DESIGN A SMALL DIGESTERS UNIT HEATED BY STORED SOLAR ENERGY TO PRODUCE BIOGAS

Abstract

The main objective of this research was to study and evaluate horizontal and vertical small size digesters heated by evacuated tube solar collector to produce biogas farm animal wastes. the digesters were evaluated under operating parameters such as three different temperature levels (30,35 and 40 ○C), seven different of hydraulic of retention time (HRT) from 5 to 40 day and mixing time 5 min/h and 15 min/4h. Also comparison between the horizontal and vertical digesters as a function with find product L/day and, biogas productivity (m3 gas/d), and biogas energy (kWh/ m3 manure /d). The results indicate the digester yield was varied in both horizontal and vertical with different heating temperature, mixing time and hydraulic retention time . the optimum condition with small vertical and horizontal types at a temperature 40 ○C and (HRT) 35 day , get high final product 6.23 and 12.95 l/day, biogas productivity 0.074 and 0.226 m3 gas/m3 manure/d, and biogas energy 0.632 and 0.634 kWh/ m3 manure /day for vertical and horizontal, respectively.