Prelims Syllabus : Science & Technology Mains Syllabus : GS-III Science and Technology-Developments and their Applications and effects in Everyday Life
Why in News?
- India is planning to make use of the Swedish torrefaction technology to reduce stubble burning issue.
What Is Torrefaction?
- Biomass torrefaction is a thermal process used to produce high-grade solid biofuels from various streams of woody biomass or agro residues.
- The end product is a stable, homogeneous, high quality solid biofuel with far greater energy density and calorific value than the original feedstock, providing significant benefits in logistics, handling and storage, as well as opening up a wide range of potential uses.
How it Functions?
- Biomass torrefaction involves heating the biomass to temperatures between 250 and 300 degrees Celsius in a low-oxygen atmosphere.
- When biomass is heated at such temperatures, the moisture evaporates and various low-calorific components (volatiles) contained in the biomass are driven out.
- During this process the Hemi-Cellulose in the biomass decomposes, which transforms the biomass from a fibrous low-quality fuel into a product with excellent fuel characteristics.
- To make a biomass torrefaction plant economically viable it is crucial to use the energy “lost” in the volatiles. This can be done by burning the volatiles (torgas) in a lean gas combustor. This combustor can provide the heat for the drying and torrefaction also.
Possible Benefits of the Technology:
- Torrefaction of biomass results in a high grade biofuel which can be used as a replacement of coal in electricity and heat production and as input for gasification processes in the production of high value bio-based fuels and chemicals.
- The Torrefied pellets becomes an ideal coal replacement because of its following features:
- 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 sulphur and Ash Content (compared with coal)