Danish Company Provides Technology, Innovations for Cellulose Biorefining

By Roger Moore | January 03, 2009
In the Brothers Grimm fairy tale, Rumpelstiltskin spins straw into gold to save the miller's daughter. In energy-thrifty and eco-sensitive Denmark, biomass conversion company Inbicon has been spinning straw into ethanol since 2003, using a patented process company officials say could help save the United States $700 billion per year spent on foreign oil.

Inbicon, along with its parent company Dong Energy, has been at the leading edge of energy innovation in Denmark. The country is a net energy exporter, and now the biorefinery concept could further enhance that status.

Niels Henriksen, Inbicon's president and chief executive officer, outlines the thrust of his company's global marketing strategy for Ethanol Producer Magazine. "Our first step is to enable owners of grain-fed plants in the United States and Canada to add biomass-to-ethanol production to their existing operations," Henriksen says.

While other perhaps more well-known companies such as Poet LLC and DuPont Danisco Cellulosic Ethanol LLC are developing biomass-to-ethanol processes, Inbicon hopes to make its mark soon. The company says it has taken a unique approach to developing a biomass refinery. "We've taken a road less traveled with our process technology," Henriksen says. "Instead of focusing on making ethanol, we've concentrated on adding value to biomass by converting it into other forms of energy and products. Because we don't insist that all the sugar in the biomass ends up as ethanol, we keep production costs low."

Inbicon's process produces four high-value end products: ethanol, a powdered biomass-based fuel that can be burned to generate additional process energy, a bacteria inhibitor that can be substituted for antibiotics or hops in fermentation processes, and molasses syrup used as livestock feed. "By integrating the powered biofuel into a co-gen conversion, you reduce the plant's use of fossil fuels to zero," says Tom Corle, the long-time ethanol marketing executive and G-Team founder that Henriksen has enlisted to rollout the technology.

The company's patented innovations came from focusing on the front end of the second-generation biorefinery process, breaking down wheat and barley straw, corn stover, or other agricultural residues into liquefied sugars ready for fermentation into ethanol. "Handling millions of tons of straw is tricky, but Dong Energy has more than a decade of practical experience working out the logistics of the infrastructure, and coordinating all the transportation, storage and handling of huge volumes of biomass," Corle says. "This expertise in developing the workable infrastructure has put Inbicon several years ahead in its ability to do commercial-scale straw conversion."

Synergies with electric power generation are another key the company plans to demonstrate at its demonstration project located at Denmark's port city of Kalundborg. "Waste heat from the power plant next door will help process the straw, and the powdered biofuel byproduct from ethanol production will replace some of the coal burned by the power plant," Henriksen says.

An Innovation in Technology
Inbicon, a biotechnology spin-off of Dong Energy A/S, has its roots in its parent company's quest for alternative uses of biomass. Dong Energy's predecessor companies played an important role in shifting Denmark's near total dependence on Middle Eastern oil in 1973 to today's energy independence (see sidebar on page 100). The company began developing its biomass expertise in the mid-1990s.

Denmark's farmers raise a considerable amount of wheat, and the disposal of wheat straw provides an energy opportunity. Dong Energy initially burned straw with coal in its power plants, but Inbicon officials considered other uses for it. "We're engineers," explains Christian Morgen, Inbicon engineer and marketing director. "We like practical solutions. We reasoned that the straw could be converted to higher-value products if we could discover a way to separate the cellulose so it could be converted to sugars. But it had to be a simple, efficient and inexpensive way."

By 2003, Inbicon had designed and built a pilot plant that continues to convert biomass to ethanol, according to Henriksen. Now the company looks to prove its process with a larger facility. "In September [2008], we celebrated the groundbreaking for our new larger-scale biomass refinery at the Kalundborg port in Denmark," Henriksen says.

The Kalundborg facility is slated to produce 1.4 MMgy of ethanol by December 2009, which will coincide with the United Nations Climate Change Conference to be held in Copenhagen.

Inbicon's biomass refinery technology is a patent-protected sequence combining mechanical preparation, hydrothermal treatment and enzymatic hydrolysis. Developing it "wasn't rocket science," Morgen says. The straw is cooked with steam under high pressure with little water. In the cooker, the heat and pressure break down the straw fiber, exposing the cellulose molecules. "By using less water, the savings ripple throughout the plant," Morgen says. "You can use smaller equipment, smaller diameter piping [and] smaller valves.
[The plant will] use less energy for heating water because there's less water to heat, and reduce or eliminate wastewater and its handling systems and treatment."

After the cook step, the treated fiber is tumbled for several hours with a minimal amount of enzymes in a liquefaction stage. During this step, the enzymes convert the cellulose into a sugar slurry. "Our hydrothermal treatment allows us to avoid lots of expensive, exotic enzymes in the hydrolysis stage," Morgen says. "[It's] a big savings. Our special mixing equipment is designed to accelerate the conversion to sugar, requiring fewer enzymes for a shorter period, so we save not only enzyme expenses but energy costs. Both Genencor and Novoyzmes are pre-qualified to supply the enzymes to our process."

The liquefied fiber that is turned into sugar is then fermented with yeast and distilled into ethanol. The powdered biofuel and livestock feed are captured along the way. "By not separating the lignin (until) after the distillation we avoid losses of sugar or ethanol," Morgen says.

Inbicon's pretreatment yields a higher concentration of sugar in the liquid going to fermentation, resulting in beer, or alcohol concentration, at least double the normal percentage in cellulosic ethanol processing, according to the company.

Partnering for Progress
Inbicon is making use of several ethanol industry partnerships to further its process. Vienna, Austria-based technology provider Vogelbusch is slated to provide the Kalundborg plant's ethanol plant technology, starting after Inbicon's pretreatment and continuing through dehydration.

Corle says the Kalundborg facility is expected to showcase the energy integration capabilities possible by using the excess energy provided by Inbicon's process as a green energy
source for power manufacturing. The Inbicon process provides biomass to replace a portion of a power plant's coal. It will also produce a liquid fraction containing high levels of C5 sugars, salts and inhibitors. Inbicon's first demonstration plant will use the fraction as a molasses feed for domestic animals. By feeding the molasses to livestock, nutrients are returned to the soil through the animal's manure. "Again, it's all part of nature's recycling plan," Morgen says.

The company has lofty goals, planning to use its technology to reach 10 billion gallons per year of biomass-based ethanol production capacity. Additional companies, including Siemens, Alfa Laval and Atlas-Stord, are helping the company in pursuit of its goal. Atlas-Stord is a Denmark-based company providing thermal drying, evaporation and mechanical dewatering equipment.

Henriksen also touts the synergies between his company's conversion technology and the starch-based ethanol plants that comprise the current industry. "We'd welcome talks with most any agribusiness using soft lignocellulosic material that's both plentiful and inexpensive," he says.

With the current energy and economic issues surrounding the globe, its likely opportunities will sprout. Governments worldwide seek energy independence without sacrificing clean air and lower greenhouse gas emissions. The implications are huge. "Given the economic woes cascading around the world, independence from foreign oil becomes more critical every day," Corle says. "Inbicon can play a role in helping the United States and Canada shift to lower-cost, cleaner renewable fuels such as ethanolespecially ethanol made from agricultural leftovers such as wheat straw and corn stover.

Roger Moore is freelance writer located in Lancaster, Pa. Reach him at (717) 653-5700 or moorecreative@comcast.net.