Frequently Asked Questions – Digesters
Are the microorganisms safe?
The microorganisms are perfectly safe, naturally-occurring and non-pathogenic, i.e. they do not cause disease. There are also no harmful effects to local drains or sewage systems. In effect the microorganisms boosts the population of beneficial bacteria in the system, and there would actually be beneficial effects further downstream.
How much food waste can I put in the Digester?
The Digester can process up to 2,500 pounds of food waste over a 24 hour period but because it is a continuous feed process, the additions of food waste must be staged over the course of the 24 hours. Trying to put too much food waste into the Digester at one time will overload the machine and slow the digestion process. Operators should aim to add approximately 100 pounds per hour to achieve maximum performance.
What can I put into the Digester?
The Digester is designed to process a wide range of food waste types like, fruit, vegetables, cooked and uncooked meat and poultry, fish, dairy, bakery items, etc.
What CAN'T I put into the Digester?
The machine cannot process anything that is not food waste and cannot be easily broken down such as large bones, mussel and clam shells, pineapple tops, packaging, general waste or cutlery. Placing the wrong items into the machine could cause damage and could void the warranty.
Can I put hot soups or frozen foods in the machine?
No. Please allow for the food waste to come to room temperature before adding. If very cold or very hot food waste is added it could change the core temperature of the digester and kill the microorganisms that breakdown the food waste.
How long can the hatch door be open for?
It is best to have your sorted food waste (out of all plastic and packaging) ready to be fed into the machine before opening the door. Extended periods of time the door is open, more than five minutes, will cause the core temperature of the digester to come down. The microorganisms thrive in a consistently warm environment. Over exposure to cold temperatures could kill the microorganisms.
What can I do to keep the machine running at 100%?
Keeping the machine fed and clean is the most important. Daily inspections and removal of any in-organic materials that may have accidentally been added to the digester is suggested.
Does the machine grind or chop the food waste?
No, the Digester does not grind or chop the food waste it gradually digests the food waste into a liquid.
What is the warranty on the digester?
Each Digester comes with one year limited warranty.
How much water is consumed and discharged per day?
When operating our largest machine in a 24 hour period, the fresh water consumption is no more than 300 gallons per day. The effluent discharged is 400 to 500 gallons per day.
Why are there plastic chips in the digester?
The plastic chips are the BioMedia where the microorganisms live. The plastic media remains in the machine at all times.
How often and how much can I feed my Digester?
The key to BioHiTech Digester’s success is balanced feeding. Like your stomach, If you feed it too much at once it takes longer to digest. A balanced diet is the best way to allow BioHiTech Digester to be most effective.
Frequently Asked Questions – Renewables
What permits are possibly needed (varies by state)?
Solid Waste Permit
Air Quality Minor Source Permit to Construct
Encroachment Permit for public road access
Local Planning and Zoning Permits
Building permits and local compliance requirements – Ongoing as required for construction.
What is the time frame for completion?
Once all major permits have been issued, construction is expected to take 12-16 months.
What are the advantages to Mechanical, Biological Treatment (MBT)?
MBT, when applied to municipal solid waste (MSW) leads to a significant weight loss. The process will lead to the recovery of additional metal recyclables (while not impacting current or future recycling activities), substantial reduction in the need for landfilling and the creation of a final product that is EPA recognized as a renewable alternative fuel called SRF. Each of these accomplishments will result in a substantial reduction in Greenhouse Gasses. There is no hazardous waste or incineration or combustion involved in the MBT process.
What is the MBT Process and how is the Solid Refuse Fuel made?
Reception – Municipal Solid Waste (MSW) placed by resident’s curbside as it is today, will be brought to the proposed facility by a local hauler. The MSW will be deposited into an indoor aerated reception pit. Air is continuously drawn into the building to avoid odor buildup inside the Facility. There is no combustion or incineration in this process.
MSW processed at the Facility is anticipated to include all of the waste currently allowable by local waste haulers including but not limited to, kitchen organic waste, mixed unsorted paper, plastics, etc. Excluded waste includes all wastes that are currently prohibited by the local waste hauler such as hazardous waste, used oil, source separated recyclables, white goods and construction debris.
Pre-screening – MSW will go through an initial screening process using a large rotary drum that will tear open the trash bags and combine the bagged waste with other non-bagged MSW. Large pieces of waste such as plastic, paper and cardboard are separated from the MSW and set aside for use during the refining stage. The remaining waste, including organic waste is referred to as “underscreen” material, is smaller in size and goes directly to a holding area. An air circulation system will be used to ensure rapid composting of the organic fraction of the waste. The air circulation system blows warm air through the under-screen waste in order to quickly start up the aerobic composting fermentation process.
Biological treatment (oxidation/composting) – The underscreen material is moved from the holding area and placed on a pre-fabricated concrete floor that contains slots through which processed air is moved. The processed air is comprised of a controlled combination of fresh air and re-circulated warm air, which ensures a consistent breakdown of the waste. This reduces the amount of water in the material leading to a dry paper-like product. There is no combustion or incineration in this process.
Refining – After the biological treatment stage, the now dried under-screen material will be re-introduced to the previously removed over-screen material in the refinement area of the facility. Using rotary screens, air separators and magnetic/infrared technology, the material is further separated to remove any metals and PVC plastics that may remain. Metals will be sent to the County Recycling Center on Grapevine Road. The PVC plastics will be sent to the local landfill. The product is then shredded into smaller pieces resulting in a product that can be used as an alternate fuel replacing traditional fuels, such as coal and petroleum coke.
How will emissions/odors from the facility be controlled?
Who will build the facility?
- A bonded Engineering, Procurement and Commissioning (EPC) Contractor
- A bonded General Contractor
- A design-build and construction management firm specializing in pre-engineered metal building design and construction
- Local contractors will be selected as sub-contractors for various elements of the construction of the proposed facility
- It is estimated that approximately 50-100 individuals could be involved in the construction project
What is the estimated cost for construction of the proposed facility?
The total investment for the facility, construction, and equipment will vary.
What type of construction is the proposed facility?
SOLID RECOVERED FUEL
Is this SRF manufacturing facility an incinerator?
No. The proposed process does not combust any waste materials as a method of waste disposal. The proposed process uses mechanical (e.g., conveyors, sorters, and cranes) and naturally occurring biological processes (oxidation or composting) to produce an alternate fuel.
Where will the MSW come from?
- The MSW would come from surrounding counties needed to operate the facility
- Household waste and C&D waste can be accepted.
- Select commercial waste may be accepted