Setting out to succeed with making biogas from your family food scraps, at home, make sure you choose the right path and do things correctly. If you do not do it right, the end results are likely to be disastrous. You could potentially find yourself with a lack of gas to cook your meals, or perhaps a biogas digester in the back yard which becomes a white elephant, unused and unproductive.
Listed here are a trio of tactics to sidestep that kind of failure, and succeed.
First and foremost, remember
You're going to want to get in the habit of putting your food scraps into your liquidizer, or chopping them up fine and mixing with water, every day since that can help avoid the bacterial culture in your digester becoming less than as efficient in gas production than it would otherwise be. Failing to have this done may cause the supply of biogas to fluctuate. So do not make the miscalculation of ignoring this crucial step!
The second is, to keep your home biogas digester warm
Almost as important as remember to feed your home biogas digester regularly as you are working to succeed at making biogas from food scraps will be to keep your home biogas digester warm. I am here to inform you, you don't want to overlook this. It's very helpful to avoid big temperature changes in your digester, which can be something which everyone who wants to succeed with making biogas from your food scraps wants.
Lastly, take care to look after the pipework that delivers the methane biogas into your kitchen where it is used, usually by burning it in a gas ring burner beneath a saucepan, kettle etc. It only needs a small link for the gas to escape
Finally, when working with making biogas from food scraps you will want to be sure and avoid smoking while attending to your home biogas digester. This will assist you with avoiding a fire in which it is possible to get burnt, after all methane burns hot and, an essential component of such a project is always the need to ensure all work is done safely. Failing that may mean you may unintentionally cause an accident that you will regret allowing to occur. And I believe that we could be in agreement that this would not be good...
As stated above, if you would like to ensure success at making biogas from food scraps, you need to avoid the sorts of problems which could make you finish up with a lack of gas to cook your meals, or maybe a biogas digester in the back yard which becomes a white elephant, unused and unproductive. What you really want is consistent half an hour to 40 minutes of biogas flow daily for cooking, once daily, which goal you could attain by carefully using the three steps outlined above.
Benefits of manure derived biogas
High levels of methane are produced when manure is stored under anaerobic conditions. During storage and when manure has been applied to the land, nitrous oxide is also produced as a byproduct of the denitrification process. Nitrous oxide (N2O) is 320 times more aggressive as a greenhouse gas than carbon dioxide[18] and methane 25 times more than carbon dioxide.[19]
By converting cow manure into methane biogas via anaerobic digestion, the millions of cattle in the United States would be able to produce 100 billion kiloWatt hours of electricity, enough to power millions of homes across the United States. In fact, one cow can produce enough manure in one day to generate 3 kiloWatt hours of electricity; only 2.4 kiloWatt hours of electricity are needed to power a single 100-Watt light bulb for one day.[20] Furthermore, by converting cattle manure into methane biogas instead of letting it decompose, global warming gases could be reduced by 99 million metric tons or 4%
Biogas upgrading
Raw biogas produced from digestion is roughly 60% methane and 29% CO
2 with trace elements of H
2S: inadequate for use in machinery. The corrosive nature of H
2S alone is enough to destroy the mechanisms.[23][24]
2 with trace elements of H
2S: inadequate for use in machinery. The corrosive nature of H
2S alone is enough to destroy the mechanisms.[23][24]
Methane in biogas can be concentrated via a biogas upgrader to the same standards as fossil natural gas, which itself has to go through a cleaning process, and becomes biomethane. If the local gas network allows, the producer of the biogas may use their distribution networks. Gas must be very clean to reach pipeline quality and must be of the correct composition for the distribution network to accept. Carbon dioxide, water, hydrogen sulfide, and particulates must be removed if present.[23]
There are four main methods of upgrading: water washing, pressure swing absorption, selexol absorption, and amine gas treating.[25] In addition to these, the use of membrane separation technology for biogas upgrading is increasing, and there are already several plants operating in Europe and USA.[23][26]
The most prevalent method is water washing where high pressure gas flows into a column where the carbon dioxide and other trace elements are scrubbed by cascading water running counter-flow to the gas. This arrangement could deliver 98% methane with manufacturers guaranteeing maximum 2% methane loss in the system. It takes roughly between 3% and 6% of the total energy output in gas to run a biogas upgrading system.
Biogas in transport
If concentrated and compressed, it can be used in vehicle transportation. Compressed biogas is becoming widely used in Sweden, Switzerland, and Germany. A biogas-powered train, named Biogaståget Amanda (The Biogas Train Amanda), has been in service in Sweden since 2005. Biogas powers automobiles. In 1974, a British documentary film titled Sweet as a Nut detailed the biogas production process from pig manure and showed how it fueled a custom-adapted combustion engine.In 2007, an estimated 12,000 vehicles were being fueled with upgraded biogas worldwide, mostly in Europe
Biogas in United States
With the many benefits of biogas, it is starting to become a popular source of energy and is starting to be used in the United States more. In 2003, the United States consumed 147 trillion BTU of energy from "landfill gas", about 0.6% of the total U.S. natural gas consumption.[34] Methane biogas derived from cow manure is being tested in the U.S. According to a 2008 study, collected by the Science and Children magazine, methane biogas from cow manure would be sufficient to produce 100 billion kilowatt hours enough to power millions of homes across America. Furthermore, methane biogas has been tested to prove that it can reduce 99 million metric tons of greenhouse gas emissions or about 4% of the greenhouse gases produced by the United States.[36]
In Vermont, for example, biogas generated on dairy farms was included in the CVPS Cow Power program. The program was originally offered by Central Vermont Public Service Corporation as a voluntary tariff and now with a recent merger with Green Mountain Power is now the GMP Cow Power Program. Customers can elect to pay a premium on their electric bill, and that premium is passed directly to the farms in the program. In Sheldon, Vermont, Green Mountain Dairy has provided renewable energy as part of the Cow Power program. It started when the brothers who own the farm, Bill and Brian Rowell, wanted to address some of the manure management challenges faced by dairy farms, including manure odor, and nutrient availability for the crops they need to grow to feed the animals. They installed an anaerobic digester to process the cow and milking center waste from their 950 cows to produce renewable energy, a bedding to replace sawdust, and a plant-friendly fertilizer. The energy and environmental attributes are sold to the GMP Cow Power program. On average, the system run by the Rowells produces enough electricity to power 300 to 350 other homes. The generator capacity is about 300 kilowatts.[37]
In Hereford, Texas, cow manure is being used to power an ethanol power plant. By switching to methane biogas, the ethanol power plant has saved 1000 barrels of oil a day. Over all, the power plant has reduced transportation costs and will be opening many more jobs for future power plants that will rely on biogas.[38]
In Oakley, Kansas, an ethanol plant considered to be one of the largest biogas facilities in North America is using Integrated Manure Utilization System "IMUS" to produce heat for its boilers by utilizing feedlot manure, municipal organics and ethanol plant waste. At full capacity the plant is expected to replace 90% of the fossil fuel used in the manufacturing process of ethanol.
