GASCO Habshan SRUs - Challenges of Operation. Abdulkader Ahmed Al Kasem, Jumaa Al Marzouqi

Transcription

1 GASCO Habshan SRUs - Challenges of Operation Abdulkader Ahmed Al Kasem, Jumaa Al Marzouqi 1

2 General Overview Habshan Overview Configuration of GASCO Habshan SRUs Challenges of Operation 1- Feed Quality 2- Maintenance 3- Health, Safety, Environment 4- Catalyst Challenges 2

3 Habshan Overview Th-B OAG/IGD Bab NGL Hab-5 Rich To sales gas header & injection NGL Hab-0 Cond & NGL Hab-5 SRUs Granulation Plant Th-C Hab-1 Tr1&2 Cond & NGL Hab-5 Lean Trains Granulated Sulfur Hab-1 Tr3 Cond & NGL Hab SRUs Th-F Hab-2 Cond & NGL Hab-3 AGEU Cond & NGL 3

4 Habshan Overview Processes 5.55 bscfd H2S content ( 0.7% to 6.0% ) 14 trains of SRU 3 stage Claus, CBA, Super Claus, Claus+TGTU Total installed SRU capacity about 11,500 tpd 4

5 3 Stages Process Thermal Stage Catalytic Stage Burner Incinerator STH Air Steam drum Acid gas Burner Reaction Furnace WHB condenser condenser condenser condenser H2S: mole% Cap: 400 tpd Efficiency: 95 % Sulfur Sump 5

6 CBA Process Thermal Stage Burner Incinerator STH Air Steam drum Acid gas Burner Reaction Furnace WHB condenser H2S: mole% Cap: tpd Efficiency: 99 % condenser condenser condenser condenser Sulfur Sump 6

7 SUPERCLAUS Process Thermal Stage Catalytic Stage Burner Incinerator AGEU Off gas STH Air Steam drum Acid gas Burner Reaction Furnace WHB condenser condenser condenser condenser H2S: mole% Cap: 800 tpd Efficiency: 99.2 % Sulfur Sump 7

8 Claus + TGTU Process Combustion Air Acid Gas Natural Gas Combustion Air Air Preheater AG Preheater Reaction Furnace Waste Heat Boiler H2S: 46 mole% Cap: 1300 tpd Efficiency: 99.9 % First Reheater First Reactor Second Reheater Second Reactor First Condenser Second Condenser Final Condenser Claus Tail Gas Liquid Sulphur Natural Gas LP Steam RGG Hydrogenation Reactor DCC Lean Amine Amine Absorber Air Incinerator Reactor Effluent Cooler Rich Amine Natural Gas 8

9 General Overview Habshan Overview Configuration of GASCO Habshan SRUs Challenges of Operation 1- Feed Quality 2- Maintenance 3- Health, Safety, Environment 4- Catalyst Challenges 9

10 Feed Quality 1 2 Commissioning of Habshan 5 Feed flow came down to the existing Amine units & SRUs (1300 MMSCFD cut) 3 H2S concentration fell in AG by ~ 6 mole % 4 Fuel Gas co-firing (200 Nm3/h per unit) 10

11 Feed Quality Treated Gas Number of trays was reduced in AGRU Two units were mothballed (30 Knm3/h) Sour Gas Two amine units were stopped (300 Knm3/h) Reaction Furnace pyrometers were calibrated

12 Knm3/h Mole % Feed Quality Effect of feed flow on Concentration AG feed H2S concentration 0 6-May Aug Nov-13 2-Mar Jun Sep Dec-14 6-Apr Jul Oct

13 One SRU Trip SRU trip Feed flow divert AG KOD level sudden increase Feed reduce and may unit trip 13

14 General Overview Habshan Overview Configuration of GASCO Habshan SRUs Challenges of Operation 1- Feed Quality 2- Maintenance 3- Health, Safety, Environment 4- Catalyst Challenges 14

15 CBA Condenser Failure Thermal Stage Burner Incinerator Unit tripped on 21-Nov 2012 due to low level in WHB Acid gas Air Burner Reaction Furnace WHB STH Steam drum Unit restarted within an hour condenser condenser condenser condenser condenser planned shut down from 22- Nov to 04-Dec 2012 Sulfur Sump 06-Dec after start up, E-109 outlet nozzle liq. Sulfur leak Emergency shut down 6th 29th Dec, Unit was under shut down for E-109 repair 15

16 CBA Condenser Failure Thermal Stage Burner Incinerator 30th Dec, Unit start up Air STH Steam drum Acid gas Burner Reaction Furnace WHB Run down line of E-108 Choke condenser condenser condenser condenser condenser Acid Gas Feed reduced Sulfur Sump unit shut down on 31st Dec 36% of the tubes found blocked 16

17 Common Stack Three sets of two incinerators with common stack Isolation is required for one Incinerator maintenance Slide gate used once and it was bended Maintenance philosophy changed Burner Incinerator Incinerator Burner 17

18 General Overview Habshan Overview Configuration of GASCO Habshan SRUs Challenges of Operation 1- Feed Quality 2- Maintenance 3- Health, Safety, Environment 4- Catalyst Challenges 18

19 SuperClaus Bypass Feed flow variation Air demand analyzer fluctuation Superclaus reactor bypass Emission increased 19

20 CBA sequence change CBA sequence changing Emission and SO2 exceeding 2500 ppm 20

21 Emission Monitoring & Control CO Concentration (ppmv dry) O 2 Concentration (mol% dry) Frequent blockage of stack sample point CO emissions is higher than ADNOC limit of 400 ppmv y = 2E+11e -0.03x R² = Incinerator Temperature ( C) CO ppmv dry O2 mol% dry Expon. (CO ppmv dry) 21

22 General Overview Habshan Overview Configuration of GASCO Habshan SRUs Challenges of Operation 1- Feed Quality 2- Maintenance 3- Health, Safety, Environment 4- Catalyst Challenges 22

23 Catalyst Deactivation Purpose of TGU: Convert Sulfur Components to H2S & Recycle to Extinction 23

24 Catalyst Deactivation Total DT across TGTU reactors remain constant 24

25 Catalyst Deactivation The contribution to the exothermic reaction from the middle of the catalyst increased and decreased in the top bed 25

26 Catalyst Deactivation Majority of the exothermic reaction observed in the top bed but after Nov-2013 shutdown in unit 552 the reaction shifted to middle bed 26

27 Questions 27