IT’s ALL ABOUT CRYOGENIC TECHNOLOGY

In physics, cryogenics is the study of the production and behaviour of materials at very low temperatures (below ?150 °C, ?238 °F or 123 K). Cryogenics" terms come from Greek and mean "the production of freezing cold". However, the term is used today as a synonym for the low-temperature state. Cryogenics is the study of how to attain low temperatures and how materials behave when these low temperatures are attained. Cryogenics deals with low temperatures, from about 100 Kelvin to absolute zero. Absolute zero is the lowest temperature that could ever be. Scientists noticed that for all gases, the temperature at which they reached zero volume was about -273 Celsius. This temperature is known as absolute zero and is the zero point on the Kelvin temperature scale.

Usage: Cryogenic Liquids Commonly used gases, in their liquid form, are nitrogen, helium, hydrogen, and LNG. These are the common cryogenic liquids. Liquid helium and nitrogen are usually stored in vacuum-insulated flasks. Nitrogen condenses at -195.8 C (77.36 Kelvin) and freezes at -209.86 C (63.17 Kelvin). Liquid nitrogen is used in many cooling systems. Helium boils at -268.93 C (4.2 Kelvin) and does not freeze at atmospheric pressure, whereas LNG condenses at -165 C and becomes liquid for transportation purposes.

Propellants like oxygen and hydrogen in liquid form give very high amounts of energy per unit mass due to the way the amount of fuel to be carried aboard the rockets decreases. Hydrogen and oxygen are extremely clean fuels. When they combine, they give out only water. This water is thrown out of the nozzle in the form of very hot vapour. Consequently, the rocket is nothing but a high-burning steam engine.?The use of oxygen and hydrogen as fuels is very economical, as liquid oxygen costs less than gasoline. The entire world is planning to change the transport of traditional fossil fuels to LNG by storing them in cryogenic containers. This will not only reduce carbon emissions in the long run, but will also provide price competitiveness with other fossil fuels. Due to the abundance of LNG sources around the world, all developed countries have already adopted LNG as an alternative to fossil fuel.

WHAT ABOUT INDIA ?

Right now, India has had success with this technology. But during 1991-92, India faced many problems in getting the cryogenic engine from Russia to India. The U.S., Japan, and France either refused to provide the technology or did?so only at an exorbitant price. ISRO opted to go ahead with the import. In May 1992, the U.S. imposed sanctions on ISRO, followed by Russia. ISRO then had no option but to develop the technology on its own. Finally, after many failures, in January 2014, India mastered this technology and became the sixth country in the world after the U.S., Russia, Japan, France, and China to master cryogenic technology.

APPLICATIONS : Cryogenic technology is primarily used in rocket engines, electric power transmission in big cities, transportation of gases in liquid form, frozen food, blood banking, infrared sensors, amongst others.

?CHALLENGES : There are some challenges as well, due to maintaining the low temperature of propellants. There are complex storage, transfer, and it operations that require an ignition system. Consequently, overall capex and opex are relatively high.

?HOPE : Of late, the government of India has taken several steps to encourage and adopt this technology. Several policy level discussions are going on and in the coming 2-3 years we may witness massive development in this area due to GOI's proactive approach, which is a good spark of hope for all, keeping in mind India’s large geographical territory and population.