Transforming Paper Mill Pollution into Commercial Resource
EPA-pioneered green chemistry technology that filters toxic pollutants from industrial waste and turns it into a marketable resource has the potential to pay big dividends for paper mills.
You’re cruising down the highway, windows open, fresh air in your face. “What is that gosh-awful smell?” Suddenly, the fresh summer air smells as though a hundred cooks are boiling a thousand cabbages right under your nose. You have just driven by a pulp and paper factory.
The chemical pollutant causing this odorous essence of cabbage is called dimethyl sulfide. It is a waste product of the pulp and paper industry along with numerous hazardous chemicals including highly toxic sulfur compounds, called total reduced sulfur compounds (TRS), and volatile organic compounds (VOCs) like methanol gas.
“The dimethyl sulfide in one pulp and paper company alone was being generated at about 400 thousand pounds per year,” reports John Leazer, director of EPA’s sustainable technology research. A toxic pollutant, methanol gas, is also very common in pulp and paper industry waste. “Methanol was being emitted at roughly 600 thousand pounds per year at the same company,” says Leazer.
In an effort to reduce these harmful pollutant wastes, EPA scientists have developed a green chemistry technology that captures and converts such chemicals into useful resources.
In 2006, the US pulp and paper industry generated over 200 million pounds of hazardous wastes, including TRS and VOCs. Currently, standard practice is for pulp and paper mills to direct hundreds of thousands of pounds of such waste into giant incinerators for burning, which in itself entails large energy costs.
Where others saw only the creation of waste and the consumption of energy, a handful of EPA researchers saw opportunity. The scientists have now pioneered a safe technology that captures certain polluting compounds and converts them into chemicals that can be sold on the open market—commodity chemicals.
EPA chemical engineer, Endalkachew Sahle-Demessie (Sahle), states, “This technology takes the methanol from the pulp and paper industry waste streams and selectively converts it into methyl formate, an environmentally friendly blowing agent and solvent, and a precursor to formic acid which is used as a preservative and antibacterial agent.” In addition to creating a marketable resource, the new technology even clears the factory air of most of its unpleasant odor.
Studies have shown that the new technology removes roughly 98% of the chemical pollutants responsible for the boiling cabbage smell of pulp and paper mills. Ninety percent of toxic methanol gas is also removed from the factory waste.
Based on the average amount of waste from pulp and paper mills, this new technology has the potential to remove up to 13,000 pounds of pollution per day, saving the factory between $500,000 and $1 million each year.
“This technology is new. This technology doesn’t use any toxic chemicals. And it doesn’t disrupt the current core process of the pulp and paper industry. It simply converts the industry waste into useful product,” says Sahle of the aspects of green chemistry prevalent in this research.
This unique technology is the result of collaboration between university, government, and industry researchers. Presently, EPA scientists have completed a small-scale trial of the waste converting technology they and their partners have pioneered at a pulp and paper mill in Kentucky.
“A lot of innovative bench work has been done, but most of the research does not simply transfer to an industrial scale, so you can’t see the impact of it yet,” cautions Sahle. “What we are doing now in the EPA lab is trying to move from the discovery of this technology to small scale research trials, and then to collaborate with industry to take this technology and scale it up.”
Future large-scale use of this innovative green chemistry could significantly decrease the amount of pollution released by paper mills, the amount of energy paper mills use to dispose of waste fluids, and greatly reduce the smell surrounding paper mills. At the same time, such technology could increase mill profits as they harvest marketable chemical resources.