Liquefied Natural Gas - LNG

Application of Gas PTi & VE Technology

Orbital Global Solutions, | T: +44 1785 857007 |

Cold Meece, Stone, Staffordshire ST15 0QN | W: www.orbitalglobalsolutions.com |

United Kingdom | E: enquiries@orbitalglobalsolutions.com |

Orbital Global Solutions is a wholly owned subsidiary of Orbital Gas Systems. Registered in England No. 1868383.VAT Registration No. 363 3612 64

© 2015 Orbital Global Solutions. All Rights Reserved. This material may not be copied or distributed in whole or in part, without prior permission of the copyright owner.

Background

This note has been prepared for the purpose of illustrating the

effects which natural gas sampling, conditioning and analysis

can have on LNG applications.

In many countries in recent times there has been a significant

shift from a single source of indigenous natural gas towards

multiple sources of gas from new interconnector pipelines and

shipped LNG. The terminal operations for LNG import and

export require accurate monitoring of gas quality and flow at

numerous points in order to satisfy process control and energy

accounting standards.

GasPTi has been developed to provide accurate and rapid

measurement of gas properties so that LNG operators can

monitor and control gas blending, storage and export.

Issues

Traditional methods for gas quality analysis have used gas

chromatographs to provide CV measurement but this requires

vaporisation to be carried out homogenously - without any

possibility of separation of the constituent components during

phase transformation from liquid to gas. Partial vaporisation

gives erratic readings on a GC which will affect the calculation

of CV. Raman spectroscopy can be used to determine LNG

composition and CV in the liquid phase but this is an expensive

option.

Speed of response of traditional GC analysers is several

minutes. This can be an issue if gas is being exported out of

specification and needs to be diverted rapidly for further

process treatment.

LNG Applications

Gas quality monitoring on LNG export and importation

terminals:

1. Boil-off gas recondensers inlet and outlet

2. Gas metering

3. Export sales gas

4. Fuel gas for revaporisation heaters

Gas quality monitoring on marine LNG tankers:

1. Boil-off gas prior to reliquefaction

2. Ship to ship transfer boil-off gas

Solution

GasPTi is a unique integration of gas sampling, gas

conditioning and gas analysis which provides rapid and

accurate monitoring of gas quality, with T90 response time

less than 10 seconds and to a CV error less than ±0.5%. A

small LNG vaporiser can be linked to the system and this

avoids partial vaporisation. The system mounts directly onto a

pipeline or can be post-mounted nearby with a short gas

sample line. Best response and accuracy is gained from

pipeline mounted systems with short sample line and

electropolished internal surfaces.

Depending on the application, GasPTi signal outputs can be

either serial, Ethernet or analogue interfaces. Calorific Value

(Gross and Net), RD, Wobbe, Compressibility, Methane

Number, Motor Octane Number are all standard physical

properties which are output from GasPTi.

In addition to ATEX, IECEx and CSA approvals, American

Bureau of Shipping approval has been obtained for GasPTi

marine LNG tanker applications.

(Certificate Number: 13-LD1105876-PDA 04/MAR/2014)

A Zone 0 GasPTi-LNG system has been developed specifically

for LNG applications to improve speed of response and

accuracy.

Figure 1 – LNG terminal import/ export applications.

Figure 2 – Ship to ship LNG transfer boil-off gas application.

Conclusions

1. Traditional GC analysers and vaporisers may have

issues with speed of response and gas sample partial

vaporisation.

2. A small LNG vaporiser has been developed to provide

representative LNG sampling.

Liquefied Natural Gas - LNG

Application of Gas PTi & VE Technology

Orbital Global Solutions, | T: +44 1785 857007 |

Cold Meece, Stone, Staffordshire ST15 0QN | W: www.orbitalglobalsolutions.com |

United Kingdom | E: enquiries@orbitalglobalsolutions.com |

Orbital Global Solutions is a wholly owned subsidiary of Orbital Gas Systems. Registered in England No. 1868383.VAT Registration No. 363 3612 64

© 2015 Orbital Global Solutions. All Rights Reserved. This material may not be copied or distributed in whole or in part, without prior permission of the copyright owner.

3. GasPTi provides gas sampling, conditioning and

analysis to give rapid and accurate CV data which can

be used for process control and alarms on LNG

terminals.

Example LNG Applications

Project Company Location Application

Isle of Grain National Grid UK Importation

terminal

South Hook Qatar

Petroleum UK

Importation

terminal

Dragon BG Group UK Importation

terminal

Teesside

GasPort Excelerate UK

Floating

regasification

Cryostar

Marine CNOOC China LNG tankers

Kanto Tokyo Gas Japan Importation

terminal

Kansai Osaka Gas Japan Importation

terminal

Gwangyang POSCO S.Korea Importation

terminal

Publications:

Development and Testing of a New Gas Properties Transmitter

INGAS International Gas Conference, Istanbul, 2013.

Development of Real-time Gas Quality Measurement

International Gas Union Research Conference, Copenhagen,

2014.

Figure 3 – Gas PT – LNG – Sampling, Conditioning & Analysis.

Natural Gas Sampling (Eliminate Uncertainty)

Canadian Gas Association, Gas Measurement and Regulation

School, Edmonton, 2014.

Orbital Global Solutions have launched the ground breaking

GasPT-LNG.

The benefits represent a remarkable quantum leap in

technology that has literally revolutionised the LNG industry.

CV &WI of LNG plant feed line

Hg, H2S, H2O & other trace

sample stations

Storage Boil Off Gas

Export Boil Off Gas

Ship to Ship Boil Off Gas

Import Boil Off Gas

CV & WI Gas Blending

CV &WI for blending & in to

Transmission Network

LNG Supply Chain Applications - where our products are used:

Dehydration