Thermal Hydrolysis Achieves Asset Optimisation and High Biomethane Yields

Balasundaram, G., Gahlot, P., Tyagi, V.K., Kazmi, A.A., Kleiven, H., Sahu, A.K.

11th International Conference on Sustainable Solids Waste Management, 2024

Abstract

In the next five years, the UN predicts that the world shall have 43 mega cities (population >10 million), which will result in having utilities to optimise their assets by either upgrading their infrastructure or build new sewage treatment plants (STPs). Urbanisation trend in many cities worldwide have led utilities to think and adapt to smart, compact, modular systems when it comes to technology selection and also keep to the pressures of local governments and people to address the circular economy, resource recovery and sustainability trends.
One such technology for sludge management is thermal hydrolysis process (THP) prior to anaerobic digestion (AD), which currently has over 80 installations in over 22 countries. THP + AD has been gaining prominence around the world by utilities for its sustainable ways of managing sewage sludge (SS) while producing usable biosolids to address the circular economy. Several countries in Europe, India, South Africa, etc have smaller STPs and make use of sequencing batch reactors (SBRs) as their core wastewater treatment technology. Limited research work has been done to investigate the SBR sludge using THP+AD, since most applications have delved on waste activated sludge (WAS) from medium to large STPs. This study investigated SBR with long retention times on THP+AD, in addition, how low of a hydraulic retention time (HRT) for AD one can achieve, without compromising methane yields to design smaller digesters was further investigated.

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