By Pulp & Paper Canada
By Pulp & Paper Canada
What new techniques are being applied to recycling operations in Canada’s pulp and paper industry? Although a lack of capital upgrades to any part of the industry ensures that forward movement is slow…
What new techniques are being applied to recycling operations in Canada’s pulp and paper industry? Although a lack of capital upgrades to any part of the industry ensures that forward movement is slow to come, Gilles Dorris of FPInnovations highlights some of the projects the organization is working on with its members.
“We have assisted our members in their quest to reduce cost and increase yield by introducing in the last five years, near-neutral de-inking and column flotation for recovery of valuable material from recycling rejects. Because these technologies are not capital-intensive, they have a better chance of being adopted. Last year, two small columns started up and the payback was good in both cases. These are universal remedies for current problems but they are good examples of innovative steps that need to be pursued to do stay ahead of the pack.
“Other trends include better separation steps, namely screening and novel flotation cells, for the removal of stickies. Many researchers in the world are tackling the control and elimination of stickies because this material is the worst enemy of recyclers and papermakers. With the single-stream collection system and the worldwide competition for cheap sources of recovered papers, the input of stickies and other contaminants is rising. One of our contributions to this field is the development of an on-line “macro stickies” . analyzer. This apparatus will help to identify the sources of stickies and to optimize the unit operations that remove them from the pulp.
“Indeed, I feel the development of on-line sensors in recycling is a priority to introduce advanced control systems. Many companies also feel this way. Recovered paper is a highly variable raw material. Indeed, much more so than wood chips. With the number of technical personnel decreasing steeply in mills, regular and systematic testing in a recycling plant is not systematically practised. Hence, reliable sensors or analyzers to monitor this variability and are furthermore integrated in control strategies, will be welcomed by recyclers.
“Another example is the on-line air content analyzer that we introduced recently. It is a multi-signal unit that can be used to control the aeration and chemical addition in flotation cells and in numerous unit operations.”