Schmack Biomass, LLC (Schmack Biogas) has received a final air permit from Ohio Environmental Protection Agency (EPA) for its proposed biogas production facility at 2500 Jackson Pike, Columbus. The air permit establishes emission limitations, installation regulations and operational restrictions at the proposed anaerobic digestion facility.

The system consists of several components: a processing building for material receiving, dewatering and shipping; tanks (e.g. anaerobic digester, storage and pasteurization); a flare for emergencies or disposing of excess gas; and a biofilter for round-the-clock odor control.

Air emissions from this renewable energy plant would include combustion products from biogas- and natural gas-fired boilers (heat sources for the anaerobic digester process); combined heat and power unit (an internal combustion engine); excess gas flare; and facility roadways and parking lots.

Emission limitations and permit conditions were established to ensure compliance with federal and state clean air standards; minimize odors from the facility; and protect public health and safety. The permit also would require the use of best available control measures to minimize dust from roadways and parking lots. The total tons per year (tpy) of emissions from all air units at the proposed facility are: carbon monoxide (84.1 tpy); sulfur dioxide (23.8 tpy); nitrogen oxides (20.8 tpy); volatile organic compounds (7.3 tpy); particulate matter (1.0 tpy); and hazardous air pollutants/air toxics, i.e. formaldehyde (0.03 tpy). Additionally, as long as the biofilter is properly operated and maintained, odorous compounds should not exceed emissions levels of 1.0 tpy.

Ohio EPA issued a draft permit-to-install and a draft wastewater permit to Schmack Biomass, LLC. These draft permits would require the digested sewage sludge be tested and managed to comply with state and federal regulations. The draft permits are for construction and land application of exceptional quality sludge.

The project as proposed includes the development, construction and operation of a state-of-the-art anaerobic digester system to process municipal wastewater sludge and other organic materials at a centralized plant. The facility would be able to process approximately 150 wet tons per day of sewage sludge and 8,000 tons of fats, oils and grease. The company expects to produce an average of 12 million BTUs (British Thermal Units) per hour of biogas.

The facility proposes to accept various organic feedstocks, including sewage sludge, manure, fats, oil, grease, food waste and agricultural energy crops. The maximum input to be processed through the digestion system is 14,000 dry tons of sludge per year. The outputs from the digestion system will be approximately 6,000 dry tons per year of stabilized, pasteurized sludge and 600 standard cubic feet per minute of biogas. The digested and pasteurized sewage sludge will be dewatered and used for exceptional quality sludge land application according to regulations established by the state.

Schmack Biomass expects biosolids and other feedstocks will be delivered to the facility six days a week via about a dozen 20-ton dump trucks each day. Due to the nature of the material being handled and processed, there is a potential for unpleasant odors. To reduce odors, all process tanks would be covered and the feedstock receiving hopper doors would remain closed when not receiving waste. The hopper, conveyor and pumps would be fully enclosed to reduce odors. During normal operation, raw waste would not be stored in the hopper but discharged immediately to the feedstock tank. Air exhausted from feedstock receiving and dewatering rooms would pass through a continuously operating biofilter.

Schmack Biogas is a joint venture of Kurtz Brothers Central Ohio, LLC, and Schmack BioEnergy, LLC.