che_november-2024 - 28

Feature Report
Investigating
Decarbonization Strategies
for Steam-Cracker Furnaces
Significant sustainability benefits can be gained through optimization in steamcracking
furnaces. The study detailed here shows the specific decarbonization
strategies that can help improve energy efficiency and reduce emissions
Ghoncheh
Rasouli
KBC (A Yokogawa
Company)
IN BRIEF
DECARBONIZATION
STRATEGIES
SIMULATION AND
OPTIMIZATION
RESULTS AND
DISCUSSION
BEYOND THE SCOPE OF
THIS STUDY
FINAL THOUGHTS
T
he chemical process industries
(CPI) rely heavily on steam cracking
to produce essential olefins - especially
ethylene, a key feedstock
for polyethylene, polystyrene, polyethylene
terephthalate and polyvinylchloride. Over
the past decades, there has been significant
growth in ethylene demand, with an anticipated
increase of approximately 5.58% by
2030, and the associated global polyethylene
market is expected to increase 9.6%
by 2032 [1-3]. Steam crackers are the main
technology to produce ethylene from light
gas or liquid hydrocarbon feedstocks in
petrochemical plants (Figure 1). The process
is severely endothermic, meaning that
conventional steam cracking is the largest
energy consumer, and thus also the largest
emissions producer, among process units
in the CPI, with more than 8% share of the
total energy use in these sectors [4, 5]. The
energy consumption
of ethylene
production varies
from 15 to 27 GJ/
kg of ethylene produced,
depending
on the feed used in
this process [6, 7].
Since energy costs
may constitute as
much as 70% of
the net product
cost of an olefin
plant, advancing
energy efficiency
is crucial to reduce
energy costs [4].
Ethylene production
stands
among the top
three CO2 emitShutterstock
28
ters
in the CPI, with studies indicating
that
worldwide CO2
emissions
from
steam crackers could increase by 33%,
from 198.9 million metric tons per year
(m.t./yr) to 264 million m.t./yr [8]. In conventional
crackers, roughly 0.85 to 1.8 m.t.
of CO2 is emitted per metric ton of produced
ethylene, depending on the type
of feedstock [9].
As a result, decarbonization and energy
efficiency have become major concerns for
olefin producers. While they are compelled
to take measures to improve environmental
sustainability, most refiners prefer to keep
their existing steam cracker configuration
and implement energy-optimization and
carbon-reduction strategies without any
significant changes to their hardware and
infrastructure, rather than taking drastic
measures to re-design their processes or
equipment. Such decarbonization strateFIGURE
1. Steam crackers are nearly ubiquitous across the petroleum refining and petrochemicals
sectors. They are also major consumers of energy and contributors to carbon emissions, so
the optimization of steam crackers is often a central part of sitewide sustainability initiatives
CHEMICAL ENGINEERING WWW.CHEMENGONLINE.COM
NOVEMBER 2024
http://WWW.CHEMENGONLINE.COM
che_november-2024

Table of Contents for the Digital Edition of che_november-2024
