che_november-2024 - 33

are studied: one with carbon
tax included and the other
with CCUS.
The comparison
margin
of both cases with the
base case are presented
in Table 3. In the first case,
where a carbon tax index of
0.05 $/kgC2, C3 and a hydrogen
price of $2/kgH2
were considered, decreasing
the CH4/H2 ratio leads
to a marginal loss of about
5.4%. In the second case,
considering
CCUS
cost
Steam Cracker KPI
TABLE 4. SIMULATION KPI RESULTS
(MULTI-OBJECTIVE OPTIMIZATION CASE)
Base
Adjusted variable
Firebox efficiency, %
Bridge wall Temp, °C
Ethylene yield, wt %
Severity, P/E
Fuelgas consumption
Energy intensity
Emissions efficiency KPIs
Fluegas rate
of 15-25/m.t. CO2 and
a hydrogen price of $2/
kgH2, changing the CH4/
H2 ratio reduces the margin
by 4.6%.
The results of the various
investigated scenarios in this
study show that hydrogen
integration with combustion
fuel has the highest impact
on emission and energy intensity
reduction. However,
components like carbon tax
index, CCUS cost and the
price of hydrogen determine
if this method is economically
viable and sustainable.
Scenario (E). In the final study, outlined
in Table 4, a combination of
investigated scenarios is examined
(E). In this scenario, a multi-objective
optimization
scheme is employed
by defining object functions
aimed at maximizing margin and
reducing energy consumption and
emissions. The defined objective
functions prioritize maximizing yield
while minimizing emissions rates
and energy consumption by adjusting
independent variables (such as
S/C, COT, excess air and CH4/H2
ratio). The optimal operating conditions
derived from this analysis
are as follows: S/C= 0.33 wt./wt.,
COT = 844°C, excess air = 7%,
hydrogen-rich fuel composition of
CH4/H2 = 1.5 wt./wt. Table 4 presents
the KPIs under these optimum
conditions for steam cracker decarbonization.
Notably, this approach
results in an energy saving of about
4.6% and emission reduction by
44%, while achieving a marginal
gain of about 3.7%. The subtle increase
in margin is attributed to reFluegas
composition
(CO2, O2)
Carbon intensity
Energy savings
Emissions reduction
Margin improvement, CT
Carbon-capture (CC)
KPIs
CC efficiency
CC energy intensity
Margin improvement,
CCC
85
5.34
2.80
98
5.50
3.72
Base Case: S/C = 0.4 wt./wt., COT= 840°C, Excess air = 10%,
CH4/H2 = 4 wt./wt., Air temperature = 60°C
ductions in energy cost via reduced
fuel consumption, decreased cost
associated with carbon capturing
due to CO2 emission reduction and
improvements in ethylene yield and
radiation efficiency.
The integration of a gas turbine
(GT) with a steam cracker is another
applied method to realize energy
savings in olefin plants. This technology
facilitates energy savings
through the dual mechanisms of
electricity generation and reduction
of energy consumption in the convection
section of the furnace. The
improved energy efficiency attained
via GT implementation is realized by
utilizing the hot fluegas generated
in the GT to provide oxygen-rich,
preheated air. This air is then mixed
with fresh air, serving as combustion
air for the burner heater. This
process leads to significant energy
savings by effectively reducing energy
intensity [19].
GT implementation may not be
feasible for every existing steam
cracker due to certain limitations.
Specifically, the increased rate of
hot fluegas necessitates a larger
CHEMICAL ENGINEERING WWW.CHEMENGONLINE.COM
NOVEMBER 2024
Maximize Yield and
Minimize Variability
with Draft Tube Solutions
from EKATO.
* Maximized Yield:
Perfect crystal size and shape
for peak production efficiency.
* Superior Product Purity:
Consistent crystal quality,
achieving even stringent
specifications like batterygrade.
*
Reduced OPEX:
Faster filtration and drying
times due to narrow particle
size distribution.
Ready to optimize your draft
tube crystallization?
Talk to our experts and discover
how EKATO can elevate your
process!
LEARN MORE
36.40
1,129
38.70
0.254
5,295, 789
0.35
128/152
5.44, 1.6
0.77
39.54
1,230.9
39.1
0.247
4,006, 944
18.42
109.9, 129
3.5, 1.12
0.43
-4.6
-44.2
0.63
PERFECT CRYSTALS,
EVERY TIME
(E) Optimized case
Your contact in the US:
Phone: 1 201 825 4684 Ext. 205
info@ekato.com
For details visit adlinks.chemengonline.com/86469-12
33
http://adlinks.chemengonline.com/86469-12 http://WWW.CHEMENGONLINE.COM
che_november-2024

Table of Contents for the Digital Edition of che_november-2024
