192
5 Fourth Industrial Revolution and India
kind of conversion is possible in nuclear reactions where basis changes are initiated
in the nucleus of atom. Two known types of nuclear reactions where mass to energy
conversion occurs in a remarkable way are fission (splitting of the nucleus of an
atom) and fusion (combining of nuclei of two atoms).
The solar energy, which we are trying to convert into electrical energy, is essentially a product of fusion reaction that goes on incessantly inside the sun, whereby
nuclei of hydrogen atoms continuously fuse to form nuclei of helium atoms releasing
tremendous amount of energy in the process. But unlike fission energy that has been
produced on commercial scale, power from fusion energy is still many years away.
One of the major impediments in this process is that it is very difficult to fuse
two atomic nuclei as both are positively charged and thus repel each other. What
is required is to give sufficiently high velocity to these nuclei by heating them to
hundreds of millions of degrees as happens in case of Sun. Once fusion starts, it will
generate enough heat for other atoms to fuse and start a chain reaction. That is why
fusion reaction is also called thermo nuclear reaction or nuclear reaction caused by
heat.
Energy from human fusion process, whenever realized, will change the landscape
of this planet with sustainable solution to the climate-related threats. There will be
zero GHG emission and no long-lasting radioactive waste disposal issues. Scientists
have been relentlessly working for more than seven decades to realize the dream
of human controlled nuclear fusion that will be carbon-free and thus change the
energy landscape of the planet. There are three primary conditions that need to be
fulfilled in a fusion reactor—high temperature exceeding 100 million °C for collision
of hydrogen atoms, optimum plasma density to enhance probability of collision, and
sufficient confinement to hold the plasma and ensure continuous collision. There are
many types of fusion reactors being tested in various countries such as ‘Tokamak’,
‘Stellarator’, ‘Demo’, and ‘ITER’.
29 Tokamak is the oldest design invented in 1950s
and ITER is latest device. In the Tokamak reactor, atoms of deuterium and tritium
are heated in a doughnut-shaped containment till the time their electrons and naked
nuclei (called plasma) are separated. Further heating of plasma leads to merger of
nuclei and release of free neutrons that act as transporter of heat (generated by fusion)
out of plasma and this heat can be used of electricity generation. Currently research
is going on in several countries to have a flawless reactor. Scientists are hopeful
that within a decade or so, fusion reactors will be ready for commercial electricity
generation.
2. Fuel Cell
A fuel cell converts chemical energy of a fuel (such as hydrogen) directly into electricity and is similar to a battery
30 with an anode (to supply electrons) and a cathode
(to absorb electrons) immersed in an electrolyte (solid or liquid). The difference
between the two is that fuel cell can be continuously supplied with fuel and air from
an external source unlike a battery that has fixed quantity of fuel material. One of
29 Ref—The Economist Technology Quarterly, December 6th 2014.
30 https://www.britannica.com/technology/fuel-cell.
5 Fourth Industrial Revolution and India
kind of conversion is possible in nuclear reactions where basis changes are initiated
in the nucleus of atom. Two known types of nuclear reactions where mass to energy
conversion occurs in a remarkable way are fission (splitting of the nucleus of an
atom) and fusion (combining of nuclei of two atoms).
The solar energy, which we are trying to convert into electrical energy, is essentially a product of fusion reaction that goes on incessantly inside the sun, whereby
nuclei of hydrogen atoms continuously fuse to form nuclei of helium atoms releasing
tremendous amount of energy in the process. But unlike fission energy that has been
produced on commercial scale, power from fusion energy is still many years away.
One of the major impediments in this process is that it is very difficult to fuse
two atomic nuclei as both are positively charged and thus repel each other. What
is required is to give sufficiently high velocity to these nuclei by heating them to
hundreds of millions of degrees as happens in case of Sun. Once fusion starts, it will
generate enough heat for other atoms to fuse and start a chain reaction. That is why
fusion reaction is also called thermo nuclear reaction or nuclear reaction caused by
heat.
Energy from human fusion process, whenever realized, will change the landscape
of this planet with sustainable solution to the climate-related threats. There will be
zero GHG emission and no long-lasting radioactive waste disposal issues. Scientists
have been relentlessly working for more than seven decades to realize the dream
of human controlled nuclear fusion that will be carbon-free and thus change the
energy landscape of the planet. There are three primary conditions that need to be
fulfilled in a fusion reactor—high temperature exceeding 100 million °C for collision
of hydrogen atoms, optimum plasma density to enhance probability of collision, and
sufficient confinement to hold the plasma and ensure continuous collision. There are
many types of fusion reactors being tested in various countries such as ‘Tokamak’,
‘Stellarator’, ‘Demo’, and ‘ITER’.
29 Tokamak is the oldest design invented in 1950s
and ITER is latest device. In the Tokamak reactor, atoms of deuterium and tritium
are heated in a doughnut-shaped containment till the time their electrons and naked
nuclei (called plasma) are separated. Further heating of plasma leads to merger of
nuclei and release of free neutrons that act as transporter of heat (generated by fusion)
out of plasma and this heat can be used of electricity generation. Currently research
is going on in several countries to have a flawless reactor. Scientists are hopeful
that within a decade or so, fusion reactors will be ready for commercial electricity
generation.
2. Fuel Cell
A fuel cell converts chemical energy of a fuel (such as hydrogen) directly into electricity and is similar to a battery
30 with an anode (to supply electrons) and a cathode
(to absorb electrons) immersed in an electrolyte (solid or liquid). The difference
between the two is that fuel cell can be continuously supplied with fuel and air from
an external source unlike a battery that has fixed quantity of fuel material. One of
29 Ref—The Economist Technology Quarterly, December 6th 2014.
30 https://www.britannica.com/technology/fuel-cell.