Setting up CBG plants can reduce Delhi's pollution by 30%: Nomura study

One CBG plant offsets emissions equal to 1.5 lakh electric cars, study finds

Setting up of compressed biogas (CBG) plants, which uses paddy straw as one of the feedstocks, could be used to reduce the winter pollution in Delhi by about 30 per cent, a study done by Nomura Research has stated.

 

Moreover, the study mentioned that one CBG plant helps remove emissions equivalent to 1.5 lakh electric cars. "Vehicles contribute 20-30 per cent to Delhi's PM (particulate matter) emissions...The majority is from older vehicles with the new BS-6 compliant vehicles contributing the least. For example, the BS-6 compliant cars added every year account for 0.2 per cent of Delhi's pollution," it added.

   

The city's toxic air comes from multiple sources—vehicle emissions, construction dust, biomass burning (including paddy straw stubble burning), and industrial emissions. "While vehicles contribute 20 per cent to Delhi’s pollution in summers and stubble burning 16 per cent, these numbers rise to 30 per cent and 23 per cent in winters respectively. Worse, during peak stubble-burning season, biomass-burning emissions frequently exceed 30 per cent," the study mentioned.

 

CBG is a renewable biofuel produced by anaerobically digesting organic matter, then purifying and compressing the biogas into biomethane. It can be used in CNG-run vehicles. Unlike fossil fuel-based CNG, CBG comes from biomass, making it a sustainable alternative.

 

India has an abundant supply of feedstocks suitable for CBG production such paddy straw, press mud, municipal solid waste, cow dung and chicken litter. "Among these, paddy straw is the most promising, on account of its high CBG yield (11 per cent) and large-scale availability. Punjab and Haryana alone generate nearly 12 per cent of India's surplus agri-residues, making them ideal for large-scale CBG expansion. Due to these advantages, CBG can play a key role in tackling Delhi’s air pollution. For instance, a CBG plant producing 10 tons of CBG per day requires 90 tons of paddy straw," the study mentioned.

 

Ashim Sharma, Senior Partners, Nomura Research Institute, told Business Standard that to facilitate the establishment of more CBG plants, a multi-pronged approach is needed. "This should include introducing penalty clauses for non-compliance with mandatory CBG blending obligations, formulating dedicated bioenergy policies at the state level that provide additional capital subsidies, tax benefits, and exemptions for setting up CBG plants and machinery—similar to those in Uttar Pradesh, Andhra Pradesh, and Bihar—and encouraging corporate CSR spending in the CBG sector," he explained.

 

The Union petroleum ministry will make CBG blending mandatory from 2025-26, requiring CGD (city gas distribution) entities to procure and distribute CBG under the CBG-CGD synchronization scheme. The blending targets are set at one per cent in FY26, three per cent in FY27, four per cent in FY28, and five per cent from FY29 onward. However, there are no penalties for non-compliance.