Shanghai Daily: Just think of the foul, methane-rich manure produced by 500,000 million chickens. Don’t turn up your nose. That’s a lot of green biofuel. Zhang Qian gets a whiff. Feeding plants to farm animals and using animal manure to fertilize plants is an environmentally friendly, but old-fashioned way to farm today. But generating biogas – especially flammable methane gas – from manure and organic waste and using that to generate electricity is far better and tackles air, water and ground …