Scholarly article on topic 'Targeting Briquetting as an Alternative Fuel Source in Tanzania'

Targeting Briquetting as an Alternative Fuel Source in Tanzania Academic research paper on "Agriculture, forestry, and fisheries"

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{Bioenergy / briquetting / biomass / Tanzania / Dartmouth / DHE}

Abstract of research paper on Agriculture, forestry, and fisheries, author of scientific article — Scott Gladstone, Victoria Tersigni, James Kennedy, Julie Ann Haldeman

Abstract Charcoal and firewood are the primary cooking fuels used in many developing countries, even though they both pose a number of environmental, social, and economic challenges. Aside from the ecological impacts of deforestation and resource destruction, indoor air pollution produced by cooking with solid fuels causes 2 million deaths each year [1]. The Bioenergy Project of Dartmouth Humanitarian Engineering (DHE) aims to develop clean cooking technologies that improve the health and environmental conditions of communities traditionally reliant upon wood as a fuel source through capacity building sessions.

Academic research paper on topic "Targeting Briquetting as an Alternative Fuel Source in Tanzania"

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ScienceDirect Procedía

Engineering

Procedía Engineering 78 (2014) 287 - 291 =

www.elsevier.com/locate/procedia

Humanitarian Technology: Science, Systems and Global Impact 2014, HumTech2014

Targeting briquetting as an alternative fuel source in Tanzania

Scott Gladstonea, Victoria Tersignia, James Kennedya, Julie Ann Haldemana*

aDartmouth Humanitarian Engineering, Dartmouth College, 800 Cummings Hall, Hanover, NH 03755, USA

Abstract

Charcoal and firewood are the primary cooking fuels used in many developing countries, even though they both pose a number of environmental, social, and economic challenges. Aside from the ecological impacts of deforestation and resource destruction, indoor air pollution produced by cooking with solid fuels causes 2 million deaths each year [1]. The Bioenergy Project of Dartmouth Humanitarian Engineering (DHE) aims to develop clean cooking technologies that improve the health and environmental conditions of communities traditionally reliant upon wood as a fuel source through capacity building sessions. © 2014 Elsevier Ltd. Thisisanopen access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/).

Selection and peer-review under responsibility of the Organizing Committee of HumTech2014 Keywords: Bioenergy; briquetting; biomass; Tanzania; Dartmouth; DHE

1. Introduction

The Bioenergy Project aims to develop clean cooking technologies that improve the health and environmental conditions of communities traditionally reliant upon wood as a fuel source. DHE has developed a number of clean cooking technologies to tackle such issues and started working in Tanzania in 2008. Our technologies include a clay rocket stove, which uses less firewood and produces less smoke than the traditional three-stone stove, a loose biomass stove, which uses agricultural waste such as coffee husks and sawdust as fuel sources to yield a clean burn, and briquetting, which involves processing low value plant materials into blocks that can be used in a traditional charcoal stove. DHE is currently focusing more heavily on the fuel briquetting and the mechanical versatility offered by a generalizable production process. There is also supporting research that many health and environmental benefits come with cleaner-burning cooking fuel [2]. This paper will show that DHE's work with briquetting in

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* Corresponding author. E-mail address: Julie.Ann.Haldeman.14@dartmouth.edu

1877-7058 © 2014 Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/).

Selection and peer-review under responsibility of the Organizing Committee of HumTech2014 doi:10.1016/j.proeng.2014.07.069

Tanzania has nurtured alternative fuel sources in Arusha and Kigoma, and outline processes of future data collection in-country.

1.1 History

DHE first started working in Tanzania in 2008. Since then, over 30 DHE members have traveled to Tanzania to assess, design and promote clean cooking technologies. Students work closely with Dr. Rajabu, a Professor of Engineering at the University of Dar es Salaam and leading expert in improved cookstove evaluation. From 2008 to 2011, we collaborated with the Jane Goodall Institute in a rocket stove training program; ultimately, this led to the construction of 10,000 rocket stoves in 26 villages around Kigoma, Tanzania. In 2012, DHE shifted its focus to Arusha, Tanzania and began a strategic initiative focused on alternative cooking fuels through its charcoal briquetting training program with Enterprise and Rural Development Community Initiatives (EARD-CI), Vision for Youth, Educational Model Organization (EMORG) and AISE, all of which are local NGOs.

First explored as a project in the summer of 2011, fuel briquetting is now the main focus of DHE's Bioenergy group. Taking into account both research and in-field experience, we determined that the development of new methods of fuel production, as opposed to new methods of fuel consumption such as improved stove design, would be a more robust, flexible and effective means of assisting the rural peoples of Tanzania. Many factors played into this decision, including our observation that individuals using the cookstoves were generally more reluctant to change to a new stove than to a new fuel.

Fig. 1. (left) A crowd listens as a demonstration carbonizer is prepared to make charcoal.

Fig. 2. (right) Charcoal briquettes of various shapes and sizes.

1.2 Current Operations

In the summer of 2013, DHE sent a group of four students back to the Arusha region to continue developing the project's briquetting knowledge base. The group split their time between streamlining an appropriate briquetting process at EARD-CI's facilities and working with partner organizations to set-up small-scale, community-run production operations.

Another group of students are traveling to the Arusha region in the winter of 2014. They are working with the same Tanzanian partners that the summer team worked with in order to help them progress further. The team has three main goals focused around impact analysis, capacity building and building connections between partners. While in Arusha, the team is conducting surveys to learn the impact that DHE has had since the beginning of the project and more specifically, the impact that the 2013 summer team had. They are also continuing to hold capacity building sessions with partners so they may continue to optimize their own systems after DHE is no longer present in the Arusha region. Finally, they are beginning to establish connections between DHE's partners in Tanzania by making them aware of each other and encouraging them to be in contact with each other.

Additionally, two of the students from this travel team are traveling to Dar es Salaam for three days to speak with Dr. Hassan Rajabu from the University of Dar es Salaam in order to discuss development of appropriate kiln designs as well as improving methods for capacity building.

2. Technology and Process Design

Briquetting is a versatile, multi-step process. One exciting possibility is to cleanly carbonize biomass feedstock, utilizing off-gases heat, and producing a charcoal dust. This charcoal stock is then mixed with a binding agent, and the resulting slurry is pressed tightly into briquettes, which vary range in shape and size. The biomass feedstock can be a range of materials, including but not limited to sawdust and agricultural waste. Binders can range from pulped paper to thrashed grass, though recent experiences in Tanzania indicate that starch-based binders such as cassava flour gels provide a much more reliable level of cohesion.

In order to change the biomass into charcoal, as opposed to burning it into ash, the feedstock must be heated to temperatures upwards of 400 oF in a low-oxygen environment to complete the pyrolysis. This requires a pyrolyzer, a burn chamber specifically designed to allow control of airflow. Pyrolyzers, which can take the form of modified barrels or large brick kilns, share several common design features, including a door or opening towards the bottom to allow the controlled inflow of the primary air that allows the fire to ignite and grow, openings toward the top to let in secondary air, which facilitates the chemical cracking of gases from harmful saturated hydrocarbon chains into benign flue gases, and a chimney to facilitate the flow of primary air up and through the chamber and to provide an outlet for the cracked gases. During standard pyrolyzer operation, the bottom door is propped open until the fire is self-sustaining, at which point it is closed to restrict the levels of oxygen inside and allow for a pyrolysis-favorable environment. Fans can be used to control airflow.

3. Capacity Building

With the intention of helping others make more informed fuel choices, DHE's impact in Tanzania is not directly caused by technological advancement, but rather through capacity building. This has been achieved through round table discussions, guided briquetting production with audience participation, presentations via visual information materials, emails and other virtual communications with advice and support, and written guides that describe the generalized briquetting process and informal dialogues and conversations. Every group DHE works with has a different set of priorities and level of technical experience, but it has been a priority to understand the common body of knowledge that all capacity building can rest upon. This foundation includes process scheduling, capital and operational cost prediction, marketing, biomass selection, carbonization safety and operation, binding agent selection, heat-integration, molding and pressing techniques, storage of feed, packaging of product, and pricing.

4. Impact Analysis

Over the course of three trips, the impact analysis team evaluated the Bioenergy Project's effect on fuel producers who go through DHE's briquetting workshops and briquette consumers. Through surveys, semi-structured interviews, and most-significant change stories, our team collected data on local communities' demographic composition, along with briquettes' impact on the communities' environment, health, economy, and energy consumption. The 2013 summer trip focused on assessing producer workshops' effectiveness and gathering baseline data on average households. The 2014 winter trip evaluated briquettes' short-term effect on households several months after their introduction. The 2014 summer trip will evaluate briquettes' long-term effect on the same households.

4.1 Metrics and Analysis

Currently, DHE is working with Dartmouth College's Chemistry Department in order to obtain quantitative values of energy density of various biomass feeds and briquette products using a bomb calorimeter. Extensive data has been collected concerning the emissions data from all of DHE's cooking technologies using Aprovecho's IAP

(Indoor Air Pollution) meter. Mass flows are documented as briquetting operations are run, offering a method of measuring processing efficiency. Human input in the form is also a key component in measuring an operation's efficiency. Lastly, the values of fuel, labor, capital equipment, and feed are used to understand the potential of profit.

Fig. 3. Informational posters indicating the processes and materials required for briquetting. Posters are also available in Swahili to facilitate capacity building.

4.2. Impact Results

DHE defines direct participants as individuals who have either participated in briquette-making training as producers or received briquettes for testing as consumers.

Table 1. Number of people trained in briquetting during summer 2013 in Arusha, Tanzania.

Type of Training Number of Hours of Training Training Sessions

Participants Completed

Producer Training 36 41 18

Consumer Group 5 9.5 4

5. Discussion and Future Work

The Bioenergy Project of DHE has targeted briquetting as an alternative fuel source for use in Tanzania. Our hope is that by partnering with local NGOs and other groups, health will be improved and resources such as timber will no longer have to be used for charcoal. This summer DHE will partner again with the Jane Goodall Institute who will apply the capacity building techniques developed to begin their own briquette-training program. The beginning stages of collaboration with the Dartmouth Organic Farm are now progress, allowing for a larger and more dynamic production site to be operated. This partnership is meant to offer a space where students can design and evaluate three types of engineered systems: briquettes and other carbon products; processing units (carbonizers, presses machines, grinders); process designs (scheduling, material flow, and energy/mass balances). Chemical process design thinking can be utilized in any part of the world that has access to large enough quantities of suitable biomass, such as wood shavings, coffee and rice husks, corn stalks, and bamboo, among other plant products that typically go unused. This realization has led to discussion of moving operations to Latin America, which presents a new opportunity for the expansion of humanitarian work.

Acknowledgements

Members of Dartmouth Humanitarian Engineering come from all corners of the globe. Although at heart DHE is an organization dedicated to solving global issues through engineering solutions, implementing new technologies requires a thorough understanding of their economic, environmental and cultural impact. Our diverse membership, supportive partners, and experienced advisory board each bring a variety of skills to the group, all of which are crucial for successful implementation of our projects. Without these dedicated student members, these important projects would not be possible.

We would like to thank our faculty advisors from the Thayer School of Engineering: Dr. Charles Sullivan, Associate Professor of Engineering; Holly Wilkinson, Assistant Dean of Academic & Student Affairs; Dr. Joseph J. Helble, Dean of Thayer School of Engineering; Everett Poisson, Director of Development; and Jeanne West, Associate Dean of Development & External Relations. We would also like to thank the members of our Board of Overseers, including: Jessica Friedman, Global Health Program Coordinator of Dickey Center for International Understanding; Dr. Edward Stritter, President of Stritter Consulting; and Michel Zaleski, Chairman of Soros Economic Development Fund. Special thanks is due to Professor Mark Laser, for sharing both his expertise in chemical process design and his valuable time

We would lastly like to thank our partners and sponsors from around the globe: AISE, EMORG, EARD-CI, University of Dar es Salaam; Thayer School of Engineering at Dartmouth; John Sloan Dickey Center for International Understanding; Jane Goodall Institute; CARE; Ministry of Infrastructure of the Republic of Rwanda; Wildlife Conservation Society; e.quinox; Kigali Institute of Science and Technology; Tuck School of Business; Byrne Foundation; and Rockdale Foundation.

References

[1] World Health Organization. http://www.who.int/mediacentre/factsheets/fs292/en/.

[2] Ahmed, Kulsum, et al. Environmental Health and Traditional Fuel use in Guatemala. World Bank Publications, 2005. Web. 20 Jan. 2014.