Reflecting on a fabulous summer

The team has spent these last few days facilitating final capacity building sessions and wishing the groups the best before completing our work this summer in Arusha. While we are nostalgic about leaving a place we have grown so fond of and many people who have welcomed us so warmly, we look back on an incredible experience and are satisfied with our work. We made significant progress in capacity building, technical development, and impact analysis and are encouraged by the groups’ interest in continuing their relationship with DHE. We look forward to continuing our relationships with the groups and are highly encouraged by the briquette entreprenuer’s enthusiasm and dedication.

This final week has been a push to complete our final meetings, briquette production and evaluation, and guide/report writing. On Monday, the team headed out to Kisongo to conduct a kiln burn demonstration with EMORG. After doing some minor repairs to the kiln, we walked through step-by-step how to operate the kiln to produce charcoal. The staff at EMORG and the four Kisongo community members at the meeting were very engaged and enthusiastic, especially when the kiln began to the burn so well. After about 10 minutes the emissions from the kiln turned clear, the kiln became very hot after about twenty minutes, and we noticed minimal gas-leakage from the kiln. We are keeping our fingers crossed for a high charcoal yield! As an interesting side-note, one of the reasons why EMORG was interested in having a kiln is to gather the community and involve them at EMORG, which moved to Kisongo this past March. And sure enough, as the meeting progressed more and more people started to join training; by the end of the meeting the group of six people had grown to about thirteen!

On Tuesday, the team visited Vision for Youth’s worksite to demonstrate the use of their metal kiln, compound lever press, and ratchet press. Like the meeting at EMORG, Vision for Youth was enthusiastic about briquetting, and we enjoyed this final meeting with the group. After enjoying a wonderful lunch with Vision for Youth, we wished the group our best and headed back to conduct briquette evaluation back in Leganga.

And speaking of briquette evaluation, we have been conducting thorough evaluation on various briquette recipes. Briquette recipes can differ in the types of binder and filler, and we are interested in determining what recipes produce the superior briquette (essentially one that burns hot, long, and cleanly). There are three tests that we are conducting on the briquettes: the standard water boil test quantifies the energy density and rate of combustion, the drop test determines the durability of the briquette, and the charcoal comparison test helps us understand how well the briquettes work in the cooking setting.

The team also presented at Vision for Youth’s Youth day camp this past Saturday. This three day camp for youth (about ages 13-22) aimed to inspire youth and educate them about opportunities for the future. We spoke for about twenty minutes during the entrepreneurship segment of the program, and discussed briquetting, how it can be used in an entrepreneurship, and what lessons Briquetting can teach for other entrepreneurships. The one-hundred youths at the presentation appeared to be very interested in the opportunities with Briquetting and it was an honor to share our thoughts and knowledge at this event.

We also said our goodbyes to Sossy and delivered a load of about 360 briquettes to him for the Upendo group to test. Sossy and the group are very enthusiastic about continuing their work with charcoal briquettes, and welcomed DHE winter ’14 travel team to continue capacity building.

I am excited to announce the completion of the five Bioenergy Guides and the three 13X trip reports! In many ways, the guides are a culmination of years of DHE work and the 13X trip reports detail the team’s progress this summer. We produced about 160 pages in total, and it is amazing to look through the documents and think about the progress DHE has made on so many fronts.

As one of the last blogs for this summer, I want to share the team’s gratitude for our ability to work here in Tanzania. We are truly honored to be furthering the mission of Dartmouth Humanitarian Engineering and to be working with so many people who deeply appreciate our help. We wanted to extend our sincerest thank you to the numerous people who have made this trip possible: fellow DHEers, Dartmouth faculty and staff, and family members of the travel teams. And we’d like to specifically thank Jessica Friedman, Holly Wilkinson, Professor Sullivan, Dean Helble, and Professor Laser.  And finally, thank you for reading our blogs, we whole-heartedly appreciate your interest.

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!



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!


Pyrolyzer Team Tests First Pyrolysis Kiln

Yesterday afternoon, the Pyrolyzer team tested the first version of the pyrolysis kiln. We filled the kiln with layers of shredded paper, heavy grained sawdust, small blocks of wood, and crumpled pieces of thick paper, and we used tall pieces of cardboard to provide structural support and airflow. After about 20 minutes of pyrolyzing, we ended the pyrolysis by dumping snow into the kiln and we observed some charcoal but also many un-pyrolyzed materials. The cold temperatures and wind likely had a negative impact on the performance of the kiln, but we hope to improve the effectiveness of the kiln with new designs in the near future!

Ideas for design improvement and further testing

  • Design a simple method to warm secondary air and to protect secondary air holes from wind
  • Experiment using different types of fuel, such as hay, in the kiln
  • Consider new options for secondary-air hole location
  • Measure the temperature in the chimney and metal drum during a burn; use chimney temperatures to identify if combustion is possibly occurring in the chimney