Advanced 3 step digestion process for biosludge (WAS) (chemical cracking + thermophilic hydrolysis followed by methanation), doubling organic conversion efficiency compared with conventional digestion.
The THEAREX process is a powerful process that converts primary and secondary sludge (WAS) from domestic or industrial waste water treatment plants into valuable electricity and heat (or steam) by means of a combination of a chemical pretreatment and a two stage biological fermentation process.
Primary sludge is eventually first thickened and pumped into a thermophilic acidification reactor (TAR). This reactor is operated under anaerobic thermophilic conditions. Special seed material is supplied by GWE. Complex carbohydrates are fermented to a range of “volatile fatty acids”. Oils and fats are also hydrolysed into shorter molecules which are easily converted into biogas in the next methanogenic step.
Secondary sludge is mechanically thickened and subsequently submitted to a chemical cracking process. The cracked sludge is than pumped into the thermophilic acidification reactor (TAR).
The outlet of the TAR is a concentrated “wastewater/sludge mix” that contains dissolved and undissolved organic matter. This preconditioned substrate is treated in an ANAMIX digestor. The biogas producing digester is operated under mesophilic or thermophilic conditions, depending on the ratio between primary and secondary sludge.
The THEAREX treated sludge is suited for further treatment using conventional systems: sludge dewatering, lime treatment, landfilling, incineration, etc.