Trials of Communication

Communication with Tanzanians who speak limited English is a tricky balance between talking down to people and expecting too much of an understanding of English. Heat measurement devices, for instance, are difficult to explain. We were preparing to light our kiln on Friday while a VICOBA meeting took place in the other corner of the yard. Our activity around the kiln proved too much of a fascinating distracting for the meeting attendees and we were soon surrounded by a small and curious crowed. One man began asking questions about our work; what are you doing? Is that going to light? What is this for? We tried to answer as many questions as we could, assisted by Tim, one of the Dutch students who has taken an interested in our briquetting work and knows all about the work we do.

“What’s that?” asked the man, pointing to our heat sensors that we were inserting into the wood shavings.

“That’s for measuring temperature,” explains Tim. A blank look. “To see how hot. For heat. Like a thermometer? It tells you how much heat there is. Like, uh, how warm?” Gesturing with his hands he trails off.

“Oh, thermocouple. Ok,” the man says nodding. Way to whip out that terminology. I swear Tim’s jaw hit the ground. He looked quite taken aback. “Yep. That would be it. That would be the technical term.” Turning to me, “Yeah, didn’t see that one coming. Thermocouple.” Priceless.

At dinner that night, Tim told the story to the group to much laughter. “But Tim,” says Tucker. “The thermocouples say thermocouple right on them, right on the side in bold letters.” Well then. Does this make the interaction better? I don’t know but I’m still giggling.

Besides our attempts to communicate in English and Swahili which have been to varying degrees of success, we have had a very productive week. Last Saturday was the official opening of EMORG’s library (the library which we helped to paint a few weeks ago) which we arrived for promptly on Tanzanian time, by American standards, an hour and a half late. The building was shining and bright in the sun and, I do say so myself, looked beautiful. Didas and others gave speeches about the library and the community being built around it which was followed by a fabulous auction run by our very own James. James talked up the shirts and fabric quite well. I see a fulfilling time as an auctioneer in James’ future.

Sunday began a full working week for us. We now have the tanuru up and reliably running (horray!). We do a burn about every day now and produce about a 20% yield of charcoal. Basically, if we put in 17 kg of sawdust or wood shavings, we can press upwards of 300 briquettes. Slowly but surely we are covering the EARD-CI yard in drying briquettes. At the end of last week we put our stash of dry briquettes to good use by giving a few batches to Vision 4 Youth and to the Upendo group in Moivaro. Tucker and I brought the briquette batch to V4Y on Thursday for them to test themselves so they could begin thinking about pricing. But perhaps more exciting, we also gave V4Y a grant to begin their briquetting business. We just funded a start-up. That’s wicked cool. The week after next we’ll return to V4Y to help them build their very own kiln so they can start fuel production. Both we and they are very excited to finally start the physical work.

On Friday Tucker and Emily dropped of hundreds of briquettes with Sossy to pass on to the Upendo group so that they might test the briquettes and decide whether they’d like to try making their own again. The briquettes were warmly received (by everyone except the unfortunate cat which happened to be in the wrong place at the wrong time and was stepped on, quite by accident, by Tucker. Ouch.) and the women are excited to put them to the test.

We also have one more group which we’re setting up with a briquetting operation: EMORG. During his speech at the library opening ceremony, Didas mentioned that he hoped the Americans had not forgotten that they promised to build a kiln. Well great! We decided to give another grant to EMORG to fund the supplies necessary to construct a kiln and begin a briquetting operation and the week after next we’ll return for a full day of briquetting lesson and kiln building. So many kilns to build, so little time.

After a full working week, we took some time this weekend to relax try the touristy side of Arusha. Anna and Liliana came up from Dar for the weekend and James’ father and brother flew in from New York for the week. It’s a full house! Friday, we defied all American stereotypes and won a trivia game at a fundraising night held at Mango Tree to raise funds for EMORG. Ok, so we Americans won the first two rounds and then we were joined by our 8 European friends for the last few rounds. And maybe we were 16 people on the team when the other teams only had 4 or 6 members. But hey, it was fun.

One of the weekend’s highlights was a trip to the snake park. Thanks to Emily’s research we arrived on Sunday afternoon, perfectly in time for the weekly feeding. We watched, fascinated, as live chicks were tossed unceremoniously into the snake cages and the snakes sedately slithered their way over to the chirping birds, bit them, and, well, ate them. As we learned, eating is quite the process for snakes and took some snakes twenty minutes to consume a single chick. The main attraction was the python’s lunch: live rabbit. We have plenty of pictures if anyone is really curious.

And now we are ready for our mid trip break: a safari! We head out tomorrow morning. Many pictures to follow. Lala fofofo! Sleep well!

Kiln 2.0 and Improved Briquettes

I’m happy to report that all is well here in Leganga! We have made solid progress on the project and have also been continuing to enjoy our home here in Leganga. Recent discoveries include a great local restaurant, an interesting road that wanders through town, and some unfamiliar— but delicious— vegetables at the local market. The weather has been beautiful, with daily sightings of Mt. Meru and occasional views of the distant Mt. Kilimanjaro.

Mt. Meru keeping an eye on Leganga and Arusha town.


      We’ve reached the midway point in the summer, and we look back on significant progress and enthusiastically look forward to more technical development, capacity building, and impact analysis in the coming month. Last Friday, we visited Vision for Youth’s proposed site for a briquette operation and discussed charcoal kilns, briquette presses, and possible worksite layouts. The work site has access to water, has adequate space, and is located close to their proposed market; all of these make their worksite seem very promising. In addition to the encouraging worksite, it was also fabulous to hear several of Vision for Youth’s creative ideas and to share our enthusiasm about briquetting.

After our weekend in Leganga, the team showed Bernard our charcoal kiln and briquette press technology. As a bit of background, Bernard is an inventor who worked with last summer’s Bioenergy travel team, and although we are no longer working on last summer’s stove design, Bernard had some incredible advice for us. He demonstrated an improved technique for mixing charcoal and binder: he showed how damp charcoal— as opposed to more water saturated charcoal— could be effectively mixed with very little cassava binder. With less cassava binder, the briquettes should be less smoky and will likely more efficient in combustion. Pressing damp charcoal also allows for a simplified briquette press; water holes or slits in the sides of the briquette mold are unnecessary, which will improve the durability of a mold. Using less cassava flour will reduce the expense of producing briquettes, especially in rural regions where cassava flour is less available. Bernard had some thoughts about our kiln design, which has led us to consider an underground counterpart to our current kiln. Underground pit kilns are fairly common, but a pit kiln could be modified using metal roofing— an easily accessible material— to create primary air holes and a chimney with secondary air, similar to our above ground kiln.

Charcoal Kiln 2.0: new mortar and higher walls.


    The team recently improved the kiln to increase charcoal yield. After identifying a large amount of ash in the combustion chamber after several kiln burns, we recognized that air was likely leaking into the kiln and allowing the biomass to completely combust. As a bit of background, the kiln aims to “carbonize” the biomass into charcoal in the absence of oxygen and to prevent complete combustion into ash. A likely culprit of the air leakage was the presence of cracks in the kiln’s mud mortar. So we re-mortared the outside seams and mortared the entire inside surface using an improved mortar: a mud and lime mixture. The lime successfully reduced mortar cracking, and appears to have created a tighter seal. The team also added two additional layers of brick to the walls of the kiln, which will increase the capacity of the kiln. Right now, the mortar is still drying, but we look forward to testing the kiln tomorrow!

And on Wednesday, we presented a batch of briquettes to EARD-CI for a cook test. We were able to successfully cook a pot of rice, but unfortunately the briquettes produced an excessive amount of smoke and did not burn as efficiently as anticipated. But we did not use the improved briquettes with less cassava. As I mentioned earlier, less cassava will reduce the amount of smoke and likely improve cooking efficiency. So we look forward to testing our improved briquettes once they have finished drying!

That’s all for now; we’ll update you again soon!



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!

To Build a Tanuru

Building the kiln

Time to get our hands (and some pants) dirty. During our meeting with Naomie on Tuesday, she pointed out a space in the EARD-CI yard where we could construct our tanuru, our kiln for making charcoal. With EARD-CI generously providing the space for our kiln, we had only to gather the materials and our engineering minds to build it.

As mentioned in the previous post, the idea behind the kiln is to produce charcoal out of biomass which can then be press into briquettes. By first pyrolyzing biomass (heating up the biomass in the absence of oxygen) and turning it into charcoal, the remaining carbon structure of the material will burn cleaner when burned in a cook stove. But what about the detrimental effect of the emissions released from the kiln during pyrolysis? Does it matter that the biomass is being pre-burned and converted into charcoal before being used as fuel in a cook stove? There are two main reasons for making charcoal in this manner for the briquettes (besides the fact that consumers prefer charcoal briquettes). First, we have designed our kiln to allow the syngas (gasses including hydrogen, oxides, and others) produced by the burning biomass to undergo complete combustion before leaving the kiln. In other words, when making the charcoal we burn away the harmful emissions. If the biomass were burned straight in a cookstove, it could release that carbon monoxide and other gasses in the syngas into the space where the cook is breathing. Secondly, biomass in the form of charcoal is much more energy dense than un-carbonized biomass making it a more appealing form for cooks who want to spend less time tending their fire.

The science is great in theory but our goal is to make it great in practice. Wednesday was the day to begin hunting and gathering our materials to construct our tanuru and as luck would have it (and good planning by us) Wednesday was also market day in Tengeru. We wandered through entire streets over crowded with tables and blankets filled with shoes, rows of mboga (vegetables) and dried beans, and interspersed throughout everything were tables overflowing with various buckets and cooking supplies. While Emily and I ventured to purchase vegetables using our limited knowledge of Kiswahili to varying degrees of success, Tucker and James searched for supplies for the technical side of cooking. Back at the house, the girls got to work cooking our first home cooked dinner of the summer including all manner of fresh veggies. As the food was just about done, James and Tucker returned from their visit to a brick maker with Naomie where they picked out a load of bricks to be purchased the following day.

Back at EARD-CI on Thursday, Naomie directed us to a hardware shop just down the road which supplied us with all the fun toys with which to build our kiln: tiles, a shovel, and one of those triangular spreader tools (now that was a tricky tool to explain through the language barrier). Then, with a delivery of 300 bricks, we were itching to get building.

Thursday afternoon was beautifully sunny and perfect for mixing mortar (also called mud) with our fingers, smearing that mud over bricks and our clothing, and building our kiln up, up, up. Five hours, many pictures, and several wheel barrows of dirt later we had a kiln. We’re very proud of it.

The kiln is designed with three main areas: the kiln body, the chimney, and the combustion tunnel. Biomass will be pyrolized in the kiln body and any gasses which are released during pyrolysis will be drawn into the combustion tunnel and up through the chimney. Secondary air from the front of the combustion tunnel will mix with the released syngas and ideally undergo complete combustion (or as close to as possible) in the chimney. Basically fire and biomass will go in and charcoal (hopefully) will come out. Or alternatively, as Naomie pointed out, fire and dough could go in and homemade bread could come out. Another very tempting option we should look into.

Again, this is the scientific theory, and we have these next few weeks to attempt to make it reality. With a newly constructed kiln, several bags of biomass composting in the yard, a hammer press in commission, reports being written, new friends to play football and Frisbee with, and an entire house to call our home for the next two months, I will say that this has been a productive and satisfying first week in Arusha. Baadaye! Until later!

Our New Home in Arusha

A monkey!
A monkey!

Our love for the wonderful city of Dar es Salaam has been rivaled by the beautiful views, fresh air, and rural landscape of the Arusha region. We are staying about a twenty minute drive from the Arusha center in the town Leganga, and have been enjoying our new home since our arrival on Saturday. After playing in a soccer game with town locals, eating our favorite lunch at a local restaurant (Chips Mayai, aka French Fry omelets) and seeing some wild monkeys, we feel that Leganga has offered us a warm welcome. And our initial concerns of the small size of Leganga were eased when we learned of the slightly larger town further down the road: Usa. After a ten minute walk along a road bustling with Dala-dalas, motorcycles, and huge trucks, we ventured through Usa’s streets that are lined with shops and street venders selling everything from yard rakes to cooking oil. We were easily able to bargain for and purchase the materials needed to begin our test briquetting operation. Some of our exciting purchases included a small charcoal stove, a rake for collecting grass, and aluminum cooking pots.

Part of our workspace at EARD-CI.
Part of our workspace at EARD-CI.

This summer, the team will be continuing our partnership with the Enterprise and Rural Development Community Initiatives (EARD-CI). And as a bit of background, EARD-CI is an organization based out of Arusha that has establish small community banks (called VICOBAs) with the purpose of improving the financial stability and health of rural families, as well as improving environmental conservation. EARD-CI generously allows us to meet with the VICOBA groups about the briquetting techniques. On Monday, we had a great meeting with Edith Benzi, the director of EARD-CI. We enjoyed learning about EARD-CI’s work and we also confirmed our ability to use EARD-CI’s yard as a work space. Edith also gave us the contact information for a person in Arusha who has been working to produce charcoal briquettes. Considering that this person’s work is very similar to our initiative this summer, we are very excited to contact this person and learn more about what she has been working on. Edith also offered us an EARD-CI house to rent for the summer, and this house is conveniently located across the street from EARD-CI. Today we moved into our wonderful home and we are already enjoying the comfortable setting.

A charcoal cooking stove.
A charcoal cooking stove.

In addition to meeting with Edith, we also had an informative meeting on Tuesday with Naomie, the Loan Officer for EARD-CI. Naomie has been an awesome person to work with and is very willing to help us out. From Naomie, the team gained some valuable information: that people greatly prefer charcoal briquettes over non-charcoal briquettes. This information— along with our previous understanding that charcoal briquettes have a higher energy density and burn cleaner— has led us to prioritize developing a charcoal kiln that can be used to carbonize biomass. Naomie also requested that before meeting with the VICOBA groups, we demonstrate a successful briquette cooked meal; so our current plan is to spend the next two weeks creating and testing charcoal briquettes. And to hasten the briquette making process, we plan to use cassava flour— which has naturally sticky fibers and requires no decomposition period— as a briquette ingredient.

The team has also been refining our plan for reporting and has decided to compile a collection of guides and reports. The guides are meant to be resources for DHE’s future work, with the intent that they will be updated continuously by both on-campus Bioenergy groups and travel teams in the future. The guides will have corresponding reports for this Summer 13X trip.

We eagerly await these next several days, and look forward to checking in again with you soon!


Swahili classes and culture

[Written by Emily Li]

Habari za maisha? Greetings from the bioenergy travel team. We have been in Dar Es Salaam for the past week, and just got to Arusha this afternoon. During the week, we studied Swahili in the morning with two teachers Mama Saada and Godfrey Allen, set up by the Dickey Center. Swahili is a really interesting language to learn because it contains vocabularies from many different origins, Bantu, Arabic, English, etc. We learned the greetings, basic verbs, four different tenses, and pretty much enough to get by (we thought). Then on Wednesday, Mama Saada assigned us to talk to Tanzanians in Swahili and ask lots of questions. I talked with our favorite cab driver, Mbaraka, and he was very eager to teach me how to say everything. I asked him a pre-prescribed list of questions, but I soon realized I didn’t understand any of Mbaraka answers. In class on Thursday, we had a lot of fun learning about the market, pretending to buy and sell vegetables, and bargaining. Then on Friday, Mama Saada and Godfrey Allen took us to Kariakoo market by the dala-dala (minibus which is the preferred local method of transportation) so we could put our Swahili to the test. The ceiling of the dala-dala was so low that Tucker, our tallest group member and the only one not to get a seat, could not even stand straight. Kariakoo is the major market where the locals shop for foods, utensils, clothes, and everything else. The market area includes the main building, which is a gigantic structure with three levels, and extends to a dozen more blocks in the neighborhood. We practiced our Swahili bargaining with the shop owners. My favorite phrase is ghali sana which means “too expensive.” Rachel and I got some fabrics with printed patterns whereas James bargained for a multipurpose knife that does both peeling and cutting! We were sad that the Swahili classes ended, but I think we have a good foundation to continue our learning.

Now you wonder what have we been working on for DHE? Well, we find learning opportunities and insights everywhere we go. The city of Dar Es Salaam always bustles with life day and night, especially in Kariakoo, the area where we stayed. We had fun observing the street food vendors using their charcoal stoves and definitely took notice of the huge bags of charcoal that are sold. In fact, right next to our hotel is a yard where bags of charcoal are stored.

On Thursday, we visited Dr Rajabu of the University of Dar Es Salaam. He is a professor of mechanical engineering who specifically work on rural bioenergy, and have been an amazing advisor for DHE bioenergy for years. The university feels very different from Dartmouth. The engineering school has its own fence and checkpoints surrounding it. We met Dr Rajabu in their machine shop during a power outage, so all the professors are just hanging around. As a demonstration, Dr Rajabu lit a small, gasifier cook-stove for us. The stove uses small, jatropha seeds pellets, of the same shape and size as broken bits of number 2 pencils, as fuel. What is cool about this stove is that flame comes out in a vortex and rises up through the holes along the wall.Within ten minutes, it produces a flame high enough to start cooking. If you take off the top part of the stove, you have a simmering charcoal stove. Next, Dr Rajabu showed us the place where engineering students develop prototypes for small business. One such prototype was an industrial sized gasifier stove unit that could be used for schools and hospitals. We also saw briquettes made by an organization called ARTI in Dar Es Salaam. The organization uses the same principle as DHE to produce its briquettes—first pyrolyzing biomass into charcoal and then using that product to produce charcoal briquettes. We then turned to dinner with Dr. Rajabu where we talked about both bioenergy and non-bioenergy related topics. We talked briefly about impact analysis and how to conduct surveys as well as heard his insights on the culture and how people tend to behave in front of interviewers. Sometimes, people say things they think the interviewers want to hear because they are used to getting free stuff from the research and really want to impress. When we asked Dr Rajabu what is the best way to approach this, he says observation is very important but also added that, “I am only an engineer.” With the experience he had in the field, he was probably just being humble.

Our week in Dar Es Salaam had not been all work though. With four other Dartmouth students, we had time to explore the city. On Tuesday, we went to Coco Beach where the local people like to hang out. We definitely stood out a lot on the beach. Vendors keep coming up to us trying to sell their products. None of us ventured out to the ocean to swim, instead we spent some peaceful time lying on the beach. Friday afternoon, we took a “ferry” (actually just a little boat) out to Bongoyo Island, about thirty minutes from the Slipway. During the ride, we saw locals in canoes pulling in what we thought was a fishing net. The beach on Bongoyo Island is very different from Coco Beach; it was quite quiet and definitely touristy. We swam in the warm Indian Ocean, and later passed the afternoon napping under a huge straw umbrella. We finished our week in Dar with a beautiful sunset dinner at the Slipway and said goodbye to our Dartmouth friends. And now we’re off to our next adventure in Arusha!

The group