Effluent industry’s role in clean energy: Exploring India’s first paper mill waste to compressed biogas facility
Pulp and paper mills rank third in effluent production, trailing primary metals and chemical industries. The paper manufacturing process generates substantial wastewater, up to 60 cubic metres per tonne of paper produced. The effluent composition depends on the technology used and the raw materials employed.
As a significant move towards sustainability, Sainsons Paper Industries Pvt Ltd, a leading machine-glazed kraft paper (agro-based) manufacturer, has inaugurated India’s first compressed biogas (CBG) plant for paper effluent. Located in Pehowa in Haryana’s Kurukshetra district, the plant addresses the challenge of managing 3,000-4,000 kilolitres per day of effluent from the daily production of 350 tonnes of kraft paper.
In a bid to enhance energy efficiency and optimise the effluent treatment system, the company integrated a compressed biogas plant on-site. Launched in April 2023, the CBG plant produces three tonnes of CBG daily, utilising 3,500 kilolitres per day of paper mill effluent with a soluble chemical oxygen demand ranging from 4,000-6,000 parts per million.
Spread across three acres, the facility employs an Internal eXperience (ICX) reactor for anaerobic digestion and utilises vacuum pressure swing adsorption (VPSA) technology to upgrade biogas into biomethane.
The generated biomethane undergoes compression at 250 bar and is distributed to nearby compressed natural gas stations for vehicular use. A unique feature of the plant is its ability to recover 200 kilogrammes per day of sulphur during hydrogen sulphide purification, with potential applications in fertilisers, as mentioned by Upendra Kumar Shukla, CBG plant manager.
Moreover, the energy required for the paper mill is sourced from a 9 megawatt biomass power plant (currently operating at 7.5 MW), using agricultural and waste residues as raw materials. To generate 9 MW of power, approximately 400 tonnes of agricultural waste is needed daily, mainly consisting of paddy straw procured from within a 20 km radius.
This practice not only boosts farmers’ income but also helps curb stubble burning in the area. The feedstock cost varies between Rs 1.5-2/kg, depending on its quality.
Due to the incomplete offtake of CBG by the region’s oil and gas marketing company, the plant is presently operating at 2 TPD capacity, with the potential to reach 4 TPD, according to Harikrishan Saini, director, Sainsons Paper Industries Pvt Ltd.
Integrating CBG with CNG presents challenges due to distinct tax classifications, with CBG falling under GST (5 per cent) and CNG subject to VAT (12 per cent). Additionally, unlike states such as Uttar Pradesh and Bihar, Haryana lacks financial support for CBG projects due to an outdated bioenergy policy.
For widespread CBG adoption, it is crucial that states with significant potential promptly implement bioenergy policies and state-level renewable energy agencies vigorously embrace and implement these policies.
Industries like paper manufacturing, producing effluents with a high organic load, offer a promising opportunity to generate clean energy in the form of CBG. If effectively harnessed, the effluent industry could play a pivotal role in accelerating India’s vision of establishing 5,000 CBG projects under the Sustainable Alternative Towards Affordable Transportation scheme.