Title:
Anaerobic Treatment of Waste Water Derived from Hydrothermal Carbonization
Author(s):
Wirth, B., Mumme, J., Erlach, B.
Document(s):
Paper
Abstract:
Hydrothermal carbonization converts biomass into a lignite-like product which has potential applications as a carbon-neutral power plant fuel or as a soil amendment. Since the process takes place in water it is well suited for biomass with a high moisture content, such as organic waste. Most of the feedstock moisture, however, leaves the HTC process as waste water highly loaded with organic and inorganic compounds. Around 10 % of the feedstock energy is contained in the waste water, and treatment requirements may impose an additional energy penalty and high cost. This paper analyzes the feasibility of anaerobic digestion as a treatment step. The produced biogas can be utilized as auxiliary energy in the HTC process, thereby improving its energetic efficiency. Biogas yield, degradability, and long-term stability of the digestion process of HTC waste water were analyzed in an experimental set-up. The HTC liquor showed a fast degradation with 60 % of COD removed within eight days. Methane rates were moderately high with up to 0.65 L gTOC-1. The results were then used for an economic feasibility study of an industrial-scale HTC plant. Incorporation of an anaerobic treatment step seems viable if OLRs of 1.5 kgCOD m-3 d-1 are achievable.
Keywords:
anaerobic digestion, biogas, efficiency, feasibility studies, wastewater treatment, pretreatment
Topic:
R&D on Biomass Conversion Technologies for Heating, Electricity and Chemicals
Subtopic:
Anaerobic digestion for biogas production
Event:
20th European Biomass Conference and Exhibition
Session:
2AO.4.3
Pages:
683 - 692
ISBN:
978-88-89407-54-7
Paper DOI:
10.5071/20thEUBCE2012-2AO.4.3
Price:
FREE
