Features Research & Innovation
Betting on Biochemicals

Truckloads of lignin are rolling out of Domtar’s Plymouth, N.C., mill. Employees in the lignin separation facility call the trucks headed to external customers “money trucks”, as opposed to the loads destined to be used within the mill site as a bio-based fuel.
Already, Domtar has completed commercial transactions for lignin with both regional and international customers, for prices in the range of US$600-US$900. The company says it has more than 100 active customers or potential customers engaged.
“We are very committed to the long-term future of this business,” said Domtar CEO John D. Williams at the ribbon-cutting ceremony in June for the new lignin removal plant.
Domtar’s long-term goal for the Bio-Choice lignin product line is to have multiple mills producing multiple grades, from different wood sources, including modified or upgraded lignin grades.
The Plymouth lignin separation plant has been operational since March. It currently produces about 30 tons/day of lignin, using Metso’s LignoBoost process. Production is expected to be 75 tons/day by the fourth quarter.
But even with commercial quantities available, it will take time to build market demand. Domtar senior vice-president Mike Edwards summarized the whole market development quandary for biochemicals this way: “Until we get a higher value for the lignin, it’s hard to justify [the investment].”
More lignin, more pulp
The mill in Plymouth has undergone
various transformations since its inception in 1937. Under Domtar’s reign, the mill
was repurposed in 2010. An investment of
US$85 million changed it from a facility with two fine paper machines and a fluff pulp line to one that produces strictly fluff pulp (444,000 ADMT/y). CEO Williams says the switch to fluff pulp “has enabled us to build out our business and invest in our customers,” referring to the genesis of Domtar’s personal care business, which includes the purchase of the Attends line of personal incontinence products and diaper manufacturer Associated Hygienic Products. This new revenue stream is expected to bring in EBITDA of US$200 million by 2017. “This has had a huge influence on the whole strategy of our organization,” Williams states.
The changeover to fluff pulp left the mill uniquely suited to this lignin project because the process was out of balance, with the recovery boiler loaded to more than 100%.
Because the lignin removal process reduces the load on the recovery boiler, it has the potential to allow the mill to produce more pulp.
Since starting up the lignin separation facility, the mill has been able to increase the operating rates of the recovery boiler. “We’ve incrementally been able to push up the solids burning at the recovery boiler,” says Marty Brian. “We’re optimistic. The early returns are positive.”
In its latest configuration, the Plymouth mill is also leading the charge for Domtar’s fibre innovation projects. Bruno Marcoccia, director of R&D for the company, explains that in order to penetrate a market with a new product, you have to first demonstrate you can produce it regularly and with consistent quality. That’s the job of the crew at Plymouth.