Chemical Engineering April 2023 - 36

that heat could easily be replaced
with electric solutions that are available
today. The concept of electrification
in chemical manufacturing
plants, then, is not about completely
changing every process altogether.
It's about proper peaking and placing,
especially for those processes
that operate at temperatures less
than 1,000ºC.
Electric motors and machines are
often smaller, lighter weight, require
less maintenance and have longer
lifespans than traditional combustion
systems. Electrified assets, therefore,
are typically more cost-effective
and use much less power than their
fossil-fuel-burning counterparts.
Manufacturers can also digitize
electricity-powered assets, combining
them with predictive solutions
to reduce downtime and total cost
of ownership. Full to partial electrification
of processes can be achieved
with three options, which are discussed
in further detail in Part 1 of
this Feature Report, Electrification of
Industrial Facilities (pp. 28-33):
1. Using heat pumps instead of reboilers
and condensers
2. Using electrical heating instead
of steam or fuel-fired heaters
3. Using electric motors instead of
steam or gas turbines
4. Using electrical boilers for process
steam needs instead of coalfired
boilers
In these instances, commercial
solutions already exist, and they
do not necessarily require a significant
process change. Chemical
manufacturing
organizations
can
focus on electrification as a series
of quick wins, replacing a boiler or
furnace running on conventional
fuel within electric arc furnaces
or powering compressors and
pumps with electric motors, rather
than as an all-or-nothing solution.
Looking at process specifics
A typical study to electrify a process
can be outlined in five key steps [5]:
1. Assess the current state, the energy
demand and electrification
opportunities
2. Identify available solutions and
study their fit
3. Study implications through the
full power system design
4. Optimize electrical architecture
5. Evaluate net impact and continue
the cycle
36
In one case, a manufacturing organization
was able to reduce about
100,000 metric tons of carbon dioxide
equivalent (CO2e) emissions each
year by switching from gas-powered
turbines to more electrically driven
solutions for large compressors and
water pumps. The industrial facility's
energy needs were optimized
by having a centralized power-generation
and waste-heat recovery
unit. With careful consideration of
process needs, electrical drives were
installed, which further optimized
overall energy needs, creating cost
savings in the process. Delving into
more specifics helps exemplify how
chemical manufacturing plants can
electrify operations.
Steam cracking is a crucial process
in chemical production. It's also
a large CO2e emitter, accounting for
more than 300 million tons of emissions
annually [6]. Steam cracking of
hydrocarbons continues to be one
of the main industrial processes employed
to produce light olefins, building
blocks for plastics, adhesives and
detergents. Steam crackers operate
at high temperatures (around 850ºC)
to convert liquid or gaseous hydrocarbons
into olefins.
While the technology to produce
that kind of temperature using renewable
energy sources is still being
finalized, chemical manufacturers
can begin planning to either retrofit
existing steam crackers or replace
gas-fired burners with electric heating
systems. BASF SE (Ludwigshafen,
Germany) and its partners recently
began construction on a plant with
" large-scale electrically heated steamcracker
furnaces " that will reach
the 850ºC needed for continuous
olefin production [7]. For less heatintensive
processes, electric heat
pumps and boilers are available
today that can take demand up to
350 to 400ºC.
Electrification
can also enable
the
use
of carbon-free
feedstocks
for chemicals,
which can
further reduce
the carbon
footprint
of chemical
manufacturing
processes.
Ideology barriers
Despite the many potential benefits
of electrification, there are also challenges
to its widespread adoption
in the chemical industry. In fact, the
industrial sector is considered one of
the most difficult to electrify, in large
part due to the complexity and diversity
of its processes [8]. Add to
those complexities worries about grid
resiliency, and it is easy to see why
chemical manufacturers stick with
what is already working for them.
The industry's inertia comes from reasonable
trepidation about mounting
complexity, as well as technological,
economic, regulatory and safetyrelated
challenges.
Although many of the essential
technological elements for electrification
exist or are on the verge of being
commercialized, every process requires
tight integration with new assets
and solutions and with other processes.
Integration requirements can
cause complexity to balloon because
any process change creates a cascade
of effects into various others. For
example, researchers point to the fact
that " using ethane from natural gas
in steam cracking instead of naphtha
from petroleum increases ethylene
yields at the expense of lower propylene
and aromatics yields [9]. "
Moreover, converting electricity
into heat and eventually chemical
products is not currently an efficient
or
cost-effective
process,
as
the
steam-cracking example highlights.
The good news is that plenty of technologies
are moving along the maturation
curve and should help reduce
carbon emissions over the years
to come [10]. Another challenge is
the integration of electrification into
existing chemical manufacturing processes,
which may require significant
infrastructure and capital investments.
One firm reduced its CO2 output by
FIGURE 1. Electrification using renewable energy sources has obvious environmental
benefits, but there are also opportunities for improvements in process reliability
and reduced energy-cost uncertainty
CHEMICAL ENGINEERING WWW.CHEMENGONLINE.COM
APRIL 2023
http://WWW.CHEMENGONLINE.COM
Chemical Engineering April 2023

Table of Contents for the Digital Edition of Chemical Engineering April 2023
