Agricultural and Kitchen Waste To Gain Economic and Environmental Benefits

By Business Of Agriculture on 16 Mar 2018 | read

'Waste to Energy' has emerged as one of the most promising fields in the renewable energy sector. While it has several implications across industries, the agriculture and food industry is poised to be the greatest beneficiaries of the technology. Due to organic and decomposable nature of the waste, generated by the agriculture industry and the use of livestock, biomethanation is the perfect method to not only reduce the amount of waste generated but also to produce electricity, bio-CNG or heat from the process, resulting in a significant economical impact for business owners and reducing pollution levels in the environment.

Overall, India produces 686 MT of gross crop residue biomass on an annual basis, of which 234 MT (34% of gross) is estimated as surplus for bioenergy generation. According to the Department of Animal Husbandry, Dairying and Fisheries, Ministry of Agriculture, the total bovine population in the country was 29.96 crore (as of 2012). Assuming 10 kg of dung produced by each cattle per day, approximately 30 lakh tonnes of cattle dung is produced daily in the country. If this dung is managed in the right manner by utilising it for biogas, there is a potential to produce approximately 54,000 tonnes of bio-CNG annually, which is the equivalent of 28.42 lakh LPG cylinders of 19 kg per day.

Kitchen waste is also a major contributor as the average person generates 100 g of food and vegetable waste per day. With a population of over 120 crore, out of which 70 percent of the population lives above minimum purchasing power parity, India is approximately generating 50-60 million tonnes of food leftovers and vegetable waste per day. India has a huge potential to produce biogas from food and vegetable waste as one tonne of food waste can produce approximately two cylinders of cooking gas.

A merger of France-based company, Lhotellier Ikos and Pune based Mailhem Engineers, Mailhem Ikos Environment Pvt Ltd aims to be a one-stop solution to all waste management problems. Mailhem Ikos has completed and commissioned approximately 300 waste management projects across India for various corporates, industries, universities and municipalities.

Mailhem Ikos’ speciality lies in the fact that due to their innovative R&D processes, they can design and build biogas plants customised to the kind of input feed, making them among the few companies that can efficiently deal with mixed organic waste as well as uniform waste. The energy produced can be in the form of Bio-CNG, which has recently been sanctioned to be used as fuel for transport by the Central Government, and is a ready substitute for LPG as well. Biogas can also be used for heating purposes for various industrial requirements. The company also has the unique capacity to handle waste from 100 kg to 100 tonnes, making their services applicable to projects irrespective of size.

In the agriculture sector, the company has worked with the University of Agricultural Sciences (UAS), based in Bangalore, to set up a biogas plant. It has designed, executed, installed and commissioned two 200 m3 tonnes per day (TPD) biogas plants at the UAS, GVK campus and the Mandya campus, based on cow dung and agricultural waste. At both the locations, biogas plants are used for power generation, which is fed into the University power grid. These two projects, which became operational in February 2012, have a capacity of 200 m3 each and generate total 600 units of electricity per day. Electricity is produced by 30 kVA biogas generators, which run for about 10 hours a day. The plants need to be fed about 4-5 tonnes of waste per day, which is a mixture of agricultural waste, cow dung and kitchen waste. The power generated is used at the GKVK farm, cow sheds, research laboratories, and for operating various equipment like chaff cutting machines, water pumps, milking machines and the biogas slurry pump.

Through utilising biogas for generation of electricity, the UAS is saving `50,000/month from the electricity bill alone. Apart from energy, each biogas plant also yields about 500 kg of organic manure a day, further reducing costs and the impact on environment caused due to chemical fertilisers. The Vice-Chancellor of the UAS advocates the use of biogas for energy generation and encourages small farmers to set up similar units. “It is worth investing in biogas power projects, which not only take care of organic waste and garbage but also gives gaseous fuel methane as an end product for generating electricity and organic fertilisers”, says the Vice-Chancellor.

Impact Calculation:

•Total organic waste going into the two UAS biogas plants: 10 tonnes per day
•Waste fed since 2012 till 31st March, 2015 (39 months): 11,700 tonnes
•Biogas production per day: 400 m3 per day from both plants with a methane concentration of 60-65 percent
• Genset used: 30 kVA genset running on 100 percent biogas
• Electricity saved since installation: 7,02,000 kWH
• Reduction in CO2 emissions since 2012: 4525 tonnes of CO2

Apart from having a considerable economic impact for business owners, biogas has significant environmental impacts as well. Utilising biogas effectively reduces emissions of methane, which is a harmful greenhouse gas. Methane emissions, which are 21 times more harmful than CO2, are reduced by digesting organic material in closed chambers, called reactors, to produce biogas.

The Central Government too has taken several steps to promote the use of biogas including:

•Exemption from excise duty, since it is a renewable source of energy;
•80 percent depreciation is available in the year of installation of biogas plant;
•Eligible to be considered under corporate social responsibility.
Considering the benefits of utilising biogas for producing energy and the nature of waste produced by the agriculture and food industry, biogas comes across as the most viable option for farmers to optimise their gains and reduce the impact on the environment.