One more kwaheri to Arusha!

Greetings from Tanzania!

For our final days in Arusha, we thought carefully about what the trip to Kigoma entails and how to make it a successful trip. As decided, Dvij and Jun went to Kigoma two weeks before the rest of us to start the briquetting capacity building while we wrapped up the process in Arusha. We spent most of the weekend of July 12-13 on our own getting ready for Dvij and Jun’s Monday trip to Kigoma. We prepared a presentation outlining DHE past and present briquetting operation in Arusha including lessons learnt as well as DHE’s future plans. We hope to use this presentation as an introduction to JGI and also as the start of a future partnership.

On Monday, July 14, we conducted further economic analysis so as to determine the economic feasibility of the briquetting operation. We did runs while taking into consideration the weight of the feedstock used. We also put into account the free feedstock like peanut shells, corn husks and corn cobs. Such feedstock helped lower the briquette production cost. We used an input-output ratio to measure the average yield of a given kiln run. From the average yield, we could determine the average char output per bag of sawdust purchased and the required minimum price per kg of briquettes to make a profit. We obtained the numbers we needed and we are currently in the process of completing the economic analysis.

Part of wrapping up the process in Arusha involved teaching the groups how to build a kiln and assisting them with the process of building a kiln if they express an interest in getting one. We met with Vision 4 Youth to discuss ways to modify their old kiln to incorporate the new kiln design. Their old kiln was well built but could use a lot of improvement to better the primary air flow and also make it more convenient to run. We later met with the group and made some alterations to their old kiln. We also got a chance to do two successful runs with them producing a lot of char. The kiln run was much longer than our regular kiln run. We suspect that is due to the large size of the kiln and the fact that the sawdust was not quite dry.

Vision 4 Youth kiln before modifications
Vision 4 Youth kiln before modifications

We also met with Tumaini Center, formerly presumed to be Upendo, to show them the new kiln design, how to run it and make briquettes from the char obtained. We did a run with them and made some large doughnut shaped briquettes. The two women present liked the process and suggested that we do further kiln runs with them so that they could test the quality of briquettes. The two women had proposed that we stop by Tuesday so that we could teach the process to more women from the Tumaini Center. We went to the center this Tuesday but only one of the women showed up to inform us that the group was no longer interested in making charcoal briquettes. This is something that DHE needs into take into account – while some groups are very excited about the prospect of briquetting, not all are. Why is that the case?

Meeting with Tumaini Center
Meeting with Tumaini Center

We organized a full day of kilns runs and making briquettes with EMORG last Thursday. We did three successful runs, each time explaining the process to the women—specifically focusing on how to pack the retort. The women liked the process except the idea of the retort. They thought the retort took up too much space that could be used to burn feedstock and was quite complicated. We had an interview with Mama Nuru, the head of the group. The group was enthusiastic as usual and we enjoyed working with them. We also discussed the possibility of helping them build a bigger kiln but they said that they were incapable of funding a full scale kiln. After deliberating on the matter we decided to leave one of our demo kilns with them so they can have a model before they can build a bigger one. We tested the kiln and we are confident that it will serve them well.

On Monday of our last week in Kigoma, we met with Lulu Vicoba for the first time. Lulu Vicoba is a large group of about 25 members. We did two kiln runs and pressed briquettes with them. They were pleased with the process and asked a lot of questions. They also mentioned that most members did not have charcoal stoves. We left our last demo kiln with them so they could practice using it more and maybe start a briquetting operation.

As a final wrap-up, we made a Swahili manual that outlines how to build a kiln, how to run the kiln and how to press charcoal briquettes. On our last day in Arusha, we dropped off the kiln manuals to the groups and said our goodbyes.


Olivia with Swahili manual
Olivia with Swahili manual

Bye Arusha. Hello Kigoma!

After a sudden flight cancellation on Sunday, Dvij and I (Jun) made our two day long trip to Kigoma from Arusha via Dar es Salaam on Monday. We arrived on Tuesday morning in good shape and excited (despite that Dvij had lost his luggage for his second time in Tanzania). We are staying in Royal Prince Lodge which we have found to be somewhat of a lonely place compared to the EMORG volunteer house due to the single rooms. Food from the lodge restaurant is delicious and is worth waiting through the forty minute preparation time.

On Wednesday morning (after Dvij finally got his luggage back from Air Tanzania), we made our way to JGI in order to meet Mary, Shadrak, and Mtiti. JGI is about forty minutes away from the Lodge by foot and about ten minutes away by taxi. Our meeting started off with our presentation of 14X travel team’s work so far in Arusha and of our four partner organizations. The people from JGI were genuinely interested to know more about TLUD kilns and charcoal briquetting. We presented them with cost analysis of building (around 44,000 TSH) and running a TLUD kiln made from barrels. Mary particularly seemed to be impressed by the low cost of building a kiln, and that about one man-hour was enough to produce one kilogram of briquettes. However, she did note that some people may not be willing to use cassava flour as a binder because its price has recently increased.

Our meeting then progressed on to discussing what the 14X team could do here in Kigoma. We learnt from Mary that lump charcoal is made in villages and then transported to urban centers in Kigoma for sales and consumption while women in these villages use firewood as fuel. Although cooking is usually done outside or inside a separate building, the use of firewood is still poses a health threat to both the women and their children. As we see it, there is a need discourage the use of lump charcoal in urban centers and encourage women in villages to use alternatives to firewood (possibly charcoal briquettes). Furthermore, according to the people of JGI, there are a variety of feedstock easily available in Kigoma. These include coffee husks and banana leaves in high-land regions, palm tree fruit fibers (which are used for kindling fire as they burn easily), and sawdust. Corn husks, however, are difficult to find because they are fed to animals.

During our meeting, a number of different organizations/individuals were mentioned who we could work with. Students in Root & Shoots program, Kigoma Youth Development Association, various women’s groups, and forest monitors are potential partner groups based in Kigoma but more specific details will come later with more meetings.

On the way back from JGI to Royal Prince Lodge, Dvij and I looked around the town for barrels. However, we only managed to find full sized barrels which are much bigger than the barrel we have been using for our demonstration kilns back in Arusha. We have visited three different shops but smaller barrels were nowhere to be found. There is a possibility that we may have to make a full sized kiln and roll up a sheet metal to make a chimney instead of using narrower barrels.

Our tentative plan for this week is to explore the town and find appropriate building materials and sources of feedstock so that we can start assembling a demonstration kiln and run it. Tomorrow, JGI will be providing us with a driver who can take us around the town. Hopefully, we will find what we are looking for.

On the other hand, the other half of our group staying behind in Arusha has an exciting week ahead of them. They will be conducting input/output analysis of a TLUD kiln as well as testing our briquettes against lump charcoal that was purchased in a town market a few days ago by heating up vessels of water to gauge the thermal outputs. The group will be also consult Vision For Youth to help them build and run their own TLUD kilns.


P.S. No photos this week. The internet connection is very slow and unstable!!!

A Hybrid is Born

Day fifteen in Arusha starts with a quick breakfast of peanut butter and honey on toast and a little one on one football in the backyard with Philbert. The nyama choma (roast beef) from last night has taken Jun out. I admit I feel a little uneasy too but my tough Bombay tummy is holding up well. We are off to EMORG today with a new kiln design and there’s a lot to say about it but first let’s rewind one week to last Thursday.

We spent the morning running our two demonstration kilns (See Olivia’s Busy, Busy for a brief description of their designs) to try to figure out appropriate feedstock “recipes” for the kilns. Fine feedstock must be mixed with coarse feedstock in a proportion that allows for the passage of oxygen through the substrate but that is not so airy that the flame eats through the substrate, turning it to ash.

If a larger proportion of finer and/ or damper feedstock is used, the kiln will take a longer time to produce char. Burn times typically take between 15 and 25 minutes. After packing the kiln, we dribble around 20 ml of petrol on the feedstock (petrol costs 2500 Tsh per liter). The petrol allows for a big flame for the first minute or two of the burn, depending on how densely the feedstock has been packed, this flame disappears after two to five minutes and the kiln begins to emit a thick white gas which is damp to the touch suggesting a high water content. The energy to draw this water vapour out of the kiln comes from the embers in the feedstock and the pressure gradient induced by the natural draft of the chimney. This second phase of the run usually takes between 10 and 15 minutes. After most of the water has escaped from the feedstock, the flame shoots back up with dramatic bravura. At this point the chimney and adapter are removed and a damp wooden stick is used to make sure that the combustion is occurring evenly across the surface of the feedstock. Pockets of raw feedstock are mixed around into the flame to ensure that the action front is descending symmetrically across the face of the drum. After four to five minutes the kiln is quenched with water, the char is removed, inspected, dried out and weighed.


With a better understanding of the recipes that worked well, we set off to meet with the women’s group at EMORG to run a demonstration of the Takachar-inspired kiln with sawdust they had purchased from the local market in Kisongo. The women were impressed with the quality of the char and used it along with cassava flour to press out briquettes.  The press that EMORG is currently using to produce briquettes is not able to apply sufficient pressure onto the molds and so although we were hoping to test the briquettes we made using the char we produced last Thursday, we were informed a couple days ago that, in a calamitous turn of events, the briquettes crumbled before they dried.


Our pressing woes disappeared on Monday, with a trip to Vision for Youth. Our buddy Miguel from Johns Hopkins volunteering at V4Y purchased a G clamp to use as a press. The G clamp was tremendously successful in producing well-packed briquettes that showed no indication of crumbling before drying. We are looking forward to testing these briquettes over the next few days, and introducing the concept of using a G clamp to press briquettes to the women at EMORG later today.

Although the retort kiln described in Busy, Busy produced high quality char, it was psychologically off-putting that the material in the outer barrel would burn completely to ash. In response to this, we decided to combine both designs into a hybrid by attempting to produce char both inside and outside the retort. This was achieved by using the retort in the traditional TLUD design (with holes only in the bottom of the outer barrel for air to enter and none on the side to aid combustion) and packing the outer barrel as we otherwise would have with no retort. The little metal tubes shown below were placed in with the feedstock to help the action front descend symmetrically. The thought was that the tubes would serve as reservoirs of heat so that the pyrolysis wasn’t at the behest of the wind—if the flame moved to one side, the metal would retain heat in the other, continuing the pyrolysis until the flame invariably returned.


On Tuesday we built a new cylindrical retort to replace the box-shaped retort we had previously been using. We were hoping that the added dimension of symmetry would help the action front descend more evenly and char the material in the report more consistently. However, we found that the added volume of the cylindrical retort rendered it useless. Having more volume inside the retort means that more energy is required to pyrolyse the material inside. Most of this energy comes from the material in the outer barrel. There simply wasn’t enough material in the outer barrel with this new design to get the reaction off the ground. We thus reverted to using the box retort in the hybrid kiln. We are glad though that we built the cylindrical retort and discovered this restriction on the ratio between the cross sectional areas of the retort and the outer barrel – this is definitely valuable information to document.


We have done some preliminary measurements to calculate the yield of our current hybrid kiln design (how much char is produced for a certain mass of feedstock put into the kiln), we will hold on to that data for the time being, as it probably does not reflect the true potential of the kiln. We get better at running the kiln every day and want to try a few more iterations before we publish yield statistics for our design. At this point, the yield looks promising enough to support a profitable business model. Our main goal over the next few days is to iron out the details of a business model, so that we may present it to our partner organizations instead of presenting a product in isolation.

Finally, we get to yesterday when we met with DHE constact Mr. Sossy, an associate with a women’s group in Tumaini Center in Arusha. We set up a time to meet with the women’s group, which has produced briquettes in the past, to demonstrate the new kiln design. We hope the group shares Mr. Sossy’s enthusiasm to see the new kiln. More on this later!



Busy, busy

Jambo from Tanzania! The team has been busy, busy, busy as we spend time meeting with more organizations and building demonstration kilns. On Tuesday, we met with two organizations that DHE has previously worked with: EARD-CI (Enterprise & Rural Development – Community Initiatives) and Vision 4 Youth. At EARD-CI, we met with Naomi, who told us of all the opportunities and struggles that Lulu Vicoba, the community bank of around 30 men and women that the organization oversees, has had in briquette production. When DHE arrived in 2012, they helped to set up a briquette operation. Lulu Vicoba used a mixture of sawdust, paper binder, organic materials and charcoal fines to make the briquettes you see below. Some of the filler materials are not carbonized before being processed and pressed. However, as you can see in the picture, these briquettes are not fully carbonized and are quite ashy, meaning they don’t work very well for cooking. We learned that, naturally, Lulu Vicoba needs to have higher quality briquettes in order to sell them. This is where our team comes in – we’ve been hard at work on different models of TLUD kilns and a more efficient carbonization process that will produce better char which will then produce better briquettes, and produce an income for Lulu Vicoba in the markets. We intend to meet with the group to complete our impact analysis study and to gauge the group’s interest in producing its own char.

Briquettes made for EARD-CI in previous years.
Briquettes made for EARD-CI in previous years.
We next visited Vision 4 Youth, who is experiencing similar problems. We went to the organization’s new headquarters, which are spacious and lovely. Violet, the organization’s director, told us about Vision 4 Youth’s many entrepreneurship and agricultural activities and history to date with making briquettes. Vision 4 Youth works with young people in the realms of poverty, drug abuse, HIV/AIDS and human rights violations, provides professional skill development programs and leads courses at academic institutions in the region. One of their foremost focuses is creating jobs and incomes for adolescents in order to prevent poverty, drug abuse, and street violence. They have a variety of means for doing this: they have a corn farm, a chicken farm, a briquetting operation, and more. In 2012 DHE came and built a BLSD kiln and taught a small group of young people (between ages 15 or 16 and 35) how to make briquettes. This past winter, DHE returned to make a small demo TLUD. The organization is extremely enthusiastic about the prospect of teaching youth how to make and sell briquettes – so enthusiastic, that they are currently taking apart their BLSD kiln brick by brick to rebuild at their new headquarters location. Nevertheless, there are still inefficiencies in the past two kiln models that have made it so that they can not actually make a profit off of the briquettes yet. The BLSD kiln takes 24 hours for a complete run, which poses a lot of problems. Meanwhile, the past TLUD design has been finicky and smoky as well and takes about 4 hours to burn.
Team meets Vision 4 Youth staff to discuss future briquetting plans.
Given this information from Vision 4 Youth, EARD-CI, and then EMORG a few days ago, we decided it was in our best interest to really think through a better TLUD model to demonstrate for each organization. We did quite a bit of research, and have been consulting with Takachar, a group successfully operating a TLUD organic waste fuel project in Nairobi, Kenya founded by an MIT PhD student. We’ve settled on two designs for demo kilns, keeping in mind that each better pyrolizes different materials and takes different inputs. The first design is a retort TLUD kiln like the one our team built on campus towards the end of the spring. It has a sealed inside compartment resting inside an outer metal drum, both of which are filled with feedstock. A chimney rests on top, pulling air upwards through the kiln. The sealed compartment is heated by the surrounding feedstock combustion and the inner feedstock is pyrolized. The second design, inspired by a kiln built earlier this spring at Dartmouth and by Takachar models, consists of an outer metal drum that, like the retort kiln, features air holes in its bottom for the entry of natural draft. It has an adapter piece that fits onto the bottom drum and is where combustion takes place. On top of that fits the chimney.
These past few days have been spent buying materials at the market to make these kilns. We found a metal shop with appropriate tools nearby and were able to make the two kilns in just 3 hours for the price of 18,000TSH (about 10 dollars). Today, we are taking data of kiln temperatures, measuring weights of each of our kiln inputs and outputs, and analyzing the quality of the char. We’ve purchased sawdust, collected corn cobs and asked to use the dried organic material of neighbors. We will be going to EMORG this afternoon to do educational test runs. Our ultimate hope is that our kiln designs work better, and that each group we are working with can learn about TLUD carbonization processes and potentially build their own models to turn their briquetting operations into lucrative enterprises.
Steffi at local metal shop building our kilns. Many were intrigued and came to watch the process
Steffi at local metal shop building our kilns. Many were intrigued and came to watch the process
I, Olivia, have been involved in all of these steps but as Communications Officer have mostly been documenting and reporting on everything that DHE has been doing. We’ve caught a number of great interviews with organization leaders on tape, and we are excited to share the history of DHE’s impact in the region and the story of briquetting successes and challenges encountered by each organization through a final documentary at the end of our trip. We also have helped EMORG to extend its online outreach, creating an EMORG volunteers Facebook group and a blog.
Though most of our days up have been filled to the brim with business matters – from engineering to impact analysis to communications efforts – it hasn’t all been business. The team has been having a truly great time here in Tanzania. Our guide, Phillibert, has been showing us around Arusha and all of its excitement. Our cook, Betha, has made so many tasty Tanzanian dishes though anything involving parachichi (avocado), has without a doubt been #1 on our list of culinary delights. This weekend some of us are going on safari, something that we would likely have never had the chance to do otherwise, while the rest are excited to be exploring some of the closer local attractions and national parks. We are so grateful for this opportunity, and will be back soon with more updates!