INFLUENCE OF IMMOBILIZATION SUPPORT MATERIAL TYPE ON THE ANAEROBIC DIGESTION

Abstract

The process of anaerobic fermentation of organic waste makes it possible to produce not only methane, but also hydrogen, which, when mixed, form a high-energy mixture - biohythane. The efficiency of biohythane production in a two-stage anaerobic fermentation process depends on many factors, including organic loading rate (OLR) and hydraulic retention time (HRT). It is known that the addition of an immobilizing support materials to anaerobic bioreactors improves the stability of their operation and increases the biogas yield. An important aspect is the nature of the immobilizing support material, which can perform not only the immobilization function, but also have a stimulating effect on the anaerobic digestion. Therefore, the selection of an appropriate immobilizing support material for a fixed bed bioreactor can ensure high efficiency and successful operation of the fermentation system. The aim of the work was to select the most effective immobilizing support material for a fixed-bed methanogenic reactor in a two-stage anaerobic digestion of cheese whey to produce biohythane. Polyurethane bed material, carbon felt, Raschig ring-type ceramic bed material, as well as a mixture of carbon felt and ceramic bed material were used in the work. The highest methane production rates (MPR) were obtained for the reactor with carbon bed material as an immobilizing support materials (753.9 ml/(L d)) and for the reactor with a mixture of ceramic bed material and carbon felt (763.5 ml/(L d )). The highest concentration of methane in biogas (68.8%) was recorded in the methanogenic reactor with coal felt. The average concentration of hydrogen in the biogas of the acidogenic reactor when using polyurethane bed material was 41.04%.