Featured Insights

Thermal Hydrolysis: Boosting Biogas Production and Biosolids for Fertilizer

Thermal hydrolysis is an advanced wastewater solids conditioning process that boasts both financial and sustainable environmental advantages. With the process in wide usage across the UK, it is now starting to gain traction in the U.S., as wastewater utilities analyze whether their facilities would make a good candidate.

The thermal hydrolysis process (THP) increases the biodegradability of wastewater residuals, thereby boosting digester loading rates, increasing biogas production, and producing a biosolids product that can be used for land fertilization.

The process kills pathogens in biosolids, thereby meeting the highest U.S. Environmental Protection Agency criteria for land application as a fertilizer, known as Class A. With THP, solids are easier to mix and pump at higher solids concentrations, which leads to increased digester loading rates. This can be appealing to facilities that need to process more solids in existing systems or need to minimize the size and number of new digesters.

“In Europe and some regions of the U.S., revenue from energy production can provide a significant additional consideration, due to high electricity costs and credits associated with green energy production.”

Martin Jolly, Black & Veatch UK Technical Director