Waste to wealth

Companies are investing in technologies to turn organic waste into natural gas.

Did you know that leftover food and kitchen waste are potential sources of energy? And now there is a way to harness this potential through “Serigas technology” developed by city-based Scalene Energy Research Institute (SERI), the research wing of bio- technology and power engineering firm Scalene Cybernetics.

Serigas technology is a simple process based on the principle of multi-stage anaerobic digestion. It uses a specifically-designed “Microbe Incubated Bio-Reactor” and a natural gas refinery to process organic waste, everything from food leftovers, to kitchen and municipal waste, oil effluent, agricultural crops, slaughter waste, poultry or fish waste, animal dung, night soil, weeds such as water hyacinth, water lettuce and so on. Serigas, the “organic” natural gas produced as a result, is enriched using a proprietary technology called the “Spiral Protium Accelerated Reactor Super Enrichment”. It can then be used as a fuel, filled in cylinders or transported in pipes for cooking, automobiles and industrial usage.

 

As much as 300 kg of gas can be produced from one tonne of organic waste which, the company claims, is 50-60 per cent more than what is produced by conventional technologies owing to the use of multi-stage digestion, pure microbes and the proprietary CO2 re-breather system. Serigas, the result of over eight years of research and development, is not just carbon neutral, claims Scalene, but carbon negative which will help reduce carbon footprint drastically.

Early this year, the company launched SERIGASTM organic gas plants in various sizes which can process waste ranging from 3 kg to 4,000 kg a day. Scalene will supply the technology to Indian Telephones Industries, a public sector unit, for production on a large scale. “This will enable organisations and households to have their own source of energy which is carbon neutral, thereby radically changing the production and usage of energy,” says A R Shukla, advisor to the Union Ministry of New and Renewable Energy.

Companies such as the UB Group and Malankara Plantations have already signed agreements with Scalene for such power plants in Nelamangala, Bangalore and Kottayam. Among others setting up the plant include Prabha Power Corporation (Hyderabad), House of Khoday’s (Bangalore), Global Green Energy Parks (Bangalore); and Krish Power & Gas( Ghaziabad).

But there is also another company, Wipro, which has been doing something similar for the last two years — producing energy from the leftover food and kitchen waste at the cafeterias on its large campus in the city. Its green efforts launched since 2009-10 have helped to save 15 million units of energy and 12,000 tonnes of greenhouse gases, Wipro claims.

Since October 2008, the company has been operating a bio-gas plant which runs on kitchen water and food leftovers, and sludge from the sewage treatment plant generated daily at Wipro's Electronic City Campus. The plant, which consumes 40-45 units of electricity a day, is designed to process three tonnes of solid waste a day and yields 160-180 cubic metre of gas.

The manure produced as a by-product is weedless, odourless and is used as a soil conditioner. The benefits include disposal of waste at source, helping keep the surroundings clean and save on LPG consumption. “We run two biogas plants in the campuses which saves us 50 tonnes of LPG and prevents GHG emissions of 100 tonnes,” says Ram Ramakrishna, vice- president, Facilities Management Group, Wipro Technologies.

At Wipro, the waste-to-wealth dictum has now spread to other areas of operations. For instance, the company has a paper-recycling plant which processes 20 tonnes of waste paper a year, saving 50 tonnes of timber and half a million gallons of water. It also recycles 32 per cent of the water used in its offices. By 2013, the company’s aim is that “not more than 5 per cent of the waste generated from the company’s operations should end up in landfills”. As of 2009-10 about 76 per cent of the waste generated is recycled by internal or external partners,” states a company report.

Indian companies, it seems, are finally going beyond paying lip service to green consciousness and doing something to cut their carbon footprint.