Kansas ethanol plant poised to start up anaerobic digester soon

By Holly Jessen | December 28, 2012

If all goes as planned, a 50 MMgy ethanol plant in Oakley, Kan., will someday produce advanced biofuel from sorghum. To qualify as advanced biofuel, the company will power the plant with methane from its anaerobic digester system as well as utilizing other advanced technologies.

There are several things that must fall into place before that happens, however. First, Western Plains Energy LLC needs to complete startup of its digesters—which it is poised to do soon. In fact, the company had planned to begin operations the day after Christmas but that was delayed due to weather conditions. “We are currently doing further thermal protection and will start up next week,” CEO Steve McNinch told Ethanol Producer Magazine on Dec. 27. “We want to make sure if we have to stop after we start that the plant is safe from freezing.”

At full digester capacity, which the company expects to reach in March, the digesters will produce enough methane to completely refire the plant’s thermal oxidizer and boiler. In other words, the facility won’t need to use any natural gas and could someday even generate its own electricity with additional equipment. “The main focus right now is just getting the plant’s boilers off of natural gas and on methane but it’s certainly something we’re looking at moving forward,” he said.

The U.S. EPA published a final rule for a grain sorghum fuel pathway in the Federal Register on Dec. 17. As expected, dry mill ethanol plants using natural gas and sorghum meet the lifecycle greenhouse gas emission reduction threshold of 20 percent, compared to petroleum fuel, qualifying it as a renewable fuel. However, ethanol plants using specified forms of biogas energy for process energy and all but 1.5 kwh electrical power per gallon of ethanol qualify as an advanced fuel with more than 50 percent reduction, compared to petroleum.

Although Western Plains Energy will have an operating digester, to qualify as an advanced biofuel producer the final rule also calls for combined heat and power (CHP,) which the company does not utilize, McNinch said. However, the company does have other advanced technologies in place and petitioned the EPA for a separate pathway a little more than a year ago. With the final rule now published in the federal register the EPA can rule on Western Plains Energy pathway. “I believe they will rule favorably but it’s not final until they sign it,” he said.

In the past, Western Plains Energy has used a mixture of corn and sorghum—commonly known as milo—however, the plan is to switch over to 100 percent milo when the digesters reach full gas capacity. “We’ve been 100 percent milo more often than we’ve ever been 100 percent corn,” he said. “Milo has kind of been our niche all around. When you live in a desert you have to use what grows well and grain sorghum certainly grows well here. It’s much more drought tolerant.”

Western Plains Energy received a $15.6 million grant from the Kansas Department of Commerce, which it used to help build the digester system, installed by Himark biogas. Although the project was estimated to cost between $35 and $40 million, the final tally is somewhere upwards of $40 million. Still, McNinch said he doesn’t expect future digester projects to be that expensive. “There was a lot of engineering being done as we were building,” he said.

The digester will primarily be fed with manure from a local feedlot. Other ingredients include thin stillage from the ethanol plant and food waste. Although there is interest in powering ethanol plants with biogas, full-scale adoption of the technology has been slow.



4 Responses

  1. Ron Wagner



    Better to just keep feeding the digester with manure, and feed the sorghum to livestock. Use the methane for fuel. It is natural gas that just needs to be filtered to use in vehicles or farm equipment. Natural gas is the future of energy. It is replacing dirty old coal plants, and dangerous expensive nuclear plants. It will fuel cars, vans, buses, locomotives, aircraft, ships, tractors, air conditioners, engines of all kinds. It costs far less. It will help keep us out of more useless wars, where we shed our blood and money. It is used to make many products. It lowers CO2 emissions. Over 3,700 natural gas story links on my free blog. An annotated bibliography of live links, updated daily. The worldwide picture of natural gas. ronwagnersrants . blogspot . com

  2. Bill Shaw



    Mr. Wagner, Please study, in depth, the downstream infrastructure challenges facing natural gas delivery to the transportation sector, i.e. automobiles. I think you'll realize the near and intermediate term market for natural gas as a fuel is only for powerplants. In fact with the exception of some centralized mass transit fleets, natural gas is a long, expensive ways from meeting the needs of the highly distributed transportation sector

  3. Joanne Ivancic



    Bill: I couldn't agree more about the infrastructure challenges. People I've talked to aren't interested in having CNG or LNG at their corner gas/fuel station. Wouldn't a much more efficient way to utilize that resource for transportation uses in the short and mid-term would be to replace the natural gas used to make biodiesel and renewable diesel?

  4. Daniel M



    I agree with the last 2 gents. First of all to even be a road worthy fuel, the methane must be processed into it's liquid state. This requires purification and a lot of energy to compress it. Secondly, in order to have liquid methane in cars, trucks, planes, etc. one needs to have a heavy pressure tank to store the methane. This of course in other terms is known as a bomb. One nice roadway accident and you have large explosions. Methane, makes much more sense to be converted quite easily into methanol. Methanol can be ran in any flex fuel vehicle. Still, in this case it is easier to use the methane to power a higher energy density molecule, Ethanol, than to convert to methanol. With the right digester's you too can make a protein feed, along with the DDGS from the plant you have more than enough feed coming from the plants feed stocks.


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