Sustainability increases if ethanol is made from sugarcane juice: Study

Sugarcane — a cash crop that requires large amounts of water and land to cultivate — has enjoyed immense political patronage and while it was responsible for making India become the second-largest producer of sugar, the country has witnessed a tremendous challenge to its resources. 

Producing ethanol from sugarcane juice instead of molasses can help India meet its nutrition requirements and make resources like land and water more sustainable, said a July 24, 2020 study published in journal Environmental Research Letters.

The first-of-its-kind comprehensive analysis of India’s sugar industry — by researchers from Stanford University, United States — showed how the country must now move towards a more sustainable cultivation of sugarcane.

The country’s use of sugar dated back to the 1950s, when it was used for meeting the population’s basic calorie requirements.

These requirements, however, are now fulfilled, with poor populations receiving a full calorie intake as well, according to Rosamund Naylor, co-author and William Wrigley Professor in Stanford’s School of Earth, Energy & Environmental Sciences.

The Union government is, thus, becoming more concerned about nutrition because illness, disabilities and death are caused by micro-nutrient deficiency, prevalent among a large section of the Indian population.

Sugarcane cultivation — which benefitted from entrenched policies that incentivised production for decades — uses up more land and water, and, thus, reduces the use of these resources for foods that are rich in micro-nutrients, said the study.

Most populations can buy sugar at subsidised rates, but do not have access to adequate protein and micro-nutrients that are needed for cognitive growth, said Naylor.

A shift to using the crop as a source of energy generation can, thus, be beneficial for not just increasing access to nutrients, but also help in transitioning to renewable energy.

The Union government’s goal of increasing the ethanol-to-blending rate to 20 per cent by 2030 from a current six per cent can be achieved if it uses sugarcane juice to create ethanol, the study said.

A national biofuel policy that encourages ethanol production from sugarcane juice will help free up land and irrigation water, allowing for the cultivation of food crops that are rich in micro-nutrients.

India’s biofuel policy only recently allowed the use of sugarcane juice in ethanol production, in addition to molasses, the study pointed out.

“If the energy industry continues to use molasses as the bioethanol feedstock to meet its target, it would require additional water and land resources and result in the production of extra sugar,” said co-author Anjuli Jain Figueroa, a post-doctoral researcher in Earth system science.

Using sugarcane juice, however, can allow for the target to be met without needing water and land beyond current levels, said Figueroa.

Government spending to subsidise sugar can also be alleviated, allowing the government to sell sugar below cost, if sugarcane juice is used to produce ethanol, the study pointed out.

To illustrate their point of sugarcane cultivation using up more resources, the researchers focused their analysis on Maharashtra, one of the country’s largest sugarcane producers.

The study found sugarcane occupied only four per cent of Maharashtra’s total cropped area, but guzzled 61 per cent of the state’s irrigation water in 2010-11.

“This resulted in about a 50 percent reduction of river flow over that period,” said co-author Steven Gorelick, the Cyrus Fisher Tolman Professor at Stanford Earth. Gorelick also pointed out that the state — which is prone to floods — will find future water management challenging.

There are no reliable sugarcane maps either, pointed out lead author Ju Young Lee, a PhD student in Earth system science. “Using remote sensing data, I am developing current time-series sugarcane maps in Maharashtra – an important step forward,” she said.

The study also pointed out how institutionalised political interests in sugar production have threatened the country’s food, water and energy security over time.