How about turning the smelly, pest-infested, unattended kitchen waste into fuel for cooking? A look at one model by Nandhini Sundar

Be it a household, apartment or a food court, kitchen waste and its accompanying disposal is a major problem to contend with. The waste is many a time left in the open, unattended, inviting unwelcome guests. A scientific mode of its disposal is a factor much sought after, with composting being one of the avenues.

But how about turning this smelly, pest-infested waste into kitchen fuel, besides addressing concerns of global warming? For, every tonne of methane gas emitted by untreated kitchen waste is equal to 21 tonnes of carbon emissions.

Instead of releasing this into the atmosphere and accelerating global warming, the methane gas can be used for cooking, similar to LPG. While this certainly involves a scientific process, in one stroke it eliminates the foul-smelling heavy wet waste disposal while offering a ready-to-use kitchen fuel in the backyard.

For small-scale operations

Currently options do prevail for converting kitchen waste into cooking gas but unfortunately the high-performance technology options available address large quantities of waste rather than small ones. The ‘Eco Digester’ designed and developed by Eco Positive Solutions, a FutureIP Group Company, fills precisely this gap, catering to small apartments, restaurants, schools and corporate canteens where generation of waste is not massive.

Interestingly, the scale of operations addressed by the Eco Digester is such that, if implemented across the board in all small apartments, hotels, restaurants, corporate canteens and other places where the wet waste generated is significant yet not large enough to accommodate the present high-performance technology options available, it has the potential to drastically transform the mode of wet waste disposal in the city.

Here, the aesthetically designed next-generation bioreactor occupies minimal space for its installation, with the slurry totally concealed from view. The reactor is also designed to address the drawbacks of existing technology such as the prevalence of gap between the bioreactor and gas holder through which methane gas escapes.

The Eco Digester, which is totally sealed and potable and is not based on the prevalent floating drum mechanism, incidentally has the gas holder separated from the bioreactor, enabling the two to be placed in separate places in case of space constraint. The gas holder, coming in a special, tough rubberised material, can also be hung like a balloon or placed in a balcony in case floor space is totally absent.

Use of wind power

Says Gururaj Kanade, CEO, Eco Positive Solutions, “The technology used here is structured to generate one-and-a-half to three times more biogas per kilogram of food waste. It needs just 30 to 50 per cent of the bioreactor capacity as compared to existing micro-scale bioreactor technologies through its unique ‘Accelerated EcoMethanation’ process. The process leverages the natural principle of lowering the impediments to energy flow. This technology uses two-and-a-half to five times less water as compared to conventional ones for every kilo of food waste processed.”

The crowning element of the Eco Digester technology over existing ones is the use of wind power to run the Eco Stirrer for kitchen waste conversion. The electricity used is minimal while the wind turbine supplies the major portion of the mechanical power requirement, with solar power absorbed merely by virtue of its design rather than through external solar cells.

Another surprise…

If you thought operation of the same would require expert technical help, you are in for another surprise as it needs little monitoring and technical expertise. The technology used makes it more cost-effective than prevailing ones in the market.

The monthly save

Says Dr. Bhat of the Institute of Ayurveda and Integrative Medicine, “Not only has the Eco Digester saved the cost of wet waste management and disposal by Rs. 3,000 per month, cooking fuel cost too has reduced as we generate cooking gas equivalent to Rs. 5,000 every month.”

Sriram Krishnan of FutureIP Labs echoes the same view. “Over the last two years, we have been using the Eco Digester to generate cooking gas for our pantry. We save on the LPG cylinders. The gas too is odourless, with the heating quick.”

The cost factor

Typically, 25 to 30 kg of cooked food waste produces about three to three-and-a-half commercial LPG cylinder equivalent methane. The 19-kg commercial LPG cylinders come priced approximately at Rs. 1,700 while the cylinders from kitchen waste of 30 kg per day yield approximate revenue of Rs. 5,000 per month.

The cost of installation is about Rs. 1.50 lakh, according to Kanade, for a 30 to 40 kg food waste per day. “This investment can be recovered in two years’ time or less depending on the quantum and type of waste generated. The gas yield is higher if starch content is higher,” he adds.

The end product slurry from the process also finds use in the garden, serving as a rich fertilizer.

Eco Positive Solutions can be contacted on 98454 52542.