Increasing ethanol production in India using sweet sorghum

Sweet sorghum stalks being transported to sugar mills. Photo: A Ashok Kumar, ICRISAT

An innovative project to mainstream sweet sorghum as a source of ethanol production is under way in sugar mills of Maharashtra, Tamil Nadu and Gujarat, paving the way to create an alternative, eco-friendly fuel source.

Considering the environmental pollution associated with the use of fossil fuels, alternative energy sources are of widespread global interest for a sustainable ecology. Although India has stipulated ethanol blending targets up to 20% by 2017, the current level of blending in India is under 5%. There is not enough ethanol available in the country to meet the blending targets and this necessitates large-scale production of fuel-grade ethanol. Sweet sorghum is one of the most suitable crops for ethanol production; the National Policy of Biofuels, Government of India, has identified sweet sorghum as an alternative feedstock for ethanol production in India.

ICRISAT, along with partners, has been working on the development of a sweet sorghum ethanol value chain over the past several years. As a result, sweet sorghum is now an established biofuel feedstock in India, China, the Philippines and Brazil. However, while sweet sorghum production is commercialized in Brazil and China for ethanol production, in India, ethanol distilleries based exclusively on sweet sorghum were not successful. With an aim to bring sweet sorghum back into mainstream biofuel production, ICRISAT and partners have developed a project, Commercialization of sweet sorghum as a complimentary feedstock for ethanol production in the sugar mills of Maharashtra, Tamil Nadu and Gujarat. Seven sugar mills in the three states have been associated with this three-year project funded by the Government of India.

Sweet sorghum juice gushing out of a crusher. Photo: A Ashok Kumar, ICRISAT

At the second Annual Review-cum-Work planning meeting of the project, Dr Ashok Kumar, Principal Scientist, Sorghum Breeding, ICRISAT and Principal Investigator of the Project, reported that sweet sorghum hybrids ICSSH 28, CSH 22 SSS, Phule Vasundhara have been identified as suitable for ethanol production in various seasons. The best-bet practices for achieving higher yields are being perfected at the Indian Institute of Millets Research (IIMR), Hyderabad and the All-India Coordinated Sorghum Improvement Project (AICSIP) center, Gujarat.

Dr Kumar stated that a Big Mill Test has been successfully conducted at Shri Ganesh Sugar Factory, Vataria, Gujarat, without changing any of the mill settings. The sweet juice was fermented, and the ethanol produced was supplied to oil market companies for blending with petrol. Innovative ways of composting using sweet sorghum bagasse was developed as part of the project. Staff of the sugar mills as well as sweet sorghum farmers were trained in achieving higher yields and in conducting multilocation trials.

Various stakeholders such as sugar mill owners and seed producers expressed an interest in strengthening their collaboration in the project.

Future goals of the project for 2017 are as follows:

• Multilocation trials in four states (Karnataka, Maharashtra, Gujarat, Tamil Nadu) using 12-15 entries from IIMR, ICRISAT and private seed companies
• Demonstration of crop cultivation in Karnataka (8 ha) and Gujarat (12 ha)
• Big Mill Tests
• Validation of sowing time and fertilizer dosage for maximizing crop yields
• Evaluation of fermentation efficiency of sweet sorghum juice from various genotypes, and fertilizer value of stillage from juice
• Assessment of effect of sweet sorghum bagasse-based compost on various crops.

The Annual Review-cum-Work Planning Meeting was conducted on 15 May. Participants included 30 scientists and managers from IIMR, National Federation of Cooperative Sugar Factories (NFCSF), Jawaharlal Nehru Technological University, Hyderabad (JNTU-H), sugar industries, private sector seed companies and ICRISAT.

This work contributes to UN Sustainable Development Goal