March 27, 2007 11:11 AM PDT
Manure power goes live in Texas
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Microgy, which makes and runs facilities that turn manure into natural gas, has started to ship gas from its Huckabay Ridge facility over pipelines.
Six of the eight digesters--large silos that effectively employ heat and microbes to transform the manure into gas--are up and running. When the facility is fully operational, it is expected to be capable of producing 650,000 million cubic feet of gas, or BTUs of heat, a year. That's the equivalent of 4.6 million gallons of heating oil. (About 1,000 cubic feet of natural gas can produce 1 million BTUs.)
The gas is being bought by the Lower Colorado River Authority, which will also get carbon-trading credits in the transaction.
The shipment, which was delayed, marks another milestone in the pursuit of making alternative sources of energy more mainstream. Farmers, mostly in Europe, have been using digesters that turn manure into gas for a few years. The farmers, however, consume the gas for their own purposes.
By contrast, Microgy, a division of Environmental Power, takes the manure from thousands of cows at different dairy farms, processes it and then ships the gas over commercial pipelines.
It's a small amount, compared with the overall consumption of natural gas. In 2003, the world used 95 trillion cubic feet of natural gas.
Getting natural gas from manure has commercial and environmental benefits, according to Microgy. Harvesting manure efficiently could help reduce natural gas exploration and imports. The carbon dioxide produced in the process is also considered renewable: alfalfa sucks up carbon dioxide from the atmosphere; cows eat it; and when it gets released from the biogas, some portion gets reabsorbed by plants. The process doesn't add additional carbon from the middle of Earth to the environmental cycle taking place on the surface.
Manure is also nobody's friend. It can cause algal blooms--an increase in algae in aquatic systems--and other problems. The stems and other solid matter left over after the gas is produced can also be used for cow beds.
Demand for energy and mandates to cut emissions are expected to drive the alternative-energy markets.
Microgy originally hoped to start shipping gas last fall. The company, however, experienced difficulties in getting the machinery that cleans and compresses the gas for commercial shipments.
Manure doesn't directly turn into gas. First, it gets turned into a substance called biogas, which is a mixture of methane (natural gas), carbon dioxide and sulfur compounds. The machinery removes the carbon dioxide, sulfur and any water vapor that happens to get into the mix.
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5 comments
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early?
friend." It's a pollutant on large industrial dairy farms and
feedlots, which also happen to be inhumane for the livestock
and unhealthy for both animals and people (e.g. antibiotic
resistance because the crowded conditions make animals
continually sick, and BSE/CJD because animals are fed totally
inappropriate substances, E. coli contamination at CAFOs). On
small, diversified farms, manure is a valuable resource!
Read Michael Pollan's _Ominivore's Dilemma_ for a glimpse at
these two very different worlds.
Until the day when most food is grown on small diversified
farms near where it's consumed (instead of the now-typical
1500 miles that put an enormous amount of carbon into the
atmosphere), it's great that somebody has come up with
something useful to do with the massive amounts of excrement
from the big "farms" instead of sullying aquifers -- but it would
be far better to reduce the scale of those operations in the first
place.
One man's trash is another one's treasure...
Algal blooms is caused by excess phosphorus. The methane in natual gas is CH4. Do you see any P in that formula? The phosphorus remains and will probably be land-applied just the way the manure originally would have been, meaning it's subject to the same runoff that manure is. So this digester really doesn't solve the algae problem and probably makes it worse because now the P is more concentrated than the manure P.
Did the author actually think the P just disappears?
Shipping manure which is mostly water to the digester from farms, then shipping solids back to the farms is extremely expensive in terms of equipment, labor and energy. An interesting question for the author to have asked is what the net energy is from the process? And what government subsidies are involved?
Having the digesters on-farm perhaps makes more sense.
An example of limited context was the old engineering 'fact' that the gasoline engine was 21% efficient, in thermodynamic terms -- compared to the 'inefficiency' of steam at only 11%. It wasn't bad press that killed the Stanley Steamer but seeing only some variables in a complex equation.
A current example of blinkered thinking is Planktos, Inc. Whoopie, we've got a theory and two limited tests: so let's dump 50 tons of iron oxide in the Pacific Ocean. It's a nutrient, you see, and plankon will thrive and absord that nasty CO2.
Yeah sure. Anyone who grew up in Florida in 1948 onward would shudder at the potential for creating a 'red tide' of mammoth proportions. All I can say about this misguided answer to ~climate change~ is: eat your shellfish and seafood now, it'll likely be reeking with neurotoxins Real Soon Now.