How to Turn Domestic Waste into the Biogas and Garden Compost

Kitchen Waste and Spoiled Vegetables into Biogas

According to scientific studies, any kind of spoiled material emits gas, including kitchen waste and spoiled vegetables that are easily accessible in any household. Biogas is a mixture of gases, generally methane and carbon dioxide, produced by microorganisms present in the kitchen waste due to absence of oxygen. Biogas is a renewable source of energy, as it is produced with growing microorganisms inside the kitchen waste and spoiled vegetables. Let us see how biogas produced from such materials can be useful.

How biogas is produced from kitchen waste and spoiled vegetables

The kitchen waste and spoiled vegetables is minced to pulp less than 10mm in size in a specialized mincing machine. After that, this pulp is charged to a special bio-gas reactor, where biogas rich in methane is generated within a period of 30 days. Kitchen waste and spoiled vegetables are mixed in a mixing tank with water. The slurry obtained is fed into a digester through its inlet chamber. Anaerobic fermentation takes place gradually, thus producing the desired biogas. A new biogas plant may take around 6 to 8 weeks to start producing biogas at an efficient rate. When pressure of the gas inside the plant’s dome increases, it starts pushing the slurry spent into the outlet chamber, finally coming into the over-flow tank. This slurry is an excellent source of plant nutrients and can be used as manure in agriculture.

Advantages of using biogas from kitchen waste and spoiled vegetables

In North America alone, biogas generates electricity enough to meet up to 3% of its total electricity expenditure. It also helps significantly in reducing global climatic change. Manure left behind to decompose can release two major gases which case global climatic changes: methane and nitrogen dioxide. Methane warms up the atmosphere 21 times more than carbondioxide and nitrogen dioxide 310 times than that. By converting kitchen waste and spoiled vegetables into biogas, several billion kilowatt hours of electricity can be produced which can power millions of households in a country. In addition to this, global warming gases can also be reduced by converting kitchen waste and spoiled vegetables into biogas instead of allowing it to decompose. In some countries, it is being used as one of the most reliable sources of rural energy.

Uses and applications

Biogas produced from kitchen waste and spoiled vegetables can be efficiently used for production of electricity on sewage works, in CHP gas engines, where the engine’s waste heat can be used for cooking, water heating, space heating, process heating and digester heating. When compressed, it can be used to replace CNG in vehicles, which is efficient enough to fuel cells and an internal combustion engine. Biogas can be efficiently used for heating and cooking purposes, and for running a tube well or water pump-set engine. It can also be used for illuminating a domestic or street lightning with the help of a mental lantern.

5 kg of decomposed vegetable is enough to produce one hour of clean blue flame in a domestic gas burner. This biogas is as good as LPG for heating and cooking.

How to turn Domestic Waste into Garden Compost

Adding compost to the soil of your garden can highly improve its productivity. If your garden’s soil is sandy, you can add compost to it in order to retain moisture, while clayey soils can become looser with compost. In addition to improving the soil’s structure, compost also helps in protecting plants from pests and diseases. You will be amazed to know that you can make rich compost from your own garden and household waste. Let us see how.

Materials required

Making compost from your household and garden waste is an easy process. Most suitable materials for making compost include grass clippings, weeds, leaves and household vegetable waste. A mixture of all these materials will make the best compost for your garden soil. Although you can find a multitude of compost bins in the market, you can make a compost just by making a heap. This pile should be minimum 3 cubic feet, so that the bacteria receives optimum condition for growth. Bacteria will be required for breaking down, multiplication and survival of organic matter. Only moisture and air are required in the pile to break down organic matter into compost.

How to make compost

Once you have made up a pile of materials required, you need to turn it regularly with a pitchfork in order to give it air. Special compost tumblers are also available in the market which help you in making the heap properly. You will need to keep the heap moist with water, but not saturated. Too much of water can make the compost slimy, while the bacteria will not be able to survive in too little water. You can just add water whenever you think the heap has become too dry. If it is raining, you can cover the pile with tarpaulin.

Things to take care of

There is no exact science associated with making compost. With time and experience, you will be able to understand what can work best for you. If you think that nothing is happening in your compost, you can add more air, water or nitrogen into it. If it is too hot, you have probably supplied too much of nitrogen. You can reduce the heat by adding some carbon. A bad smell may also be an indicator of too much of nitrogen. Cold composting is better for warmer areas than cooler climates. Adding kitchen waste to your compost can attract insects and flies. To prevent this, make a hold in your pile’s center and bury your waste. You can also buy a rodent proof bin for composting.

How long it takes

The time taken by compost to be ready largely depends on the temperature of the heap and the materials used. Your compost can be ready in just 12 weeks, or it can as long as one year. You will know that it is ready if it becomes black or dark brown in color, crumbly in nature and a pleasant earthy odor starts coming out of it. No original waste will be visible or identifiable in a compost that is ready.

The compost that you made is used as mulch on the top of your garden soil, where it will be helpful in retaining moisture. It keeps adding nutrients to the soil, and also keeps the weeds down.

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Comments 3 comments

Anna Sternfeldt profile image

Anna Sternfeldt 3 years ago from Svenljunga, Sweden

Interesting info, I voted thumb up. We need to know more about how to create our own energy, to reuse our waste and to make our own composts. It is time for life style change, and this knowledge will be part of it.


Ruby H Rose profile image

Ruby H Rose 3 years ago from Northwest Washington on an Island

Great information, I am sharing it, coming back to read and learn how to do some more things to turn our waste into wonder......


Kevin Peter profile image

Kevin Peter 3 years ago from Global Citizen Author

Thanks a lot to know that you found my hub interesting.

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