Natural Gas Quality Management. April 24, 2013

Transcription

1 Natural Gas Quality Management April 24, 2013

2 Agenda Background Natural Gas Basics Existing & Future Natural Gas Supply to BPPS West East II Pipeline Natural Gas Quality Gas Receiving Station Process Gas Turbine at Black Point Power Station (BPPS) Fuel Gas Nozzles Gas Heating for Quality Treatment Fuel Quality Management System (FQMS) FQMS Process Fuel Flexibility Existing MWI Operating Range New Operating Range with FQMS

3 Background

4 Natural Gas Basics Natural gas is a naturally occurring hydrocarbon gas mixture consisting primarily of methane (C1), but also including varying amounts of other hydrocarbons (C2 C6+), carbon dioxide, nitrogen and hydrogen sulfide. Commonly used for domestic use (cooking & heating), electricity generation, vehicle fuel; also used as feedstock in Gas to Liquid (GTL) process Liquified Natural Gas also known as LNG where natural gas is condensed into a liquid at close to atmospheric pressure by cooling it to approximately 162 C.

5 Existing & Future Natural Gas Supply to BPPS Current BPPS Gas Supply from Yacheng at Hainan, Y13 1 (780km). MoU signed between HKSAR and National Energy Administration on Aug 28, Future gas supply to BPPS will be by West East II Pipeline from Turkmenistan. Peak Shaving by a proposed LNG Terminal in Shenzhen

6 PetroChina s 2 nd West East Gas Pipeline The project includes 1 trunkline and 8 branches. China s first major energy project to transfer natural gas from outside PRC. From Khorgos Port (Xinjiang) to Guangzhou, Shanghai and Hong Kong. Total length: ~8,600km Capacity: ~30Bcm/yr

7 Gas Quality

8 Natural Gas Quality Physical cleanliness : Amount of foreign materials presented in the gas, i.e. debris from pipeline Problem can be solved with filters Total Sulphur Taken care by gas supplier at upstream with Sulphur removal facilities to maintain Sulphur under an mutually agreed level. Gas Compositions and corresponding heating value & density Wobbe index of a specific natural gas = HHV / S.G The Wobbe index is a measurement of the degree to which fuels with different compositions such as natural gas and propane can be interchanged Gas with different compositions but same Wobbe Index usually can be used in the same appliance

9 New GRS Process Flow Future GRS FGR-HT TT FGR-HT TT FGR-HT TT Offshore PL ESD Filtering Station Off-take to others Pig Receiver 36 BPPS Header 28 Heating Station (New) 18 YOC Header (Existing ) CPPS 24 ESD (Existing) ESD 300# 600# YOC GRS HIPP S PT PT PT PT Metering Station FE FE (Existin 24 g) ESD Pressure reduction Station 18 FE 28 2 FE

10 Overview of Gas Receiving Station Overview of Gas Receiving Station Pig Receiver Filter Skid Pig Receiver Filter Skid Metering Skid Metering Skid

11 Gas Turbine at BPPS

12 Fuel Gas Nozzles MWI LHV SG gas T gas LHV = lower heating value of gas fuel (Btu/scf) SG gas = specific gravity of gas fuel relative to air T gas = absolute temperature of gas fuel ( R) Measure of interchangeability for heavy duty GE gas turbines defined by Modified Wobbe Index (MWI) There are other fuel gas criteria that must be met as well as MWI

13 Gas Heating for Quality Treatment Pipeline Gas Lean LNG Rich LNG Rich + Modified Wobbe Index % 2% Temperature ( C)

14 Fuel Quality Management System

15 Fuel Quality Management System (FQMS) Design Schematic

16 FQMS Process Flow

17 FQMS at BPPS

18 Fuel Flexibility

19 Existing MWI Operating Range for BPPS Current BPPS Gas Supply from Yacheng at Hainan, Y13 1 (780km). Equipped with Electric Heater which can heat the gas to 55 o C to prevent Sulphur deposition Cannot deal with natural gas with potentially changing compositions, i.e. changing MWI at constant temperature

20 MWI Operating Range for BPPS with FQMS Potential new nozzle gas ratings (47.8 Btu/scf R½ ) 53 ½ Modified Wobbe Index (Btu/scf R ) % % % 46-5% 45 Blue box operating range C maximum gas heating temperature 25 C exit temperature from GRS Temperature ( C) Case 9 Case 10 Case 11 Case 12 Case 13 Case 14 Case 15 Case 16 Case 17 Case 18 Case 19 Case 20 Case 21 Case 22 Case 23 Case 24 Case 25 Case 26 Case 27 Case 28 Case 29 Case 30 Case 31 Case 32 Case 33 Case 34 Case 35 Case 36 Case 37 Case 38 WEII Liwan LNG Rich LNG Lean

21 End