Topic Advances in Distillation for Petrochemicals and Other Hydrocarbons Presented by Sachin Joshi Licensing Manager GTC Technology US, LLC
Topic
Advances in Distillation for
Petrochemicals and
Other Hydrocarbons
Presented by
Sachin JoshiLicensing Manager
GTC Technology US, LLC
Advanced Distillation
GT-HIDS℠
(Heat Integrated Differential Separation)
Improving Efficiency in Distillation
What is HIDS ?
• Direct Heat Integration by
Vapor compression
• Low pressure Top Section
(Rectification)
• Low-Low Pressure Bottom
Section (Stripping)
• Maximizes Relative Volatility
Heat Integrated Differential Separation (HIDS)
Propane
Feed
Propylene
LLP Column
LP Column
HIDS Application
• Applicable to close boiling pure component distillation
• Preferentially for C2 to C5 component fractions
• Reduces the CAPEX and OPEX compared to
traditional distillation and Vapor Re-Compression
(Heat Pump)
• GTC patent protected
Case Study – C3 Distillation
Traditional Process Options:
Mechanical Vapor
Re-Compression (VRC)
High pressure distillation
(HP Distillation)
Case Study - C3 Distillation HP Distillation - Schematic
• Typically Operates at 220
Psig@Top
• Below feed or Bottom Section
(Stripping) operates at higher
pressure
• Designed for utilizing cooling water
• Highest Energy for Separation due
to lower relative volatility
• Lower Pressure, typically operates at 160 Psig
• Lower Temperature
• Higher Relative Volatility compared to HP distillation
• Compressor power is determined by reboiler
temperature pinch and overall system ΔP, and
overflash from hot reflux
Case Study – C3 Distillation Vapor Recompression (VRC)
Effect of Pressure on Relative Volatility
HP Dist.VRC.
1.11
1.115
1.12
1.125
1.13
1.135
1.14
1.145
1.15
1.155
1.16
0 25 50 75 100 125 150 175 200 225 250
Rela
tive V
ola
tilit
y
Pressure in Psig
Relative Volatility of Propylene to Propane
Relative Volatility
Traditional Process Options
• High pressure distillation (HP Distillation)
• Vapor recompression (VRC)
HP Distillation VRC
CAPEX Base Higher than Base
OPEX Base Lower than Base
• GTC Option
– Heat Integrated Differential Separation
Case Study – C3 Distillation Process Options
GT-HIDS℠ - Heat Integrated Differential Separation
Propane
Feed
Propylene
LLP Column
LP Column
Top
Se
ctio
n
Bo
tto
m S
ect
ion
Pressure Reducing Valve
GT-HIDS℠ Advantage
• Non linearity of relative volatility is addressed by Pressure Segregation
– Pressure segregation between Stripping (Bottom) and rectification
(Top) to optimize relative volatility
– Temperature effect on Relative volatility is taken advantage
– Significantly improved relative volatility
Relative Volatility
Temperature Pinch
• Direct coupling of top (rectification) and bottom (Stripping) section
– Eliminates temperature pinch in the reboiler
– Avoids overflash from hot reflux in VRC schemes
– Thermally coupled columns reduces the overall energy consumption
GT-HIDS℠ Operating Range for C3 Separation
1.11
1.115
1.12
1.125
1.13
1.135
1.14
1.145
1.15
1.155
1.16
60 80 100 120 140 160 180 200 220 240
Re
lative
Lo
latilit
y
Pressure in Psig
Relative Volatility of Propylene to Propane
Rectification Zone
(Top Section)Stripping Zone
(Bottom Section)
Case Study – C3 Distillation Process Options
1.08E+00
1.10E+00
1.12E+00
1.14E+00
1.16E+00
1.18E+00
1.20E+00
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240
Rela
tive
V
ola
tilit
y
Stages
Relative Volatility of Traditional Distillation methods & GT-HIDS
HP DIST-RV
VRC Dist-RV
HIDS Stripping
HIDS-Rectification
VRC - Feed PointHP DIST Feed Point
HIDS - LLP Column - Bottom
HIDS LP Column - Top
GT-HIDS℠ Advantages
• Maximizes the natural behavior of components to
separate from each other
• Lower energy compared to traditional distillation
methods
• Distillation done at best relative volatility efficiency point
• Thermally coupled columns consume lower electricity
compared to a VRC
• Independent control of stripping and rectification zones
offer stability and ease of operation
Case Study: C3 Distillation
Feed Specification
Component Mol %
Ethane 0.02 %
Propane 20.86%
Propylene 79.11%
i-Butane 0.01%
• Feed Capacity = 30 KBPD
Case Study : C3 Distillation Product Specifications
Propylene specification
• Recovery: 99.87% of Propylene
Propane specification
• Recovery: 98% of PropaneComponent Mol %
Ethane 0.02%
Propane 0.38%
Propylene 99.58%
i-Butane 0.01%
Component Mol %
Ethane 0.01%
Propane 99.38%
Propylene 0.59%
i-Butane 0.02%
Case Study: C3 DistillationOverall Comparison: CAPEX & OPEX
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
CAPEX OPEX
HIDS 43% 85%
VRC 100% 100%
Co
st
1. 4Q of 2015
2.Electricity = $0.04 per KW-Hr
3.Cooling water = $0.075 per 1000
gallons
HIDS
HIDS
MVRC MVRC
C3 Splitter Debottleneck with HIDS
Distillation C3 Splitter C3 Splitter Revamped to GT-HIDS℠• Capacity Increment: by up to 50%
• Energy Required: less by 40% compared to new system
Propylene
Propane
Feed Column B
Column A
New LLP
Column
New
Compressor
C3 Splitter Debottleneck with HIDS
Vapor Recompression C3 Splitter C3 Splitter Revamped to GT-HIDS• Capacity Increment: by up to 50%
• Energy Required: less by 40% compared to new system
Propylene
Propane
Feed
Column A
New LLP
Column
Case Study: Grassroots Mixed Xylenes Recovery Unit at a Refinery in Japan
• TG had an existing unit which produced C7+ product for gasoline blending.
• TG wanted to separate high purity petrochemicals (Toluene, Mixed Xylenes) from the feed.
• TG decided for a DWC solution against a two column configuration because of lower CAPEX and lack of plot space.
Comparison: Two Column System vs DWC
Parameter UnitsTwo Column
Configuration
GT-DWC℠ Configuration
Mix-xylenes product Kg/hr 29,332 29,334
C8 aromatics wt%. 99.2 99.3
Reboiler duties MMkcal/hr. 21.6 17.2
Operating cost savings % - 20.0
Capital cost US $ MM 26.0 21.0
Steam savings due to heat
integrationTPH - 20.0
TonenGeneral Mixed Xylenes Recovery Unit
• Installation of GT-DWC℠ Column at Chiba Refinery, Japan
• Column Operational since March 2016
GT-DWC℠ Internals Manufacturing - Korea
GT-DWC℠ Trays
Testing of GT-DWC℠ Internal
Liquid Split Distributer
Summary
• Advanced distillation applications are an overlooked
means to reduce refinery energy consumption
– GT-DWC reduces 20–30% OPEX through energy
savings
– GT-DWC reduces 20–30% CAPEX by requiring a
single column for multi-component separation
• GT-HIDS can make significant energy reduction
and/or capacity enhancement with simpler
modifications.
29