BIOLOGICAL REMOVAL OF COAL MINE METHANE

ATMOSPHERIC CONCENTRATIONS OF METHANE ARE CURRENTLY INCREASING AT A RATE OF ONE PERCENT ANNUALLY. EMISSIONS OF THIS GREENHOUSE GAS FROM COAL MINES NOW AMOUNT TO ABOUT 65 MILLION TONSANNUALLY, AND ARE INCREASING STEADILY. METHANE ADSORBED ONTO INTERNAL COAL SURFACES IS RELEASED AS THE COAL IS MINED. THIS GAS IS VENTED TO THE ATMOSPHEREFROM GOB WELLS OR WITH VENTILATION AIR. THE METHANE CONCENTRATIONS ARE DILUTE, AND RECOVERY IS RARELY ECONOMICAL. THIS PROJECT INVOLVES A NOVEL CONCEPT TO CONVERT WASTE METHANE INTO A HIGH VALUE PRODUCT, SINGLE CELL PROTEIN (SCP) FOR ANIMAL FEED. METHANOTROPHIC BACTERIA CONVERT METHANE INTO CELL MASS WITH A HIGH PROTEIN CONTENT THAT HAS BEEN SHOWN TO BE A SUITABLE SUPPLEMENT FOR PROTEIN IN ANIMAL AND POULTRY DIETS. THE FERMENTATION IS AEROBIC, REQUIRINGAT LEAST AN EQUAL VOLUME OFOXYGEN WITH METHANE; CONSEQUENTLY, DILUTE METHANE CONCENTRATIONS AREREQUIRED. PHASE I WILL SCREEN THE VARIOUS METHANOTROPHS TO SELECT THOSE THAT HAVE THE FASTEST GROWTH RATES AND HIGHEST YIELDS OF SCP. CONTINUOUS CULTURE STUDIES WILL BE CONDUCTEDWITH THE BEST BACTERIA TO DEFINE REACTION KINETICS AND MINIMAL REACTOR VOLUME. THE DESIGN ANDECONOMICS OF A PROCESS TO PRODUCE SCP FROM COAL MINE METHANE WILL BE PROJECTED TO DETERMINE FEASIBILITY. PHASE II WILL DEFINE ENGINEERING AND MARKETING PARAMETERS FOR LARGE SCALE PRODUCTION OF SCP. A PROTOTYPE UNIT WILL BE CONSTRUCTED AND OPERATED IN PHASE III TO DEMONSTRATE SCALE-UP.