PROCESS FOR THE PRODUCTION OF BIOGAS MAINLY FROM ABATTOIR WASTE AND WASTEWATER

摘要

A PROCESS FOR THE PRODUCTION OF BIOGAS MAINLY FROM ABATTOIR WASTE AND WASTEWATER COMPRISES THE STEPS OF FON-NING A SLURRY FROM SOLID AND LIQUID ABATTOIR WASTE AND WASTEWATER, THE SLURRY SUITABLE AS FEEDSTOCK FOR AN ANAEROBIC DIGESTER, INTRODUCING THE SLURRY AS FEEDSTOCK INTO A FIRST STAGE (21) OF A TWO-STAGE ANAEROBIC DIGESTER (20), MAINTAINING THE FIRST STAGE OF THE ANAEROBIC DIGESTER AT A PH SUITABLE FOR HYDROLYZING AND ACIDIFYING THE FEEDSTOCK, A FIRST BIOGAS EFFLUENT AND A FIRST LIQUID EFFLUENT BEING GENERATED IN THE DIGESTER FIRST STAGE, DILUTING THE HYDROLYZED AND ACIDIFIED FIRST LIQUID EFFLUENT, MAINTAINING A SECOND STAGE (22) OF THE ANAEROBIC DIGESTER AT A HIGHER PH VALUE THAN THAT OF THE DIGESTER FIRST STAGE, FOR GENERATING A SECOND BIOGAS EFFLUENT AND SECOND LIQUID EFFLUENT FROM SAID DILUTED FIRST LIQUID EFFLUENT BY METHANOGENESIS, AND COLLECTION OF THE FIRST AND SECOND BIOGAS EFFLUENTS PRODUCED BY THE FIRST AND SECOND STAGES OF THE DIGESTER. THE PROCESS OF THE DIGESTER FIRST STAGE INCLUDES TRAPPING AND RETAINING SUSPENDED SOLIDS, AND GENTLE MIXING OF SUSPENDED SOLIDS. THE PROCESS OF THE DIGESTER SECOND STAGE INCLUDES TRAPPING AND RETAINING SUSPENDED SOLIDS. THE DIGESTER IS CONFIGURED TO UTILIZE AN UPFLOW SLUDGE BLANKET PROCESS AND COMPRISES A MESOPHILIC SUSPENDED GROWTH SYSTEM. THE VOLUME OF THE SECOND BIOGAS EFFLUENT IS SUBSTANTIALLY GREATER THAN THE VOLUME OF THE FIRST BIOGAS EFFLUENT. THE CONDITIONS OF BOTH FIRST AND SECOND STAGES OF THE ANAEROBIC DIGESTER ARE MAINTAINED SUCH THAT THE SOLID RETENTION TIME IS SUBSTANTIALLY LONGER THAN THE HYDRAULIC RETENTION TIME.