The installation of a LignoBoost lignin extraction system in North Carolina is proceeding on budget, on time, and injury free, reports Bruno Marcoccia, director of research and development with Domtar. The line under construction at Domtar’s Plymouth, N.C., site is expected to start-up in the fourth quarter of this year, and begin production early in 2013.
Marcoccia provided an update on the Metso-supplied LignoBoost project for participants at the International Lignin Biochemicals Conference on June 21. The Plymouth mill will produce 50-100 tons per day of lignin, which will initially be used as a fuel, by the mill and external customers.
“One hundred tons per day is a significant amount,” he noted. “You do not just pile that up.” Since there are not yet any customers for such a large, continuous supply of lignin, Domtar will use it as fuel. Domtar’s facility will be the first commercial source of lignin to enter the market in about 25 years.
Through collaborative product development, Marcoccia expects to eventually exploit higher value applications for lignin.
The R&D executive explains that the Plymouth mill was uniquely suited for the lignin project because it has been recovery-boiler limited for several years. In the nineties, the Plymouth mill was rebuilt with two new fibre lines (one hardwood, one softwood) and new bleaching capacity. It was producing 3000 tons/day of product. At that time, the mill was an integrated facility, with five paper machines. One by one, for various reasons, the paper machines were shut down, and by 2010 Plymouth was no longer producing paper.
Domtar acquired the mill in 2007. Following the closure of the paper machines, the mill was converted to produce fluff pulp using 100% softwood furnish. Softwood strains the recovery boiler more than the hardwood did, so the recovery boiler is overloaded.
Marcoccia explains that the LignoBoost process will cost effectively remove lignin from the black liquor stream, and reduce loading on the recovery boiler. That, in turn, will allow an increase in production for the pulp line.
The Plymouth mill also has co-gen capacity, so the mill can use the recovered lignin to produce additional steam.
In effect, producing 50 to 100 tons per day of lignin should allow the mill to produce an equivalent amount of incremental pulp.
“The vast majority of mills are more balanced (in terms of energy) than Plymouth. This is the only mill in our company that can justify the cost of the lignin plant based solely on its debottlenecking benefits.”
Marcoccia notes that if the mill does begin selling the lignin, it will need a replacement, low-cost fuel to use in the pulp manufacturing process.