After Gutenberg

Subtitle: And, here you were beginning to suspect that I was going to ignore the RNC (Republican National Convention) completely.

“Cow Power” has environmental implications, in terms of the amount of current environmental pollution and how much GHG emissions could be reduced by a change in the way waste is processed. Such a sea (ice) change is relevant in all countries with cow farts a sizable livestock industry.

This blog previously noted such development underway in Japan. Biopact reminds us that biogas from manure could generate energy for millions of Americans while resulting in less GHG (Green House Gas) emissions.

Following an example set in Germany and elsewhere in Europe, researchers from the University of Texas at Austin have outlined “a procedure for quantifying the national amount of renewable energy that herds of cattle and other livestock can generate and the concomitant GHG emission reductions.

Livestock manure, left to decompose naturally, emits two particularly potent GHGs – nitrous oxide and methane. According to the Intergovernmental Panel on Climate Change, nitrous oxide warms the atmosphere 310 times more than carbon dioxide, methane does so 21 times more.

The journal paper creates two hypothetical scenarios and quantifies them to compare energy savings and GHG reducing benefits. The first is ‘business as usual’ with coal burnt for energy and with manure left to decompose naturally. The second is one wherein manure is anaerobically-digested to create biogas and then burnt to offset coal.

“Converting livestock manure into a domestic renewable fuel source could generate enough electricity to meet up to three per cent of North America’s entire consumption needs and lead to a significant reduction in GHG emissions.”

Through anaerobic digestion, similar to the process by which you create compost, manure can be turned into energy-rich biogas, which standard microturbines can use to produce electricity. The hundreds of millions of livestock inhabiting the US could produce approximately 100 billion kilowatt hours of electricity, enough to power millions of homes and offices.

And, as manure left to decompose naturally has a very damaging effect on the environment, this new waste management system has a net potential GHG emissions reduction of 99 million metric tonnes, wiping out approximately four per cent of the country’s GHG emissions from electricity production.

The burning of biogas would lead to the emission of some CO2 but the output from biogas-burning plants would be less than that from, for example, coal. Authors of the paper, Dr. Michael E. Webber and Amanda D Cuellar from the University of Texas at Austin, write, “In light of the criticism that has been levelled against [liquid] biofuels, biogas production from manure has the less-controversial benefit of reusing an existing waste source and has the potential to improve the environment.

Nonetheless, the logistics of widespread biogas production, including feedstock and digestates transportation, must be determined at the local level to produce the most environmentally advantageous, economical, and energy efficient system, the study finds.

Such logistics include collection and closed loop storage of feedstock, to include co-digestion, which includes the processing of human waste in addition to waste from animals kept, bred, and raised to generate an income or food. Waste from converting the livestock to food also could be feedstock for anaerobic digestions. There are more biological hazards with co-digestion, thus, more care is needed.

Furthermore, before a usable product can be added to the gas line, significant upgrading must occur. And, logistics is not the only approach that must be considered. Since manure to biogas could supplant coal fired electric power generation, it also becomes the subject of political intervention from Big Farm and Ole King Coal.

Biopact References

• Amanda D Cuéllar and Michael E Webber, “Cow power: the energy and emissions benefits of converting manure to biogas”, Environ. Res. Lett. 3 (July-September 2008), doi:10.1088/1748-9326/3/3/034002