Icrisat inks pacts with Rusni, VSI

The International Crops Research Institute for the Semi-Arid Tropics (Icrisat) is strengthening its collaborations to promote sweet sorghum varieties, hybrids and technologies to extract alcohol from the crop.

The Agri-Business Incubator (ABI) at Icrisat has signed a memorandum of agreement (MoA) with Rusni Distilleries Private Ltd of Hyderabad to incubate the ethanol production technology using sweet-stalk sorghum lines.

Icrisat has also signed another MoA with Vasanthadada Sugar Institute (VSI), Pune, for identification and development of improved sweet sorghum varieties, characterising the juice, ethanol quality and quantity, and also providing process technology to Rusni Distilleries through ABI.

William Dar, director general of Icrisat, said that the sweet sorghum varieties, hybrids and technologies developed by Icrisat hold high promise for the farmer of the semi-arid tropics. The Icrisat varieties can grow with less water and thus can be grown in the drylands of the world.

In addition to the grain, the crop can be used to produce alcohol (ethanol) in a more environment friendly manner when compared to sugar cane. The ethanol can be used to blend with petrol and diesel for producing gasohol.

"Icrisat's strategy is two-pronged," Dar said. "Using our sorghum breeding skills, we are developing hybrid parents and varieties that are good for ethanol production. We are also helping in the incubation of the production technology for ethanol from sweet sorghum."

Icrisat is hopeful that private seed companies in India would complement the efforts of the national programme in the development of location-specific hybrids with sugar-rich high stalk yield to meet the expected increased demand for raw material for ethanol production in the years to come.

Sweet sorghum (sorghum bicolour) is similar to grain sorghum with a sugar-rich stalk, almost similar to sugar cane. Besides having wide adaptability, rapid growth and high sugar accumulation and biomass production potential, sweet sorghum, is tolerant to drought, water logging, soil salinity and acidity toxicity.

It has great potential for jaggery, syrup and alcohol (most importantly gasohol, which is ethanol blended with petrol) production. The sugar content in the juice extracted from sweet sorghum varies from 16-23% Brix.

In recent years, there is an increased interest in the utilisation of sweet sorghum for ethanol production in India as its growing period is only about four months, and the water requirement of 8,000 cubic meters (cu m) for two crops is one-fourth that of sugar cane, which has a growing period of 12 to 16 months and a water requirement of 36,000 cu m per crop.

In addition, sweet sorghum is better suited for mechanised crop production and seed propagation.

According to a pilot study conducted by VSI, sweet sorghum is the best alternative raw material, which can supplement the use of sugar cane in ethanol production.

At 5,600 litres per hectare per year (over two crops, at 70 tonnes per hectare of millable stalk per crop at 40 litres per tonne), the ethanol production from sweet sorghum compares well with the 6,500 litres per hectare per crop for sugar cane (at 85-90 tonnes per hectare of millable cane per crop at 75 litres per tonne).

According to estimates made by the National Research Centre for Sorghum (NRCS), Hyderabad, the per litre cost of production of ethanol from sweet sorghum is Rs 13.11 (at Rs 500 per tonne of stalk), when compared to Rs 12.55 (at Rs 1,600 per tonne of stalk) from sugar cane molasses.

However, the increased cost of production of ethanol from sweet sorghum is more than compensated by the grain yield of one tonne per hectare (which can be used as food or feed) and the superior quality of ethanol.

The really significant advantage is that the production of ethanol from sweet sorghum is environment friendly since it uses the non-molasses route.

In India, the estimated requirement for ethanol to blend with petrol (at 10%) is about 1,000 million litres, and for blending with diesel (at 5%) another 3,000 million litres.

The total ethanol requirement including other purposes is 5,000 million litres. The possible ethanol production from available sugar cane molasses (8.2 million tonnes) and other sources is 2,000 million litres. This leaves a gap of 3,000 million litres of ethanol. The deficit of ethanol can be made good if sweet sorghum cultivation is promoted for ethanol production.