Filing Cabinet Smoker DIY Video

Ever wondered how some butcheries smoke their meat? Build your own cold smoker and experience the thrill of creating your own smoked sausages, chicken fillets, pork ribs, pork belly that can be carved into bacon strips etc; etc.

Place a heating source (in our case carbonized Casuarina wood) into the bottom drawer and some wood chips in a bowl above it. The thermometer (pinched off an old gas barbecue) placed halfway up the side of the cabinet indicated less than 50 deg C / 100 deg Fahrenheit consistently for 3+ hours – perfect for a cold smoke. I think briquettes or a single plate electric stove will work even better🔥

The difference between a cold smoke- and other smoking techniques is vast so do your research and decide what system works best for you as a filing cabinet can be converted into both types. Search YouTube and you’ll find many enthusiasts showing off their smokers. Also visit to see how you can turn your smoker into a biltong maker or visit the video directly here. Happy smoking!



The Vuthisa Biochar Initiative

By Kobus Venter

Welcome to the ‘Vuthisa Biochar Initiative’ blog page. On this page you will learn more about our project and what we hope to achieve. The project officially kicked off in December 2013.

The project actually has many outcomes, but the primary goals are:

Create Employment – Up to 30 workers will be employed in year one. Unemployment is rife (>50%) in the rural areas of KwaZulu-Natal especially with a minimum wage now being introduced for farm workers. The feedstock for the Biochar project will be secured by ‘Vuthisa Charcoal Projects’ through a contract signed with the Department of Environmental Affairs, Natural Resource Management Programme, that pays the wages of our workers.
Eradicate Invasive Alien Plant Species and restore the Natural Biodiversity of the land – We intend to clear over 300 hectares of Wattle in this area and restore the land back to virgin grassland. The main culprit being Acacia mearnsii (Black Wattle) and Acacia decurrens (Green Wattle). Unmanaged Wattles in KwaZulu-Natal has now reached more than 300,000 hectares in extent, according to the Agricultural Research Council (ARC) report commissioned by Water Affairs, 2010. Left untouched, this alien vegetation would spread at an average rate of one percent a year, threatening water and food security.  Concerted efforts are being made to prevent the further spread of these invasives especially in water catchment areas and it is estimated that R 34 Billion ($ 3.4 Billion) will have to be made available over the next 25 years to stop this spread.


Increase streamflows and reduce erosion – The Wattle trees spreads vigorously through the seed it puts out and these typically germinate in or near river systems, reducing filtration into underground aquafirs and streamflows. At the onset of the infestation when the trees are young, only 500 mm of water is preserved within a typical annual rainfall area of 1200 mm. As the invasives spread, after 24 years only 25% of the entire potential water yield namely 300 mm of water will become part of water supply into the local catchment.


Develop Emission Reducing Biochar Kilns and reduce greenhouse gas emissionsAcacia mearnsii is a hardwood species and makes excellent charcoal.  Conventional pyrolysing tecnologies in South Africa however are less than 20% efficient.  Our first goal is to achieve a minimum of 25% wood to biochar conversion efficiency. Using more efficient methods to produce charcoal (or Biochar) has the potential to save about 100 MtCO2 per year in Sub-Saharan Africa (See  CO2 production from Emission Reducing kilns has not been quantified, but a 5 to 10% reduction in GHG’s is expected. We plan to produce 150 tons of Biochar in the next two years and we expect that 20% of this will be bought indirectly by fertiliser companies which could result in at least 30 tons of carbon being sequestered back into the soil.


Develop Biochar Eco-fertilisersBiochar as a soil amendment will allow rural folk to improve their subsistence agriculture. Mixing biochar with soil or a good active organic compost before it goes in the soil will soak up its full compliment of water, nutrients and microbes so that it can make those available immediately to the plants as soon as it is added to the soil. Ultimate concentrations after some time of repeated applications of these eco-fertilisers (chemical free) will work up to about 8 to 10% biochar by weight of the soil content.

biochar trials

See this Google Earth map below of precise location of the clearing operation:

What is Biochar?Biochar is charcoal mixed with compost and applied to the soil as a soil amendment and has the same benefit to plants than chemical fertelizers. The act of burying the Biochar in the soil, removes carbon from the air (CO2) and sequesters carbon into the soil for thousands of years and prevents the release of Methane from harvested plant material into the atmosphere. Methane is a key fuel component to providing the heat into the retorts and in the Biochar forming process.  Venting un-burnt Methane into the atmosphere contributes 26 more times to the greenhouse effect than CO2 alone.  For more information on biochar, feel free to research the many references to Biochar on Google or read more on our Biochar web page:

Harvested IAPs ready to be charred


Biochar Retorts being primed for firing in Guatemala

Please donate to the project.

The Energy and Environment Partnership fund for Southern and East Africa (EEP-S&EA) have kindly stood up and agreed to fund 50% of the Project Management fees, Site Preparation, Tools and equipment and Administration fees. The EEP Programme in Southern and East Africa is jointly funded by the Ministry of Foreign Affairs of Finland (lead donor), The Austrian Development Agency (ADA) and the UK’s Department for International Development (DFID). For further information visit: or


To donate to the project please get in touch with us.  We offer branding opportunities on Hippo Water Rollers, send out T-shirts and give shout outs on Social Media. Contact us here to find out more.

We accept SWIFT payments whereby money is wired into our project bank account.  Please approach your local bank’s FOREX department and request the appropriate procedure and instructions to follow to expedite this type of payment.

Contact us here for our bank details.

Donate via PayPal (pay with a credit card):

Please Donate


Donate via EFT:






Please indicate in your bank reference which activity you wish to sponsor.

What will the money be used for?

We will have the following expenditures:

1 –  Water and Sanitation

Instead of purchasing large stationary water tanks to supply drinking water from rainwater harvesting, we thought it would be cool to use Hippo Water Rollers and collect water from the nearby fresh water vlei. Each water roller can hold 90 litres of water. This presents branding opportunities for companies out there, by having their name or logo printed on each Hippo Roller. Visit the website for Hippo Water Rollers here for more information: The cost of each Hippo Roller is R 1,500 ($ 136) including delivery to the site. We require a minimum of 4 Rollers and a total of R 6000 (± $ 544).

The cost of purchasing and delivering 2 x Portable toilets to the site is R 14,000 (± $ 1,272), and we’ll pay for the fortnightly servicing of the units.

[0%] of “Water and Sanitation” funded to date.

Reviewed on: 20 January, 2015

2 – Cooking Stoves

The cooking stoves we require are special portable wood- and charcoal fuel saving stoves and because we are re-sellers of this product we can provide them at cost to our workers. We require 8 of these stoves to offer the staff with a means to cook their food safely or to boil water. More information here:
The cost of delivering 8 stoves to the site is R 3,880 (± $ 352).

[0%] of “Cooking Stoves” funded to date.

Reviewed on: 20 January, 2015

3 – Protective Clothing

To ensure our workers are operating safely and are fully kitted out, we need to supply them with adequate protective clothing (PPE). These include Two-piece overalls, T-shirts, Rainsuits, Gloves, Chainsaw operator safety gear, Goggles and Masks. The most recent quotation revealed that we need R 22,560 (± $ 2,051).

[60%] of “Protective Clothing” funded to date.

Reviewed on: 20 January, 2015

4 – Tools & Equipment

The basic tools and equipment required for the project include Hatchets, Loppers, Knapsack sprayers, Combi-cans, First-aid kits, a Fire extinguisher and Spades. This will cost R 14,500 (± $ 1,318). We have already paid for 2 chainsaws worth R 11,300 (± $ 1,027).

[65%] of “Tools and Equipment” funded to date.

Reviewed on: 20 January, 2015

5 – Biochar Kilns

The specialized Biochar kilns have been developed over many years and are professionally constructed by a light engineering company in Mkondeni, Pietermaritzburg. The cost of each kiln ex-factory is R 9,000 (± $ 886) and we require 3 to start off with for a total of 27,000 ($ 2,658).

[18.5%] of “Biochar Kilns” funded to date.

Reviewed on: 20 January, 2015

6 – Environmental Impact Assessment consultancy cost

The planned activities for the biochar project and charcoal activities will require an Environmental Impact Assessment (EIA) and an Atmospheric Emission License (AEL).  The entire process is expected to take 11 months to complete.  Cost: R 329,543.22 ($ 32,954) including VAT.

[57%] of “EIA” funded to date.

Reviewed on: 20 January, 2015

When everything is tallied up we need R 87,940 (± $ 7,995) PLUS R 164,771.61 (± $ 14,979) for the EIA and AEL.  The EIA and AEL will be funded from biochar sales, but any donation towards this cost would be very much appreciated.

[33%] of “Vuthisa Biochar Initiative” funded to date.

Reviewed on: 20 January, 2015

In conclusion we would like to thank everyone for their support and that we will do everything in our power to meet the goals of the project.

Or for more information contact us here:


Charcoal gas stove

By Vuthisa


This blog post aims to provide the reader with some background on charcoal stove usage as well as charcoal burn characteristics.  Vuthisa developed a unique charcoal stove, able to extract and burn harmful Carbon Monoxide gases inherent to all types of charcoal.

Jiko charcoal stove

We discovered that charcoal use by households is not a new concept and constitutes the primary urban fuel in most of Africa and it is estimated (2003) that approximately 250 million people cook with charcoal. The prevailing tendency in household fuel usage has been to move away from wood fuel towards charcoal for reasons ranging from smokeless burn, ease of use, easy storage, no insect infestation, no need to air-dry, cost effective to transport and high temperature burn.

Rural village in the Eastern Cape provinceSeveral intervention studies have also shown that switching from wood to charcoal can substantially reduce respiratory infections, which may also account for the move over to charcoal. Much of the world’s charcoal feedstock is not plantation wood and the unsustainable harvesting of biomass result in widespread deforestation, thereby handing charcoal its bad reputation. In our context, countries like South Africa (and most developing countries) with well managed commercial plantations and exotic invaders however can provide a sustainable supply of charcoal for household end-use applications. In our opinion improved charcoal stoves should only be sold to communities if the charcoals are produced from carbonised invasive alien vegetation or managed commercial plantations. See our Welcome post in this regard. The manufacturing process is also very polluting and wasteful and there is a serious need of improved charcoal kilns. Join the Portable Kiln Google Group, which I started in order to improve the efficiency of this design or for more information visit this information page and join our design challenge.

More modern fuels such as paraffin- and LP Gas are becoming more popular than fuel wood for cooking and space-heating, but have led to several deaths due to accidental shack fires or lethal gas leaks. Burning charcoal conventionally inside a home is a hazardous and potentially fateful undertaking due to the dangers of Carbon Monoxide (CO) poisoning. I highly recommend Carbon Monoxide Poisoning – A Medical Dictionary, Bibliography, and Annotated Research Guide to Internet References.

Some experts agree however that if issues of concern related to CO such as ventilation and education can be successfully addressed, the widespread implementation of improved charcoal cook stoves should be considered. Traditional charcoal burning stoves such as the metal and ceramic Jiko and Loketto were designed to retail cheaply and provide durability during extended usage, which they do, but failed to address the problem of Carbon Monoxide (CO) poisoning once the occupants go to sleep.

Vuthisa decided to investigate charcoal burning by developing and field testing many prototypes. Feedback from stove users indicated that charcoal can be very abrasive on metal surfaces in direct contact with flames and due to the rapid heating and cooling tendencies of a charcoal fire. Charcoal burned in coal or fuelwood stoves reduced the lifetime of these stoves significantly. Refractory ceramics (and low-density clay bricks) offered the best results as it insulates the fuel from the stove body, but also allows combustion temperatures to rise above 600°C for complete combustion of volatiles.

We discovered that the volatile Carbon Monoxide (CO), a fuel in its own right should instead of being vented off be re-combined with pre-heated Oxygen (O2) from the air in a process termed Gasification. This results in a LP gas-like flame, venting harmless CO2. The process occurs spontaneously and the charcoal fuel batch will burn out in its entirety within 90 minutes from lighting the stove. Depletion of Oxygen levels in a poorly ventilated room can therefore not occur and CO issuance build-up remains below Health and Safety limits.

Best Burn Method

We found it is possible to light the stove indoors with minimal particulate issuance by top lighting the stove using kindling (visit to see the advantages of the top down lighting technique). We monitored CO build-up inside the room with a Draeger X-am 5000 CO monitor, maintaining adequate ventilation. The maximum CO ppm (parts per million) recorded was 30 ppm over a 1.5 hour period. Once the occupants gets exposed to levels of around 200 ppm for extended periods they will experience nausea, headaches and vomiting. Higher levels of around 1000 ppm for example, have far more serious consequences, including falling into a coma and never waking up.

Back to charcoal burning: After the stove is lit, temperatures will continue to rise inside the chamber and more coals will start to combust, although the top layer will be protected by a so-called “pyrolysis wind”. Primary air is drawn up the combustion chamber by virtue of the internal chimney. The stack length has been optimized to control the draft to combine 6 parts air to 1 part fuel, with the secondary air supplying the remaining 6 parts air to resultant 1 part producer gas. Pre-heated secondary air (drawn in along with the primary air before splitting off) will spontaneously interject into the area above the charcoal particles and mix with a constantly escalating supply of producer gas (CO and other volatiles) from the coals. Stoichiometric air/fuel ratio is achieved after approximately 8 to 10 minutes following start-up and gasification commences, the visual clue being a blue flame front forming off the burn plate (catalyst). Most charcoals contain approximately 20 to 30% producer gas, i.e. is not vented during the charcoal manufacturing process and the stove will deplete these supplies in approximately 30 to 40 minutes. The resultant ‘coke’ will also partially gasify and burn to ash over the remaining 30 to 45 minutes. The stove can be operated on a maximum fuel load of 500 grams of charcoal for approximately 1.5 hours. It can use as little as 150 grams of charcoal, sufficient to cook a small meal or for boiling approximately 1 L of water. A full patent was granted in 2006 and is still in force. Double click on video image below to see charcoal stove in action.

We’re not the only ones thinking charcoal gasification has potential in the developing world. See this publication by Ulrich Graf called Low Cost Charcoal Gasifiers for Rural Energy Supply (GTZ, 1994, 49 p.). The publication demonstrates to interested laypersons and experts the conditions and applications under which small charcoal gasifiers can be one option for development within a range of simple energy technologies.

It is also possible to “pipe off” volatiles produced by a charcoal gasifier to run a generator as can be seen in this example:

Or watch this video below showing some of our Bioenergylist discussion group members experimenting with a burner attachment. Double click on the still image below to start video.

I also converted a barbecook® into a charcoal gasifier.  Just to prove the concept as I think flame grilling with charcoal has a lot of potential.


Remainder of mix poured over mold

Bricks extracted from mould and ready to be firedVuthisa partnered up with the University of KwaZulu-Natal’s Ceramic Department in Pietermaritzburg to develop insulated fire bricks. We have made significant progress with our insulated fire bricks, with the mixture consisting of mainly Al2 O3, Fe2 O3, SiO2, CaO, grog and a light-colored refractory clay. An external supplier was contracted to supply the pre-mixed clay in powdered form. The cost per cubic metre is low and lends itself perfectly for this application. The density is lower than what can be achieved with clay mixes that contained sawdust. Our most recent bricks achieved a density of approximately 0.5 g/cm3 which qualifies it as an extremely lightweight yet durable refractory brick. The bricks and the ash filtering base are then joined together via a specially formulated paste-like cement that can withstand temperatures of up to 1300°C to form a hex shaped combustion chamber.

We also have a monolithic, precast, pre-fired, silicon-hardened, fibrous, refractory ceramic sleeve (not replicable outside South Africa) with a density factor of around 0.5 g/cm3, which is being used in our outdoor camping stove.


Stove programs in South Africa have a poor track record (Wood as a source of fuel in South Africa, MV Gandar, 1983). Attention is all too often focused on fuel efficiency, economics and ease of construction at the expense of the socio-cultural environment. It is therefore important to slowly introduce a new stove concept to the target community to test their acceptance of it, but also to demonstrate the advantages that owning such a stove offers. It will be vital to do product acceptance trials in the proposed project implementation area and adopting a successful dissemination technique will take the stove project towards success through inception to maturation. Extension workers should record cooking technique and fuel usage information. The information must be interpreted to fine tune the design specific to the needs of the community.

In summary

It is hoped that by informing a wider audience, strategies can be formulated to improve charcoal making and charcoal burning technologies.

Camping stove to create awareness

Our prototype portable charcoal camping stove aims to highlight the plight of millions of people cooking on inefficient and unsafe charcoal stoves. It is not for sale at this time. Kindly donate (on the sidebar to the right) to help us bring the stove to the market!

In line with creating awareness around issues concerning indoor air pollution, we also promote the clean-burning StoveTec Rocket stove. Click here for more information.

Enquiries welcome via our Contact us page or visit the News link from time to time for updates.

What is a Rocket Stove?

By Vuthisa

Dr. Larry Winiarski, now Technical Director of Aprovecho, began developing the Rocket stove in 1980 and invented the principles of the Rocket stove in 1982. The Winiarski Rocket stove’s simple design and use of common materials make it easily modified for optimal performance. In the last 29 years, variations of the Rocket stove have been built in over 20 countries. The Rocket elbow can be made from different materials such as sand/clay (Lorena), pumice/concrete, heavy steel pipe, 430 stainless steel or refractory ceramic. Find a comprehensive list of Websites, Videos, Downloads and Manufacturers at the bottom of this page with regards to building, using or purchasing a Rocket stove. Click here to go to References

What’s wrong with an open fire?

An open fire, as shown above, is often 90% efficient in turning wood into energy. But only a small proportion (10% to 40%), of the released energy makes it into the pot. Improving combustion efficiency does not appreciably help the stove to use less fuel. On the other hand, improving heat transfer efficiency to the pot makes a large difference. Improving the combustion efficiency is necessary to reduce smoke and harmful emissions that damage health. Improving heat transfer efficiency can significantly reduce fuel use. Fire is naturally good at its job, but pots are not as good at capturing heat because they are inefficient heat exchangers. In order to reduce emissions and fuel use, the stove designer’s job is to first clean up the fire and then force as much energy into the pot or griddle as possible. Both of these functions can be accomplished in a well engineered cooking stove and a Rocket stove. A Rocket stove is a type of stove combining the air-intake with the fuel-feed slot in an opening into the combustion chamber extending into an “internal chimney” before exiting through the vertical chambered heat exchanger.  Some models have the chimney located in a different location, drawing emission gases along a horizontal path (sometimes below cooking points) before exiting through the vertical chimney.

Click on image above to play GIF animation

Or download image here.

A Rocket stove is signified by ease of construction and simplicity of building materials while accepting small-diameter fuel such as twigs or small branches, yielding high combustion efficiency and directing the resultant heat most effectively. A Rocket stove achieves efficient combustion of the fuel at a high temperature by ensuring that there is a good air draft into the fire, controlled use of fuel, complete combustion of volatiles, and efficient use of the resultant heat.  As the fuel burns within the combustion chamber, convection draws in new air from below ensuring that any smoke from smoldering wood near to the fire is also drawn into the fire and up the chimney. The chimney should be insulated to maximize the temperature and improve combustion.  The design of the stove means that it can operate on about half as much fuel as a traditional open fire and can use smaller diameter wood. Some models can accept whole logs, with only the tips combusting. In horizontal feed magazines the fuel has to be pushed into the combustion chamber at regular intervals. The advantage of this system is that the heat output can be adjusted as required, but the disadvantage is that if left unattended the fire will extinguish.

Rocket stoves are usually insulated and some are raised up from the floor which reduces the danger of children burning themselves. For space heating purposes the heat is transferred to a heat store which can in some cases be part of the structure of the house itself. The exhaust gases then pass out of the building via the chimney. The use of a cooking hood is recommended as the hood and chimney combination does not influence the rate at which air is introduced to the fire. The “internal chimney” creates the optimum amount of draft for fuel-efficient combustion.

A Rocket stove’s main components are:

Fuel magazine: Into which the unburned fuel is placed and from where it feeds into the combustion chamber. The fuel magazine can be horizontal where additional fuel will be added manually or vertically for automatic feeding (gravity feed) of fuel. The fuel magazine can be simple steel piping or even ceramic pipe. Fuel shelves serve as the platform for the fuel that is used with the stove. This slightly raised platform makes it possible for air to flow over and under the fuel source.

Combustion chamber/Internal chimney: At the end of the fuel magazine where the wood is burned. Internal chimneys are mere extensions of the combustion chamber and may be constructed from a larger tin can to piping and provide the required draft to maintain the fire. The top of the combustion chamber/chimney serve as the support for the cooking area. Some Rocket stove designs have chimneys in a separate location to the combustion chamber.

Chimneys: Located above the combustion chamber or to one side or can be part of the hood extraction system.

Heat exchanger: To transfer the heat to where it is needed, i.e. the cooking pot. From the chimney the heat passes into a suitable heat exchanger to ensure the efficient use of the generated heat. For cooking purposes the design keeps the cooking vessel in contact with the fire over the largest possible surface area by use of a pot skirt to create a narrow channel which forces hot air and gas to flow along the bottom and sides of the cooking vessel. The pot is usually encompassed by a fixed or adjustable pot skirt. The pot skirt functions as a shield to force the emission gases to pass close to the container holding the food. The gap between the skirt and the pot is also known as the pot gap. The pot gap calculation is crucial to the performance of the stove and excel spreadsheets are usually used to calculate this gap.

Rocket stoves are found more commonly in third world countries where wood fuel sources are scarce but it has been introduced in the United States in recent years. Some of them are small for portability with insulation inside a double-walled design with a chamber for partial biomass gasification and additional mixing to increase power output and provide a cleaner, more complete burn. In some models, as the wood is converted to charcoal, it falls through a grate for later collection and carbon sequestration. Since the Rocket stove is a wood burning cooking stove, obtaining fuel while on a camping trip is easy. Unlike a campfire, the Rocket stove will function very well using small branches and limbs that tend to litter the floor of the woods. This means there is no need to chop larger sections of wood into smaller sections in order to feed the fire.


Websites Definition of a Rocket stove Larry Winiarski’s Rocket Stove Principles (Dean Still) Biomass Cookstove Design and Testing How to Build a Winiarski Rocket Stove How to Build a Rocket Stove How to Build a Rocket Stove for Camping Where you go on the web to find (or to learn how to make) Rocket stoves that work (Peter Scott) Rocket Stoves: Build Your Own Ultra-Efficient Cook Stove (Video) Rocket stoves: Tips for designing your own Website of the Book Rocket Mass Heaters PYRO-Eco Stove for Cooking on Rural Areas (Junji Takano) Rocket stoves (9 web pages) Campus Center for Appropriate Technology (CAT) Rocket stove Rocket Stoves – Cool Name, Hot Stove Our Rocket Stove Rocket stove How to build and understand a Rocket stove Holey Roket (as in Rok+et) : a biomass briquette stove type by Rok Oblak Home to the Ecocina Rocket stove Examples of Rocket stove installations in South Africa The DK Rocket stove (UK)

Videos How to Make a 16 Brick Rocket Stove DRTV Rocket Stoves 12 Rocket stove mass heaters – efficient wood heat How to build a Rocket Stove How to make a Rocket stove by Vavrek Coffee can Rocket stove by Rich How to Make a Tin Can Rocket Stove by Larry Winiarski How to build an institutional Rocket stove – Part 1 to 8 by Peter Scott Build a Rocket stove by Aprovecho Operation of the StoveTec Combo Two Door Stove by Dean Still Rocket stove mass heater – website containing various instructional videos Redneck Rocket Stove using cinder blocks How to assemble special bricks into a Six Brick Rocket Stove with Ken Goyer by Aid Africa The principles of a Rocket stove and how to build one – Institutional type Holey Roket Making (as in Rok+et) by Rok Oblak Ecocina step by step Happy Rocket stove users in South Africa World News now hosts many YouTube videos on Rocket stoves

Downloads The Institutional Rocket Stove Designed by Dr. Larry Winiarski Design Principles for Wood Burning Cook Stoves Rocket stove design guide (See page 9 for fire brick recipes) Introduction of Rocket Stove Technologies (Institutional stoves, Household stoves and insulative refractory bricks) Into Malawi, March- July 2004 Malawi Report
Feb 1st – April 11th, 2005 MINISTRY OF ENERGY AND MINERAL DEVELOPMENT Energy Advisory Project HOW TO BUILD THE IMPROVED HOUSEHOLD STOVES Institutional Rocket Stove (IRS) Assembly Guide Designed by Peter Scott Pot gap calculation

Manufacturers – StoveTec – Envirofit Grover Rocket Stove DK Rocket Stove


Briquette Producers Workshop – Arusha (Tanzania) 2010

By Vuthisa

Vuthisa (South Africa) was invited to participate in the Briquette Producers Workshop held in Arusha, Tanzania between 10 and 14 November, 2010 at Olasiti Garden Lodge. Arusha lies at the base of Mount Meru, one of Africa’s highest and most beautiful volcanoes. Apparently after scaling the summit one is met with stunning views of the Ash Cone lying several thousand feet below in the crater and Kilimanjaro in the background. See map below.

The conference/workshop was facilitated by the Legacy Foundation (Oregon, USA) through funding from the McKnight Foundation of Minnesota. It is part of a three-year project backing environmental conservation in Africa. For more information on Fuel Briquettes, background to the technology and press construction manuals, kindly visit our Fuel Briquettes page. Participants arrived from Tanzania, Uganda, Kenya, Rwanda, Chad, Burkina Faso, Democratic Republic of Congo (DRC), South Africa and Botswana. The main aim of the conference is to create an African Briquette Producers Network so that new knowledge and improved recipes can be passed on to producers even if they are working in different regions. Over the next couple of weeks we will be highlighting some of the challenges facing briquetting groups, entrepreneurs and organizations alike in achieving successful transference of theoretical knowledge into practical know-how. This is no easy feat as there are many constraints and challenges facing briquette producers, such as obtaining presses or tools, many lack business skills, standardizing of briquette size and quality, packaging and marketing and end-use issues such as briquette combustion techniques.


Our presentation on Thursday (11th) intended to bring participants up to speed with rocket stove technologies as well as discussing air/fuel ratios to effect optimum stove performance. We had two stoves at the conference, namely the StoveTec wood rocket stove and the Vuthisa charcoal gasifying stove. Although the StoveTec was not originally designed to burn briquettes, it coped very well with smaller diameter- or broken up briquettes. The Vuthisa charcoal gasifying stove was lit on the final night of the conference to better showcase the blue flames that can be achieved through the optimal combustion of charcoal. The stove was lit using approximately 450g of lumped charcoal pieces kindly provided by the Olasiti Gardens’ kitchen staff. After approximately 45 minutes of operation, showcasing complete combustion and mesmerizing blue flames, briquettes consisting of agro-residues (and very little charcoal fines) were broken into pieces and inserted into the combustion chamber. The briquettes were quickly pyrolized into char without any smoke and the char-gas burn commenced shortly thereafter. We then donated the StoveTec to a grateful participant.

Below is a collage of photos taken by Peter Stanley, myself as well as other participants. Click on it to go to my Flickr slideshow. The Legacy Foundation will be bringing out their final report and we will be putting a link to it here in the next couple of weeks. Here is a link to press coverage of the conference.

More updates to follow…


Final report by Legacy Foundation:

Download site for training manuals:

Is it better to burn wood or charcoal?

By Kobus Venter

Is it better to burn wood or charcoal? Half the World’s population of nearly six billion people prepare their food and heat their homes with coal and the traditional biomass fuels of dung, crop residues, wood and charcoal  (Inheriting the world: The atlas of children’s health and the environment, by Bruce Gordon, Richard Mackay and Eva Rehfuess, WHO 2004). In China, India and Sub Saharan Africa, up to 80% of urban households use biomass fuels for cooking. Wood fuel usage is the most predominant with charcoal a close second. What is their respective influence on global warming? Sorry, but this post will not attempt to discuss this complex issue, because the reality is that for most people struggling with energy security, saving the environment is not exactly high on their list. The following paragraphs will instead focus briefly on the burning characteristics of wood and charcoal, because in many cases availability and affordability of the fuel type will dictate which fuel type is being used.

Typically wood has an energy value of between 14 and 18 MJ/kg when burned. Charcoal has an energy value of around 29 MJ/kg, in other words charcoal burns hotter than wood, but when not insulated or not receiving sufficient air supply (including secondary air), the absence of flames or fast flowing CO2 gases will result in less efficient cooking due to a lower heat transfer efficiency (HTE). In other words with conventional charcoal burning (glowing embers) the pot will receive radiant and infrared heat, with the pot positioned close to the coals. Wood burning flames (especially from open fires) tend to ‘lick’ the pot and transfer heat more effectively, but contain products of incomplete combustion (PIC), also known as ‘particulates’, that are harmful to humans when inhaled. In many instances households cannot afford to purchase or install chimneys that remove the smoke. The flames (yellow colored) will also tend to blacken cooking pots. Indoor smoke inhalation gives rise to pneumonia and other respiratory infections – the biggest killer of children under five years of age. Indoor air pollution (IAP) is responsible for nearly half of the more than 2 million deaths each year that are caused by acute respiratory infections (ARI). Good ventilation and improved cooking stoves can dramatically reduce children’s exposure to smoke. Vuthisa currently promotes the StoveTec stove which is very fuel efficient (conserves wood) and emits 70% less smoke. Visit for more information.

Charcoal is preferred over wood as a cooking fuel in many parts of the world because it does not produce smoke, is easier to transport and ready to use in a convenient dry- and broken-up form. Charcoal burning however produces large amounts of Carbon Monoxide (CO) which is harmful to humans when exposed to very high levels. Increasing air flow through the charcoal emits more CO, so if you don’t mix secondary air with the CO and insulate the fuelbed to raise temperatures to spontaneously combust that mix, you’re better off with a glowing ember burn. Most charcoal stoves (i.e. Ceramic Jiko) are not designed around this principle and won’t be much different to your barbecue, whereby you vent all the gases first and then cook on the glowing embers. There is anecdotal evidence that family members have succumbed to CO poisoning, but families using charcoal are very aware usually of it’s dangers and allow for adequate ventilation. Why is CO harmful to humans? Let me explain: The effect of high levels of exposure to CO can be lethal, but even low levels of exposure can have harmful effects. CO diffuses rapidly via blood vessel membranes. Once it’s present in the bloodstream, CO binds to hemoglobin 200 times more readily than oxygen. This forms carboxy-hemoglobin (COHb). COHb reduces the oxygen carrying capacity of the blood and impairs the release of oxygen from hemoglobin. The neurobehavioral effects include impaired coordination, tracking, and driving ability. Cognitive performance is impaired at COHb levels as low as 5%. During exposure to a fixed concentration of CO, the COHb concentration increases rapidly at the onset of exposure. This levels off after about three hours, and reaches steady state after 6 – 8 hours of exposure. Headaches, nausea and loss of consciousness occur at COHb levels of 25-40%. Permanent brain damage and death follow if COHb levels exceed 45%. Vuthisa developed a safe charcoal stove over the last few years to address this very issue.

I don’t advocate charcoal usage over wood, because of the wasteful manner in which charcoal is made and the charcoal trade destroys naturally occurring forests and contributes to global warming. There are signs that governments are trying to regulate the industry by introducing more efficient charcoal-making kilns and establishing plantations to ensure sustainability of the timber source. In Namibia, millions of hectares of encroachment bush is being converted to charcoal and sold to neighboring South Africa as barbecue charcoal. South Africa itself (according to the most recent South Africa Yearbook) is plagued with alien plant infestations, totaling more than 10 million hectares, about eight percent (8%) of the country’s land surface area. The rate of spread is alarming and their numbers are projected to double over the next 15 years.  More recently Vuthisa Technologies started to convert slashed invasives into charcoal and biochar using Emission Reducing Biochar kilns in a project known as the Vuthisa Biochar Initiative.

My verdict: It seems there is no clear winner, just spare a thought for the millions of people that rely on either wood or charcoal for their day to day survival.


Charcoal camping stove saves electricity

By Vuthisa Our prototype portable camping stove aims to highlight the plight of millions of people cooking on inefficient and unsafe charcoal stoves.  It is not available for purchase yet. The camping stove will weigh less than 4 kg and consists of a easy-to-clean powder coated hex-shaped shell, containing a shock-proof low-density ceramic combustion chamber or insulated fire bricks.  The top of the stove has a detachable potholder made from stainless steel and will come with an optional padded and waterproof carry bag with extra pockets for charcoal and fire lighters/matches.  There will be a multitude of colors to choose from i.e. signal red, deep sky blue to dark gray.  The base of the stove is also removable in order to shake out the ash after use. We propose the stove be used to save on electricity costs which are set to sky rocket.  In South Africa, ESKOM (State owned power company) has applied to NERSA for a 35% increase per year for the next three years – a 200% increase from current rates in three years time. [***Update***24 February 2010 – The national energy regulator decided to fix electricity tariff hikes at roughly 25 percent annually for the next three years rather than 35 percent.] [***Update***23 March 2015 – A further 12.69% tariff increase will be implemented from 1 April, 2015 onwards.] The cost of operating this stove 4 times a week is estimated at R19 ($1.60)!  This is at the current cost of R 48 ($4) per 5 kg bag of charcoal and using 500 grams of charcoal per burn.  Of course it would be much cheaper to make charcoal in your own backyard. Please send through your comments to Vuthisa on our Contact Us page or visit the News link from time to time for product updates or visit our Home page.