A new report by researchers at an Ames company says coal-powered ethanol plants release as much as 92% more carbon dioxide than those powered by natural gas. Carbon dioxide is a gas scientists often blame for global warming.
The coal vs. natural gas issue has surfaced in a pending decision by the Des Moines City Council concerning two competing proposals to build an ethanol plant in southeast Des Moines, within the city limits. Council members on Dec. 4 are scheduled to select one of the two ethanol plant proposals. Coal would power a plant proposed by Lincolnway Energy of Nevada, Iowa. The plant proposed by Vision Fuels of Urbandale, Iowa, would use natural gas.
Council members are divided on which proposal to choose—and the split has caused delays in moving forward on the $200 million project. On November 1 the council voted 3 to 3 and tabled the decision to the December 4 meeting.
Pros and cons of coal vs. natural gas
The city owns the property where the ethanol plants are proposed to be built, thus the city council has to decide which company to sell the land to, explains Des Moines Mayor Frank Cownie. He has supported Lincolnway's proposal. He now says the information he is gathering from experts on emissions will help determine if he will change his vote away from the coal-fired plant and instead support the Vision Fuels proposal to build the plant.
Lincolnway, which is owned by 900 farmers and other local investors who reside in central Iowa, already operates a very successful coal-fired plant at Nevada in Story County. Lincolnway officials point out that a coal-powered plant has greater flexibility to use alternative energy sources that will likely be developed in the near future. Natural gas is higher priced than coal.
Backers of the coal-powered plant believe Lincolnway's plan holds the most potential of someday using renewable energy sources such as switchgrass to power the plant. Supporters of using coal also point out that the large amount of natural gas used by ethanol plants could drive heating costs up for people who live in the Des Moines area.
No limit on carbon dioxide emissions
The carbon dioxide report was released last week by Frontline BioEnergy--the Ames consulting firm. Frontline is promoting technological advancements to convert plants into a mixture of gases that could be used to replace some natural gas burned in ethanol plants. Frontline is not associated with either of the two companies competing to build the Des Moines plant.
State and federal environmental laws do not limit carbon dioxide emissions, although more than 150 other chemicals or compounds are regulated. Technology exists to capture carbon dioxide emissions but it costs more to do that and capturing the carbon dioxide is not required by law. If that "capture" technology were used at the coal-fired plant, the price to use coal would be about the same as natural gas, according to Frontline officials.
The plant would be built on a 166-acre plot owned by the city near Vandalia Road on Des Moines' southeast side. The two proposals vary, but each would create about 50 jobs and generate at least $1.6 million a year in property taxes for Des Moines. The ethanol plant would be a major new development in an area of the city that is run-down with older factories, abandoned buildings and junkyards. Des Moines leaders want to clean up the area and turn it into a technology park. They want an ethanol plant to be built there, to serve as a catalyst for future developments on the 230-acre parcel of land.