FremgangsmÕte for behandling av organisk materiale

摘要

The present invention relates to a method for treatment of organic material, grown for energy production or being organic waste which is slurried, suspended or dissolved in liquid, in a two-step anaerobic biochemical reactor configuration comprising recirculation between the two reactors. The organic material is fed to the first reactor where most of the hydrolysis and dissolution of the organic material takes place, resulting in formation of volatile fatty acids (VFA). Liquid material from the first reactor is transferred to the second, methanogenesis reactor where the treatment is finalized. The amount of VFA in each reactor is forced to oscillate within pre-set upper and lower limits by pulsed recirculation between the two reactors. The amount of VFA in the reactors can be controlled by varying the recirculation rate of liquid between the reactors. The pH or the conductivity in the reactors can be monitored and used for calculating and controlling the amount of VFA in both reactors.