Guardian: It was barely 18 months ago that the British biofuels industry was surfing on a wave of euphoria. There were almost weekly announcements from companies big and small that they were going to invest heavily in a sector that promised to play an important role in the battle against global warming. On April 15, the sector is to be given an even bigger boost when the government introduces its Renewable Transport Fuels Obligation (RTFO) that requires the station forecourt to supply at least …