Part of the show Parasites and Clean Water
US researchers have found a way to turn corn on the cob leftovers into gas storage tanks for cars running on methane (Liquified Natural Gas - LNG). The problem with LNG tanks is that they are often bulky, heavy, and store gas at very high pressures (over 3600 psi). Instead Peter Pfeifer, from the University of Missouri-Columbia, has found a way to produce a porous carbon matrix capable of storing large amounts of gas at much lower pressures. He first adds corn-cob waste to a solution of phosphoric acid, heats the mixture to over 450°C in a reactor, and then bakes it at 160°C for 3 hours. The product is then washed with water, dried, ground and pressed into briquettes. The resulting carbon matrix contains a network of pores and channels that can soak up 180 times their own volume of methane, but at a very low pressure. Normally methane needs to be stored at pressures of 3600psi, but with this technique 500 psi is needed, allowing designers to build shaped, space-saving lighter tanks. The team are currently road-testing the technique using a pickup truck, which has been using the new system since mid October.