Thermal hydrolysis of excess biomass such as sewage, realizes a significant reduction in pathogenes and vector attractors during the process. Conventional disposal to landfill is no longer required. And, with the TurboTec, DMT can now utilize biomass as a source to produce renewable fertilizer.
Substances which are difficult to digest are hydrolised during the process. As a result you receive more biogas from the same amount of biomass, while less biomass is being left after digestion. In addition, you can increase the biomass load going into digesters, due to the change of the hydrodynamics of the biomass.
The patented TurboTec® THP set-up with mixing and separation gives you a continuous configuration. The equipment is operating under stable conditions, without idle periods for process equipment at optimal investment costs. Furthermore, auxiliary equipment and energy consumption are at a continuous operation tailored to the project demand. Configuration adjustment can be made to customer requirements to avoid any contact with pre-hydrolised and post-hydrolised material.
Pre-treatment and heat exchanging
The raw biomass is sieved prior entering the system. This can be done by for example static-drum-or step screening. This avoids operational downtime not only in the TurboTec® THP but also in the digester and improves the quality of the final biomass all in once. After being sieved, the raw biomass is partially warmed up by utilizing heat from the outgoing hydrolised biomass. This can be done by the mixing-separation step, by heat exchangers or a combination of both.
The continuous flow of warm raw biomass is heated up with steam to 140 – 160°C and enters the reactor. Here the material is retained during sufficient time to provide sufficient hydrolisation. The reactor set-up is CSTR-style, meaning that the content is constantly in a turbulent environment. This way, all material is hydrolised and accumulation is prevented.
After hydrolisation, the biomass is cooled down either through contact with the raw sludge, the heat exchangers, or both. It is now lower in viscosity, easier to pump and good to handle in conventional digesters. Due to the hydrolisation, more phosphate and ammonia will be released in the digestate. This can be recoved in the form of struvite and ammoniumsulphate.