Capturing Carbon

The real issue with CO2 exists in policy debate, but that hasn't stopped some ethanol plants from capturing and selling the greenhouse gas.
By Luke Geiver | May 21, 2010
Talk of CO2 in the ethanol industry garners mainly just that, talk. From the reporting requirements, cap and trade, and tailoring issues addressed in never-ending reports issued about the gas, the answer on CO2 policy always seems to be just around the corner, another month or two away. Some ethanol producers, however, don't seem to be waiting, and have already taken CO2 action.

Pinal Energy LLC, Arizona's only ethanol plant, may look like any other facility in the U.S. when driving by, but the Maricopa ethanol producer is actually capturing and selling CO2. In Wisconsin, Badger State Ethanol produces and sells 140,000 tons of raw CO2 per year, and Bonanza Bioenergy LLC of Garden City, Kan., has partnered with a Texas oil company to sequester the plant's emissions into an adjacent oil field. Across the pond, the Ensus ethanol facility in Wilton, England, which recently came on line, planned from the start to capture and sell the emission coproduct. It will produce and sell roughly 300,000 tons annually.

Each of these plants developed their system and business model for specific market conditions, demonstrating different approaches being taken by the growing number of ethanol plants monetizing the increasingly scrutinized gas.

Making Sense
The constant grind for plant efficiency and coproduct utilization is nothing new for ethanol producers and is especially apparent at the Ensus facility. "We see ourselves as a refinery rather than just a biofuels producer," says Alwyn Hughes, CEO of Ensus. "We want to be effective with all of our processes." Before initial construction even began at the plant, Hughes says the facility planned on capturing and selling its CO2 coproduct. "It is a very important part of the plant. Our driving rational is to maximize the carbon we produce," Hughes says. "You don't run a plant to make CO2, but it makes sense to do this."

John Skelley, general manager for Pinal, mentioned a similar reasoning for selling the CO2, and his plant was designed and outfitted with that capability. "We are trying to get value out of every product that comes from the production of ethanol," Skelley says, "and especially for a plant that transfers its raw grain 1,100 miles from the Midwest." Other plants might appreciate the extra revenue, even if they don't receive their feedstock from such a distance. "In these tough times, every little bit helps," Skelley says.

Along with the financial gain possible with selling the coproduct, most plants also feel the necessity to play a part in the reduction of GHGs and the dependence on fossil fuel. Tom Willis, CEO of Bonanza Bioenergy, spoke about the role of the plant in reducing both. "We live in a time where carbon footprints are important," he says. "Whether you buy into [global warming] or you don't, it's definitely a concern." Echoing that, Hughes says, "Our rational is to refine wheat with an underlying objective [to make] a contribution to climate change. CO2 produced in our process is sustainable. If we are going to reduce our dependence on fossil fuels, we have to do what we can to get away from that."

To realize the financial gains and environmental impact that the capturing and selling creates, the plants have to understand the targeted market. Hughes explains that part of the reason his plant is in the market is because of its proximity to bottling facilities using CO2 in their products. For Pinal, Skelley says the plant is in a similar situation, located close enough to a bottling facility. The plant in Arizona has a bit more opportunity, however, being the only ethanol facility in the state that can supply a constant source of CO2.

While the importance of recognizing what the local market for CO2 is, who the other suppliers are, and how many vendors need the coproduct, an ethanol facility still has an opportunity to sell the coproduct regardless of the local demand. Yara Industrial, the Norway-based chemical company that runs the CO2 operations at the Ensus plant, says that ethanol facilities have a major draw and advantage in the CO2 market because the facilities' shut-down periods are very short.

Wiebe Buist, vice president of Yara, says companies like his need a reliable source of CO2 year-round. Yara mainly receives its product from ammonia fertilizer plants, but those plants do not run year long. Buist explains the Norway-based company contacted Ensus for this reason. "We wanted to diversify our raw gas sourcing portfolio and not be solely running on ammonia plants," Buist says. Now, the partnership supplies liquid CO2 to beverage companies and other vendors that use the product in fire extinguishers, to extract nicotine for low-nicotine cigarettes and in greenhouses to stimulate the growth of plants, Buist says.

Partnering Prevails
To sell CO2, a plant must first capture the gas, which most plants do by partnering with companies such as Yara. Pinal works with Reliant Energy LLC out of Houston and Badger State Ethanol works with EPCO Carbon Dioxide Products LLC out of Louisiana. "We basically tie in with a pipe and then capture the CO2," says Buist on the Yara partnership with Ensus. "That pipeline brings it across the road to the Yara processing facility."

Buist explains the captured gas is cleaned in processes that include pressurization, carbon bathes and molecular sieves. The end result is a liquid product that is transported in a cooled tanker at minus 25 degrees Celsius. The ethanol plant operations have been integrated with the CO2 facility at Ensus, as they have at the Pinal and Badger State facilities. At Ensus, "the operation has been integrated into the control room of the ethanol plant," Buist says. "We have provided training to the Ensus operators so they are able to operate the plant on our behalf."

The Wilton plant produces a large amount of raw gas per year, but Buist says the capture of CO2 for sale can be downsized and fit to each plant no matter the size. Badger State produces less than half of what Ensus does at 140,000 tons. Regardless the size of the plant, Hughes says, "the industry is looking for ways to maximize a reduction for plant emissions. Our challenge is to do the best we can."
When the GHG regulation eventually takes effect in the U.S., the carbon scene will forever be altered, but plants such as Pinal or Badger State have already started taking action to utilize their emissions even though the focus on carbon is on policy and less on current use. "If you looked at the set-up (of the Pinal plant) you would think this is one big plant," Skelley says about the co-located ethanol and CO2 facilities, noting that most people don't even know it's there. "We are virtually one plant." EP

Luke Geiver is an associate editor of Ethanol Producer Magazine. Reach him at (701) 738-4944 or