A university in Massachusetts is developing a new laser technology aimed at dramatically reducing the emissions and energy consumption generated by the paper and pulp industry in Maine. Worcester Polytechnic Institute recently received a $2.75 million grant from the U.S. Department of Energy to bring the industrial drying technology to commercial use. "We are very excited about this, this could be a revolutionary technology," said Jamal Yagoubi, founding director of the institute's Center for Advanced Research in Drying.
Maine's paper and pulp industries emit about 1 million tons of carbon dioxide annually, accounting for about half of the state's total industrial emissions. Most of these emissions come from the drying process where wood pulp is mashed, pressed and rolled into paper. There are three major paper mills in the state, and they account for most of the emissions.
If Maine wants to become carbon neutral by 2045, it must address the emissions from these paper and pulp mills. Moreover, most of these factories are in low-income neighborhoods, and two of them are in areas with a higher risk of cancer from air pollutants, according to Industrious Labs, an environmental group that focuses on industrial impacts. This suggests that there may be a strong link between the operation of these plants and the health of local residents, especially cancer rates.
On the other hand, the paper and pulp industry remains vital to Maine's economic development. "These plants provide a significant number of local union jobs, and the paper industry remains very important to our community," said Matt Cannon, director of state conservation and energy for the Sierra Club's Maine chapter.
The Drying Research Center at Worcester Polytechnic Institute has been exploring an entirely new way of drying: using lasers. They hope that by focusing the energy of the laser, they can efficiently dry various materials such as paper and pulp. The head of the research team, Yagoubi, said that the laser they used is very different from the powerful laser weapons in science fiction movies. Although the laser is so powerful that it can even melt metal, dispersing it over a larger area allows its energy to be soft and evenly applied to the material being dried.
Through experiments on food, the researchers have demonstrated the feasibility of this technique. Next, they will delve into the effects of laser energy on different materials to ensure that the drying process does not compromise the quality of the product. "For paper, we have to ensure that the toughness of the paper is not reduced," Yagoubi stressed. "For food, we have to ensure that the color and taste are not affected."
Therefore, the research team will need to collect more data before putting the technology into commercial use. These data include: the distribution of laser energy on the surface of different materials, and the depth of the laser energy can penetrate the material. With this data, the most appropriate system size and operating conditions can be selected for different materials, and the corresponding laser module can be designed for each specific application scenario.
Once these details are worked out, this laser technology can be easily applied to new commercial-scale drying equipment, or directly retrofit existing equipment. "This kind of technology is perfect for retrofitting," Yagoubi said.
According to the U.S. Energy Information Administration, the U.S. industrial sector emitted about 1.3 billion tons of carbon dioxide in 2023, accounting for nearly a third of the country's total emissions. Evan Gillespie, co-founder of Industrious Labs, notes that about half of these emissions come from the heating required in industrial processes that often rely on natural gas or other fossil fuels. Gillespie also mentioned that many industrial drying processes are very temperature demanding and traditionally difficult to replace fossil fuels with clean energy, so the industrial drying industry has been a difficult point to reduce carbon.
"The biggest challenge is how to move away from dependence on natural gas in industrial production and towards clean energy." Says Richard Hart, industry director of the American Council for an Energy Efficient Economy. "The transformation of the industrial sector is a huge project, but it also has huge potential."
Evan Gillespie, co-founder of Industrious Labs, believes that making new technologies work will require a concerted effort by companies and governments to invest more in retrofitting older industrial facilities. He stressed that such investment is well worth it, not only to enhance the competitiveness of industry and preserve jobs, but also to bring significant environmental benefits. "Climate protection and jobs are not opposites," Gillespie said, "we can achieve an economic and environmental win-win by modernizing our industrial facilities."
