2011 is Shell's "year of choices" -- a time when the company plans to cut down on its biofuel research paths from 10 technologies to five. Last week, Shell exited its investment in Choren, a biomass gasification business. This week, Shell will exit its shareholding in Cellana, a joint algae biofuel venture between Shell and HR Biopetroleum Algae, according to Renewable Energy World.
There are still a number of oil companies working on algae biofuel, including BP, Exxon, Chevron, and Valero. It's not surprising -- Pike Research recently predicted that algae biofuel production could reach 61 million gallons a year and a market value of $1.3 billion over the next decade.

We'll be watching as Shell continues to whittle down its biofuel portfolio. Still in the running: Cosan's sugar-cane ethanol business, Iogen's straw-based ethanol, Codexis' biomass-to-ethanol technology, Virent's plant sugars-to-petrol process, and a number of research agreements.