Prof. Rajnish Kumar, Department of Chemical Engineering, IIT-Madras
For a long time, scientists have recognized that fuel hydrates — ice-like crystals fashioned when water traps sure gases below low temperatures and reasonable stress — may, in precept, purify contaminated water.
The concept was all the time enticing: Water locks itself into crystals whereas salts and different impurities are left behind. But there was a catch.
Separating the crystals from the remaining wastewater proved cumbersome and energy-intensive, stopping the know-how from competing with membrane-based methods, reminiscent of reverse osmosis (RO).
Researchers on the Indian Institute of Technology, Madras, now say they’ve overcome that bottleneck.
The workforce has developed and patented a fuel hydrate-based course of that kinds hydrate crystals straight within the gaseous section, eliminating the necessity for filtration or centrifugation to separate them from wastewater.
In assessments utilizing precise petrochemical effluent provided by GAIL (India) Ltd, the system recovered greater than 65 per cent of the water, eliminated 84-93 per cent of contaminants, and recycled over 99 per cent of the hydrate-forming gases used within the course of.
Developed by Dr Subhash Kumar Sharma below the supervision of Prof Rajnish Kumar, the method affords an alternate to RO. (RO’s membranes are inclined to fouling, require periodic alternative and generate strong waste. Thermal processes keep away from membranes however eat considerably extra power.)
A combination of propane and HFC-134a is launched into the contaminated wastewater below fastidiously managed temperature and stress. Water molecules assemble across the fuel molecules, forming strong hydrate crystals whereas salts, ammonia, suspended solids and natural contaminants stay within the liquid.
The crystals are then gently melted to get better purified water, whereas the gases are captured and reused within the subsequent cycle.
The know-how consumed 3.88 kWh of electrical energy for each cubic metre of water recovered — comparable to seawater reverse osmosis and considerably under thermal desalination strategies. The researchers estimate a levellised water price of about 14 paise a litre and report a carbon footprint 35–70 per cent decrease than that of standard membrane- and heat-based applied sciences. The handled water met the Central Pollution Control Board requirements for industrial reuse.
Kumar stated the method may assist industries scale back freshwater consumption whereas assembly more and more stringent zero liquid discharge necessities.
The know-how is at readiness stage 6, indicating it has moved past laboratory proof-of-concept. The workforce plans pilot-scale demonstrations utilizing wastewater from the pharmaceutical, textile and fertilizer industries.
Published on July 13, 2026