Published September 13, 2012
Havana – A Cuban farmer has devised a method for packaging biogas in plastic bags to facilitate domestic use of the fuel, the Communist Party daily Granma reported Wednesday.
"Although it's just an isolated experience for now, it could end up being a highly useful innovation," the paper said, noting that the method has been successfully employed in the western province of Pinar del Rio.
Six months ago, Daniel Garcia installed a biogas system at his pig farm to make use of that renewable energy source and obtain organic fertilizer, but after a few weeks the volume of fuel he produced exceeded his own needs and he decided to share it.
Garcia told Granma he would have needed several large hosepipes to transport the biogas to other nearby houses and that would've been cost-prohibitive, so instead he came up with an alternative method.
The solution was to store the biogas in hermetically sealed plastic bags that are used at a tomato pulp preserve factory in the region and are "very resistant and capable of withstanding high temperatures."
"With them, there's no need to compress the gas and so the process is much simpler and efficient. You simply usea hose to connect it to the (biogas stove) and the bag inflates like a balloon," Garcia said.
Each bag takes about 30 minutes to fill and provides a two-day supply of cooking gas for a family of three.
The bags, which Garcia says are re-usable, are based on the same principle as the gas cylinders found outside the kitchens in many Cuban households and connected to the stove by a regulator to prevent accidents, the daily added.
Granma said this system will be a low-cost way of solving "the old dilemma of how to gather this important energy carrier" and avoid the cost of hoses or pipes in transporting it to people's kitchens.
The newspaper also hailed the idea as ecologically sound.
It noted that when launched into the atmosphere in uncombusted form one cubic meter of biogas (mostly methane) is "equivalent to a ton of CO2" and extremely harmful to the environment.
By contrast, it can be burned to generate "clean and safe energy" and used to "cook three meals for five people."
One cubic meter of biogas has an energy content "equivalent to 0.5 liters of diesel or 0.6 liters of kerosene" and can produce 1.6 KW/h of electricity, it added.
That amount of biogas can be collected "by processing the excrement produced in one day by three cows, four horses, nine pigs, 10 sheep or 130 chickens," Granma said.