount of fat, a press capable of at 125bar pressure is required. The fat must then be cleared of all residues by bringing it to the boil together with okra, lemon juice and water. To increase the output, the process can be repeated. The resulting press cake is excellent for use as fuel for ovens and reduces the fuelwood demand. The amount of fat derived is determined by the condition of the shea nut. The yield will be greater if the harvest carefully stored and preserved. Complete inactivation of enzymes will prevent the formation of free fat acids. The heating of the powder to between 100° and 120° Centigrade is not difficult but the unassisted use of the press needs longer to learn. In order to get a maximum pressure of 125 bar a lot of force is required by the user.
Food
Used as baking fat and to substitute cocoa butter to make chocolate and other products.
Cosmetics
Shea butter is used as a base for cosmetics, skincare products moisturising cream anti ageing treatments. It also has anti inflammation properties.
Soapmaking from Shea
The cake left after the second pressing can be burned to produce potash for soapmaking or for fertiliser.
References and further reading
• Soapmaking, Practical Action Technical Brief
• Oil Extraction, Practical Action Technical Brief
• Shea Butter Extraction in Mali, Appropriate Technology Bulletin No 6, Appropriate Technology International, 1985
• Oil Extraction, Food Cycle Source Book 1, UNIFEM and IT Publications, 1987
• Appropriate technology for shea-butter production: A women’s technology in Mali GTZ/GATE
• Appropriate Technology Products of Ghana, DAPIT Project Secretariat, Ministry of Environmental, Science & Technology, 1995, ISBN 9988-7615-0-3
• Minor Oil Crops, Intermediate Technology Consultants, 1991
Useful contacts
Raise
Website:http://www.raise.org/natural/shea/shea.stm
GRATIS (Ghana Regional Appropriate Technology Industrial Service)
P.O. Box 151, Tema, Ghana
Tel: 010 233 221 4243, Fax: 010 233 221 6251
COVOL (The Cooperative Office for Voluntary Organizations)
4680 Portola Drive, Santa Cruz CA 95062, USA
Tel: 831 462.2182
Web site: http://www.covol.org/shea.html
COVOL have a shea project working primarily with women's farming groups across northern Uganda
International Centre for Underutilised Crops
Institute of Irrigation and Development Studies
University of Southampton
Southampton SO17 1BJ
United Kingdom
Telephone: +44 (0)2380 594229
Fax: +44 (0)2380 677519
E-mail:
Website: http://www.soton.ac.uk/~icuc/
Post Harvest Programme
NR International
PO Box 258
Chatham Maritime
Kent ME4 4PU, UK
CEPAZE (Centre d'Exchages et Promotion des Artisans en Zons a Equiper)
18 rue de Varenne
75007 Paris
France
CEPACE began developing equipment for shea butter production in 1980
DFID Crop Post-harvest Programme, Improved processing of Shea nuts in northern Ghana (R6631). A bridge type screw press was developed for the extraction of shea butter, local construction of the press was carried out by the Intermediate Technology Transfer Unit in Tamale
KIT - Royal Tropical Institute (Koninklijk Instituut voor de Tropen)
Postbus 95001
1090 HA Amsterdam
The Netherlands
Tel: +31 (0)20 568 8711
Fax: +31 (0)20 6684 579
</u>
Web site: http://www.kit.nl/
Equipment suppliers
Note: This is a selective list of suppliers and does not imply endorsement by Practical Action.
|
Farmers' Technical Service and Technological Training Centre
P. O. Box 9899
Accra
Ghana
Manufacture batch toasters, a vertical Hand Press and motorised oil expellers.
|
S.I.S Engineering Ltd.
P.O. Box 45
U.S.T Kumasi
Ghana
Produced a churning and washing machine and a manual screw press.
|
|
UNATA (Union for Appropriate Technology Assistance)
G. Van den Heuvelstraat 131
3140 Ramsel
Belgium
Spindle press oil expeller
|
IITU (Intermediate Technology Transfer Unit) -
GRATIS
P.O. Box 951, Northern Region
Tamale
Ghana
Produce a shea nut grinder/mill
10 hp electric & 8hp diesel
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