MSU Researchers Develop Biorefinery to Convert Animal Wastes into Energy and Chitin

Anaerobic digestion (AD) is an effective and widely used technology to treat feedstocks for bioenergy production. However, the AD is limited by two by-products of the nutrient-rich liquid digestate and the fiber-rich solid digestate. To overcome these, Zhiguo Liu and a team from Michigan State University, demonstrate a biorefinery concept to utilize animal waste and create a new value-added product from them.

The studied biorefinery includes an AD, electrocoagulation (EC) treatment of the liquid digestate, and fungal conversion of the solid fiber into the fine chemical, chitin. The process starts with the animal wastes undergoing AD to produce methane gas for energy generation for the biorefinery. The resulting liquid digestate from AD will then undergo EC to reclaim water.

The cellulose-rich solid digestate will then undergo enzymatic hydrolysis and fungal fermentation to produce chitin. Water from EC will be used for the fungal fermentation. Results reveal that the studied biorefinery converts 1 kg dry animal wastes into 17 g fungal biomass containing 12% chitin and generates 1.7 MJ renewable energy and 8.5 kg irrigation water.

This study describes a biorefinery for simultaneous treatment animal wastes and production of chitin. The concept provides a plausible solution for agricultural waste management.