Coal Combustion Residuals (CCRs), also referred to as “Coal Ash”, result from the burning of pulverized coal in power plants. There are several by-products produced from burning coal, such as:
Fly Ash – a very fine, powdery material composed mostly of silica made from the burning of finely ground coal in a boiler.
Bottom Ash – a coarse, angular ash particle that is too large to be carried up into the off-gases so it drops to the bottom of the coal furnace.
Power plants also benefit from the revenue of the sale of coal ash (mainly fly ash that meets certain specifications) while at the same time reducing the cost of sluicing and ponding the ash, which in turn creates a negative environmental impact.
PENTA serves the needs of its clients from both ends of the spectrum: The power industry with feasibility and environmental studies, engineering and construction to transport, deliver and store fly ash; and additional services, such as process engineering to use coal ash by-products as alternatives to other costly raw materials currently used in downstream industries.
For example, fly ash (and potentially bottom ash) is used in the production of concrete and as a raw material in Portland cement manufacturing. PENTA has designed ash distribution terminals and engineered the material handling and storage systems for fly ash from the source Owner’s site to the End User’s site.
Design of a System to Transport Fly Ash
PENTA performed basic engineering services for the installation of a new fly ash handling system to dispatch over one million short tons of dry fly ash per year by rail and truck. Fly ash is currently ponded while it can be sold as a ready-mix concrete additive. The design was prepared accounting for plant operating and logistics requirements.
The fly ash handling system consists of an air slide system and bucket elevator, which transports fly ash from the existing fly ash silos to a new silo capable of loading both railcars and trucks simultaneously. Process equipment includes:
- New silo designed with adequate fluidizing air to allow for the transfer of dry fly ash to both the rail cars and trucks
- Bucket elevator, air slide(s), loading chutes, and dust collection equipment
- Associated air locks, flow control valves, and slide gates
- Electrical hardware and controls
- Rail scale and truck scale certified for federal trade
- Associated roads for truck traffic
PENTA’s team performed 3D scanning of the facility and initiated surveying and a geotechnical study. PENTA also prepared the equipment list, equipment and silo specifications, plot plan, P&IDs and General Arrangements; structural and electrical designs; issued bid packages to vendors and subcontractors; evaluated the bids and submitted a report to the Client, which included an EPC CapEx estimate and Project Execution Schedule.