Biobased Insulating Panels and Anaerobic Digestion of Farm Waste, 2017


Project Leader

Joseph Greene, professor, Dept. of Mechanical Engineering and Manufacturing Technology, CSU Chico

Work on this project focused on two main areas in 2017:

  • Evaluation of the commercial viability of the Biobased Structural Insulating Panel developed in previous research.
  • Development of an anaerobic digestion system for agricultural waste, including rice straw.

Biobased Structural Insulating Panel

The Biobased Structural Insulating Panel that included rice straw as one of its ingredients has been proven to be technically feasible. However, ingredient costs besides rice straw were higher than those used in similar commercial products made with particle board and Styrofoam™.

A gun company has shown interest in use of the biocomposite material to create biodegradable sport pigeons to replace clay pigeons.

Anaerobic farm waste digester

Current technology exists for converting a variety of waste products with anaerobic digestion to methane gas that can in turn be burned to produce electricity. Examples of feedstocks include manure, sugar beets, sewer sludge, pulp and paper, processed food, rice straw, potatoes, algae, corn stover, and wine.

Different inputs can generate varying amounts of methane. Dairy manure creates the most biogas. Rice straw produces a lesser amount.

Laboratory test equipment was developed to convert farm waste to methane using a two-step anaerobic digestion process. Different food waste was placed in separate jars with an inoculum and stored in an incubator. Gas production was then measured.

This research is intended to result in the development of a recipe of farm materials that will biodegrade with rice straw. In one trial, rice straw and apple waste were mixed together to determine biogas production. A second trial included different amounts of peach, olive, rice straw, and cellulose. Biogas was measured with a gas chromatograph.

The olives and apples had high biodegradation that generated much biogas. The peaches generated less biogas for unknown reasons, something that will be studied further. Rice straw produced less biogas. In the next phase of this research, rice straw will undergo preconditioning.

The results from this year’s experiments will be used to predict methane generation from a 100-gallon anaerobic digester to be used for further research on food and farm waste in 2018.

Technical viability of this project is very good. An anaerobic digester is currently in use at a biogas plant south of Chico. The project leader will work with Chico State engineering students in the design and building of a new digester.