Chance Encounters

On Monday we made our fourth visit to Nkoarisombu to check on their progress after the briquetting training. We went primarily to answer questions or to fix any problems that arose during the two weeks after the training. The VICOBA members did not have any issues thus far and have been working on their own compost piles at home. We also asked them about charcoal sellers in the area, as we would like to look into making briquettes using charcoal dust. The group does not have ready access to charcoal and they primarily use wood, so we will continue emphasizing biomass composting. We will meet with them again next week to take a look at their compost piles and give them feedback.

A few weeks ago, we were getting out of a dala dala and met a pastor named Sossy who worked in a town called Moivaro, close to Arusha. He showed interest in our work and said that he would like for us to visit his home before we left Tanzania. After our visit to Nkoarisombu on Monday, we headed over to Moivaro to visit Sossy and see his workplace. Sossy works at Moivaro Tumaini (“Hope”) School, a non-governmental school dedicated to providing a good education to children from impoverished families. Sossy described his frustration with government schools, many of which have one teacher for 300 students. Sossy wants to lower this student to teacher ratio in his school, aiming to have 5-6 teachers educate around 150 students. Currently, his school has 2 teachers with salaries larger than what Sossy can pay them. Most of the children’s parents cannot pay more than $1 for their child’s education, so the school is struggling to obtain funding to complete construction.  Sossy relies on volunteer groups and donations to continue construction of the school.

The school's two classrooms

Nik and Sossy in front of the multipurpose building

As his wife sat us down for coffee, Sossy explained the issues with cooking meals for the children. Charcoal is readily available to the area, but it costs around 4,000-5,000 TSH every 2-3 days. This fuel cost is very high, but Sossy and his wife have not been able to find cheaper options cleaner than wood. We talked to them about our briquetting and stoves projects, and Sossy  and his wife were very interested in both technologies. They asked us to teach them and the surrounding community about briquetting, so they might be able to save money and possibly create revenue for the school. We eventually decided that if we provided  a training program, Sossy would gather interested members from the community to learn about briquetting  and create their own program. We plan on having the training next week and will adopt a program similar to what we taught Nkoarisombu.

Inside a classroom

In front of the gate to the school

Our briquetting project goal for the upcoming week is to create a poster highlighting the most important aspects of briquetting, which we will use in training programs and plan on giving to EARD-CI so they may continue briquetting training programs after DHE has left Tanzania. We look forward to teaching more communities about briquetting, so they may cut down on fuel costs and even generate a source of income.

Coffee Industry Visit

  For two days last week, we explored the various levels of the coffee industry in Arusha and Moshi. We hoped to obtain some coffee husk for stove testing and more importantly, better understand how coffee is processed. We began our journey on Thursday at a coffee plantation before continuing on to a wet mill and then a dry mill in Arusha. On Friday, we traveled to Moshi to learn more about coffee on the industry level by visiting with the Director of Marketing and Promotions in the Tanzanian Coffee Board as well as visiting two more curing and processing facilities. By traversing nearly every level of the coffee industry we were able to gather several important observations related to coffee husk and our stove.

First, we clarified our understanding of the path coffee takes in processing. After the bean is handpicked from coffee plants at the plantation, it is immediately sent to wet mills. This is where the outer fleshy portion of the coffee "nut" is removed. This fleshy pulp is returned to the plantation to be used as mulch and fertilizer while the rest of the bean is sent on to the dry mill. It is here at the dry mill that the coffee bean is finally separated from its husk. The bean can then be roasted and sold to consumers as the wonderful caffinated substance we all know as coffee. From understanding the processing path of coffee, we noted two related conclusions. One conclusion is that the coffee plantations usually don't have access to the coffee husk that would be used as fuel for the stove so plantation workers may not be an optimal user group to target. Plantations simply harvest and send the whole "nut" to wet mills. The husk is only produced and kept inside the dry mills. This leads to the second conclusion, that the coffee husk is essentially trapped inside those dry mills. When we visited Arusha Coffee Mills, we had to get clearance from security and be let in through a large  steel gate before being able to see the coffee husk. Without some dissemination scheme, it seems difficult for the average consumer to have access to coffee husk.

Second, it seems as though there is some interest in the coffee industry in promoting the use of coffee husk and creating distribution channels for it. With the difficulty of accessing coffee husk, this interest is very important. In speaking with the owners of Arusha Coffee Mills and managers of the Tanzania Coffee Curing Company, we found that coffee husk is really a seasonal fuel as it is only produced when coffee is being milled. However, when it is available, it lies in huge piles within the coffee mills. This coffee husk either decomposes naturally or is sold to nearby factories to be burnt in boilers.Though the coffee husk would ideally be free for stove users, its cost is still remarkably low. Both mills sell the husk at 15 TSH per kilogram and 14,000 TSH per metric ton. What was most apparent was the desire for mill management to utilize coffee husk better. One possibility is distributing the stove to the mill workers so the coffee husk can be used inside the mills to cook their meals. Another possibility is setting up networks to buy husk by the ton and sell it to consumers. Though coffee husk may be difficult to obtain for the typical stove user, the option of setting up husk distribution networks to offer a cheap fuel and utilize an agricultural waste should be explored in the future.

Third, agricultural wastes in Tanzania are already being utilized well. In between visiting the wet mill and dry mill, we also visited a branch of the Tanzanian Bean Research Program near the wet mill. Inside, we met with a researcher and described our project, hoping to see his perspective on our stove and if he thought there were any other loose biomasses that our stove could utilize. He told us that few agricultural by-products are wasted now. Farmers have found clever ways to use by-products in their operations as fertilizers or animal feed. He did note some agricultural by-products that are not being used include bean stalks and sunflower heads. While we do not foresee these burning well in our current stove design, we wondered about the possibility of using a loose biomass grinder to convert these biomasses into a granulated form similar to husk or sawdust. Combining what we learned at the research facility and coffee mills, it was clear that loose biomasses are not always available as free or nearly free fuel. Rather, it seems that using biomasses as fuel exists in an equilibrium with its other agricultural uses. For our stove and briquetting projects, this balance must be kept in mind.

        The two days we spent visiting the coffee industry taught us a lot about the phases of coffee production and important details about fuel availability and the willingness of various actors in the coffee industry to market coffee husk. We hope that the knowledge we gained can play a significant role in informing our decisions, especially as we move into stove distribution. We will surely visit these people again and thank them so much for teaching us so much!

Stove Development

The testing and development of the loose biomass stove from this past two weeks have yielded many important and interesting results. We had many moments of utter frustration when facing the problem of power output, but after some small, crucial changes, we are tremendously excited about our current product.

As mentioned in the previous development blog post, the current design is based largely on the design of the Kisangani Stove Group (KSG) in Njombe, Tanzania.  Testing showed that the design produces a long, steady burn that did not require tending for at least three hours. However, the stove lacked the power needed to boil water in a reasonable amount of time. Following the Aprovecho Water Boil Test (WBT) protocol and using five liters of water, we were only able to heat the water to 90 degrees Celsius, peaking at the two hour mark of the burn. Additionally, the first thirty minutes of every burn were always extremely dirty and did not produce a lot of heat. 

A new lid design seemed to solve some of these issues. Instead of the assorted concentric concentric cylinders and rings of metal rod in the KSG inspired lid, the new lid is simply a disk with an opening and three triangles of sheet metal to support the pot. Despite its simplicity, our new lid produced positive results.

With this new lid, the burn was clean within five minutes and the stove was able to boil the Aprovecho prescribed five liters of water (The local boiling point in Arusha is 95.7 degrees Celsius).  It seemed as though the innermost cylinder on the KSG lid was actually restricting airflow in the first thirty minutes of the test burns, thus producing inefficient combustion and visible smoke. With just a simple opening, the new lid design allowed more airflow for cleaner combustion. Furthmore, the smaller pot stand on the new lid lowered the pot, allowing more heat to be transfered to the pot.

Nevertheless, the new lid still did not solve a crucial problem: boil time. Once again using the Aprovecho standard of five liters, the stove still  required two hours (126 minutes) to reach a rolling boil. After conducting the WBT and performing some rough calculations, we found that our stove had less than 1/10th the firepower of other improved cook stoves currently being sold. Even without these calculations, it was clear that power output was a huge problem. Mamas using three-stone fires only a short walk away were able to boil our five litres of water in just twenty-five minutes.

Thinking that updraft and the height between the heat at the bottom of the stove and the pot were part of the power problem, we built a version 70% as tall as our original prototype. We hoped that the shorter chimney would provide less resistance to the primary air for hotter combustion and the smaller design might become a cheaper alternative to our earlier design. Unfortunately, the smaller stove was extremely difficult to light and even when lit, could not sustain a burn.

At this point, we seemed to be at an impasse. Though we could achieve a clean burn for over three hours using a cheap alternative to firewood on the KSG inspired design, we still could not complete the Aprovecho Water Boil Test in a reasonable amount of time. This suggested that our design lacked the power that would be needed to cook foods as well or as fast as traditional, less clean stoves. Knowing that our stove would ultimately be judged by the cooks of Tanzania, we were unsure of how to progress with the design.

However, we stumbled upon a solution to the power output problem the next day in the AISE workshop. Instead of just one pipe, we packed our stove with two pipes for the chimney simply out of curiousity. The difference was astounding. Just by changing the chimney from a single cylinder to a double cylinder ‘8’ shape, we were able to boil water in 18 minutes. Though the start was slightly dirtier, the burn became clean after only a few minutes. Furthermore, this configuration produces more complete combustion- much more of the fuel was burned to white ash when peering into the fuel canister after the burn. Subsequent tests have been able to duplicate this remarkable result and sustain burns between ninety mintues and one-hundred minutes. Eureka!

Since the stove group had been planning to visit EARD-CI and the stove demonstrated such strong results, we all brought the stove to EARD-CI headquarters yesterday. As we explained to them the progress of the stove and our plans to conduct a test using rice husk, Edith suggested we try to cook a meal on our stove. It was such a treat to enjoy a delicious lunch of fresh corn with avocado cooked on our own stove! Despite all of this good news and good food, it does bear note that the stove was unable to burn rice husk in the later burn.

These past few weeks of development have yielded truly exciting results. With enough power achieve a rolling boil in a time comprable to similar improved cook stoves, the efficiency to sustain the burn for over ninety minutes, and the consistency of each burn, we feel that we are close to having a mature product. However, we still have a lot of work to do. Next steps include:
1) Completing a full WBT as well as using the IAP meter to accurately quantify power and  air pollution from the stove.
2) Resume testing with coffee-husk and even explore other loose biomasses so communities with different resources can still benefit from the stove.
3) Polishing the design. Namely, designing stronger handles, adding a gate to regulate primary air, and a more sophisticated pot stand
4) Investigating distributors and possible distribution channels

Friday Afternoon Meetings

On Friday afternoon, following a very informative meeting with members of the Dochi VICOBA, we met with an environmental engineer named John Mshunju. He is the man who alerted Edith to the flourishing briquetting operations in Lushoto.  He is setting up his own private briquetting enterprise which will offer two products. One is a donut-shaped briquette of the type propagated by Legacy Foundation, made with one of the compound lever presses constructed by the carpenter of the Dochi group.  The other is a solid, cylindrical briquette that closely resembles traditional charcoal. These are made by first carbonizing the waste residues from shoe polish production. This fine material is then combined with a binder and compressed into the final state with a hand operated extruder. He is currently finalizing his business plan.

As the conversation turned to biogas, he offered to introduce us to Peter Jally of the New Rural Children Foundation (NRCF), the implementing partner of the Tanzanian Domestic Biogas Program (TDBP) for the Lushoto area.  Peter indicated that NRCF has built fixed-dome type digesters of up to thirteen cubic meters in size, mainly for farmers and livestock owners.  They build four, six, nine or thirteen cubic meter plants, with CAMARTEC, the organization coordinating the TDBP on a country-wide scale, taking over on any digester larger than that. The actual construction is done by masons specially trained at VETA Tanga (Vocational Educational Training Center in Tanga ), with their pay covered by the Tanzanian government and SNV. The recipient of the plant is responsible for providing the building materials including brick/stone, cement, and any plumbing necessary.   Peter noted that using the slurry exiting the digester as fertilizer has been increasingly promoted in the past year, due to its well-documented superior quality, offering higher levels of available nitrogen than even commercially available fertilizers.  We hope to visit with CAMARTEC next week to continue to learn about the TDBP (and connect with groups interested in the loose biomass stove).

After we finished up the meeting with Peter,  John showed us the offices of an NGO he co-founded, in part with a man named Hande Mwanjela. We met Hande earlier in the day at the briquetting event, as he originally introduced the technology in the area.  He has since done several briquetting trainings across the country (he is slated to do a training in the Kigoma region next month).  Interestingly, he cited fuel availability issues as a contributing factor to the Dochi group’s increased success relative to other parts of the country. Where firewood is still free in many places, expensive charcoal is the most prominent fuel source in the Lushoto area.  This situation parallels the Lulu VICOBA, where a seemingly large fraction of family income is spent on firewood.  Seeing the office gave us a chance to again thank Hande for the time he spent with us in the morning as well as finishing trading contact information with him.

Lushoto Briquetting Investigation

During our first week in Tanzania, Edith, the director of EARD-CI, told us of a briquetting project in Lushoto and recommended that we visit them. Emil Cashin, a member of the Summer 2011 DHE trip, echoed this recommendation and passed on contact info for people involved in the project.  On Wednesday, Amelia and I arrived in Lushoto and met with the a VICOBA located in Dochi, a thirty minute walk from the town center.  The group’s highly organized briquetting operations had clearly fostered immense success.  Most indicative of this success was the VICOBA building in which we sat, purchased with the proceeds of their briquetting business.

We quickly learned through the aid of our translator, a local teacher named John, that the group had been producing briquettes since 2007. The group was trained by the masters of briquetting themselves, the Stanley’s of the Legacy Foundation. We were also told that the Legacy Foundation supplied them with two grinding machines and a metal ratchet press. In addition to this press, they had a wooden compound lever press constructed by a carpenter within the group.

At the Dochi VICOBA, briquette making occurs when there is no rain, meaning most of the heavy briquette production happens in the dry season. The group quoted the long drying time as the reason production was abandoned during wet conditions.  VICOBA members work in rotating groups of five for five days a week when weather permits. They make 400 per day, with a portion of these distributed within the group for personal use and sold to generate individual income. The remainder are sold by an agent in Dar es Salaam.

This group’s effective time management and organization contributed heavily to their success. As we continue to help the Lulu VICOBA develop their project, we need to highlight the need for a clear leader of briquetting operations, as well as establish a regime for keeping track of material processing and recording production. We will also locate charcoal sellers in the Nkoarisambu area, as this may offer a valuable source of raw materials and an profitable venue for Lulu’s entrepreneurs to sell their briquettes. 

Nkoarisombu Briquetting Training

Nik and I visited Nkoarisombu (Lulu VICOBA) on Monday morning to hold our intensive briquette training session for interested VICOBA members. Naomi from EARD-CI came along with us as a translator, and was very helpful at translating for the four hours of training.

We began with discussing how the group plans on gathering materials for their briquetting program. Each member will be bringing materials from their home to their meeting location. After establishing the group's source for raw materials, Nik and I reiterated the general briquetting process. We then went into details about material processing, including material grinding, decomposition, and mixing. We took the group outside for demonstrations as we explained each process. We brought materials that had been composting for the past 3 weeks to show the group how to compost and how to tell when the biomass is ready. With help from the Legacy Foundation's instruction manuals, we taught Lulu everything we knew about briquetting, emphasizing the group's role in knowing how to compost different materials and develop new mixtures at different seasons. We wanted to ensure that once the DHE Summer group left, the VICOBA would be able to adapt once new materials such as coffee husk came in harvesting season. Nik and I explained to them the "ooze", "spring back", and "shake" tests, and had the group make their own biomass mixture with sawdust, paper, and rice husk Nik and I prepared the week before.

 After going over material processing, Lulu members were eager to press briquettes out of the mixture they had just prepared. We went over briquette production, explaining pressing and drying of the briquettes and press maintenance. The group continued to make briquettes until they were out of mixture, and then brought out the sawdust and banana leaf mixture they had prepared earlier. This mixture was not suitable for making briquettes (and now they knew exactly why), so they added some paper as a quick fix so that they would be able to make more briquettes once Nik, Naomi and I left. We thanked the Lulu members for taking the time to attend our training. Nik and I will be returning in 2 weeks to give them feedback on the compost piles they  are going to create. We will be traveling to Lushoto this Wednesday and we hope to use the information we learn about briquetting on our trip to improve Nkoarisombu's briquette program and DHE's briquetting project overall. 

Week 2 Stove Development

Last week, the stove project began a new prototype mostly based on a design by the Kisangani Smith Group (KSG) in Njombe, Tanzania. After much angle-grinding, hammering, and metal turning, we finished the stove on Monday, July 2nd. Bernard was enormously helpful as a consultant and a master welder throughout the process.
The reasoning behind building a prototype similar KSG’s design is that their stove is similar to our stove in many respects, but has interesting technical differences and is a vastly successful stove thus far.  The hope was that by building a prototype and comparing the burn characteristics of the stoves, we would gain insights about how their design choices affected the end success of their product.
Principally, there are two design characteristics we are interested in. First, the primary air entrance is on the side of the fuel canister rather than the bottom in previous DHE designs. A pipe enters through a side-entrance to the central chimney. We are interested in this pipe’s effect on primary air delivery to the fuel bed. Second, the new model includes a separable heat-transferring lid instead of a basic opening at the top of the stove. We would like to explore the effectiveness of a heat-transferring system versus an open chimney. Furthermore, the small openings in this different type of lid would seem to cause very different airflow from that of our stove. We would like to see whether this causes a more efficient mixing of secondary air with wood gas and possibility eliminate the outer shell of our stove.
Yesterday July 3rd, we conducted our first burn with the new prototype. To prepare the stove, we packed fuel just as we had done in our old model- sawdust around a 2 inch PVC pipe. Packing entailed pressing down on a specially dimensioned disk of metal for evenly distributed pressure.
The design calls for lighting the stove by dropping a match or heat source down the chimney of the fuel bed before placing the lid on the stove. Due to inexperience with this new design, it took several tries to light the stove. We eventually were forced to pour some kerosene down the central chimney of the stove to aid the burning husk we placed through the side air inlet. Until introducing kerosene, the sawdust on the bottom of the pot simply wouldn’t catch, despite the burning corn husks we put in the central chamber. Eventually, we hope to avoid utilizing kerosene as the cost is significant and increasing for Tanzanians.
After we got the fuel to begin combusting and the burn steadied we placed the lid on the stove. A serrated ring of metal on the bottom of the lid (which we termed the “bite” flange) dug into fuel bed and formed some degree of an air tight seal. After placing the lid on the stove, we used mud to seal the slight gaps between the lid and the stove. Ideally, these gaps should not exist as the flange on the lid should fit snuggly with the stove.
For the first twenty minutes, the burn was somewhat dirty. We speculated this might be due to an ineffective bite phalange- much of the fuel had become disorganized at the top from our unsuccessful attempts to light the stove. The flange may not have been properly trapping the wood gas and heat in the center of the stove. More investigation into this will be important in the coming days.
After twenty-five minutes or so, the burn became considerably cleaner. Our pot of water kept heating up, and within little time, wispy vapor began emanating from the surface. We waited with the stove, watching the vapor, for another twenty minutes. When the hot water didn’t reach a boil, at the fifty minute mark, we put a cover on the pot. Ten minutes later, the water began to boil.
Fuel continued to burn for at least another 30 minutes. A healthy flame could be observed at the bottom of the fuel bed from the primary air entrance as well as at the top of the sawdust pack. Presumably, this flame near the top was the combustion of fuel bed. After nearly two hours of watching the stove, we left to get lunch and acquire some cost figures from the hardware store. Unfortunately between leaving and returning, the burn had finished and uncombusted wood gas flowed from the lid.
Removing the lid, we found an interesting sight. All of the fuel opposite to the primary air tube had combusted into white ash. We could see much exposed steel of the inside of the fuel canister. On the other side above the primary air tube, we found much more char and some uncombusted sawdust. It looked somewhat similar to the fuel after the unsuccessful burns in our old design. This side exhibited some degree of hollowing as the uncombusted char was thicker near the top of the fuel bed. Ostensibly, a somewhat circular flow of air developed as it entered the air inlet, collided with one side of the fuel bed and “bounced” back to the other side. Because the air was not directly thrown at this side of the fuel bed there was not the complete combustion of the other half.
Overall, it was a very exciting burn. Despite the difficulty in the beginning, we were able to produce a steady burn lasting between two and three hours using just sawdust and a bit of kerosene. We hope to continue to improve our ability to light this stove, to complete a burn (without grabbing lunch in the middle…), and begin conducting the various Aprovecho testing protocols.

The next steps for us are to modify this design for increased efficiency and user friendliness. We want to produce a product that is easy to use and that is a wholly DHE design. These steps include:

1) Investigating why the first twenty minutes were a dirty burn as well as measuring the emissions from a complete burn
2) Finding ways to start the burn without kerosene. Kerosene is an already expensive commodity of rising cost.
3)  Increasing heat transfer into the pot. We would like to achieve water boil without a lid as some Tanzanian foods require this
4) Looking for ways to burn the fuel that did not combust fully
5) Determining the cost of producing this new stove design and reducing unnecessary components  in construction and in the stove itself.
6) Acquiring coffee husk and various other loose biomass source to perform burns with.



- Aneesh and Kevin