Innovative Enzyme Technology Paves the Way for Ethanol Production from Rice Stubble, Tackling Pollution and Fuel Needs in India

 

Innovative Enzyme Technology Paves the Way for Ethanol Production from Rice Stubble, Tackling Pollution and Fuel Needs in India

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The issue of stubble burning in Punjab, Haryana, and Uttar Pradesh has been a persistent environmental challenge, particularly affecting the air quality in Delhi during the onset of winter. Every year, the burning of rice stubble after the harvest season releases significant amounts of pollutants into the atmosphere, leading to severe air pollution and health problems for millions of people.

Recognizing the gravity of the situation, scientists and administrators have been exploring innovative solutions to mitigate the environmental impact of stubble burning. One promising development is the establishment of enzyme manufacturing facilities to support the production of second-generation (2G) ethanol from rice straw. This innovation not only addresses the problem of air pollution but also contributes to the production of renewable energy.

The first such enzyme manufacturing facility is expected to be set up in Manesar, Haryana. This facility will supply enzymes to 2G bio-ethanol plants located in Mathura, Bhatinda, and Patna. These enzymes are crucial for the conversion of rice stubble into ethanol, an environmentally friendly alternative to fossil fuels. India is projected to require around 13.5 billion liters of ethanol annually by 2025-26, with approximately 10.16 billion liters needed to meet the E20 fuel blending mandate (a fuel blend consisting of 20% ethanol and 80% gasoline).

In 2022, Indian Oil Corporation (IOC) established a 2G ethanol plant in Panipat that utilizes rice stubble as feedstock. This plant has the capacity to produce 100,000 liters of ethanol per day, although it currently operates at only 30% capacity. To run at full capacity, the plant requires between 150,000 to 200,000 tonnes of rice straw annually, which is readily available after the September-October sowing season.

One of the critical components in the ethanol production process is the enzyme that facilitates the conversion of stubble into ethanol. Until now, these enzymes have been imported. However, a newly developed enzyme, which is comparable in effectiveness to the imported ones, is poised to change the landscape of ethanol production in India. The enzyme technology is licensed from Novozymes, a Danish biotechnology company, by Praj Industries, a Maharashtra-based firm. The enzyme itself was developed by the International Centre for Genetic Engineering and Biotechnology (ICGEB), an autonomous organization with over 45 state-of-the-art laboratories.

The enzyme is derived from a fungus belonging to the species Penicillium funiculosum. Through several steps of genetic engineering, scientists have been able to produce this enzyme in sufficient quantities to act as an efficient hydrolyser of organic waste. This cell-free system enables the enzyme to digest biomass, resulting in the production of free sugars that can be fermented into ethanol. Beyond ethanol, these sugars can also be used in the production of cosmetics and active pharmaceutical ingredients (APIs).

The potential of this technology extends beyond agricultural biomass; in the future, municipal solid waste could also be used as feedstock for ethanol production. However, the scale of the challenge remains significant. For instance, the Panipat plant can process only 200,000 tonnes of rice stubble annually, whereas Punjab alone produces an estimated 20 million tonnes of rice stubble each year.

The development and deployment of these enzyme technologies represent a crucial step towards reducing the environmental impact of stubble burning while simultaneously advancing India's renewable energy goals. However, scaling up these efforts to match the vast quantities of biomass available remains a challenge that will require continued innovation and investment.