A Cargill joint venture is expanding a soybean biodiesel plant in Kansas City, Mo., as the agribusiness giant deepens its investment in alternative fuels.

The expansion, expected to be complete by March 2013, will boost the plant's biodiesel production capacity by 40 percent, the company and partners said in a news release Tuesday. The company isn't releasing the cost of the expansion.

Currently the plant churns out 40 million gallons of pure biodiesel each year, which is later refined and blended into fuels used to motor large agricultural equipment and trucks. It also produces 30 million pounds of food-grade glycerin.

The plant, which opened in 2008, uses soybean oil as its primary feedstock and is one of two that Minnetonka-based Cargill Inc. operates. The other soybean biodiesel plant is in Iowa Falls, Iowa. Cargill operates other types of biodiesel plants around the world.

The biodiesel portion of the Kansas City plant is co-owned by Paseo Biofuels LLC, a joint venture of Cargill and a group of private investors that includes the Missouri Soybean Association.

The biodiesel industry has been pushing hard for Congress to reinstate a $1 per gallon biodiesel production tax credit that expired at the end of 2011. The credit goes to fuel blenders.

The tax credit and mandates are credited with helping grow the industry, which saw record production last year, according to the National Biodiesel Board.

The federal Renewable Fuel Standard requires refiners to blend 1 billion gallons of biodiesel into the fuel supply this year. Next year, the requirement increases to 1.28 billion gallons.

Jennifer Bjorhus • 612-673-4683