A new spin on clean energy

Waste to energy
Last Updated 03 August 2015, 18:38 IST

Sanjeev clicked on a small icon on a big screen to turn on the agitators that shred the plastic packets containing food waste and pushed them towards the conveyor belt where dry materials are removed by employees before the organic matter is sent to the grinder. “I just started the chain of processes that turns the food you left on your plate at your favourite hotel into cooking gas,” he said.

Sanjeev is the project manager at Noble Exchange Solutions (NEX), one of the two major companies in Bengaluru that convert the stinking leftover hated by all of us into high-efficiency methane gas that is sold back to food joints where we run searching for a special menu. While the NEX plant at Kannalli off Magadi Road — the only such unit in India with an intake capacity of 100-tonne per day — started functioning recently, another plant at Doddaballapura is already supplying the ‘green fuel’ to hotels. Livegreen Consulting is bottling methane at the 50-tonne plant run by Maltose.

Finding alternatives
In 2012, the Bruhat Bengaluru Mahanagara Palike (BBMP) decided to set up 12 waste processing plants after it ran out of landfills and uproars broke out demanding closure of the remaining ones. Landfills on the fringes of Bengaluru had helped the municipality for decades to rub out from the face of earth the garbage the City produces daily and keep its people happy — no more stench.

Villagers came running to all kinds of special hospitals with health problems as unprocessed municipal solid waste (MSW) with all its toxic elements poisoned their land, air and water. The resultant protests, most recently in Mandur and Mahadevapura, forced the BBMP to realise that garbage is the dark underbelly that will soon turn the garden city into an electronic desert. Besides, ghosts of the ignorant past are now haunting the BBMP — be it the burning Bellandur Lake or the old landfill at Laxmipura near Bannerghatta National Park in Bengaluru.

Old plans and initiatives (for example, Terra Firma set up in 2007) now seem ineffective and a hogwash when put against the mountains of trash near Terra Firma. Segregating biodegradable element from MSW, the basis for waste-to-energy idea, has become a mantra. An official in the BBMP admitted that despite all the rules and efforts to make segregation popular, people remain ignorant.

According to conservative estimates, Bengaluru generates 5,000 tonnes of MSW per day. Of this, nearly 50 per cent is biodegradable while 30 per cent is used for producing residue-driven fuel, and the remaining 20 per cent needs to be sent to treatment plants.

BBMP Special Commissioner for Solid Waste Management Darpan Jain said the present set-up can only process about 2,000 tonnes of waste. He said the civic body has plans of setting up a biomethanisation plant of 5-tonne capacity at each ward in the City within the next three years.

“Apart from this, we have plans for setting up six new plants which will be commissioned soon. Karnataka Compost Development Corporation (KCDC) plants will also be upgraded to compost biomass. Two upgraded plants at Kannalli and Seegehalli will start functioning by mid-August,” he said.

Pramod Siddagangaiah, founder of Livegreen Consultancy, said only 10 per cent of the biomass generated by Bengaluru was being processed at present. “We have effective rules. What we require is effective implementation. BBMP officials are very cooperative at the level of governance. However, their enforcement of segregation is poor. The civic body is hugely understaffed in this sector,” he said.

Pramod said garbage contractors undo what the authorities work hard to do. For example, the rule says establishments that generate garbage above 100 kg should take necessary steps to process it. However, the contractors collect the trash from them for which they charge the BBMP. “The BBMP has failed to monitor this situation. Biomass plants hold out promise of a better future. Methane fuel is safer than LPG. It complements sustainable livelihood model as it reduces dependency on non-renewable resources,” he said.

The city administration has asked the hotels, which come under the category of bulk waste generators, who account for 30 to 40 per cent of garbage, to compost the biodegradable waste or make arrangements approved by officials to process it through a third party. A 2013 tripartite agreement between the BBMP, the Bruhat Bengaluru Hotels Association and NEX has laid the foundation for systematic disposal of nearly 1,000 tonnes of daily food waste. Authorities have announced plans to build more biomass plants.

Pramod informed, anaerobic digestion, a process where bacteria break down the organic matter to form biogas, does not emit greenhouse gas. “Biogas is scrubbed to separate about 60 per cent of methane from CO2 and the corrosive hydrogen sulphide. The gas with 92 to 96 per cent of methane that is bottled after scrubbing is as efficient as LPG and is more nature friendly compared to the latter,” he said.

Konark Kanteerava, a restaurant at Kanteerava Stadium, has stopped using LPG for cooking purposes for the past one year. “We pay Rs 5 less per kg of methane compared to commercial LPG. Moreover, the Government keeps hiking the price of commercial LPG. The best feature of using bottled methane is that the gas does not get frozen, a common problem with LPG cylinders,” said Dhananjay who is in-charge of the kitchen at the restaurant. Noting that the efficiency of both the gases was the same, he stressed that the methane cylinder stands out because of the sustained release of gas. “In LPG cylinders, the force of outflow goes down gradually. But it is not so with methane cylinders,” he explained.

Back at NEX, Sanjeev showed around the plant and explained how leftover onion dosa and chicken tikka, once ground and dumped into feeder tanks, not only produce methane gas, but also turn into top-quality organic manure that restores land fertility. “The capacity of the plant will soon increase from 100 tonnes to 250 tonnes per day,” he said.

Proper planning is essential for sustaining a biomass plant. Keeping the supply chain active and making the venture commercially viable — after all, 50 kg of biomass produces only 2 kg methane — are two big challenges. In a mega city like Bengaluru, supply is always assured. However, segregation remains a problem. Sumedh Dapat, technical director at NEX, said, “Segregation at source is very critical. Even the Supreme Court has stressed this. Any positive change requires total enforcement of segregation.”

If all wards in Bengaluru operate their own plant that convert waste into energy, then the City can become a model for other cities. K R Market, which is electrified entirely by a biomethanisation plant, has already set an example. Is Bengaluru on its way to becoming a self-sufficient City that fulfils its energy needs by processing its waste? Urban policy planners may dismiss it as a daydream. Will that dream come true at least in the 100 smart cities programme that the Union Government has announced? The vision documents related to the plan do not explain more than the efficient use of energy. With the gradual draining of natural resources, we definitely need a smarter approach for smart cities. We also need a garbage disposal system that does not compromise the lives of villagers in order to keep a city clean.

“They forced poison down her (Earth) throat; now they are stifling her,” said a villager at Laxmipura. He was reacting to the ‘success’ story of the authorities who dumped two feet of soil to close the fissures through which methane emanated, triggering panic of an explosion at the village. The State Pollution Control Board has warned that soil capping of fissures will not stop methane formation and may lead to explosion. It’s time the BBMP authorities sat down and reviewed all the landfills, to see how many of them have become ticking bombs. Isn’t it, then, an urgency for all cities to scrap the landfill method of disposing garbage and implement a system where waste is valued?

(Published 03 August 2015, 17:14 IST)

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