The Facility is planned to process approximately 500 tons per week (only 5 transfer trucks, or 11 tree chipping trucks per day on a 5 day week) of biomass to produce approximately 7.5 tons of mineral ash materials per week. The ash looks like fine beach sand and contains only those minerals that were contained in the wood used to fuel the facility.
The Company anticipates that the electricity produced at the Facility will be used to power manufacturing equipment used to support the equipment production needs of the Company, including electronics, emissions scrubbing equipment, and structural frames for combustion systems. The surplus power is planned to be sold to the local Utility on an "as available" basis under California Public Utility Commission Tariffs. This allows the use of the Facility as a true "cogeneration" unit for the manufacturing scrubber systems and heavy steel components for other combustion units, at effectively one-third the cost for electricity. The Facility is designed to export to the local service (12 KV) grid approximately 2.4 MW on a continuous basis with only minor down time (95% uptime). The Kittyhawk Renewable Energy Facility will also be applying for certification under the State of California's Renewable Portfolio Standard.
All fuel for the Facility is expected to come from a radius of less than 20 miles. The Company believes that approximately 100,000 tons of suitable fuel material will be available for the Facility each year in this small radius. This fuel is typically from tree trimmings and clean wood sources. The fuel material can be delivered to the Facility as opposed to the surrounding landfills, allowing existing landfill space to be utilized for materials that are truly not recyclable, thereby extending the life of the landfills.
How Kittyhawk Works
The project requires the delivery of coarsely ground wood via end dump transfer trucks from local wood trimming companies located in the greater North County area. The facility is anticipated to consume approximately 70 tons of ground wood in a 24- hour period, or approximately 500 tons per week. This equates to approximately five 22 ton truck loads per day of raw fuel on a five day delivery schedule.
Truck trips would consist of inbound trips to dump material and outbound trips to return to the off-site wood transfer facilities; no material delivery trucks would be staged or stored on-site for outside fuel storage. Trucks and/or trailers may be staged during normal business hours in the back yard of the facility during the time required to unload the ground wood. Trucks would provide delivery of ground wood to the site from Monday through Friday, during normal business hours with no truck deliveries planned on Sundays.
The ground wood will be delivered directly into a receiving bin located within the existing truck unloading area on the South side of the building. Once dumped into the unloading bin, the rough ground wood will be transferred to a sizing grinder and screen system, which then stores the finished ground fuel in a storage bin located inside the building. All fuel is to be stored inside the building, and delivered to the combustion systems as needed to produce clean renewable energy.
Waste from the combustion process will consist of a sterile ash that resembles fine grained sand, which will be trucked off-site approximately once every week. No hazardous chemicals, compounds, wastes or other hazardous materials that could be discharged to the environment are to be used in the normal operation of the facility other than standard cleaning products and lubrication grease for the components of the combustion system. Anti-corrosion chemicals are used in the high pressure boiler system, they are recycled in the normal operation of the boiler system, and are no more dangerous than anti-freeze used in automobiles every day.
Control and Monitoring Systems
The controller for the combustion unit consists of a PLC computer system with panel view and graphics terminals for operator monitoring of the system. Motor controls for pumps, fans, conveyors etc. use Variable Frequency Drives where variable speed is required, or soft-start contactors for fixed speed motors. The wiring points are centrally distributed to fixed point motor controls throughout the facility. The PLC system controls the combustion unit’s primary, secondary, excess air, boiler, scrubber, ash removal, and fuel feed systems. Control between the PLC and display panels, variable frequency drives, and other controllers utilize Ethernet controls. All motors are be hard wired with manual start/stop controls for safety issues or manual operation.
The cooling system for the facility is comprised of a low noise, multi-cell water filled radiator/cooling tower with electric fans to cool the steam turbine and provide heat to the warehouse portion of the building if needed. The radiator/cooling tower will be located on the South side of the building. All equipment and associated components of the system will be located inside the building with the exception of the ground wood delivery bin. Exhaust from the facility will be handled via an exhaust pipe that would be roof mounted on the South side of the building.
Operational Characteristics
The proposed biomass combustion demonstration unit will operate continuously, 24 hours a day, 7 days a week. The delivery and processing of ground wood will occur Monday through Friday and would be limited to daytime hours of 8:00 AM to 5:00 PM in accordance with normal business hours.
The proposed co-gen facility is estimated to generate approximately 2.8 megawatts (MW) or 2,800 kilowatts (KW) hourly. It is estimated that approximately 0.4 MW (or 400 KW) will be required for operation of the facility and up to 0.25 MW will be used periodically for manufacturing activities onsite.
The average excess electrical energy generated by the facility (estimated at approximately 2.4 MW or 2,400 KW) is anticipated to be sold to a municipal customer with the excess sold to San Diego Gas & Electric under CPUC tariffs for small renewable energy generators.
Operational Emissions
The proposed project consists of the development and operation of a biomass combustion system within an existing industrial building. The facility will operate a combustion unit that would use indirect combustion techniques to convert biomass into electrical energy using a steam turbine generator. The project will use computer controlled temperature limits for the combustion process to prevent combustion gas temperatures from exceeding 1,900 degrees Fahrenheit, and the use of bleed air injection to avoid the formation of compounds above the 2,100 degree Fahrenheit range. Proposed emission control devices for use in the facility include solid urea injection into the fuel supply, a passive NOx catalytic converter, three (3) dust cyclones, a wet misting spray scrubber, a wet electrostatic spray precipitator, and CO2 recovery scrubbers. Total emissions from the project site are expected to be less than 10 pounds per day of any regulated air contaminate (NOx, SOx, HC, PM), which would be roughly 5% or less of what traditional biomass combustion systems would produce using the same feed stock for fuel.
Emissions generated by the manufacturing of scrubber systems, electronics, or combustion systems are consumed by the biomass combustion system. This leaves only the vehicle tailpipe emissions of the employees driving to work as the environmental impact coming from the operations of the facility.