| Temperature is one of the most influential factors and is the most important control parameter in anaerobic digestion. However, in order to maintain required temperature of anaerobic digestion, large amount of extra energy is needed. The study was conducted to investigate the possibility of using solar energy to increase anaerobic temperature.Greenhouse and solar converter were integrated to establish a combined solar system to get solar energy for increase anaerobic temperature, a experimental system was set up. First, it is necessary to make sure the controlling method of solar energy heating system and compile the temperature controlling program. Second, an experiment with this system using tap water was started to verify the feasibility of the system to increasing temperature, the results showed that the system was capable to obtain temperatures of 32 to 36℃in spring and fall, and 44 to 53℃in summer.Based on results of water experiment, mesophilic anaerobic digestion experiment with activated sludge was started. Comparing anaerobic digestion with solar energy heated and that without solar energy heated, it could concluded that, when TS loading rate of sludge was 60g·L-1:biogas product period decreased 3 days;maximal daily biogas production became 6 days earlier;accumulative biogas production increased by 35%;accumulative production of methane increased by 71%;conversion of solar energy increased 12492 KJ and increased by 24%.It shows that the efficiency of anaerobic digestion and biogas production advances obviously after using solar energy.The results showed that this combined solar system is an effective approach to increase temperature for high performance anaerobic digestion and could be put into practical application. |
PDF Full Text Request