Purge to atm.
Water Air
ASU and/or electrolyser
Others
CO capture
O
H O
UOP
Recycle blower
20-30% of total flow
70-80% of total ow
Synthesi z ed A ir (CO + O )
CO recycle
Reactor vapours
Third stage separator (optional)
SH steam
BFW
100% of total ow
Regenerated catalyst
Electricity
nViro FCC De-SO & PM removal x
Regenerator (coke combustion)
DeNO x
Reactor
KOD
HRSG
PRT (optional)
Cooling/ condensing
Spent catalyst
BFW
Blowdown
Fresh feed Recycle(s) Steam
H O
BFW
Flue gas under ow
CO product
Large catalyst nes
Figure 3 Honeywell UOP Synthesized Air FCC (indicated flow ranges highlighted in orange are typical ranges as determined by Honeywell UOP proprietary process models)
Synthesized Air FCC as an enabler for CO 2 utilisation Once the CO 2 has been captured (see Table 1 ) and puri- fied, per Figure 4 , multiple CO 2 utilisation pathways are unlocked, such as blue and green MeOH and SAF, in addi- tion to CO 2 electrolysis and mineralisation. Findings by IHS Markit and the CO 2 Capture Project, respectively, show that FCCs are among the largest CO 2 emitters in a refinery.² , ³ In this regard, as shown below in sections ‘Key advantages of Synthesized Air FCC’ and ‘Case study’, Honeywell UOP Once the CO 2 has been captured and purified, multiple CO2 utilisation pathways are unlocked, such as blue and green MeOH and SAF, in addition to CO 2 electrolysis and mineralisation Synthesized Air Technology could be a key enabler for: i) carbon (CO 2) intensity reduction of refining operations; ii) blue and green fuel/chemicals production; iii) continued FCC operation in a low(er) carbon intensity future. Key advantages of Synthesized Air FCC • Helps increase the concentration of CO 2 in flue gas from the typical 15 ~ 20 mol% to more than 80 mol%. d This pro- vides an opportunity to adopt a lower Capex/Opex CCU to produce a high-purity CO 2 product stream and elim- inate the requirement for solvent-based carbon capture technologies. • Eliminates concerns relating to solvent degradation 9 and replacement by using CO 2 capturing technologies that do not require solvents. • For an existing regenerator converted to synthesised air
inlet valve will throttle to control the regenerator-reactor dif- ferential pressure. From the expander, the flue gas flows to the HRSG, where high-pressure steam is generated from the cooling of the flue gas stream. In some cases, provisions can be made to the HRSG to accommodate the removal of NOx contaminants. For units where HRSG cannot accommodate a NOx removal system, the same can be designed as part of the nViro FCC system or wet gas scrubber. After the HRSG, the flue gas stream flows into the nViro FCC section. Here, the flue gas stream is treated for SOx and residual particulate matter contaminants. After this treatment, water is partially removed b to minimise the water concentration in the flue gas, followed by splitting the flue gas into two streams. Water removal prevents undesirable impacts (hydrothermal deactivation) of FCC catalyst. The first stream flows to a recycle blower, where it is compressed and then combined with a high-purity oxygen stream. The high-purity oxygen is typically provided by an air separation unit (ASU) or electrolyser. The recycled flue gas, along with the high-purity oxygen, forms the synthe- sised air, which is then recycled back into the regenerator for the combustion of coke. The second stream flows to the Honeywell UOP FCC carbon capture section. In this section, flue gas is treated and processed to recover the CO 2 . The CO 2 separation technology is designed to achieve the desired product CO 2 temperature and pres- sure conditions as well as the desired phase: liquid, gas, or dense. Since a CO 2 -rich stream in the form of synthe- sised air is used for FCC catalyst regeneration, the flue gas stream from the FCC unit concentrates to a CO 2 level of 90 mol% or more after partial water removal. b,c Water is the bulk contaminant in the flue gas to the car - bon capture section and is removed to achieve a higher purity CO 2 stream. The high-purity CO 2 stream is sent to further separation steps to remove additional contami- nants, such as oxygen, to meet the required CO 2 purity of CO 2 product stream.
21
PTQ Q4 2023
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