What Are Cow Methane Scrubbers?

In an age of rising energy demand, alternative fuel sources are becoming less a conversation topic and more an active area of research and development. Scientists are working to come up with win-win scenarios as they design technologies that recycle greenhouse gasses to be used as fuel. One example of this is "methane scrubbing" systems that capture the gasses from cow manure before they enter the atmosphere and redirect it for use in heat and light generation.

How It Works

• Housing cows in an open-stall barn designed with methane scrubbing in mind is necessary for the quick and thorough uptake of manure. The stalls are configured such that the manure collects in a central canal running the length of the row. Water periodically flushes the waste down the canal and into a pool for collection. Subsequently, the material is processed by a device that separates liquid component from solid, the latter being composted for fertilizer. The sludge is transported to the operative technology, called the anaerobic digester, where it is deprived of oxygen and thus releases its biogases, composed principally of methane. The gas moves by pipe to a compartment where the sulfur is removed and the carbon dioxide combusted, leaving methane suitable for fuel.

How It Helps the Economy

• The methane scrubbing systems, if adopted more widely, will create engineering and manufacturing jobs. Moreover, when placed in rural communities, anaerobic digesters can be used in common by neighboring farms, saving them capital that would otherwise go to individual compliance with burdensome greenhouse gas restrictions. Additionally, the fertilizer created from the by-product is of a purer and healthier quality, and can create an additional income stream for users of this technology. Finally, the competition from biogases can insulate the economy from oil shocks and price spikes.

How It Helps the Environment

• The reduction of methane in the atmosphere means the reduction of greenhouse gases. Should scrubbing technology be adopted, it could account for a 70 percent cut in methane emissions, tantamount to 1,500 tons of methane annually at a 5,000-head dairy operation. While climate change is a contentious subject, few could argue that the capture and use of methane as an energy source, displacing the burning of petro-chemicals, would not have a salutary effect on the air.

Challenges

• Anaerobic digesters are large and expensive machines. Whole farms may have to be redesigned to accommodate scrubbing systems, calling for additional financial outlays. Even then, these technologies will only pay for themselves when utilized by very large dairy farms. The small- and medium-sized farms are still left with possible regulation of methane emissions and no affordable method to address the problem. Amid these challenges remains the very possibility that power companies will not be interested in methane as a source fuel.