Biogas yields from food waste

Abstract

The aim of this study was to determine the anaerobic digestion possibility of fish and rapeseed processing by-products to biogas. Different types of wastes from oil and fish processing industries were used – two samples of rape press cake (hulls, light dehulled and press cake, not dehulled) and two samples of fish wastes (fish waste after filleting and fish bones). The samples of rape press cake were with concentration of total solids in the range of 92.3-95.0 % and fish waste after filleting was wet – 41.6 % of total solids in the material. The waste from rape oil industry had 90.9-95.5 % volatile solids, while the fish waste after filleting had 92.5 % and fish bones contained only 50.4 % VS. Investigation was carried out on laboratory biogas digesters. The biogas yield from hulls varied in the range of 917 l·kg-1·VS-1 to 1064 l·kg-1·VS-1 and from rape press cake – in the range of 667 l·kg-1·VS-1 to 734 l·kg-1·VS-1. The biogas yield from fish waste after filleting varied in the range of 1006 l·kg-1·VS-1 to 1104 l·kg-1·VS-1 and from fish bones – in the range of 741 l·kg-1·VS-1 to 807 l·kg-1·VS-1