A new tech can reduce India’s pollution levels as well as fuel imports. What is standing in its way?

An early November evening in Punjab’s Sangrur district was different compared to the last few years. The sky was clear; there was no chill in the air, and no smoke to disrupt these sights. Stubble-burning incidents in Punjab, notorious for smog and air pollution in Delhi, were down by 30% in 2022. The maximum contribution of farm fires to the daily Particulate Matter 2.5 levels in Delhi was 34% in 2022, as against 48% in 2021.

Sangrur, a hotbed of intensive wheat-rice agriculture in Punjab and Chief Minister Bhagwant Mann’s home constituency, topped the charts regarding farm fire incidents. But in June, the district became home to an innovation aimed at producing Bio-CNG or compressed biogas. It is a technology that converts agricultural residue into highly concentrated methane that can replace compressed natural gas mined from the earth. In June 2022, India’s biggest compressed biogas plant, and the only one on paddy straw, was commissioned in Sangrur. The plant can produce 33 tonnes of compressed biogas and 600 tonnes of organic manure daily from a feedstock of 1.1 lakh tonnes of straw annually. Verbio, a German company, has set up the plant at the cost of Rs 20.3 million on 20 acres of land in the district’s Lehra Gaga block.

India imports 85% of its crude oil, making it the third largest importer in the world. It has the potential to produce 80,000 tonnes per day of compressed biogas, replacing 50% of the current diesel use in transport, says a study by Indian Institutes of Technology, Guwahati. However, the study says that only 0.5% of the compressed biogas potential in the country is currently being utilised. “Compressed biogas is a circular technology where the by-product of agriculture becomes an input for a fuel, and its by-product nourishes back the soil,” said Ram Chandra of Indian Institutes of Technology, Delhi, who has been working on improving the technology since 2015. Unlike other renewable energy sources, compressed biogas can be produced round-the-clock and employs more people than the solar and wind energy industry, said several experts.

As many as 42 more compressed biogas plants are planned in Punjab, which will utilise 1.7 million tonnes of paddy straw annually to produce 495 tonnes per day of compressed biogas, says Punjab Energy Development Agency. Punjab produces 19 million tonnes of straw every year, so there is no shortage of feedstock. According to the Punjab Energy Development Agency, there is potential for 250 more projects. “The state government is giving incentives such as no registration charges, stamp duty on buying land, and exemption on electricity duty. They are also lending the Panchayat land on long-term lease to companies who do not want to buy land,” said MP Singh, the director of Punjab Energy Development Agency. Under its dedicated compressed biogas programme, Sustainable Alternative towards Affordable Transportation, the central Ministry of Petroleum and Natural Gas gives a subsidy of Rs 40 million for every 4.8 TPD plant.

Despite this, the progress of compressed biogas projects in the state has been rather slow. Only one plant is operational, and two more are expected to start production in this financial year (March 2023). The main reasons include high capital costs, challenges of collecting and transporting paddy straw, and the sale of fermented organic manure. “Compressed biogas industry can only progress if the idea of balanced crop nutrition is promoted,” said Sanjeev Nagpal, who owns Sampurn Agri Ventures Private Limited, a biogas-based power plant in Fazilka district.

Compressed biogas

Compressed biogas is an upgraded version of biogas that is used as cooking fuel in many parts of India. It can be made from different feedstocks such as agricultural residue, cow dung, press mud from sugarcane factories, and biodegradable garbage. To make compressed biogas from paddy straw, first, the straw is spread in the field to dry after the harvest. This process is called teddering. It is then raked in rows and tied into 450 kilograms of round bales. “The bales are fed into the pre-treatment area where the straw is shredded and mixed with water and cow dung for microbial breakdown,” Pankaj Jain, plant head of Verbio, said. “The mixture is then fed into the main digester tank, which ferments in anaerobic conditions for a month. The biogas produced is collected from the top of the digester and piped to the gas cleaning area.” The gas, upgraded to 95% methane, is compressed in cylinders and filled in vehicles at compressed natural gas stations, while the leftover slurry can be used as manure.

“The CFA was discontinued in 2021 and only resumed in November,” said Yogesh Sehgal of PES Renewables Private Limited, which has nine compressed biogas plants planned in Punjab. “For entrepreneurs to venture into a new technology, subsidy matters. The banks offer loan packages for compressed biogas plants, but they keep changing conditions like requirement of collaterals, etc.”

Compressed biogas production is also linked to the market demand for compressed natural gas. An IOCL official, on condition of anonymity, said that there are 11 compressed natural gas outlets in Punjab, and there is no significant difference between petrol and compressed natural gas prices at present, so the consumer demand is not as much. “The government must promote compressed biogas by converting public buses from diesel to compressed biogas, setting up model districts where vehicles use maximum compressed biogas and organic fertiliser generated by it. Only then will such clean technologies be mainstreamed.”

Short window challenge

Randhir Singh is a farmer from Khai village, 2 km from the Verbio plant. Seven years ago, he stopped setting fire to his two-acre field, but in 2022, he had no choice.

In 2021, he gave his straw to Verbio during their trial run period. “I registered in 2022 too. They sent rakers to make piles, but nobody showed up after that,” Randhir said. “I called them, but when they didn’t turn up, I had to set it on fire.” He added that this wasted a lot of his time and money.

The 15-20-day period between October and mid-November, when paddy harvest happens, and the rabi wheat is sowed, is crucial for both the farmer and compressed biogas companies. Compressed biogas companies have to collect and store their feedstock for the entire year during this period.

Paddy is harvested with a combine harvester that works optimally only when the crop still has some moisture. Otherwise, the machine breaks the grain. This means the leftover straw still has moisture. The farmer either burns this straw or mulches it in the soil.

The compressed biogas company requires farmers to use a reaper machine to cut the straw, after which they take over. Four machines, teddering equipment, a raker, a baler, and a loading trolley are involved in the process. The baling happens a week after spreading the straw in the field to dry. “Dry straw is very important because bales with wet straw start rotting from inside, and the methane is lost to the atmosphere,” said Pushpinder Singh, field supervisor at Verbio. “Last year, we lost 3,000 bales to moisture.”

However, one week is too long for a farmer. “Drying the straw means the land underneath is drying up too, and one cannot sow wheat in completely dry soil,” said Balkar Singh, a farmer in Khandewal, a village 1 km from the Verbio site. “Once they take the straw, we will have to irrigate the field again and wait 15 more days to attain the requisite soil moisture for sowing wheat. So, 3-4 weeks are lost along with an additional cost of irrigation in this water-starved region, so it does not work for most farmers.”

“They go to the fields where land holdings are large. But for small farmers, the only option is to light the matchstick because they can neither afford expensive mulching machines nor does the company pick up the straw from him,” said Jagsheel Singh, who set fire to his two-acre leased farm this season. Pushpinder said this is because smaller fields sometimes do not have adequate passage to take the machines inside.

Ashish Kumar, managing director at Verbio India, said that the cost of collecting, transporting, and storing 1 tonne of straw is Rs 3,000. “All these machines are imported and have a life of only 5-6 years.”

Now aggregators are emerging into the picture. Karan Kaushal, director of Farm Gas, which has an undertrial 12 tonnes per day plant in Khanna, said, “There are very few aggregators in Punjab, and the demand for straw is increasing. They were selling us at Rs 1,500 to Rs 2,000 per tonne right at harvest time, but we might now have to buy mid-season at a hiked-up rate of Rs 3000.”

In 2022, the state government did not impose any fines for stubble burning, said Dinesh Nagpal, a supply chain management head of Ever Enviro India Ltd that has 11 compressed biogas plants proposed in Punjab. He said this made things difficult for them. “Earlier, the government would put a red mark on the land deeds of farmers who burnt straw,” he said. “Fearing this, they would even pay us to collect straw from their fields. In 2022, the government relaxed all the rules.”

Market for manure

A compressed biogas plant derives 20%-25% of its revenue from fertiliser organic manure. While inaugurating the Verbio plant in October, Bhagwant Mann announced manure produced from the plant would enrich 2,150 acres of farmland. Sustainable Alternative towards Affordable Transportation envisaged the production of 50 million tonnes of manure from compressed biogas plants by 2023. The Fertiliser (Inorganic, Organic or Mixed) (Control) Order, 1985, commonly called the FCO, was amended in 2021 to include fertiliser organic manure and Bio-slurry from compressed biogas plants. In May 2022, the Ministry of Chemicals and Fertilisers issued an order to fertiliser companies to mandatorily uptake fertiliser organic manure from compressed biogas plants under the integrated nutrient management scheme.

Despite this, Verbio has 20,000 tonnes of fertiliser organic manure lying on its premises, which cannot be sold. “Buying manure from compressed biogas plants is compulsory, but we cannot take it unless the Punjab Agriculture Department issues them a license,” said JS Brar, senior state marketing manager of the fertiliser company Krishak Bharat Cooperative Limited.

“Unless the fertiliser organic manure issue is sorted, companies who have committed to set up plants in Punjab will not come up,” said Ashish from Verbio. For every tonne of paddy straw used in the compressed biogas process, double the amount of fertiliser organic manure is produced, 75% of its content being moisture.

Despite its quality as bio manure, which can help regulate environmental cycles, Punjab has not been able to resolve the obstacles hampering its best use. Underlining its quality, Ram Chandra, in his 2017 paper, says that spreading fertiliser organic manure is better than direct mulching of straw.

To market fertiliser organic manure, compressed biogas companies need three things. They need to meet the specifications of the Fertiliser (Inorganic, Organic or Mixed) (Control) Order, get a license from the state Department of Agriculture, and get dosage recommendations for various crops from PAU, Ludhiana. Punjab Agricultural University is testing the manure in its research fields. “We will be able to share the results only after 1-2 crop seasons, which means at least two years,” said AS Dhatt, director of research at Punjab Agricultural University.

Verbio’s manure does not meet the fertiliser organic manure specifications defined by the Fertiliser (Inorganic, Organic or Mixed) (Control) Order on two parameters: moisture and carbon to nitrogen ratio. A higher carbon to nitrogen ratio means the manure has not decomposed well. Carbon and nitrogen-rich material should be balanced to get a narrow carbon to nitrogen ratio. “Paddy straw has a high carbon to nitrogen ratio because of its dry matter,” said GV Ramajaneyulu of the Centre for Sustainable Agriculture, Hyderabad.

“A well-decomposed manure will release its nutrients in 2-3 months, but one that is not digested well can take up to six months. Adding dung, kitchen waste, or green biomass can adjust the carbon to nitrogen ratio,” said Ramajaneyulu.

“Nitrogen comes from protein, and straw does not have protein. In Agri-residue-based compressed biogas plants, we can never meet the Fertiliser (Inorganic, Organic or Mixed) (Control) Order’s carbon to nitrogen ratio requirement unless we enrich the manure. So, either the Fertiliser (Inorganic, Organic or Mixed) (Control) Order should be broadened to include this aspect or a new category of fertiliser organic manure from agri-residue-based compressed biogas plants should be introduced,” said Kumar. He added, “The Department of Agriculture will not give us a license unless we meet specifications.”

Gurvinder Singh, the director of the Department of Agriculture, Punjab, said that they could give the license, but fertiliser organic manure will not be able to enter the market unless the Punjab Agricultural University gives dosage recommendations. “Even if the farmer uses it, fertiliser organic manure cannot replace all other fertilisers, so why will a farmer increase his cost.”

Kumar feels the pressure from the strong chemical fertiliser lobby is responsible for the government’s inaction. “This manure is significantly small in comparison to millions of tonnes of chemical fertiliser that is getting sold. But it can become big in the future if the government really wants to promote organic farming and gives subsidies to it equivalent to chemical fertilisers,” he added. In budget 2023, the government has allocated Rs 1.75 lakh crores towards chemical fertiliser subsidy.

“When the Green revolution came, agri extension workers gave us free urea and Di-ammonium Phosphate. Why will a farmer not buy organic fertiliser today if they are available at the same rates as chemical fertilisers. But, it will make him break away from the rut of intensive chemical farming and save Punjab,” said Jugraj Singh, a farmer in Ramgarh village of Sangrur.

This article first appeared on Mongabay.