Wood Pellet Mill Saves Millions with Chemical Treatment Program

The Customer
A wood pellets manufacturer incurring high costs associated with maintenance of their process equipment.

The Problem
The facility was already reusing their wastewater but incurring high costs for maintenance activities on their process equipment:

• RTO media replacement every 2 to 3 years, costing them >$1 million each time.
• Once per month, the plant had to shut down production to clean out the equipment, consuming about 70 man hours each time.
• During downtime, they were having to store wastewater on site and ship it off-site, costing them thousands per month.
• Their centrifuges were generating 100 tons or more of 80% moisture solids that they had to dispose.

The culprit was the excess tars, tannins, and lignins in their wastewater that left deposits in the WESPs, RTOs, and centrifuges when they reused the water.

The ProChem Solution 
After analyzing the wastewater, ProChem designed an all organic CleanWESP™ chemical treatment process, utilizing coagulant and polymer, and a new wastewater treatment system. This program removes TSS, tars, and saps while reducing the TDS in the recycle tank water, which will provide the facility with cleaner water in the recycle tank and clean WESP flush water. Additionally, a treatment program was provided for shutdown water, which will enable the facility to treat and discharge that water within the discharge permit limits (instead of storing it and shipping it off-site).

The Win
This program will allow the facility to practically eliminate the high costs and maintenance activities they were experiencing before:

• Eliminate the need to haul off water.
• Eliminate compliance issues by no longer having to store wastewater on site.
• Eliminate the need to replace RTO media.
• Reduce costs and manpower required for routine planned maintenance by 80%.
• Eliminate the need for hydro blasting to clean up the WESP and associated piping (the system can now be cleaned on site).
• Reduction in solid waste generation by 60% - 70%, by increasing solids in the filter cake, bringing the moisture content to 40% - 50% (as compared to the previous 80%+).
• 7,000 BTU/lb - 10,000 BTU/lb filter cake, which creates a potential fuel blending source from a product of their waste stream.