ABERCROMBIE POINT
There’s a little more being burned and a little less floating out of the smokestacks now that Northern Pulp has implemented a number of fixes improving the quality of emissions.
Fourth quarter regulatory testing of particulate matter levels from the power boiler at the pulp mill revealed a boiler particulate matter level of 50mg/Rm3 (reference cubic metres).
As of September 2017, the power boiler particulate matter is at 72mg/Rm3 – an amount that information from Northern Pulp describes as within the range of industry-approved emission levels (150mg/Rm3).
The improvements made to equipment at the mill came after boiler experts were brought to the site in August to identify areas that could be improved upon or had been overlooked. Northern Pulp reports that it implemented the recommendations.
Many of the changes made were ones related to the power boiler. These included changes to what went into the boiler, and how it was burned, which led to more efficient burning of that material and fewer particles leaving the boiler.
One significant improvement was to reduce the amount of sawdust and shavings, and to increase the size of the bark put into the power boiler. That had a significant improvement on performance, said Kathy Cloutier, director of communications for Paper Excellence, the parent company of Northern Pulp.
“Essentially, if you have smaller matter going into the power boiler, the smaller it is the less chance you have of it burning. The air is more likely to drive it up the stack,” Cloutier explained. “By reducing the amount of sawdust in the biomass and increasing the bark size, you have more material burning, as opposed to more escaping in the form of particulate.”
Another improvement Northern Pulp implemented was a number of repairs on the vibrating grates that sort biomass material at the facility. These include changing the control logic on the grate, which improved ash management and particulate emissions.
“If your grates are operating at max capacity, it improves the burning of the biomass in conjunction with changes in biomass size,” said Cloutier. “This also fixes problems in terms of air leaks or vibrations.
Cloutier said that fixing the vibrating grates and the quality of material entering the power boiler are complementary improvements to the facility since they have a positive effect on one another.
In a part of the facility called the boiler penthouse, a number of leaks were discovered – those were subsequently repaired during an 18-20 day, $20 million maintenance shutdown in 2017. These helped cut down on excess oxygen getting into the boiler.
“Maintenance and repairs are part of operations,” said Cloutier, who added that maintenance shutdowns allow them to undertake significant improvements that help upgrade machinery at the pulp mill and increase the longevity of the facility.
“We’re committed to continuing to improve our environmental footprint. We want to keep emissions well within our level of industrial improve and be a good corporate citizen,” said Cloutier.
