How to Process Animal Manure into Biogas
Where there are farms, there must be waste in the form of feces (urine / urine) from the livestock itself. In certain concentration limits, livestock waste is classified as dangerous, not only for livestock, but also for human health and the environment because it produces hydrogen sulfide, methane gas, ammonia, and carbon dioxide. For example, ammonia, which is a sharp-smelling gas.
To overcome the problem of sewage waste, farmers need to know how to manage waste into something useful. Animal waste will be of high economic value if treated properly. One way to manage waste is to make it into manure.
However, this method also still causes gas or pungent odor that also impacts on health and the environment.
The National Institute of Occupational Safety and Health from the United States has set the maximum level of ammonia (NH3) in poultry cages to be 25 ppm. At high concentrations, ammonia can cause eye irritation, respiratory disturbances, and damage to the lungs. Humans can only smell ammonia at a concentration of 20-30 ppm.
One alternative treatment of livestock waste is biogas. Biogas production using liquid extract, biogas is gas produced from anaerobic (airtight) processes made from organic materials such as livestock manure, human waste, and household waste. Biogas technology has been widely applied since decades ago by farmers in Britain, Russia and the United States.
Chicken manure can be used as biogas. Biogas is the result of breaking down animal waste by microorganisms. The gas elements formed from the decomposition are carbon dioxide (30-40%), hydrogen (1-5%), methane (50-70%), water vapor (0.3%), nitrogen (1-2%) , and hydrogen sulfate (sludge). Methane gas, as the biggest element, can be used for cooking and heating (brooding).
Biogas installation. The most important tool of biogas installation is a digester that functions to collect methane gas produced by organic matter by bacteria.
The most widely used type of digester is the continuous feeding model, where the filling of the organic material is carried out on an ongoing basis every day.
One unit of biodigester with 13m3 volume is able to process dung from 1,000 chickens. One biodigester cycle usually requires approximately 100 kg of wet chicken manure. The biodigester will produce methane gas which can replace the use of 3-4 12 kg household gas cylinders. Whereas in cattle, on average one cow produces 20 kg of manure every day and can produce 0.36 m3 of biogas.
Digester, which is connected to the biogas container.
Digester (left), Digester, which is connected to the biogas container (right). The size / size of the digester depends on the amount of manure produced and the amount of biogas desired. In making digester, building materials such as sand, cement, river stone, coral, red brick, construction iron, paint and prolon pipes are needed.
The process of making biogas. After the digester is finished, the next process is making biogas in the following way:
Mix cow dung with water to form sludge at a ratio of 1: 1 in a temporary holding tank. The shape of the mud will make it easier for us to put it in the digester.
Discard the first gas produced (including CO2 gas) on days 1 to 8. While the 10th to 14th day, new methane gas (CH4) and CO2 began to decline.
At the composition of 54% CH4 and 27% CO2, biogas will ignite.
Insert mud into the digester through the inlet. On the first refill, the gas valve above the digester is opened so that the entry process is easier and the air inside the digester exits. This first sludge filling requires a lot of cow dung for the full digester.
Add starter (bacteria) as much as 1 liter and fill fresh rumen from slaughterhouses by 5 sacks for a 3.5-5.0 m2 digester capacity. After the digester is full, the gas faucet is closed so that the fermentation process occurs.
On the 14th day, it can produce biogas energy that is always renewable and to light a fire on a gas stove or other needs. Please note that this biogas does not smell cow dung. Next, the digester can be continuously filled with cow dung sludge to produce optimal biogas.
The problem of livestock manure can be overcome by making biogas. The positive effects have certainly reduced human health, livestock and environmental pollution. In addition, what is certain is to add economic value because it can be used as vehicle fuel, substitute for LPG gas and power plants.