Ethanol production is slightly up in Iowa. The Iowa Renewable Fuels Association says the state's 43 ethanol plants produced a record 4.2 billion gallons in 2017. The organization is linking the increase to plant expansions, which it says increased demand and higher blends like E15. The executive director of the association says several plant expansions just finished or would be in the first three months of the new year might push numbers for 2018 even higher. The renewable fuel standard mandates that certain amounts of renewable fuels be blended into the gasoline supply of the country.