Cascaded production of biogas and hydrochar from wheat straw: Energetic potential and recovery of carbon and plant nutrients

Microbial community shifts 2.6 years after top dressing of Miscanthus biochar, hydrochar and feedstock on a temperate grassland site

“…As a result of the production process HTC has, compared to feedstock, an additional nutrient supply, such as phosphorus, as well as a proportionally higher amount of ligneous components. This could have triggered fungal growth or the microbial community shift (Allison et al 2007;Funke et al 2013;Funke and Ziegler 2011). The C/N ratio is considered to be an indicator for microbial biomass, with high C/N ratios pointing to a higher abundance of fungi (Eiland et al 2001) which is consistent with our results.…”

Evaluation of Integrated Anaerobic Digestion and Hydrothermal Carbonization for Bioenergy Production

“…Dry digestate has lower atomic oxygen and hydrogen concentration, which is another indication of degradation of polysaccharides and simple sugar degradation during anaerobic digestion 22,23 . Moreover, lower H, and O concentrations increase the HHV of the digestate 24 . HHV of dry digestate is 22% higher than dry raw feedstock.…”

“…This is another indication of cellulose being reacted rather than lignin. Atomic carbon concentration in lignin is much higher than that of cellulose [24][25][26][27][28][29] . As a result, HTC biochar has an HHV of 29.6 MJ/kg, which are 61% higher than raw straw and 32% higher than dry digestate, respectively.…”

“…Elemental analysis, HHV, mass yield, and fiber analysis of raw wheat straw, digestate (thermophilic), and corresponding HTC biochar. HHV is calculated from CHNS composition as shown in literature 18,24 . Table 1 is the experimental results of elemental analysis, and mass yield after AD and HTC.…”

Optimization of Nutrient and Carbon Recovery from Anaerobic Digestate via Hydrothermal Carbonization and Investigation of the Influence of the Process Parameters

“…Previous works designated temperature as the parameter with the highest impact on composition and built-up of hydrochar from anaerobic digestate [17,18]. Within this work a clear description of the impact of the process parameters (time, temperature, pH) is made.…”