00.00
Images:
Planes over
Traffic
Petrol
station
Cars
Aston
University exteriors
Pyrolysis
rig
Guide Voice: The transport sector is now the
fastest growing consumer of energy, and also the fastest growing
source of greenhouse gas emissions, yet few people are prepared to
even reduce their flying or driving, let alone cut down on heating
and lighting for their homes.
So as reserves of fossil fuels dwindle, and the need to cut
carbon dioxide emissions becomes paramount, the search is on for
renewable alternatives, which are also carbon neutral. The hunt for
viable forms of bioenergy is well advanced at Aston University, in
the West Midlands of the UK, where a research team are leading the
field in the development of “fast pyrolysis”, which can
convert biomass and bio-waste into a biofuel through a carbon
neutral process.
00.41 SOT Professor Tony Bridgwater, Chemical
Engineering and Applied Chemistry, Aston University -
“Fast pyrolysis is a process similar to the traditional
way of making charcoal, but it does it in a far quicker way. It
processes small pieces of biomass from trees or crops like
miscanthus or straw, heats it very quickly to a carefully
controlled temperature around 500 degrees, and cools the products
down very quickly and in so doing we make a liquid we call bio-oil,
which is like this, and then bio-oil can be used for energy for
power for heat and for chemicals.”
01.13 Images:
Lab shots
Biomass
samples
Close
up oil
Oil
poured out
Leaves
Guide Voice: The bio-oil end product is an easy
form to store and transport, and its versatile, it can be developed
as a fuel itself, or converted to electricity, transport fuels or
chemicals. At Aston they have experimented with a number of
different forms of biomass and successfully turned them into this
oil. All organic matter is basically biomass, crops, forests,
agricultural waste, and can be used to produce clean energy
sources, in a sustainable way, in a closed carbon cycle.
01.43 SOT Mr. Mark Coulson, Chemical Engineering and
Applied Chemistry -“In the case of biomass, when
you’re growing the crop you’re storing carbon dioxide
out of the atmosphere into the crop, when you then burn or convert
the crop into energy, you release that carbon back into the air in
the form of carbon dioxide so the carbon goes round and round a
closed circle in a very short time scale. In the case of fossil
fuels the energy has been stored underground for a very long period
and so we’re releasing carbon that has been there for
millions of years.”
02.13 Images:
GVs fields, straw
GVs
rape seed
Hay
harvested
GVs
general agriculture
Professor
at computer
Elephant
grass on computer screen
Lab
GVs
Guide Voice: While using biomass to create
energy is clean and sustainable in contrast to fossil fuels,
deciding what biomass is best to use and how, cuts to the heart of
two of the bioenergy field’s key considerations, yield, and
cost.Where rape seed and other vegetable oils have been
successfully used as additives to diesel fuel, they can only be
replace up to 5% of diesel.
And vegetable oils are not necessarily the most effective use of
limited land resources producing just 1 to 1 ½ tonnes of
bio-diesel per hectare. By contrast the fast pyrolysis process
could generate up to 3 times the amount of renewable liquid fuel
from the same land area, if you use a different biomass resource
with a higher yield such as miscanthus or elephant grass. The
pyrolysis process itself however also needs to be done on a
sufficient scale to bring the costs down.
03.08 Sot Professor Tony Bridgwater -
“We’re limited in the UK by the amount of suitable
land we have available for growing biomass. The second limitation
is the high cost of producing that biomass in a country like the
UK. But if there was sufficient biomass available one can consider
what’s called a biorefinery of the order of millions of tons
per year. A biorefinery will take in bio-oil or biomass and will
produce an optimised combination of energy products, fuel products
and chemicals that is energetically and economically as efficient
as possible.”
03.45 Images:
Ablative pyrolyser
Lab
Rig shots
Mark
points out char and gas collection
Close
ups small rig
Petrol
pumps
Leaves
Guide Voice: At the moment in the lab their
fast pyrolysis test rigs can deliver up to 5 kilos of bio-oil an
hour, on an industrial scale a fast pyrolysis plant would need to
produce at least five tonnes an hour to be commercially viable. As
they continue to research the best ways to improve the pyrolysis
process, there are other factors that could make a biorefinery even
cheaper and more efficient, by-products of the process include char
and gases that could be used to provide the entire power
requirements of the refinery process.
At the moment fast pyrolysis cannot produce fuel at a
competitive cost to fossil fuels, but with rising oil prices and
greater political commitment it could make a major contribution to
a cleaner and more sustainable planet in the future
04.30 SOT Professor Bridgwater - "We
see fast pyrolysis as satisfying the short term needs for producing
heat and power and in the medium to long-term as being the heart of
a biorefinery process that produces transport fuels and chemicals
as well as heat and power and if you build a biorefinery large
enough, maybe millions of tons per year of biomass you can reduce
the costs to a much more acceptable level."
04.53 Ends
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