JEC COMPOSITES MAGAZINE - Issue #81 - May/June 2013 - 77

carbon

The greening of carbon fibre

Carbon fibre is a material that has, and will continue to revolutionize the products we use every day by making them stronger,
lighter and more durable. Experts estimate that this specialty
material is twice as stiff as steel and five times stronger, per unit
of weight.

Abatement trends and techniques

arbon fibre is made from organic
polymers which consist of long
strings of molecules held together
by carbon atoms. The manufacturing
process is often unique to each supplier
and can be as complex as the molecules
themselves. Gases, liquids and other
materials used in the manufacturing
process create specific strengths,
qualities and grades of carbon fibre. A
series of ovens and furnaces also give
strands the desired characteristics by
varying temperatures, dwell time and
oxygen levels. As you can imagine, the
energy demand and heat input needed
for the processing of carbon fibre are
extensive.
When the industry first began, the
costs of operation for the first carbon fibre conversion plants were not
critical design parameters, and neither
were the environmental effects. As the
demand for carbon fibre expanded,
much has been done on the production
side to increase efficiency while reducing the energy demands of oxidation
and carbonization furnaces and ovens.

Manufacturing carbon fibre can have
serious environmental ramifications
and pose immediate danger to humans
if careful consideration is not given
to emission control at the production
phase of these materials. The primary
air pollutants of concern are hydrogen
cyanide (HCN) and ammonia (NH3),
which are immediately dangerous to
human health in small quantities. Greenhouse gases (GHGs) such as carbon
monoxide (CO), nitrogen oxide (NOX)
and volatile organic compounds (VOCs)
are also controlled pollutants, not only
for their warming effects on our climate
but also for their direct correlation to
energy consumption. The manufacturing
process also generates tar residues and
silicone which further complicates the
destruction of pollutants.
As is the case with many industrial
manufacturing operations, emissions
are best destroyed through the use of
thermal oxidation technologies via hightemperature combustion – CnH2m + (n
+ m/2) O2 ==> n CO2 + mH2O + heat.
However, very few industries use cus-

Rich GRzanka
Vice PResident of Business deVeloPment
anGuil enViRonmental systems

tom-designed solutions like the carbon
fibre processing industry does on the two
following abatement devices.
Regenerative thermal oxidizer (RTO)
The energy-efficient operation and high
destruction efficiency of the RTO make
it a great emission control device for
a wide variety of industrial processes.
However, unique aspects of carbon fibre
processing dictate several oxidizer modifications in order to maintain system
effectiveness, reliability and safety.
Theoretically, emissions from the lowand high-temperature furnaces, as well
as the ovens, can all be handled by
the RTO; however it is used most
frequently for the oven exhaust. The
regenerative component to the RTO
makes it ideal for handling high-flow,
low-concentration streams. With
achievable

How air flows, and heat is transferred in the Anguil
Regenerative Thermal Oxidizer for fuel-free
combustion

No81 May - June 2013

/ jec composites magazine 77

JEC COMPOSITES MAGAZINE - Issue #81 - May/June 2013

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #81 - May/June 2013