Methane has been getting a good run these days due to it being the energy ingredient in a little-known resource we call "natural gas".....
Yet, while the gas boom has been a silver lining in the cloud of the US economic recovery, it comes with a price: methane is not going to help the effort to curb greenhouse gases. In fact, it has 21 times the heat retention properties as carbon, so hurting it seems more likely.
This chart shows the many sources of methane by-product Unfortunately, in every case, the gas is too contaminated for energy use. |
That's where Craig Criddle, professor of civil and environmental engineering at Stanford University, comes in. Criddle has a different idea for methane; while its energy seems near impossible to draw on a cost-efficient scale, turning it into plastic is very doable.
Groundwater bacteria munching on methane. |
While it's not going to solve energy issues, this method makes a solid argument that methane, not petroleum, should be looked at as the chief source of our plastic products. Criddle himself gives an economic reason:
“From a business standpoint, it makes far more sense to use methane as a polymer feedstock than to burn it for power production...PHB sells for $3 to $4 a kilogram on today’s market, while methane burned for electricity production would return from 40 to 80 cents a kilo.” - Craig Criddle to Glen Martin, Stanford Engineering
In addition, converting methane to a polymer sequesters all the carbon that would usually and eventually make its way into the atmosphere under our current petroleum-based process. Thus using methane-based polymers are not only cheaper, but have a direct effect on greenhouse gas emittance, as well.
Seems like a pipe-dream? Not at all. Stanford alum Molly Morse, PhD, is the CEO of Mango Materials, which has just recently been permitted to operate a PHB production facility at a wastewater plant in the Redwood City area of San Francisco County. If all goes well, methane-based polymers could be a commercial product- and a welcomed innovation- within a few years.
Donal Thoms-Cappello is a freelance writer for Rotor Clip Company.