Disintegration in the biogas sector – Technologies and effects

• Recent data about disintegration technologies (German biogas market 2011/2012).
• Overview on energy demand of selected physical disintegration technologies.
• Evaluation of technologies by reference to the Technology Readiness Assessment Guide.
• Data of the prevalence of disintegration technologies on German biogas plants (2012).
• BMP-tests with un-/treated barley straw (TPH) and calculations of conversion rates.

Pretreatment of organic material prior to anaerobic digestion is seen as an option to increase the overall efficiency of the process. An overview of physical, chemical, and biological disintegration (DT) of substrates in the biogas sector is given. The energy demands DT were surveyed. The technologies were evaluated by reference to the Technology Readiness Assessment Guide of the U.S. Department of Energy. The evaluation focuses on ligno-cellulosic substrates like straw. Data of a survey among biogas plant operators were analyzed regarding the prevalence of disintegration technology classes in Germany. Furthermore, biochemical methane potential tests were conducted in laboratory scale to determine the specific methane yields of un-/treated barley straw (thermal pressure hydrolysis (TPH)). A methane potential of 228 ml CH4/g VS was measured for untreated barley straw; and of 251 ml CH4/g VS for TPH-straw (190 °C, 30 min). The reaction rates in BMP were calculated between 0.0976 and 0.1443 d−1.