Few of us think about heat as an essential ingredient in the products we
use every day. And, yet industrial
process heat constitutes two-thirds of all energy used by industry.
It is used to melt and form metals, to make ceramics, to refine crude oil,
to make industrial chemicals, to dry crops, to process food, to sterilize
medical instruments, and to heat the facilities within which industries
operate. Practically, everything we use on a regular basis has at some
point required heat to process. And it turns out that the challenges
society faces obtaining process heat mirror in many respects the energy
challenges for society as a whole.
Without process heat, much of the world would grind to a halt. That's why
the ready availability of fuel for creating that heat is so important.
Currently, fossil
fuels dominate as energy sources for process heat, chiefly natural
gas and coal. There are two reasons to be concerned about their supply.
First, evolving regulations regarding fossil fuel emissions in order to
address both pollution and climate change may make fossil fuels more
expensive and difficult to use (for example, due to the need for advanced
scrubbers and carbon capture). Second, the underground supplies of fossil
fuels may not be as plentiful as the public has been led to believe.
(Regarding oil and natural gas, see this
piece. For coal, see this
piece.)
Process heat is so central to some industrial operations that if it
becomes too expensive, it may make operations unprofitable. We've already
seen several
energy-intensive industries in Europe shut down operations due to high
prices for natural gas resulting from the loss of Russian natural
gas imports due to sanctions and sabotage. So, not only must fossil fuels
be available to those requiring process heat, those fuels must also be
cheap enough to maintain the profitability of the operations that rely on
them.
So what are the possible alternatives? This
piece (linked previously above) outlines some of them.
1. Geothermal has much to recommend it. It takes heat
from deep in the earth, and once set up needs very little carbon-based
fuel to maintain itself. Trouble is, it is not cost-effective compared to
current fuels and would require technological advances to drill the extraordinarily deep holes required that would often have to be deeper than 12
kilometers (not a typo). Moreover, it is not a portable fuel like coal and
natural gas which can be transported to the site where they are needed.
And so, a geothermal well would have to be drilled in every place where
process heat is required.
2. Electricity sounds great until you realize that
currently almost 62
percent of the world's electricity is generated using fossil fuels.
Since the amount of energy lost in the form of heat at the generating
plant is significant—somewhere between two-thirds to just under half
depending on the fuel and equipment—it makes more sense to bring the fuel
to the facility where the process heat is needed and burn it there. If, on
the other hand, renewable energy sources are used, electricity as a
heating source makes more sense. But renewable energy is often just
fraction of what is delivered via the grid to an industrial operation.
Dedicated solar and wind power along with storage batteries at the plant
can solve this problem, but that's costly to set up and run in most places
compared to fossil fuels.
3. Heat pumps operate using electricity so concerns
listed under "Electricity" above apply. And, the pumps only generate
low-level heat and tend to become less efficient as temperatures outdoors
and indoors diverge too greatly.
4. Hydrogen is an energy carrier, not an energy source.
Currently, it is made primarily using natural gas through steam
reforming. It can also be made from water using electrolysis (which means
the electricity has to come from somewhere).
5. Nuclear reactors can supply heat, but typically not
at the levels needed for high-temperature applications like melting
metals. The development of so-called microreactors may allow nuclear
reactors to compete more favorably in the process heat market.
There is, of course, the larger question of how quickly human societies
can transition away from fossil fuels for ALL applications in the world
economy given the urgency due both to depletion and climate change. And,
that urgency is becoming greater with every passing day.
ABOUT THE AUTHOR
Kurt Cobb is a freelance writer and communications consultant who writes frequently about energy and environment. His work has appeared in The Christian Science Monitor, Resilience, Common Dreams, Naked Capitalism, Le Monde Diplomatique, Oilprice.com, OilVoice, TalkMarkets, Investing.com, Business Insider and many other places. He is the author of an oil-themed novel entitled Prelude and has a widely followed blog called Resource Insights. Point of contact: kurtcobb2001@yahoo.com.
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