4. Conclusions
The HTPT reversed the bad anaerobic biodegradability of the CPCAR, one category of “hazardous wastes”. Under the optimized hydrothermal conditions the biogas and methane yields reached the high values of 290 and 200 ml (g TS)−1, respectively. The energy balance analysis of the proposed process combining HTPT and anaerobic digestion for treating the CPCAR showed that the process was energetically self-sufficient. The main technical difficulty - the inhibition caused by ammonia accumulation occurring during digestion of the hydrothermally pretreated CPCAR could be smoothed over by ammonia stripping, indicating the charming potential of the process for biogas production from the CPCAR.