Does Thermal Depolymerization Solve the Problem of Peak Oil?

Thanks to Martin Bento for this article

Thermal Depolymerization is a process that breaks down polymers into simpler compounds, much of which can be used for fuel. Polymers include essentially all organic matter (matter made of living or once-living things), which, in this sense,
includes petroleum products like plastic, styrofoam, and nylon, as well as plant and
animal material, and manure. A company called “Changing World Technologies (CWT)”
has a depolymerization process for which it claims 85% energy efficiency, i.e., the
energy requirements of the process are only 15% of the energy it produces. Does this
solve the problem of Peak Oil?

It depends on which “problem” of peak oil you mean. Many people have pointed out
that the polymers that CWT uses require energy to produce and that energy, these
days, comes mostly from fossil fuels. Depolymerization cannot extract more energy
from the polymers than went into creating them; it will always extract less. In this
view, depolymerization is very useful for making the downward slope from peak oil
less steep because it makes our use of fossil fuel energy more efficient (almost all
proposed source materials for depolymerization are wastes of one kind or another, so
the energy it produces is a gain relative to the energy we get from fossil fuels
now), but it does not ultimately change anything.

But that is not the whole story either. Although biomass is commercially produced
largely with fossil fuels, this need not be so and is not so in nature. It is
debatable whether alternative approaches can ever equal the productivity of fossil
fuel approaches, but they certainly do not have a productivity of zero, and they
certainly do produce polymer waste products. Also, humans and animals will always
produce manure. So long as there are plants and animals on the Earth, there will be
biomass whose polymers can potentially be harvested for energy. After all, eating
itself is largely a way to harvest energy from other biomass, and eating is a
sustainable project in the ecosystem (though not, perhaps, for a human population of
its current size). Viewed this way, depolymerization can be a sustainable source of
energy and, indeed, of “oil”. In the shorter term, of course, it will be a pleasure
to deplete the backlog of synthetic polymers we have created.

For example, if we reform our behavior so as to improve the health of our oceans,
there may well be a sustainable level of harvesting of micro-algae (technically
cyanobacteria) for energy. Micro-algae is probably responsible for the majority of
the world’s photosynthesis. Depolymerization could enable us to capture this some of
this energy in a sustainable way (attention Changing World: I expect a ten percent
royalty on this idea!).

This doesn’t necessarily mean that we will be able to continue consuming energy at
current first-world levels. For the next few decades at least, we must tame our
energy consumption. But current levels are very wasteful and dangerously polluting
in any case, and more efficiency would be a good thing. By cushioning the fall and
promising an eventual sustainable supply of oil, depolymerization can indeed
contribute significantly to the vital task to saving civilization. Though no cause
for complacency, it is indeed some cause for hope.