Final Report: Fair Trade Ethanol: Fuel Production from Coffee Wastes

EPA Grant Number: SU833921
Title: Fair Trade Ethanol: Fuel Production from Coffee Wastes
Investigators: Winston, Susan , Martin, Jack , Ramsdell, Jeff , Ferrell, Jeremy , Cockerill, Kristan
Institution: Appalachian State University
EPA Project Officer: Page, Angela
Phase: I
Project Period: August 15, 2008 through August 14, 2009
Project Amount: $10,000
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet (2008) RFA Text |  Recipients Lists
Research Category: P3 Challenge Area - Air Quality , P3 Challenge Area - Safe and Sustainable Water Resources , Pollution Prevention/Sustainable Development , P3 Awards , Sustainable and Healthy Communities


This research examines systems that utilize wastewater from wet coffee processing and associated materials to provide water treatment and produce fuels, specifically biogas and ethanol. The production of biofuels has the potential to improve the quality of life in developing nations, while mitigating the environmental damage caused by the polluting wastewaters. The team took a trip to Nicaragua to learn about the nature of this process specific to coffee wastewaters. While in Nicaragua, team members assessed the environmental and social problems associated with current coffee processing methods in order to determine the viability of the production of biofuels.

The research objective is to determine the most appropriate method for effectively utilizing the waste to produce ethanol and biogas. By producing valuable fuel from the waste, the potential is created to ensure long-term sustainable environmental protection. The challenge is to develop a bioremediation system that works towards a closed loop approach to coffee production that is affordable and appropriate for communities where the systems are implemented. Surveys were conducted in Nicaragua in order to ensure that the design is appropriate and will be accepted by community members. This field research was an invaluable tool for determining the best biofuel systems for the users based on evident and unmistakable needs: clean drinking water and an inexpensive and clean cooking fuel. Therefore, ethanol as a cook fuel has tremendous potential to do well in this situation.

The challenge to this approach is the economic feasibility of ethanol distillation, which has three implications. Distillation heat is one challenge that can be combated through the use of biogas and additional preheating measures, such as solar thermal for distillation heat. Secondly, an alternate feedstock is needed during the coffee off-season that is also a waste; rotten bananas and banana peels are good candidates and have been explored. Thirdly, the system design must have low initial capital cost to incubate a sustainable business model for developing nations so that the project will continue after we are gone.

Proposed Phase II Objectives and Strategies:

This project has implications to transform the fundamentals of farm practices, environmental impacts, and consumption patterns of the world’s most traded agricultural product. The potential benefits of broad based adoption of Clean Water Coffee practices are profound and far reaching the world over and most powerfully in impoverished coffee producing regions. For the project to be a genuine success and have the best chance to spread beyond Matagalpa, Nicaragua it is imperative that the technical innovation and expertise we bring serve to empower the local Nicaraguan businesses, community leaders, and farm owner/operators to both take ownership of the implementation process and realize the benefits for their communities.

The Clean Water Coffee approach to Phase II seeks to close the loop in coffee production. The challenge is to identify and implement the most appropriate and cost effective methods to cleanly and safely process/transform the location-specific seasonal coffee farm outputs of liquid and solid organic "waste" into usable agricultural and energy resources. A pilot scale ethanol production facility will be constructed at on our partner’s commercial coffee facility, El Quetzal Estado. An educational outreach ethanol distillation model will be constructed at Finca Esperanza Verde, another partner of Clean Water Coffee. Both facilities will be conducting anaerobic digestion waste remediation techniques. The fermentation by-products acquired during ethanol fermentation and distillation could be used as feedstock for the anaerobic digester. Using these two technologies in conjunction will consider each aspect of the waste stream and can create a unique closed loop cycle.

Ethanol cooking fuel renewably produced from a local organic agricultural waste product and environmental contaminate can enhance the resilience of local economies, create new education and skilled labor positions, and improve the general standard of living for the community. For this to become a reality we must answer the following question. Who will use this new cooking fuel and how will they use it? The most common method of cooking in Nicaragua is an unventilated indoor wood fired cook stove. Smoke inhalation and the large portion of a family’s time and effort spent to gather fire wood were two major concerns identified in our surveys. People want a healthier more sustainable alternative, but ethanol cannot be used in a wood stove.

One potential scenario for a win-win-win arrangement to solve this demand-side dilemma is as follows. Ethanol producers employ local metal workers to manufacture and repair home use ethanol cook stoves to be provided to the coffee pickers. The coffee pickers and other farm workers would also receive cooking ethanol beyond the coffee season after they have left the farm/estate. In exchange the workers could either receive a lower salary or pay a distributer.

Would farms have to hire and train for new skilled metal worker positions, only to have to buy the materials and pay the labor costs of fabricating the stoves that will then be given to their workers?

No. Some of the metal workers the farm contracts for system installation would likely be the same ones that stay-on to build ethanol cook stoves. In this scenario the farm owner would buy materials for the stoves. This would not have to be any great expense as many very effective models can be constructed with minimal materials. For example, alcohol cook stoves are commonly constructed with few to no tools using only an empty aluminum soda can (albeit not extremely long lasting).

Would farm owners be stuck with a large capital investment and only the limited market of their own farm hands for this new ethanol product?

No. Fermentation and distillation equipment suitable to produce cooking fuel is much less costly and elaborate than what is needed to produce drinkable or fuel grade ethanol, and production will only be truly feasible, from a business standpoint, at large scale coffee farms. These farms must hire (and typically house) huge numbers of pickers during the approximately four month long coffee season, and during the rest of the year the farm is mostly empty. Due to the lag-time between coffee harvest and ethanol distillation from the byproducts, ethanol production would begin around the middle of harvest time. In most Nicaraguan communities many families spend many hours several days of the week gathering fire wood, often having to walk great distances. After harvest season farm workers that obtained a cook stove would return to their villages with the knowledge of simple stove construction and operation.

Would the farm owners end-up looking bad to the public because they are contributing to the extensive societal problems of alcoholism by creating this distillation infrastructure?

No. In fact, the opposite is much more likely. Coffee pickers at large scale farms are among Nicaragua’s poorest, most disadvantaged, and undereducated citizens. By providing its workers with this simple low cost equipment and opportunities for personal interaction with the fabricators of the stoves, the farm can and should be seen as confronting this social problem from both sides. On one hand they facilitate the education of the coffee pickers by the stove builders not only about the safe operation of the stoves, but also about the dangers of denatured alcohol. On the other hand providing these stoves can give the worker a sense of pride by dramatically improving quality of life at home. This can combat the feelings of inadequacy and helplessness that lead so many Nicaraguan men to excessive drinking.

Many other similar scenarios could be envisioned which are a win for the farm or estate, a win for metal tradesman, a win for the farm hand and their families and communities, and most of all a win for the health and resilience of the environment and society as a whole.

Summary/Accomplishments (Outputs/Outcomes):

Coffee is an important crop for developing countries, particularly in Latin America. It provides essential income to millions of people, but the wastewater generated threatens the environment and human health. The basic needs in Nicaragua are enormous, similar to many other coffee producing areas around the globe. This project has the ability to combat many of the problems facing humans today such as scarcity of potable water and energy supplies for the people that need it most. Coffee producers are all in developing nations and have serious problems disposing of the waste properly because they have no capital available to address the water contamination crisis and little environmental regulatory enforcement. Additionally, the people of rural coffee producing communities have inadequate health care so the availability of clean water is essential to quality of life.

Responsible treatment of the wastewater will reduce the impact on the local ecology, and decrease the need for human health care by improving the water quality. This effluent is discarded every day during the processing season to lagoons where it putrefies. We saw these retention ponds and smelled the putrefactions occurring; it ran-off the hill and leached into groundwater. The acids from the fermentation of sugars in the mucilage make the wastewater very acidic, down to a pH of 4.5. The wastewater samples we took in Nicaragua during January 2009, showed a pH of 4, ammonia nitrogen at >10 mg/L, phosphates of 150 g/L, dissolved oxygen of 0.01 mg/L and BOD >200,000 mg/L.

This effluent creates a potential for serious harm to human health and the environment because the contaminated wastewater is either directly discharged to streams or leaches into the groundwater tables like we saw in Nicaragua. In developing nations people rely heavily on shallow groundwater tables and surface water for drinking water supply; thus, coffee processing causes great harm to people living within the vicinity. In our survey conducted in the village of Yucul, Nicaragua, in May 2008, we learned that people could no longer drink the water because of contamination from the coffee farms above. People also were aware of the impact on aquatic life, which in turn affects fishing yields. As one woman said “the wastewater washes into rivers and hurts the people and species that depend on that water and it gives rise to famine.” Another perspective on how coffee production affects food supply came from one man who said “We know that wastewater from coffee production is polluting the water but people in this area are poor and have to eat, have to have some income to buy what they need and for most, coffee picking is the only work available.” 


There is a definite need for cost effective waste treatment to improve the water quality around coffee production facilities. Anaerobic biotechnology is particularly attractive for developing nations because of its good cost balance and ability to provide an energy supply. Wet coffee processing results in two types of high strength saccharide-rich wastewater, the mucilage and the pulp. Coffee wastewaters have a high content of carbohydrates, which makes them suitable for biological anaerobic treatment. Anaerobic digestion can be used to produce biogas that can be used as distillation heat for ethanol production. We have measured sufficient sugars to be able to make ethanol from the wastewater and conducted fermentation experiments on coffee wastewater and banana waste that yielded burnable alcohol (proof). The usable products improve the benefits of this type of waste treatment system.


Journal Articles:

No journal articles submitted with this report: View all 3 publications for this project

Supplemental Keywords:

Industrial symbiosis, energy technology, clean energy, green chemistry, original technologies, conservation, waste reduction, green engineering, atmosphere, cleaner production, pollution prevention, nature, natural model, biomimicry, waste equals food, multidisciplinary, environmental education, bio-based energy, biodiesel fuel, biotechnology, international cooperation, environmental engineering, alternative to petroleum, drinking water, carbon credits, discharge, emission control, green design, Arabica, Central America  , RFA, Scientific Discipline, Sustainable Industry/Business, POLLUTION PREVENTION, Sustainable Environment, Energy, Environmental Chemistry, Technology for Sustainable Environment, sustainable development, environmental sustainability, alternative materials, biomass, alternative fuel, biodiesel fuel, energy efficiency, energy technology, carbon credits, alternative energy source

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