Techno-economic evaluation of PHB production from activated sludge

Activated sludge biomass enriched under suitable conditions is a promising source for poly-3-hydroxybutyrate (PHB) production, a biodegradable polymer. The techno-economic evaluation of PHB production using activated sludge biomass has been carried out. The PHB yield and plant capacity was found to significantly affect the PHB production cost. The PHB production cost for a plant processing (fermentation) capacity of 100 m(3)/day and 44% PHB yield is about US$ 11.8/kg, which reduces to US$ 5.38/kg for 1,000 m(3)/day plant capacity and 70% PHB yield. The cost of the carbon substrate was found to significantly affect the overall economics of PHB production.