Design, Building and Techno-Economic Evaluation of Biogas Digester

This thesis describes biogas energy technology which is heavily used in China, India and Brazil. The biogas technology is rarely used in Arab countries. Palestine has a good potential for biogas production. One Palestinian family living in rural areas owns at least three cows where each cow gives 12-16 kg dung per day. This amount will produce 24.5 kg biogas per month which is equivalent to one C4H10 gas bottle, since heat value of CH4 is ½ heat value of C4H10. Some biogas production experiments were implemented in Palestine under the conditions: temperature = 350C, pH value = 6-7, and retention time = 10-60 days. A floating drum digester in Tulkarem with a volume of 14m3, and with a daily supply of 50L slurry over a period of 40 days have produced 1.17m3 /day of biogas (0.84 kg biogas/day). Economic evaluation of this digester shows that the cost of 1 m3 biogas is 1.5NIS. The recommended family digester (floating drum digester) with 3.5 m3 volume will save 4180NIS per year and its simple payback period is less than one year.