HEAT PUMPS Advanced Distillation - GT-HIDS (Heat Integrated Differential Separation)

Transcription

1 HEAT PUMPS Advanced Distillation - GT-HIDS (Heat Integrated Differential Separation) Joseph C. Gentry, GTC Technology Vice President Technology & Engineering ERTC - Lisbon 15 November 2016

2 What is HIDS? Heat Integrated Differential Separation (HIDS) Direct Heat Integration by Vapor compression Bottom section (stripping) operates at lower pressure than top section (rectification) Maximizes Relative Volatility LP Column Feed LLP Column Propylene Propane Page 2

3 HIDS Application Applicable to close-boiling, pure component distillation Preferentially C 2 to C 5 component fraction Lower CAPEX and OPEX compared to traditional distillation and Vapor Re-Compression (Heat Pump) GTC patent protected Page 3

4 Case Study C3 Distillation High pressure distillation (HP Distillation) Traditional Process Options: Mechanical Vapor Re-Compression (VRC) Page 4

5 Effect of Pressure on Relative Volatility 1.16 Relative Volatility of Propylene to Propane Relative Volatility Pressure in Psig Relative Volatility VRC. HP Dist. Page 5

6 Case Study C 3 Distillation HP Distillation - Schematic Typically operates at 220 psig (top) Bottom (Stripping) section operates at higher pressure Designed for utilizing cooling water Page 6

7 Case Study C 3 Distillation HP Distillation Separation difficulty due to lower relative volatility Bottom section (stripping zone) operates at lowest relative volatility Higher reflux to achieve the given purity More number of stages higher pressure drop Higher operating temperature expensive heating medium or larger heat transfer area Page 7

8 Case Study C 3 Distillation Vapor Re-Compression (VRC) - Schematic Column A Feed Bottom Section Top Section Column B Propane Propylene Page 8

9 Case Study C 3 Distillation Vapor Recompression (VRC) Lower top pressure, typically operates at 160 psig Bottom section operates at higher pressure, than top Higher Relative Volatility compared to HP distillation, but still having a compositional pinch Compressor power is determined by reboiler temperature pinch and overall system ΔP Page 9

10 Case Study C3 Distillation Process Options 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 Page 10

11 Thermodynamics of Relative Volatility Assumption of constant relative volatility throughout the column is not valid. C 3 splitting has slight non-ideality. Thermodynamics of binary component distillation depends on vapor pressure (i.e. composition and operating conditions). Distillation is more efficient if conditions are chosen to optimize the relative volatility. Not possible in HP distillation and VRC schemes due to linear pressure profile. Page 11

12 GT-HIDS Heat Integrated Differential Separation Propylene LP Column Feed Higher Pressure Top Section LLP Column Bottom Section Lower Pressure Propane Pressure Reducing Valve Page 12

13 GT-HIDS Advantage Relative Volatility Non linearity of relative volatility is addressed by Pressure Segregation Pressure segregation between Stripping (Bottom) and Rectification (Top) optimizes relative volatility, with significant improvement Temperature Pinch Direct coupling of top and bottom sections: Eliminates temperature pinch in the reboiler Thermally-coupled column reduces the overall energy consumption Page 13

14 GT-HIDS Operating Range for C 3 Separation 1.16 Relative Volatility of Propylene to Propane Relative Lolatility Stripping Zone (Bottom Section) Pressure in Psig Rectification Zone (Top Section) Page 14

15 Case Study C 3 Distillation Process Options 1.20E+00 Relative Volatility of Traditional Distillation methods & GT-HIDS HIDS - LLP Column - Bottom 1.18E+00 Relative Volatility 1.16E E E+00 HIDS LP Column - Top HP DIST FeedPoint VRC - FeedPoint HP DIST-RV 1.10E E+00 VRC Dist-RV HIDS Stripping HIDS-Rectification Stages Page 15

16 GT-HIDS Advanatges Maximizes the natural behavior of components to separate from each other Lower energy requirement compared to traditional distillation methods Distillation done at best relative volatility efficiency point Thermally-coupled columns consume less electricity than a VRC Independent control of stripping and rectification zones offer stability and ease of operation Page 16

17 Case Study: C 3 Distillation Feed Capacity = 30 KBPD Feed Specification Component Mol % Ethane 0.02 % Propane 20.86% Propylene 79.11% i-butane 0.01% Page 17

18 Case Study : C 3 Distillation Product Specifications Propylene specification Component Mol % Ethane 0.02% Propane 0.38% Propylene 99.58% i-butane 0.01% Propane specification Component Mol % Ethane 0.01% Propane 99.38% Propylene 0.59% i-butane 0.02% Page 18

19 Case Study: C 3 Distillation Overall Comparison: CAPEX & OPEX Cost 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% HIDS VRC HIDS VRC CAPEX OPEX Electricity = $0.04 per KW-Hr HIDS 43% 85% Cooling Cooling water water = $0.075 per 1000 gallons $0.075 per 1000 gallons VRC 100% 100% Page 19

20 Case Study : C 3 Distillation CAPEX Contribution by unit operation 120% CAPEX Breakdown Mass-Transfer Equipment Heat Exchanger Rotating Equipment 100% 7% CAPEX 80% 60% 53% 57% Reduction 40% 20% 0% 40% VRC 5% 12% 26% HIDS Page 20

21 C3 Splitter Revamp Revamp of conventional or VRC schemes are possible with HIDS to gain large capacity increase Page 21

22 Revamp of Conventional C3 Splitter to HIDS Conventional C3 Splitter Revamp Configuration Capacity Increment: by 50% Energy Required: 40% less than new system Page 22

23 Revamp of Vapor Recompression C3 Splitter to HIDS Vapor Recompression C3 Splitter C3 Splitter Revamped to GT-HIDS Capacity Increment: by 50% Energy Required: 40% less than new system Page 23

24 Summary GT-HIDS intentionally alters the process conditions in close-boiling separation system to gain a thermodynamic advantage GTC s family of Advanced Distillation technologies are useful for lowering CAPEX and OPEX of separation systems, and can debottleneck existing assets GT-HIDS GT-DWC GT-ATCS GT LPG Max Page 24

25 GTC Technology Advanced Distillation - GT-HIDS (Heat Integrated Differential Separation) Joseph C. Gentry Vice President Technology & Engineering GTC Technology ERTC - Lisbon November 15, 2016 HEAT PUMPS