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

Case Study – C3 Distillation Vapor Re-Compression (VRC) - Schematic

• 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

Dividing Wall Columns

Improving Fundamental Efficiency in Distillation

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.

Case Study: Mixed Xylenes Recovery

GT-DWC℠ for Mixed Xylenes Recovery

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

GTC Technology

DISTILLATION