Segetis, the Golden Valley-based “green chemistry” company that makes plant-based solvents that are petroleum substitutes, plans to start construction on a $105 million plant by next spring in wood-rich northeastern Minnesota.

The Iron Range Resources and Rehabilitation Board (IRRRB), the economic development agency funded with taconite taxes, has approved $21.2 million in funding for the renewable biochemical plant at Hoyt Lakes, 60 miles north of Duluth.

“Segetis is on the leading edge of the biochemical economy and will add value to our timber and forest-products economy,” said IRRRB Commissioner Tony Sertich.

Segetis, which has a small, leased commercial plant in Wisconsin and two pilot plants in Golden Valley, was pursued by several states and at least one Canadian province.

In an interview, CEO Atul Thakrar said the IRRRB commitment will allow Segetis to raise project-debt financing and equity from its existing stockholders and, possibly, new investors.

“There is a tremendous biomass basket up there in northeastern Minnesota, and in the long term this is the right place for us to be, from a logistics point of view, and we believe that we can be a catalyst to a ‘bio-economy’ cluster of companies up there. There is a lot of wood and a skilled workforce.’’

Segetis, which employs about 40 people, develops and makes bio-based material for flexible plastic products, synthetics, cleaning products, and other consumer goods that supplant oil-based feedstock.

“We have customers and we have potential customers who have tried [Segetis products] and are ready to buy,’’ Thakrar said. “We could begin construction in spring of 2015, maybe even the fall of this year. We need to finish our engineering and get our money together. And we have interest from investors, including existing investors.”

The Segetis project is forecast to have an annual $55 million economic impact, an inaugural 55 jobs, and support 545 jobs in related industries, according to a study from the University of Minnesota Extension Center for Community Vitality.

“By partnering with Segetis, we will be putting our flag in the ground as a region interested in developing a cluster of biochemical businesses willing to use our wood resources, improve our environment and create good jobs on the Iron Range,” Sertich said.

Northern Minnesota suffered from a downturn in the lumber-and-paper industry during the housing recession and as newsprint and magazine sales declined.

The Segetis bio-based plasticizers are rooted in cellulosic-based chemistry, which is ­considered nontoxic. Thakrar says the plasticizers function as well or better than oil-based ones.

One customer is Seventh Generation of Burlington, Vt., a maker of green cleaning and paper products. Another is San Francisco-based Method Products, which produces cleaning and laundry products sold by 35,000 retailers, including Target stores. Method detergent says it requires only two or three sprays of its laundry soap to clean a full load of laundry.

In 2012, Segetis raised $25 million, its fourth and largest round of venture capital, led by Saudi Basic Industries Corp. Ventures and with participation by existing investors Khos­la Ventures, Malaysia Life Science Capital Fund and Royal DSM. The company has raised a total of $60 million over several years.

Thakrar, who joined Segetis in 2009, is a 20-year veteran of the specialty chemical and energy industries and former president of Soane Energy, a Boston-based specialty materials start-up. Before joining Soane, Thakrar held positions at Cytec Industries and Rohm and Hass, including global business unit leadership.