ELECTRICITY GENERATION FROM COW DUNG :The Power of Cow Manure
Today, the electricity sector is facing problem due to increasing demands of society. Our society needs a better and more economical method to generate electricity.Cow dung is viable source of electricity but the generated current is not enough. It can be increased by addition of certain substances having higher conductance like manure, compost. This is the research work for generation of electricity from cow dung as well as effect on the current due to addition of manure and compost. Cow dung is collected in a container and then a paste is made out of it using water. Salt is added to it. A circuit is constructed using wires and two electrodes. Upper wire ends are connected to an LED, a motor etc. and the lower wires are connected to electrodes of graphite. These electrodes are kept inside the cow dung and the current is observed. The electrodes are taken out and compost and manure are added. The current is checked again using a multimeter.
The utilization of livestock manure is nothing new. Historically, it is a tried-and-true farming method for improving soil quality to assist in crop growing. Using manure as a natural fertilizer also keeps carbon in the soil and out of the atmosphere, where it can form carbon dioxide (CO2), a greenhouse gas (GHG). This is critical, as agriculture makes up 11% of total GHG emissions. Add to that the transportation and electricity industries that make up 27% and 25% of GHG emissions, respectively, and we are looking at nearly two-thirds of the causes contributing to climate change.
Fortunately, these emissions can all be decreased by using technology that already exists. Through the use of biodigesters, agricultural manure can be converted into renewable natural gas (RNG), and the remaining remnants into valuable materials including fertilizer, potable water, and CO2.
Anaerobic Digestion
According to the U.S. Environmental Protection Agency (EPA), an anaerobic biodigester is a system that uses organic waste to produce fertilizer and biogas or renewable fuel (Figure 1). It is typically an airtight, high-density polyethylene container that uses anaerobic digestion, a fermentation process that is absent of oxygen. The process separates methane from the solids and liquids that make up manure while effectively keeping the odor from escaping into nearby communities. The methane captured at the top of the biodigester containers can then be used to create RNG.
The process begins when animal manure is deposited into anaerobic biodigesters. When maintained at a temperature of 100F, biodigesters create an environment where microbes thrive and consume the volatile solids in the manure while producing methane gas.
The extracted methane gas can be repurposed in a variety of ways. It has traditionally been used to produce electricity through combustible generator engines, but it can also be used to produce clean RNG fuel. RNG is a critical component of a clean-energy future because it serves as an effective alternative to fossil fuel natural gas. The process of converting cow manure is carbon negative and equates to nearly a negative-300 Carbon Intensity (CI) score.
RNG can be injected into a pipeline and used in the transportation industry for cleaner fuel-burning vehicles. Using RNG reduces pollution and enables organizations within the transportation industry to meet those requirements. Research shows that when all climate benefits are considered together, RNG from dairy manure can reduce GHG emissions by up to 400% when used to replace traditional vehicle fuels.
Investing in anaerobic biodigesters also further benefits the agriculture industry. Local farmers who send their manure to an anaerobic biodigester facility reap the benefits from various nutrient streams once the manure is further processed. After the methane is extracted, nutrient concentration systems can break down manure further to remove pathogens like phosphorous that previously contaminated nearby water sources.
The final product of solid material made up of fiber is returned to farmers to use as compost and bedding, saving farmers the expense of purchasing sawdust, wood shavings, straw, or sand. In addition, through nutrient concentration systems, the liquid material can be further separated into a concentrated liquid fertilizer for farmers to use in their fields. This leaves stream-dischargeable water that can either go directly back to the local water system or be used by local farms for irrigation or livestock.
We explore how farming innovator Arjan Prinsen uses a modern fermentation system – a Combibag – to create electricity and heat from cow manure.
Cows cannot digest 100% of what they eat, so a considerable amount of nutrients and energy ends up in the manure.
Rather than considering manure a waste product, by processing it further inside anaerobic digesters, methane is created which can then be used as a source of energy; the solid fraction (digestate) that is left after the fermentation took place can then also be used to extract valuable nutrients with which to fertilise the land.
In the Netherlands, farming innovator Arjan Prinsen uses a modern fermentation system – a Combibag – to create electricity and heat from cow manure, which has proven to be a successful business model.
How does a Combibag work?
Combibag is a very simple storage system for liquid and gas, with a high calamity storage capacity for gas, but low total manure input capacity and low labour costs. It consists of a fermentation chamber (digester) that is filled up to 80% with manure, the rest being the biogas (primarily methane) formed as the result of the fermentation. The Combibag is placed in the ground (just above ground water level) and isolated through the earth wall with extra insulation around the bag and the thermic isolation is increased further by an air blown hall placed over the Combibag.
The manure is pre-mixed with additional organic materials and then pumped into the digester every hour. The bacteria that ferments the manure needs to eat continuously, they cannot be starved! This is (as much as possible) an automated process, because we want to keep the system as labour-friendly as possible.
The biogas produced in the digester is continuously pumped to a small electromotor, to be either converted into electricity or used as heat. The electricity is used to power farm machinery and a few neighbouring houses. The heat is partly used for private heating and partly fed back into the digester to ensure a stable fermentation temperature of 38-40°C, the optimum for the fermenting bacteria to operate.
Chhattisgarh to generate electricity from cow dung after implementation of Godhan Nyay Yojana
Speaking on the launch of the ambitious and historic project of power generation from cow dung at the farmers’ conference organized at Bemetara district headquarters in Chhattisgarh, Mr. Baghel said that there will be participation of villagers, women and youth in the production of green energy in Chhattisgarh. He said that the world is worried about global warming.
After successful implementation of scheme to purchase cow dung at the cost of Rs 2 per kg, Chhattisgarh is moving towards generating electricity from cow dung. Chhattisgarh Chief Minister Bhupesh Baghel launched the historic power generation project, taking a step further towards realizing Gandhiji’s dream of ‘Gram Swaraj’.
Speaking on the launch of the ambitious and historic project of power generation from cow dung at the farmers’ conference organized at Bemetara district headquarters in Chhattisgarh, Mr. Baghel said that there will be participation of villagers, women and youth in the production of green energy in Chhattisgarh. He said that the world is worried about global warming. There is talk of green energy everywhere, so the government has decided to make electricity from cow dung.
In every village of Chhattisgarh, a unit to generate electricity from cow dung will be installed in Gothan, the place where cattle are kept. Mr. Baghel said that the cow dung procured from the farmers under the Godhan Nyay Yojana would be used to generate electricity. This will not only benefit the environment but will also benefit the women of self-help groups doing dung procurement work.
How Much Electricity Does One Cow Supply?
A total of 1000 kilowatt hours of electricity can be obtained in a year from the slurry of a single cow
And this according to the German Ministry of Agriculture’s “Number of the Week” is enough for 1000 showers.
If the manure of a small herd of cattle – about 25 cattle – is used, then the energy produced can supply up to seven average households with electricity for a year.
The ministry says that in addition to manure making an important contribution to climate friendly and sustainable energy, other waste residues can also be used.
The contents of a compost bin in a biogas plant, for example, provides about four kilowatt hours of electricity.
Straw bales weighing 330 kg will provide enough power for an average household to cook for a year.
“Electricity from biomass is not only sustainable, but also particularly climate-friendly,” the ministry says.
The1000 kilowatt hours of electricity from the manure of a cow reduces greenhouse gas production by about 600 kilograms. This corresponds to the amount emitted by the average coal powered power station in two seconds.
On renewable energy day on 26 April numerous operators of renewable energy plants across Germany that use the energy sources such as solar, biomass, wind and hydropower, are to open their doors.
Power Generation from Cattle Dung
Compiled & Shared by- Team, LITD (Livestock Institute of Training & Development)
Image-Courtesy-Google
Reference-On Request.
