Virent Energy Adds $21 Million

Virent Energy Systems Inc., a Madison, Wis.-based developer of a catalytic biomass processing system for making transportation fuels, has raised $21 million in second-round funding. Stark Investments and Venture Investors LLC co-led the deal, and was joined by return backer Cargill Ventures. Virent Energy has raised nearly $40 million since 2005.