As Bengaluru hotels cut menus amid LPG crisis, how this restaurant is using 8 tonnes of city waste to take on more cooking

“We are facing an LPG problem across our outlets and only the Koramangala unit is self-sustained because of the biomethane supply contract with the BBMP waste disposal plant located next door. Our entire cooking is with biogas,” said Abdul Gaffar, a cluster manager for the NKP Empire Hotel Group.

“We are using the biogas to even cook our biryani for other outlets at present. We are using the Koramangala unit to cook food for the other outlets since there is a guaranteed supply of cooking fuel,” Gaffar said.

How the Koramangala biomethane plant works

The biomethane plant at the Koramangala waste disposal unit, set up by the erstwhile Bruhat Bengaluru Mahanagara Palike in collaboration with bioenergy start-up Carbon Masters, the Koramangala Residents Association, and the NGO Sahaas, was funded through CSR support from tech firm CGI, which invested Rs 2.4 crore in the project.

The plant processes eight tonnes of segregated wet waste every day, producing about 120 kg of odourless biomethane. This gas is supplied to the Empire Hotel next door via a pipeline.

An additional five-tonne-per-day waste-processing unit was inaugurated on March 21, as demand among Bengaluru restaurants for alternatives to LPG, including biomethane cylinders, grows.

“For five tonnes of input processes, the capital will be about Rs 2.6 crore. This was the cost that was tendered (when the Koramangala plant was set up five years ago). As you scale, the cost will come down. If you set up a 100-tonne plant as per the Ministry of Housing and Urban Affairs estimate, the cost is Rs 32 crore,” said Som Narayan, the co-founder of Carbon Masters.

Carbon Masters also operates a 50-tonne-per-day waste processing unit on the outskirts of Bengaluru. This facility is set to be scaled up to 200 tonnes and is expected to produce nearly 10,000 kg of biogas for supply. For the first time in South India, the gas will be distributed through a completed GAIL pipeline.

Carbon Masters is also setting up a 1,000-tonne-per-day waste-to-energy plant at one of Bengaluru’s largest waste disposal units in Kasavanahalli, on the city’s outskirts. The project is being developed in collaboration with civic authorities and Saatarem Alternate Fuel Energy Pvt Ltd.

“If all stakeholders get together, then the problem India faces of disposing 62 million tonnes of waste that is being produced can be solved, where it can be processed into useful climate-friendly products showcasing a circular economy model,” Narayan said.

According to Narayan, biomethane can reduce costs by up to 15 per cent compared to LPG, especially when supplied through pipelines. It also offers environmental benefits by reducing reliance on fossil fuels and helping divert municipal waste.

However, the fully operational biomethane plant at the Koramangala waste disposal unit, which supplies gas to the Empire Hotel, is relatively small compared to larger waste-to-energy projects yet to become operational across Bengaluru.

From pilot project to growing demand

“At present, we generate 300 cubic metres of raw gas and after purification, around 170 to 180 cubic metres of pure methane (around 120 kg) is obtained and supplied to the Empire Hotel,” said Manjunath, the Carbon Masters plant manager at Koramangala.

“BBMP gives us eight tonnes of segregated wet waste. We shred the waste into small pieces and send it for anaerobic digestion. During anaerobic digestion, gas is produced. Methane is produced along with unwanted gases,” he said.

He said the gas is first sent to a storage balloon, where it is held before being purified to remove unwanted components such as hydrogen sulphide and carbon dioxide, leaving only methane. The methane is then stored, compressed, and supplied to the Empire Hotel under a commercial contract for cooking, he added.

“We did the initial pilot where we were able to show them that organic waste, instead of being sent to landfills, can be converted into bio-CNG, which can be used for cooking by nearby restaurants,” said Narayan about the early days of biomethane production.

“If the CSR funding takes care of the capital that is needed for starting the project, then the bio CNG production at the plant can take care of the operational costs and can be competitive versus LPG,” he added.

Amid the conflict in West Asia and the resulting shortage of commercial LPG, Carbon Masters, co-founded by Som Narayan and a US-based partner, has been flooded with requests from restaurants for biogas supply.

“There are normal restaurants that you would never have imagined would use green energy that are moving from fossil fuel to carbon-lite fuels,” Narayan said. “If you see some of our smaller restaurant customers, there are people using one cylinder or two cylinders per day, but there is so much demand right now.”

Scaling demand and business viability

Compared to just three years ago, when Carbon Masters struggled to scale production, the current surge in demand is now driving the expansion of waste-to-energy enterprises, Narayan said.

“It has been a challenge to scale in terms of making the gas available. Right now, restaurants are continuously calling. Back then, it was very hard. We got the initial buyers after a lot of effort. Now, India has passed a blending mandate. GAIL has become our customer, so we have a situation where the distributing company is itself buying gas from us,” Narayan said.

“The cost of setting up a plant depends on the scale. For a larger plant processing 150 to 200 tonnes of waste per day, if the municipal authority provides the land and ensures feedstock delivery with a processing fee of around Rs 1,000–1,500 per tonne, I think private investors will come in and the government will not have to pay even the capital,” the Carbon Masters co-founder said.

“If you do two small plants like five tonnes and 10 tonnes, it is not viable to recover the capital. In the case of small plants, the capital has to be paid through some kind of CSR or financing from the government,” he said.

Narayan said there are three key components involved. The first is pre-processing the feedstock, since cleaner input material reduces the cost of extracting biogas. The second major cost is the anaerobic digesters, which are essentially RCC reactors. The third is the refinery unit, which separates and purifies the gas.

“Bio methane is on par with LPG prices, and in use, it can provide a lot of savings, like, for instance, if the customer is not using it on a cylinder basis, then the pricing is for the amount of gas that is used. There is no wastage like in LPG cylinders. I would say there is about 15 per cent saving with bio methane when you compare it to LPG,” Narayan indicated.

Around 12,000 kg of bio-CNG produced annually at the Koramangala plant for supply to Hotel Empire under a commercial contract in 2023 was estimated by some experts to be equivalent to about 600 LPG cylinders, or roughly 11,000 kg of commercial LPG.

Government push and expansion vision

Karnataka Transport Minister Ramalinga Reddy, whose constituency includes the Koramangala waste disposal unit, inaugurated a five-tonne-per-day waste-to-energy processing unit at the plant on March 21.

“Initially, the processing capacity was eight tonnes of garbage per day. Today, we have inaugurated an additional five tonnes, taking the total capacity to 13 tonnes of wet waste being processed daily to produce gas,” Reddy said.

“In Bengaluru, at least 2,500 to 3,000 tonnes of wet waste is generated every day. Most of it is dumped in yards along with dry waste, leading to problems such as foul smells, mosquito breeding, and contamination of water sources. If we properly utilise wet waste like this, about half of the city’s waste can be managed efficiently,” he said.

“If we replicate this model in two or three locations in every Assembly constituency in Bengaluru, the city will not face a waste problem at all,” Reddy said.