Effects of temperature, particle size and enzyme addition on biogas production in-vitro

• Main Author: Lamichhane, Sanjaya
• Format: Master Thesis
• Language: English
• Published: 2018
• Subjects: biogas; temperature; enzyme; moose; partical size; Arctic; Alces alces; Moose
• Online Access: http://hdl.handle.net/11250/2626072

Biogas is an anaerobically produced ecofriendly renewable form of energy which can address the harmful effects associated with conventional source of fossil fuels. The objectives of present study were to examine effects of temperature, particle size and enzymes on biogas production. Moose (Alces alces) thrives in woody browse in semi arctic region and it was presumed that it hosts unique micro-organisms capable of producing fibrolytic enzymes. An experiment was conducted in the laboratory of INN, Blæstad. Cow manure with 5% dry matter content and wheat straw with 3 different particle size were treated with 3 dose of Moose rumen bacteria (MRB) culture along with 3 temperature settings. A cubical model was selected according to DoE (Design of experiments) and 11 treatments with different combinations of temperature, particle size and enzymes were tested. 100ml Erlenmeyer flasks were used as reactors, whereas gas was collected in 100 ml syringes. Wheat straw was ground and sieved to 1, 3 and 5mm particle size. MRB was applied at 0, 2.5 and 5% v/v of enzyme and substrate. 20, 30 and 40°C temperature were maintained in room, water bath and in heating cabinet respectively. Specified treatments were applied in 11 reactors provided with 30g manure solution and 3g of wheat straw substrate. Amount of gas collected in all the syringe were measured five times during a 48h period. The data were then analyzed using MODDE pro and MS Excel. The study shows that increase in temperature and enzyme has positive main effects and interaction effects for achieving a high rate of biogas production. However, particle size was found indifferent in biogas rate conformed by the large error bars. The study reveals the positive effect of using of MRB culture on the production of biogas since it contains novel microorganisms able to promote biomass digestion. Biogass er en miljøvennlig energiform som er produsert anaerobt uten de skadelige effektene som er koblet til konvensjonelle fossile energikilder. Målene med dette forsøket var å ...