Food-Waste and Bio-gas production

Food! Who doesn’t like food? Everybody likes to eat, likes to be healthy and of course fit enough to attract folks!!

There are different kinds of food which in particular are region-specific, but for variety, people often do have different regional food.

Food Diversity in India

But the fact is, “Food” is not equally distributed among lives on earth. Some exercise to digest the excess they have consumed, some do fasting to digest the bad cholesterol stored and some starve for food and suffer from malnutrition! Truth but sad reality! We, humans have to accept it.

According to the Business Standard Report, approximately 40 % of the food produced in India is being wasted daily and this percentage touches 50% on special occasions. Globally, India stands the second position in the Agricultural sector and despite the above-mentioned fact, the United Nations of Organisation has reported that out of 135.8 crores population about 19 crores Indians remain undernourished and it’s about 7.15%. India Stands in 102nd position in under nutrients and this news makes us relax. But, we have to remember that’s not our goal! And, the goal should be to make each and every person nutritional rich! Have you ever guessed that the cost of food waste is generated? It’s about ₹92,000 crores per annul and the most interesting fact is, it is equivalent to 17.6% of Indian Military expenditure and 0.46% of Indian GDP.

But, my point is neither on the amount being not utilized properly nor on GDP. It was just to grab your attention for my upcoming writing.

The question is, whether Food Waste Management Authorities in India efficiently handle the waste or not? But the fact is after dumping into the dump yard, it’s been not looked into again. As we all know, the decaying of food waste generates poisonous gases such as Carbon Monoxide (CO), Carbon dioxide (CO2) and Methane (CH4) in small proportion with a pungent noxious smell. Carbon monoxide is a harmful gas that, when it is breathed in, displaces oxygen molecules in the blood and blocks blood to get into the heart, even to the brain and other important organs. Serious fact about CO is losing consciousness; suffocation of body and for elderly or age groups below ten may also cause death. Coming to CO2, being a greenhouse gas, exposure to CO2 can have consequential health issues such as dizziness, headaches, restlessness, a tingling sensation on face, hand and on legs, difficulty in breathing, uneven sweating, increased heart rate, change in blood pressure, and even coma for elderly people. Further, CO2 is one among the greenhouse causing gases. Why is CO2 a Greenhouse gas? The answer is simple. Oxygen (O2)in the atmosphere is 21% and CO2 is 412 ppm, but heat storing capacity (in, Mechanical terms, it’s called as thermal diffusivity) of CO2 is higher than O2. That means, it does not liberate the heat absorbed, thus increases space temperature and interesting fact is concentration CO2 increased by 47% within 200 years.

Food Waste Dump-yard

So, what can we do with this food waste? What can be done with CO2 and CO generated?

Yes, we have an option. It’s nothing but, Bio-gas digester.

So, what is a bio-gas digester? It’s a huge drum where the waste is dumped in. The organic matter decomposes itself by producing enzymes and bacteria which digests the food waste to produce the bio-gas. The bio-gas production is dependent on pH of the food waste and temperature of digestion. The ideal pH is 7–8 and bio-gas production is directly proportional to temperature. Oops! But the limitation is 25–60°C, exceeding this limit will inhibit bio-gas production.

As per Renewable and Sustainable Energy Reviews, documented Bio-gas digester is only 45.4 lakhs and the expected was 125 lakhs within 2019. Yeah! The number looks too big, But compared to the quantity of daily food waste generated in India (750–1000 tonnes), the count of the digester is too less. So, I have to justify, right away, the total bio-gas production in India stands at 5 billion m3/year and this is too low compared to the potential, which is estimated to be in the range of 60–70 billion m3/year. There is a necessity to install at least one bio-gas digester in every city to effectively use the food waste.

Let me explain some advantages of Bio-gas digester. Compared to other renewable sources such as Wind energy, Ocean energy, Tidal energy, nuclear energy etc., require prominent and continuous sources and there are many criteria to deal with but food waste is produced/generated every day in every city. As mentioned earlier, the greenhouse gases such as CO2, CO CH4 are the prime gas for energy production and it is trapped well inside the digester without letting it into the atmosphere and is used for energy generation and thus Eco-friendly re-circulation of organic waste and one can even earn Carbon credit!

People do often confuse Gobar gas digester with Bio-gas digester. The difference is simple and easy! Utilization of dung and/or human feces for energy production is called a gobar gas digester and food waste is called a Bio-gas digester.

There are many advantages by using a bio-gas digester such as, the gas produced can be directly used for cooking, in I.C engines, power and thermal applications and the list goes on! As per current trend, Non-Renewable sources of energy such as Crude oil and its derivatives will last till 2050. By then, the world should be capable of depending completely on renewable energy sources for all energy applications.

Bio-gas Plant

So, after reading this, post a comment on present bio-gas digester status in your city!