Context-India is testing a Swedish technology — torrefaction that can convert rice stubble into ‘bio-coal’.

• The Office of the Principal Scientific Advisor (PSA) to Government of India has funded a pilot project in Punjab to evaluate the feasibility of the technology. Bioendev, a Swedish company, has set up a pilot plant at the National Agri-Food Biotechnology Institute in Mohali

Torrefaction

• Torrefaction is a thermal process to convert biomass into a coal-like material, which has better fuel characteristics than the original biomass
• Torrefaction involves the heating of biomass in the low or absence of oxygen to a temperature of typically 200 to 400°C. The structure of the biomass changes in such a way, that the material becomes brittle, and more hydrophobic.
• Although the weight loss is about 30%, the energy loss is only 10%.
• Main product is the solid, torrefied biomass.
• During the torrefaction process a combustible gas is released, which is utilised to provide heat to the process. 
• Energy from 35 million tons paddy is wasted every year in India. It can be converted to bio coal and replace 21 million tons of fossil coal a year.
• This would work out to 48 million tons of carbon dioxide equivalent reduction, or equivalent to Green House Gas emissions from 10.2 million Indian cars

The benefits of torrefied pellets make it the ideal coal replacement:

• Grinds & burns like coal – existing infrastructure can be used
• Lower feedstock costs
• Lower shipping and transport costs
• Minimal de-rating of the power plant
• Provides non-intermittent renewable energy
• Lower sulfur and ash content (compared with coal)