FAQs related to methane gas generation and recovery from animal manures.
What is the process of harnessing methane gas?
What is the process of converting the methane gas into energy?
How efficient is the conversion process?
Does this process affect the smell of the manure?
Do seasonal changes affect this process?
What environment gives the best results for methane gas production?
Is the equipment mostly homemade or bought by a manufacturer?
What are some of the expenses of this process?
Is any one type of manure better than another?
How much methane gas comes from a certain amount of manure?
Does the feed given to the animal affect the production of methane gas?
Are any outside chemicals needed or used to increase the production of methane gas?
How does this method affect the environment?
Is any outside help needed?
Do you know anyone else who has had success with this process?
In the future, do you think this method will be used as a major source of energy?
I am an agent for the Texas AgriLife Extension Service. Recently I fielded a question on the use of horse manure as compost. What can you tell me about this?
The following definitions have been adopted from the Texas Natural Resources Conservation Commission.
What are “agronomic rates”?
What is an “air contaminant”?
Particulate matter, radioactive material, dust, fumes, gas, mist, smoke, vapor, or odor or any combination thereof produced by processes other than natural. Water vapor is not an air contaminant.
What is an “animal feeding operation”?
What is an “animal unit”?
What is a “concentrated animal feeding operation (CAFO)”?
Any animal feeding operation (AFO) is defined as follows:
(A) Large CAFO – Any AFO that stables or confines and feeds or maintains for a total of 45 days or more in any 12-month period equal to or more than the numbers of animals specified in any of the following categories:
(i) 1,000 cattle other than mature dairy cattle or veal calves. Cattle includes, but is not limited to, heifers, steers, bulls, and cow/calf pairs;
(ii) 1,000 veal calves;
(iii) 700 mature dairy cattle (whether milkers or dry cows);
(iv) 2,500 swine weighing more than 55 pounds or 10,000 swine weighing less than 55 pounds;
(v) 500 horses;
(vi) 10,000 sheep or lambs;
(vii) 55,000 turkeys;
(viii) 125,000 chickens (other than laying hens, if the operation does not use a liquid waste handling system);
(ix) 30,000 laying hens or broilers (if a liquid manure handling system), or 82,000 laying hens (if the operation does not use a liquid manure handling system); or
(x) 5,000 ducks (a liquid manure handling system), or 30,000 ducks (if the operation does not use a liquid manure handling system);
(B) Medium CAFO – Any AFO with the following number of animals that discharges pollutants into water in the state either through a man-made ditch, flushing system, or other similar man-made device, or directly into water in the state that originates outside of and passes over, across, or through the facility or otherwise comes into direct contact with animals confined in the operation:
(i) 300 to 999 cattle other than mature dairy cattle or veal calves. Cattle includes, but is not limited to, heifers, steers, bulls, and cow/calf pairs;
(ii) 200 to 699 mature dairy cattle (whether milking or dry cows);
(iii) 300 to 999 veal calves;
(iv) 750 to 2,499 swine each weighing 55 pounds or more, or 3,000 to 9,999 swine each weighing less than 55 pounds;
(v) 150 to 499 horses;
(vi) 3,000 to 9,999 sheep or lambs;
(vii) 16,500 to 54,999 turkeys;
(viii) 37,500 to 124,999 chickens (other than laying hens and other than a liquid manure handling system);
(ix) 9,000 to 29,999 laying hens or broilers (if a liquid manure handling system), or 25,000 to 81,999 laying hens (if other than a liquid manure handling system); or
(x) 1,500 to 4,999 ducks (if a liquid manure handling system), or 10,000 to 29,999 ducks (if other than a liquid manure handling system).
(C) Small CAFO – An AFO that is designated by the executive director as a CAFO because it is a significant contributor of pollutants into or adjacent to water in the state and is not a large or medium CAFO.
(D) State-only CAFO – An AFO that falls within the range of animals in subparagraph (B) of this paragraph and that is either located in the dairy outreach program areas or designated by the executive director as a CAFO because it is a significant contributor of pollutants into water in the state. A state-only CAFO is authorized under state law.
What is a “lagoon”?
What does “land application” entail?
What is a “liner”?
How do you define “process wastewater”?
What is “process generated wastewater”?
How do you define a “25-Year, 24-Hour rainfall event”?
Air Quality Terminology
Original article by Russell McGee and Saqib Mukhtar.
Clean Air Act
National Ambient Air Quality Standards (NAAQS)
Aerodynamic equivalent diameter (AED)
Equivalent spherical diameter (ESD)
Best management practices (BMP)
Lowest achievable emission rate (LAER)
Maximum achievable control technology (MACT)
Particle size distribution (PSD)
Prevention of significant deterioration (PSD)
Hazardous air pollutants (HAPS)
Frequently Asked Questions About Animal Manure Management (links to National eXtension Website)