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.