In a biodigester tank, the waste can mix with water in the absence of oxygen, allowing the anaerobic bacteria already present in the waste to break it down into biogas and compostable material.
Cooking with biogas is healthier and more environmentally friendly than cooking with wood.
"Fine particulates are released into the kitchen and the women who are in the kitchen all day have to breathe this in," said Heather Dorer, an engineering undergraduate student who traveled to Nicaragua in August 2009 as part of this project.
During the 10-day trip, students learned about the biodigesters currently in use there and installed one. They have since used this knowledge to develop a new conceptual design for digesters that is appropriate for rural Nicaragua and similar cultures elsewhere. They expect to have a prototype by May, and to return this summer to continue the project.
"We're improving the designs by increasing the user friendliness and also improving the yield of the biogas," said Zijia Li, an undergraduate engineering student.
Students involved in this project belong to the organization BLUElab, which stands for Better Living Using Engineering Lab. BLUElab works toward sustainable solutions to development problems both domestically and internationally.
"Today's engineering students are magicians at solving problems, but only a select few are capable of finding important problems and implementing economically and environmentally sustainable solutions in the real-world," said associate professor Steve Skerlos, founder of BLUElab and associate chair in the Department of Mechanical Engineering.
"I'm impressed with how this team of engineering students has grasped the technical as well as human and economic dimensions of this multidisciplinary design project. Their experiences in BLUElab and the Multidisciplinary Design Program will clearly place them well among the leaders and best of our undergraduates."
Michigan Engineering's Multidisciplinary Design Program sponsored the trip. Through the program, which also offers a minor, students can connect with real-world projects and integrate the experience into their academics. BLUElab students Zijia and Dorer, along with undergraduate engineering student Jinhyung Hwang, are pursuing the minor as one of the first groups of students to do so as a team.
The University of Michigan College of Engineering is ranked among the top engineering schools in the country. At more than $130 million annually, its engineering research budget is one of largest of any public university. Michigan Engineering is home to 11 academic departments and a National Science Foundation Engineering Research Center. The college plays a leading role in the Michigan Memorial Phoenix Energy Institute and hosts the world class Lurie Nanofabrication Facility. Find out more at http://www.engin.umich.edu/.
BLUElabMichigan Engineering's Multidisciplinary Design Program and minor