Could cattle dung be the new cash crop?
In a state the size of California and with as many dairy farms and head of cattle as there are, dairy farmers who have gotten with the program so to speak are cashing in their (cow) chips, that is, reaping rewards, in other words.
When “Biogas Production: From a covered lagoon digester and utilization in a microturbine,” written by Douglas W. Williams and Diana Gould-Wells was published in Resource, Engineering & Technology for a Sustainable World, in April 2004, the authors declared: “The total manure produced by dairy cows in the state of California is 30,000,000 metric tons (33,000,000 short tons) per year. As presently handled, dairy manure produces undesirable odors, biogas, and nutrient overloads resulting in air and water pollution.”1
Williams and Gould-Wells are “spot” on regarding the pollution part.
As it relates, The Fresno Bee’s environmental reporter Mark Grossi in “Tactics labeled too weak in dirty fight: Air district’s leader says it balances health, economic concerns,” in the Dec. 16, 2007 The Modesto Bee, revealed, in winter, “Gases from cars and trucks combine with ammonia from cow waste in the [San Joaquin] Valley’s booming dairy industry. The gases and the ammonia form microscopic specks of ammonium nitrate, which hang like tiny chemical bombs in the foggy air.
“The specks, called PM-2.5, can penetrate deep into the lungs, triggering asthma, bronchitis and other ailments. The tiny chemical debris can pass into the blood and lodge in the heart.”
In this regard there can be tremendous value in disposing of manure sustainably.
And in furthering discussion along these lines, Williams and Gould-Wells pointed out, “California Polytechnic State University (Cal Poly) has devised a system at its dairy to capture methane, a naturally emitted manure biogas, and convert it into a usable energy source to create electric power. By incorporating a covered lagoon digester system with a microturbine electric generation system, manure’s undesirable byproducts can be transformed into valuable assets for a dairy farmer. If the total manure produced by dairy cows in the state of California could be converted to methane, the theoretical annual production would be 20 trillion British thermal units (BTU) which would be enough to power a 200-megawatt power plant.”
Capturing biogas and turning it into electricity is not the only benefit. Correspondingly, odors become far less intense, the heat that’s created can be put to use not to mention the tremendous environmental benefit.
“By virtue of the cover capturing the gas emissions from the dairy manure, both odor and the release of greenhouse gases are considerably reduced,” the “Biogas Production” authors acknowledged.
And last but by no means least, Williams and Gould-Wells noted, monetarily, the economic benefit of the Cal Poly system is on the order of somewhere around $10,000.
And that’s no bull!
- Douglas W. Williams and Diana Gould-Wells, “Biogas Production: From a covered lagoon digester and utilization in a microturbine,” Resource, Engineering & Technology for a Sustainable World, Apr. 2004, (Vol. 11, No. 3), pp. 11-12.