Hydrocarbon Processing - November 2022 - 11A

MIKE RHODES, MANAGING EDITOR
Mike.Rhodes@HydrocarbonProcessing.com
Innovations
Expanded polystyrene
manufacturers incorporate
RTO technology to meet
clean air regulations
Anyone who has encountered foam
clamshells for restaurant takeout food,
white or green " peanut " packing to
cushion shipments, or those thick foam
blocks for protecting boxed furniture
is familiar with expanded polystyrene
(EPS). In use since the 1930s, EPS continues
to gain in use around the world
in applications from surfboard cores to
roadways and building materials. Mordor
Intelligence has estimated the 2021
EPS market at 8 MM metric tpy (impressive
for a substance that is > 95%
air), with a ~5% compounding annual
growth rate (CAGR) through at least
2027. However, EPS production does
carry certain environmental costs.
Ship & Shore Environmental (S&SE),
a multinational environmental pollution
abatement and energy solutions firm,
now offers steam-generating thermal
oxidizer (STGO) equipment (FIG. 1) that
can help mitigate these costs to help better
meet environmental regulations and
potentially qualify for " green " manufacturing
incentives.
The pentane problem. EPS begins as a
collection of polystyrene beads impregnated
with a " blowing agent " that allows
the beads to expand (with steam) up to
some 40x their original size. These expanded
foam beads then get pressed and
molded into a desired shape for eventual
use. EPS is lightweight, protective, and a
cost-effective thermal insulator.
Very often, pentane is used as the
blowing agent in EPS. Pentane compounds
are frequently used as fuels and
solvents. However, improperly managed
pentane has a host of well-known health
impacts, including damage to the eyes,
skin, lungs and nervous system. It can also
contribute to poor air quality (via ozone
damage), which causes another chain of
health effects. As a result, governments
and industry manufacturers alike have
embraced EPS treatment regulations.
Only with proper handling and processing
will EPS remain viable, responsible,
profitable and feasible for recycling.
EPS fabrication requires highly customized
abatement systems able to
handle high concentrations of volatile
organic compounds (VOCs), including
pentane. Specific requirements will depend
on regional environmental regulations
and the nature of the EPS operation
or environment generating VOCs.
These can include:
* Bead storage areas
* Bead dump to hopper
* Pre-expander operations
* Fluidized bed dryers
* Block/shape mold releases
* Vacuum system exhaust
* Pre-puffed silo storage
* Heated aging rooms.
Every such pentane/VOC nexus has
its own emissions characteristics that will
shape any abatement equipment design.
One size does not fit all, and performing
that customization in a safe, effective
manner requires considerable expertise.
FIG. 1. Ship & Shore Environmental's Steam
Generating Thermal Oxidizer (SGTO).
11A NOVEMBER 2022 | HydrocarbonProcessing.com
S&SE and the STGO solution. For
more than two decades, Ship & Shore
Environmental has specialized in the
design, construction and deployment of
high-efficiency abatement systems tailored
to a broad range of industries. As
environmental, social and government
(ESG) mandates and VOC emissions
regulations expand in tandem, S&SE
has emerged as one of the U.S.'s top resources
for abatement solutions, as durable
and reliable as they are capable of
containing operational expenses. Approximately
90% of EPS air pollution
control systems throughout the country
have been engineered, installed and
maintained by S&SE.
Most of these S&SE solutions for
EPS pentane emissions have been based
on regenerative thermal oxidizer (RTO)
technology, which has proven to be
the preferred pentane abatement technology
to present. Most RTO systems
combine combustion and heat recovery
chambers to achieve a 1,500°F operating
temperature suitable for destroying 98%
of VOCs. Exhaust heat can be captured
and repurposed by the business, such as
for building air and/or water heating-
this recapture often qualifies for rebate
incentives from local energy utilities,
with some payouts even reaching six figures.
S&SE RTOs operate from either a
minimal amount of natural gas or even
from the pentane contained within the
industrial operation, making the abatement
process self-sustaining.
S&SE has now improved on its RTO
technology with its steam-generating
thermal oxidizer (SGTO) innovation. In
essence, an SGTO is a thermal oxidizer
built into a steam boiler. The SGTO also
sustains at 1,500°F for at least 0.5 sec to
destroy pentane and other VOCs. However,
radiated heat transfers via convection
to a set of boiler tubes, which then
produce hot water or steam. Depending
on the application and environment, an
economizer installed in the exhaust stack
can capture this waste heat and convert
it to energy, which can then be used for
the SGTO or the business running it.
According to the company, any industrial
plant that uses steam, hot water
or hot oil for process heating while also
working with VOC abatement requirements
can benefit from S&SE SGTO
solutions.
https://www.HydrocarbonProcessing.com
Hydrocarbon Processing - November 2022

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