Hemp Paper Moving Forward with Pulping Technology
Photo: PureVision’s Ed Lehrburger poses in front of bales of hemp with hemp-based paper and cardboard products made from pulp at the PureHemp biorefinery in Fort Lupton, CO. Photo courtesy of Carl Lehrburger
By Jean Lotus
The world depends on paper, but the manufacture of paper is one of the most environmentally damaging industries on earth. Innovators are finding out that fast-growing industrial hemp is a tree-free source of fiber that can be manufactured into pulp for paper and cardboard at domestic paper mills, bringing sustainability to a toxic industry.
More than 40% of the world’s commercially cut timber is used to make paper and the world’s paper industry pumps hundreds of millions of tons of toxic pollution into the air and water each year.
One Colorado biorefinery, based in Fort Lupton, is processing hemp stalks into usable paper pulp and other output products that can be sold as commodities.
Since 1999, PureVision Technology, Inc., has been breaking down plant-based materials into fiber, lignin and sugars with a patented processing technology called a “continuous countercurrent reactor” (CCR), co-owner Ed Lehrburger told Let’s Talk Hemp. The company began to process hemp in 2014, after Colorado legalized the cultivation of industrial hemp. That same year, Pure Hemp Technology was created as a subsidiary devoted to whole hemp plant utilization and processing.
“Our pulping technology de-lignifies biomass continuously in a 4-minute process, whereas conventional pulp methods take about 2 hours,” Lehrburger said.
The process breaks down hemp biomass into commodity products that can be used in multiple applications.
The pulp can be used to manufacture paper for boxes, paper bags, and paper towels and toilet paper.
In a partnership with a Boulder paper company, PureHemp made a production run in 2016 with Tree Free Hemp, owned by Morris Beegle of Let’s Talk Hemp. The 100% unbleached hemp pulp was mixed with post-consumer waste paper to form paper sheets of 50% hemp 50% recycled paper. These sheets are used to this day as poster boards for NoCo Expos and other hemp-inspired events.
The company also made heavier hemp paper for business cards and packaging for CBD and cannabis projects. The 18- and 24-point paper products were made with a mixture of hemp pulp and paper pulp.
It’s not easy to produce 100% hemp paper, Tom Harrington of Rock City Falls, NY-based Cottrell Paper told Let’s Talk Hemp earlier this month.
“The fiber is significantly more expensive,” Harrington said. “And [it’s] very difficult and time-consuming to produce,” he added.
Lehrburger agreed, and added, “but as more hemp biomass comes online and as the processes for producing hemp pulp scale up, hemp pulp will be more competitive with tree pulp, creating a slow transition to more sustainable ways to produce paper.”
To that end, PureHemp is working with an Ohio pulp mill to build out a mid-sized version of the company’s patented CCR biorefining process that will generate 4 tons of hemp pulp per day, dry weight. Right now, hemp paper is used in specialty papers and as rougher, stronger stock for packaging.
Accepting different roles for more sustainable paper means that consumers will need to get used to choosing non-bleached paper with a more golden “buff color” because it’s made without environmentally damaging bleaches. That will include toilet paper, which is bleached unnecessarily, Lehrburger said.
Along with the hemp pulp, the biorefining process also generates other industrial outputs that will eventually become profit centers for the hemp industry, Lehrburger believes.
Hemp stalks contain about 20% lignin, a sort of glue substance that holds the cellulose and hemicellulose fibers together and strengthens cell walls to protect plants from pests, disease and the weather.
Lignin is a carbon-based, extremely stable ingredient that can be converted to benzene (now derived from fossil fuels) and used in all sorts of products such as packaging, car parts, building materials, pharmaceuticals, cosmetics, plastics, eyeglass lenses, carpet, medical implants, foam insulation, adhesives, footwear, contact lens, dyes, agrochemicals and more, according to research.
“So many things can be made out of lignin,” Lehrburger said. “It can be a 100% substitute for petroleum.” The Ohio biorefinery is projected to produce 1.5 tons of lignin per day by 2024, available to a growing market for sustainable ingredients, he added.
The small-scale Ohio hemp biorefinery will also pump out about 1.2 tons daily of hemp sugar that will be further processed into xylitol, which is in high demand for healthy sugars for foods, gum, toothpaste, mouthwash, etc. Hemp sugars can even be fermented into hemp beer and ethanol, he said.
As the hemp industry grows, more and more byproducts of the plant will make hemp more valuable for farmers to grow as a widespread row crop. Ed and his partner and brother Carl Lehrburger have seen the vision of hemp and paid serious dues for almost a decade.
“The start of the hemp industry seems to represent a significant opportunity for revitalizing rural America, where the bigger picture is replacing oil-based products with bio-based products,” Carl told Let’s Talk Hemp in 2016. “Processing represents the thrust of the hemp revolution,’ he added.
The supply chain and crop supply need to catch up with the technology before hemp paper is commercially available at scale and at a comparable price to tree-sourced paper, Ed Lehrburger said. He is guessing the market will take about three years to reach a more mature stage.
“It takes visionary companies that will invest in hemp paper packaging and hemp-based products now, which will help launch the global hemp industry,” he added.
You can watch a video of how hemp paper is made with PureVision pulp HERE.
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Jean Lotus is a Colorado-based award-winning journalist and hempreneur who writes about the American West and sustainable food and technologies.