Briquetting both Old and New

Hello again! Wow, it feels like a while since I’ve written here and it certainly feels like a lot has happened. Before I dive into the more official updates I would like to mention that my dad and my brother took advantage of my stay here in Arusha to come visit and see a bit of what exactly what we at DHE do. It has been wonderful to have them around and they both put in hours with us making briquettes. With them around decided to take four days off from our funded responsibilities and take some time visiting Tanzania’s national parks and conservation areas. Nice to get away from briquettes for a bit.

Jumping in the Serengeti

That said, our workshop is constant making improvements and exploring better production components and processing methods. We recently discovered a much more effective means of using cassava flour as binder. As opposed to making porridge and mixing in in with the charcoal dust we have begun mixing the dust and the flour first, and then adding boiling water. Doing so spreads the starch fibers much more thoroughly through the mixture. We have also added two new briquette presses to our arsenal: a wooden compound lever press (which was used extensively last year) and something called a Farmer Jack. We are preferring these designs to the hammer press because they are a bit easier on the molds/plungers and also produce very dense briquettes.

The Farmer Jack Press
The Farmer Jack Press

On Monday, Rachel and Emily made a very exciting visit to a group that last summer’s team spent a lot of time working with, the Lulu vicoba (vicoba = community bank). We were very excited to find out that they still are regularly making briquettes for internal consumption. They are still using the same wooden compound lever press and donut mold as DHE had originally supplied and though they are not producing their own charcoal, they were able to find a source of waste charcoal fines which are being incorporating into their mixtures. The groups seems very happy with their current operation and we plan to more thoroughly document the financial and production systems they have set up.

Using the Compound Lever
Using the Compound Lever
A beautiful briquette made by the Lulu Vicoba
A beautiful briquette made by the Lulu Vicoba


Yesterday was quite the busy day. The team split so we could run two different capacity building sessions, both on brick kiln construction. Tucker and I, with the help of my Dad and bro, headed out to Kisongo to meet with a group of women affiliated with EMORG (Educational Model ORGanizaton). We spent the morning session talking with them about briquetting and how biomass is carbonized into charcoal. The women had no experience with making briquettes and were very interested in it from an entrepreneurial perspective. EMORG sees briquetting as potentially being their first vocational training trade and as a means to fuel an in house kitchen. In the afternoon we got our hands dirty and constructed a charcoal kiln for local waste. And Emily and Rachel went to work with Vision for Youth, the group based out of Arusha town who are starting their own business. They are very eager to start selling soon and so were very excited to have built their first kiln!

The group from EMORG looking at our instructional poster on carbonizing
The group from EMORG looking at our instructional poster on carbonizing
Vision for Youth and their kiln
Vision for Youth and their kiln

And today, bright and early, we are flying out to Kigoma where we will be having meetings with some representatives from the Jane Goodall Institute. DHE has a rich history working with JGI and I hope we can set up plans so the Bioenergy Project’s next two trips in Tanzania include more collaboration with them. JGI has expressed interest in briquettes as a reliable alternative cooking fuel and we hope that going forward we can help them put together a capacity building program for the Kigoma region. We will be sure to write again soon and thanks for checking in!

Airport photo
Airport photo

Kiln to Briquettes

To begin where we left off, last weekend we busted out of Leganga and headed to Moshi for a change of scenery. On Saturday morning we caught a daladala on the Moshi-Nairobi Highway, and an hour and half later we were passing by the Coca-Cola sponsored clock tower on the north side of town. Every newspaper we saw was printed with Obama’s face in anticipation of his arrival on Monday. We spent the day walking around and exploring the streets, and stumbled upon a rice processing plant when we veered a bit off the major roads. They were drying out the grains before they were to be hulled:


Sunday we went on a walking tour around Mataruni, a village on the southern slopes of Kilimanjaro. We were able to connect with a young man named Richard who grew up there. He had recently converted a part of his family’s farm into area to bring guests (and tourists) to demonstrate how fresh coffee beans are prepared into a brew. He showed us how a large mortar and pestle is used to remove the husk from the beans before roasting. Quite a bit of work if you wanted to do it every morning. But in the end this trip was invaluable to our larger mission this summer, and the coffee was delicious.

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One of the major ventures of this past week has been the initial experiments of our freshly constructed tanuru (charcoal kiln). The charcoal from this kiln, made from sawdust, rice husk, and corn leaves given the season, will supply a clean burning filler for making briquettes. The kiln is designed to bring a large amount to biomass to a high temperature in the presence of limited oxygen. To perhaps make this a bit simpler, but also a little bit more inaccurate, let’s think of three different reactions:

1)      Gasification of Biomass: Biomass + Heat + Air (primary air) = Ash + Syngas + Heat

2)      Pyrolysis of Biomass: Biomass + Heat = Charcoal + Syngas + Heat

3)      Combustion of Syngas: Syngas + Heat + Air (secondary air) = CO2 + H20 + Heat

A bit funny to have heat on all sides of the equations, but the point to be made is that it takes heat to get started, but once going, the reactions can produce excess heat to run to completion. Syngas, essentially biomass that turned into gas, contains several compounds but has a high percentage of hydrogen gas so we can consider it combustible. Check out a picture of Rachel doing some work on our design:


The kiln is designed with four holes along the base which allow limited air to enter the packed biomass. This is where we begin 4 small fires to get the process going. The air will turn some of the feedstock into ash but it will also create a lot of heat which helps drives pyrolysis (reaction #2 above). So we let in a little bit of primary air into the kiln, sacrifice some of the biomass to ash, but create a lot of heat to make a bunch of charcoal. Because the top of the kiln is sealed shut, all the syngases produced get drawn into the chimney through an opening right below Rachel’s left hand. Rachel’s right hand is working on the secondary air tunnel which allows air to flow under the kiln and get preheated before entering the chimney. There the secondary air meets the syngas and a second round of combustion occurs. Most charcoal production systems in Tanzania simply allow syngas to escape, but our design will produce few emissions and create extra heat which can be fed back into the kiln.

Now we just need to figure out how to pack the kiln. Here’s a picture of the kiln filled with biomass (sawdust and rice husk). We are using some plastic pipes to make sure we can get primary air coming up from the base.


After removing the pipes, we have nice “biomass chimneys” that cut through the feed stock. Also nice to sprinkle some corn leaves on top.


Then take a piece of metal roofing properly cut to size and place it on top of the kiln. This will make sure that the syngas produced will enter the chimney.


Then cover the metal roof with dirt to make a tighter seal which also acts as insulation. Remember the kiln is gonna get hot! Then start some fires in the side holes (where the primary air enters). Here Tucker and Emily are inspecting one side while Naomi and Rachel work on the other. Most of the gas coming out of the chimney at this point was water vapor.


About 5 hours later we had dried out a bunch of wet sawdust and made a little bit of charcoal! We separated out our winnings, and I did a little physical processing to grind it up to dust. Thanks to Richard we had some experience with this before.


Then we mixed up some cassava flour (tapioca) and water, heated it up and made a starch binder which we then added to the charcoal mash. This acted as our briquetting mixture.


And from there we were able to start making briquettes in our new Musket Press. Exciting to see the whole process!

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But we know we can get a better yield from the kiln, so we are setting ourselves up for success. We’ve taken all the feed stock we’re planning on carbonizing and are letting it dry out in the sun. Let’s hear it for surface area to volume ratio.


Another exciting update is that DHE has a new partner in Arusha, Vision for Youth, or V4Y, which offers health education and entrepreneurial training for young adults. Rachel and I first met with Violet, a cofounder of the organization, on Wednesday and heard that they’ve been wanting to start a charcoal briquetting operation for some time. All four of us went back to visit them again on Friday to meet with Veda, the other cofounder, and Happy, Raymond, and Pendo, some of the “youths” (they’re our age…) who are interested in briquetting. A wonderful meeting that left everyone energized! They’ll be coming out to Leganga on Tuesday to see our developing briquetting operation.

Next week will be a busy one. After meeting with Didas and Maricel from EMORG (Educational Model Organization), a growing library/vocational/community center, we promised to help them paint their new building on Monday. On Tuesday morning we have the V4Y group visiting, and then we are going to go meet Julius Sossy and the briquetting group he helped DHE begin last summer in his village of Moivaro. Then on Wednesday we will be visiting Bernard, an inventor who runs an organization to inspire young Tanzanians to solve their own technical challenges who has also helped us design stoves in the past. We want to talk to him a bit kilns and briquettes. I’m sure he’ll have a lot to say. And in between all of those visits and meetings, we’ll keep making charcoal, keep making briquettes, and keep making food. More updates soon, Kwa heri!

Safe Travels and Good Times

I am excited to report here that  my three travel companions and I are all safe and well in Dar es Salaam. In fact, we’ve been safe and sound here since Saturday. But before I get into where we are now, and explain why our feet and stomachs ache, the former from walking and the latter from eating, allow me to jump back a bit.  The four of us met on June 13th, a Thursday, at JFK in New York City for our 11 PM flight out of the country. After sorting out some database issues with Rachel’s tickets (we had quite a complicated route to Dar and Royal Dutch/Kenya Airlines was struggling), Tucker, Rachel and I were able to make it past security to meet Emily who had been waiting for us after her previous flight down from Toronto. And with that, we soon were in the air headed to Amsterdam.


When we arrived to Holland, the local time was about noon, and though we struggled for quite some time to actually get some euros and though we managed to get the wrong train out of the station, we were determined not to spend our 7 hour layover in the airport, and we did eventually make it into the city. And what a city Amsterdam is, filled with young spirits and old stories that are both in the conversations of the pedestrians as well as the buildings and canals that they occupy. We were able to enjoy a little bit of a rest in one of the less busy parts of town.


After Amsterdam, we were off to Nairobi for a quick layover, with our flights finally ending in Dar es Salaam in the mid-morning of last Saturday. After an hour long cab ride through the busy streets that get overflowed with people, we spotted several shops selling cooking fuel and bikes piled high with bags of charcoal. Our driver, Bakadi, told us that the forests were disappearing, and though more people are beginning to use gas to cook in Dar, charcoal and fuelwood remain entrenched in the markets and the kitchens across Tanzania.

We are spending a week in Juba Hotel, a relatively new hostel in apparently a sketchy part of the city. Dr. Rajabu from the University of Dar’s Energy Engineering department warned us that we needed to be careful as people in the area “have lots of tricks.” Though I’ve already been to Tanzania before and have had some time in Dar, I am no expert. It was great having most of Saturday and all of Sunday to walk around the city, get acquainted with the markets, fill our wallets with Tanzania shillings, and even meet up with Anna Bladey and Liliana Ma, both Dartmouth ’14s (juniors for you folks who don’t have the granite of New Hampshire in your veins) who are volunteering at a health clinic and conducting research related to HIV respectively.

On Monday (today!), we had to get up bright and early to make it up to the northern part of the city where our Swahili classes are being held. There we met Sarah Fernandez and Pallavi Kuppa-Apte, also 14’s, who are volunteering with the Jane Goodall Institute out in Kigoma. They had only landed a few hours earlier. I am incredibly impressed by their stamina and good spirits. We are incredibly lucky to have the Dickey Center of Dartmouth College arrange Swahili lessons during our week here. Our instructors, Mama Sada and Godfrey, offer wonderful guidance and a smile at every turn.

After the class we headed out for lunch, enjoyed the breezes of the Indian Ocean and looked around some craft markets. We then headed out to the Kivukoni fish market, filled with auction goers, shell salesmen, large spiders in trees, motor driven wooden boats and a lot of wet concrete.


After the market, we had a nice leisurely walk back to the city center. We got our cell phones set up, hung out in a bar sipping water and avoiding the heat for a while, and then headed to an amazing Chinese restaurant. With our stomachs filled and our feet tired, we parted ways with our non-DHE peers who are staying in the Safari Inn. And it is in this state, a bit under the weather with a cold, that I write to you about the beginning of our summer.

Land Grabs for Biofuels

I’m going to do a shout out to Daniel Bornstein (Dartmouth ’14) who wrote a very interesting article on land grabs in Africa for the purpose of producing exportable biofuels. This is a huge issue as it challenges farmers’ independence and the production sustenance crops. DHE’s Bioenergy Project wants to work with current farmers to figure out ways to meet their energy needs which remain overlooked as they lack international profit potential. Even so, this energy shortage must be met and will be to the determent of the weakening ecologies if resources are not harvested sustainably. We look forward to Dan working with the 13X team that will travel to Tanzania this summer.

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Pyrolyzer Work Team Makes First Moves

A small group meet this afternoon to work on the pyrolyzer. Tasks completed:

  • primary door was made and intended location was marked on barrel
  • holes and round stock was prepared for the grate support to suspend the biomass above the primary air door
  • holes for secondary air were marked with future hole modifications in mind

Goals for next work session (probably Thursday morning):

  • weld primary air door to hinge and hinge to barrel
  • use plasma torch to cut primary air opening at the base of the barrel
  • weld supports for grate to barrel
  • plasma torch the hole in the barrel lid for the chimney
  • drill holes for secondary air into the chimney

And then the first version of DHE pyrolysis kiln will be ready for a test run!

The Drums are In

The Bioenergy Project recently received its delivery for four 55-gallon steel drums for the purposes of making compost tumblers and pyrolysis kilns. The are currently safe and sound in Thayer’s large frame lab but will soon be met with plasma torches and drills next week after our new members have gone through machine safety training.

To see a design for a compost tumbler look here:

To see a video on pyrolyzers, watch our good friend Peter Hirst from New England Biochar talk about them: