Enhanced Biogas Yield of Chinese Herbal Medicine Extraction Residue by Hydrothermal Pretreatment

Abstract

aChinese herbal medicine extraction residue (CHER) is a special organic waste produced in China. Because of the high content of lignocelluloses, CHER have a weak bioconversion efficiency for bio-products production. This study investigates the effect of a hydrothermal pretreatment (HTP, 140 to 220 °C, 15 min) on the organic matter solubilisation, biochemical methane potential, and methanation kinetics of CHER during anaerobic digestion (AD). The AD test was conducted with 5 g/L total solid at 35 °C for 30 d. The results showed that the HTP clearly improved the solubilisation of CHER, and the obtained soluble COD (%) reached over 30% (only 4.5% in untreated). Acetic acid, xylose, and glucose were found to be the main products in the hydrolysate. The methane yield and methanation speed of the treated CHER were also enhanced. The highest methane yield of 306 mL/g volatile solid was achieved at a HTP temperature of 180 °C, while the untreated control was only 175 mL/g VS. Moreover, a carbonisation phenomenon was observed at HTP temperatures over 200 °C, which resulted in a loss of organic matter and methane yield.

Enhanced Reactive Blue 4 Biodegradation Performance of Newly Isolated white rot fungus Antrodia P5 by the Synergistic Effect of Herbal Extraction Residue

“…However, there is a dearth of research into effective HER utilization. Hitherto, the reutilization of these resources has tended to focus on the re-extraction of other ingredients or conversion to animal feedstuff ( Li et al, 2014 ; Wang et al, 2017 ). Several studies have reported that HER can be used as culture media for microbe fermentation and stimulate the production of extracellular enzymes.…”

Biogas Production From Dairy Cattle Manure Subjected to Chemical Pre-Treatment

“…In rural areas, especially in developing countries such as Brazil, (PINAS et al 2018); Chile (RODRIGUEZ-MONROY et al 2018); China (WANG et al 2017); India (RAYCHAUDHURI & GHOSH, 2016) and Pakistan (MIRZA et al 2008) there is a great variety of lignocellulosic biomass that has reasonable potential for energy production by means anaerobic digestion, for instance cattle manure. Nevertheless, cattle manure can yield low biogas production since it has lignocellulosic structures of low degradability rate (VANHOLME et al 2010).…”