In Part 1, we gave you views of practical people in indus- try and the academic world about how realistic, sustain- able critical cleaning processes may develop over the next five years; we covered many ideas including process
design, energy efficiency, and congruent chemistries.1 Let’s
move on to organic solvents, regulatory policy, and hope for
peace on earth.
The majesty of the ‘and’
Organic solvents and organic-based process
fluids are a mainstay of industry. We think
solvents for liquid/vapor phase degreasing will
continue to be used in 2020, particularly where
a high degree of wetting is needed to remove thin
film and particles from miniature components
and from complex structures, like those produced
using 3D printing. We’ll go out on a (short) limb and say that
“classic” solvents will remain under regulatory scrutiny.
Dr. Donald Wuebbles, Professor, Department of
Atmospheric Sciences and the Department of Electrical
and Computer Engineering at the University of Illinois at
Urbana-Champaign, is an expert in atmospheric chemistry
and climate issues. Wuebbles sees a trend toward “
continuing emphasis on compounds with low ODP (ozone depletion
potential) and low GWP (global warming potential) for use
as solvents, degreasers, and in related processes.” He expects
some HFCs (hydrofluorocarbons) to be phased out due to
their higher GWP. However, Wuebbles takes a pragmatic
view; he indicates that, in contrast with what he sees as the
position of some policymakers, “the ODP should not have to
be zero.” He views continued use of a compound “that has an
extremely small (negligible) effect on stratospheric ozone” as
a realistic approach.
There are promising new solvents. “Industry can’t wait until
2020,” explains David Cooper, Global Business Director for
Honeywell in Morris Township, N.J. “The drive toward higher
environmental and safety requirements will only grow, both in
the U.S. and globally,” asserts Cooper. “We see industry making
changes now.”
Cooper explains that “it’s the majesty of the ‘and.’ Whereas
industry was once forced to choose between effective cleaning
or environmental preferability, there is now global pressure for
solutions that provide effective cleaning and environmental
preferability; worker safety and cost-effectiveness. Industry can-
not accept yesterday’s tradeoffs.”
Azeotropes
“I’m banking my research on blended solvents, particularly on
azeotropes (constant-boiling mixtures),” explains Dr. Darren
Williams, Associate Professor of Physical Chemistry at Sam
Houston State University in Huntsville, Texas, “because you can
tailor the composition to meet the requirements of the process.”
Williams directs a laboratory focused on practical aspects of
cleaning chemistry and cleaning verification. Williams explains
that azeotropes “give us the promise to achieve process consis-
tency and can be fine-tuned in terms of chemical and physical
properties to achieve fluids that are safer for workers and the
environment.” Williams adds that “where chlorinated solvents
are essential, if an azeotropic blend were to allow us to use
30% chlorinated solvent rather than 100%, it would be a great
improvement.”
Williams cautions that in developing alternative solvent
blends, issues such as VOC levels and flammability must be
considered. He adds that, because cleaning processes involve
chemicals, equipment, and product, evaluation in a relevant
manufacturing environment is essential. “Everyone is trying to
pick the demon they are trying to avoid (VOC, halogen, etc).
Blending will help expand the range of options, but there are
only so many choices,” concludes Williams.
Processes
Many cleaning process techniques could improve the safety and
environmental impact of chemicals. Anselm Kuhn, Manager
at Finishing Publications Ltd., Stevenage, U.K. predicts that
increasing regulation on chemicals will favor the use of more
physical energy including high pressure water and CO2 ice blasting technology. He also sees “an increase in the use of ultrasonic
cleaning to boost the effectiveness of mild cleaning agents as
well as the use of intelligent ultrasonic tanks that regulate power
in order to save energy.” We might add the hope that chemical
containment, such as in well-sealed solvent systems, be visited as
an option within the next few years.
Steve Derman, President of MediSHARE Environmental
Health & Safety Services in Santa Clara, Calif., explains that
process change has to be holistic and coordinated. “If you were
going to do something to improve the safety of a process, the
change has to be integrated into the process. For example, in
solvent vapor degreasing, adding cooling coils lowers worker
exposure, minimizes air and water pollution, and increases
efficiencies.” Derman recalls, however, that when the concept
was first introduced, “there was reluctance from industry
because of increased costs and higher maintenance activities.
Industry was pleasantly surprised at the decreased evaporative
solvent losses.”
Robotics
Kuhn sees that one consequence of the increased worker safety
and environmental regulations might be the increased use
of robots. “Robots are progressively being more and more
widely used in industry, mainly because of the labor (and thus
cost) saving they can bring. I could easily imagine an entirely
new phase of robotization based on the premise that their
use would allow a process to be carried out, which would be
prohibited if human beings were involved.” Building on the
approach used in decommissioning nuclear power plants,
Kuhn could envision “a sealed production plant or part of a
plant where chlorinated hydrocarbons can be used as if they
were water. No human beings routinely work in such a plant,
Barbara Kanegsberg
Edward Kanegsberg
BFK Solutions LLC
2020 Vision: Green, Safe, Sustainable — Part 2
