- Case Studies
Industry: paper production
Project Type: waste reduction
Location: Portland, OR
Kyle Elliot worked with West Linn Paper Company to identify paper-making process improvements and equipment upgrades to reduce waste.
West Linn Paper Company is a manufacturer of coated web, inkjet and specialty packaging paper and is the oldest active paper mill in the western United States. Although the mill has taken steps to achieve greater sustainability, loss of stock (the fibrous pulp mixture used to make paper) supplies a consistent waste stream. Not only are there direct financial costs to stock loss, there is also an associated cost to transporting wasted material. Although there are potential reuses for clean paper material, such as in kitty litter, the latex in the stock renders it a hazard. As of 2017, the mill loses 4 million gallons of stock each day, and an estimated $17,000 is lost due to stock loss treatment, unrecoverable resources, and shipping.
A saveall is a device that recovers fibers and other solids from wastewater during the paper making process. West Linn Paper Company has two active savealls (PM1 and PM2) to treat paper stock, each with similar but different operating systems. By analyzing trends in total suspended solids (TSS) recovered from the savealls across time, Elliot determined that the saveall's effectiveness at reducing stock loss could be enhanced through equipment upgrades and/or chemical modification.
Elliot recommended two solutions that, if implemented, would potentially save the company money, reduce solids waste, and would take less than 3 months to accomplish.
Solution 1: Modify the existing savealls to optimize the production of micro-bubbles that allow for greater separation between TSS and waste liquid, enhancing saveall efficiency. The modifications would be low cost to implement for the PM2 saveall, but PM1 would prove more costly due to its lack of a newer-technology pump.
Solution 2: Adding a chemical retention aid to stock entering the PM1 saveall would reduce the TSS for the saveall to collect. The PM2 saveall was already using this chemical, so this solution would be easy to implement.
in annual company cost
of solids waste discharge