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Cambodia has one of the worst rates of deforestation in the world. The Cambodian economy depends heavily on wood, for timber, heat and power generation, while 80% of households use wood or charcoal for cooking.
GERES helped reduce wood demand through its efficient charcoal stoves, and wanted to tackle charcoal supply. So they started Khmer Green Charcoal Co. which turns waste into clean-burning briquettes for cooking fuel. This allowed them to save 4,500 tonnes of CO2 in 2013 and 6,500 trees by May 2014.
Most Cambodians cook on wood charcoal, which contributes to the country’s rampant deforestation and air pollution. A pioneering Cambodian business is turning leftover coconut shells and other waste into clean-burning briquettes for use as cooking fuel in Phnom Penh’s homes and restaurants.
Led by Carlo Figà Talamanca, Khmer Green Charcoal Co. can scarcely keep up with demand. Users like Lin Haiy, who runs a family restaurant explains why the briquettes are so popular:
The old charcoal used to burn your clothes and it was smoky and dirty. This is much better: it burns longer.
Lin Haiy, briquettes user
Sales started in 2010, and by the end of March 2014, Khmer Green Charcoal Co. had produced and sold 626 tonnes of Premium briquettes and 27 tonnes of Diamond briquettes, a total of 653 tonnes.
Production is increasing rapidly – from an average of just 5 tonnes/month in 2011 to 22 tonnes/month in 2013 and 47 tonnes/month in March 2014. Current production is equivalent to the total cooking needs of about 1,250 households or about 6,300 people.
Replacing wood charcoal has a direct impact on deforestation in Cambodia, because the wood comes mostly from unsustainable sources. Each tonne of char-briquettes replaces the use of about 10 mature trees (7 tonnes of dry wood), so to date about 6,500 trees have been saved.
Greenhouse gas emissions are cut by replacing non-sustainable wood with biomass from waste. They are reduced further by the use of TLUD kilns, which cut the emission of non-CO2 greenhouse gases. Savings have been formally verified following CDM methodologies, and the saving in 2013 was about 4,500 tonnes CO2e emissions.
Char-briquettes are safer for cooks than wood charcoal. They produce less health damaging air pollution, because of their lower volatile content, and they also produce fewer sparks. They are somewhat harder to light – some users need training – but once alight, they burn more evenly, and pots stay cleaner.
In addition, the briquettes are less fragile, so they are easier and cleaner for both users and traders to handle and store. It also means that a smouldering briquette can be moved to start an extra stove – a feature appreciated by food stalls. And at the end of the day, any remaining fuel can be extinguished in an air-tight container and used again the next day.
Users of Premium briquettes save around US$60 per year (30%), because the briquettes produce more heat and less waste than wood charcoal. Perhaps surprisingly, the main users of the more expensive Diamond briquettes are low-income street food vendors. They value the long burn-time (about five hours) of the Diamond brand, because they don’t lose customers while waiting for a new load of charcoal to light.
The briquettes took a bit of getting used to, but now we like them much more than the old stuff. The sparks used to burn your clothes, and get in the food. And it was smoky and dirty.
Lin Haiy, Owner of Number 28 restaurant
Khmer Green Charcoal Co. currently employs three managers and 20 factory staff, in total 8 women and 15 men. All factory workers are recruited through PSE, and most are from families who sort waste on rubbish dumps and have never had formal employment in the past. A condition of employment is that workers must keep their children in school. The basic starting salary is US$85 per month, similar to the garment sector in Cambodia, with paid annual leave and sick pay. In addition, all employees receive health insurance, 13 months’ salary per year, and incentives such as attendance bonuses, production bonuses and annual salary increments. These can add up to a further US$30 per month.
Khmer Green Charcoal Co. production has grown rapidly, but demand – particularly for Diamond briquettes – has grown faster, so Khmer Green Charcoal Co. needs to expand supply.
There is no shortage of raw materials. Khmer Green Charcoal Co. uses only about 10% of the capacity of its current suppliers of coconut shell, and more suppliers are available. Wood-fired electricity generation is also growing rapidly, because of the acute shortage of power in Cambodia, so there is ample waste char.
The recent US$0.3m grant from the Spark Fund of the Global Alliance for Clean Cookstoves is therefore very timely. It will enable Khmer Green Charcoal Co. to double production capacity on its existing site to over 100 tonnes/month by the end of 2014 and build a new warehouse for raw materials. A private investor, Uberis Capital, is also working with Khmer Green Charcoal Co. to double production again between 2015 and 2017, with US$0.8m expansion funding estimated.
Khmer Green Charcoal Co. buys biomass materials, which would otherwise go to waste, and converts them into high-quality char-briquettes that are sold as a direct replacement to conventional charcoal, for cooking in homes and restaurants.
The main waste currently used is char from wood-fired electricity generation, which Khmer Green Charcoal Co. buys from businesses that run the generators. The other waste is coconut shells from markets, which Khmer Green Charcoal Co. buys from traders and converts into char in its own clean-burning kilns. Because coconut char makes higher quality briquettes, Khmer Green Charcoal Co. has also started to sell coconut shells to some electricity generators, and buy back their waste coconut char.
Char is produced by the process of pyrolysis, in which wood or other types of biomass are decomposed by heating it to a high temperature in a kiln, with a limited supply of oxygen. This produces char (which is mostly carbon), ash and gases (mainly hydrogen, carbon monoxide and methane).
Depending on the type of briquette required, the coconut-char produced by Khmer Green Charcoal Co. may be combined with bought-in wood-char. The char is finely ground and thoroughly mixed with water and about 6-9% tapioca flour is used as a binder. The resulting paste is extruded into briquettes, which are stacked on racks for drying.
The drier is a 7 metre long tunnel. Hot air is blown in from the TLUD. Racks of wet briquettes are loaded on rails from the other end and, over 18-24 hours, move towards the hot end. This counter-flow heating and drying produces strong, uniform briquettes with a moisture content of about 8%. Briquettes weigh between 125 and 180g, and after cooling are packed in branded bags for sale.
Khmer Green Charcoal Co. produces its top brand ‘Diamond’ briquettes just from coconut char, and ‘Premium’ brand from 5% coconut char and 95% char residues. Both have higher carbon content than traditional wood charcoal (see table), and thus produce more heat per kg. In addition, both contain less volatile material, and therefore produce less air pollution. Intermediate ‘Improved Premium’ briquettes with 15 and 30% coconut char are currently being market tested.
Most of the factory work is manual – moving materials, loading kilns, stacking briquettes and checking the drying process. Factory workers are trained in all tasks for flexibility, although some become specialised at one.
Khmer Green Charcoal Co. operates two parallel gasifier/drier production lines, which run 24 hours a day. Each line has two TLUD gasifiers, so that one is burning (and heating the drier), whilst the other is cooling down and being refilled. The production capacity is 7 tonnes/month of coconut char and 50 tonnes/month of briquettes.
Much of the plant was developed in Cambodia, and it can all be maintained locally. This allows continuous improvements to be made – for instance, increasing insulation on the drier to increase drier capacity, which is the current production bottleneck.
US$1 = KHR4,000 (Cambodian Riel) – March 2014.
Currently Khmer Green Charcoal Co. delivers about 50% of its production to retailers and 20% to restaurants and food stalls. The remaining 30% is bought directly from the factory by charcoal distributers for re-sale. An important achievement is to have established the Khmer Green Charcoal Co. brand in retail outlets, so that it is seen as a ‘normal’ cooking option.
Premium briquettes retail for about US$0.34/kg (KHR1,300-1,400/kg). This is similar to conventional wood charcoal, although the latter becomes more expensive during the rainy season. Diamond briquettes retail for about US$0.70/kg. SGFE’s most effective marketing strategy is providing free trial samples to restaurants and distributers. At present Khmer Green Charcoal Co. is struggling to meet demand, so not much active marketing is needed.
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