MIT/NTNU/StatoilHydro PhD Program
Download
1 / 30

- PowerPoint PPT Presentation


  • 280 Views
  • Uploaded on

MIT/NTNU/StatoilHydro PhD Program in Energy and Gas Technology MIT, Boston/Cambridge, 28 29 October 2008 New LNG Processes & LNG Chains require new Design Methodologies for Subambient Processes by Paul I. Barton Truls Gundersen Chemical Engineering Energy and Process Engineering

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about '' - adsila


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Slide1 l.jpg

MIT/NTNU/StatoilHydro PhD Program

in Energy and Gas Technology

MIT, Boston/Cambridge, 2829 October 2008

New LNG Processes & LNG Chains

require new Design Methodologies

for Subambient Processes

by

Paul I. Barton Truls Gundersen

Chemical Engineering Energy and Process Engineering

MIT, Boston NTNU, Trondheim

USA Norway

Paul I. Barton

& Truls Gundersen


Brief outline l.jpg
Brief Outline

  • Motivation

  • Project Proposal

  • History

    • Prior collaboration MIT/NTNU

    • Results so far

    • Publications

  • The Liquefied Energy Chain (LEC)

  • The ExPAnD Methodology

  • Combining Thermodynamics & Optimization

  • Optimization Formulations and Algorithms

Paul I. Barton

& Truls Gundersen


Motivation l.jpg
Motivation

  • Increased importance of Natural Gas and LNG in the World and in Norway

  • A Number of Current and Future Challenges in LNG (and Natural Gas)

  • Significant Limitations in Existing Design Methodologies and Tools for LNG and Subambient Processes

Paul I. Barton

& Truls Gundersen


Natural gas increases in importance l.jpg

Coal

Natural Gas

Oil

Natural Gas increases in Importance

Paul I. Barton

& Truls Gundersen


Slide5 l.jpg

LNG increases even more

Ref.: http://www.cedigaz.org/Fichiers/PREstimates2006.pdf

Paul I. Barton

& Truls Gundersen


Slide6 l.jpg

Challenges for the LNG Industry

  • New ways to utilize Stranded Natural Gas

  • Trend towards (flexible) Floating LNG Chains

  • Will need CCS from fossil based Energy Systems

  • Capturing CO2 will drastically change Heat/Power ratio

  • Future Large Scale use of Amines has a considerable Economic Penalty; it may have an Environmental Penalty

  • How to deal with larger H2S and CO2 fractions?

  • Could Cryogenic Distillation (Ryan-Holmes) be used?

  • Effects of breakthroughs in Equipment Design

  • Synergies in co-localization with Industrial Cluster

 Need new Process Concepts and Chain Configurations

Paul I. Barton

& Truls Gundersen


Slide7 l.jpg

Limitations of Existing Methodologies

  • Pinch Analysis (PA) has been extensively used in the Process and Energy Industry for 25 years to Design:

    • Heat Exchanger Networks with focus on

    • Heat and Power Systems Energy Efficiency

    • Distillation Systems, etc. and Economy

  • Major Limitations of PA in Subambient Processes

    • Only Temperature is used as a Quality Parameter

    • Exergy Considerations are made through the Carnot Factor

    • Pressure and Composition are not Considered

  • Exergy Analysis and 2nd Law of Thermodynamics

    • Considers Temperature, Pressure and Composition

    • Focus on Equipment Units, not Flowsheet (Systems) Level

    • No strong Link between Exergy Losses and Cost

    • Often a Conflict between Exergy and Economy

Paul I. Barton

& Truls Gundersen


Slide8 l.jpg

Why is Pressure important Subambient?

  • Pressure is significant in Process Integration efforts to reduce Energy Requirements above Ambient

    • Defines the Level ( T) of large Heat Duties ( Q )

    • Often defines the Heat Recovery Pinch

  • Pressure is even more important below Ambient

    • In Phase changes, Temperature is linked to Pressure

    • In Pressure Changes, Temperature is linked to Power

    • Subambient Cooling (Refrigeration) is provided by Compression, thus Pressure is again important

  • Pressure can be ”traded” against Cooling

    • A pressurized Cold Stream below Ambient can be expanded to provide Additional Cooling (and some Power)

    • Pressure Exergy can be converted to Temperature Exergy

Paul I. Barton

& Truls Gundersen


Project proposal l.jpg
Project Proposal

  • ”Optimal Design of LNG Processes and Production Chains  Developing new Methodologies and Tools for Subambient Processes”  (2009-2012)

    • Supported by StatoilHydro (LoI)

    • Application pending with the RCN

  • Budget and Manpower

    • 8 mill. NOK total over 3 years (1.3 mill. USD)

    • 2 PhD’s (3 years) & 2 Post.doc’s (2 years)

  • Existing Groups & Related Topics

    • Paul I. Barton & 2 PhD’s (A. Selot & E. Armagan)

    • Truls Gundersen & 2 PhD’s (A. Aspelund & R. Anantharaman)

  • Research Strategy: Simultaneous Development of new Process Concepts and Design Methodologies

Paul I. Barton

& Truls Gundersen


History of collaboration barton gundersen l.jpg
History of Collaboration  Barton / Gundersen

  • Informal collaboration since 2005

    • Joint Project Proposal for the 1st Call MIT/NTNU October 2005

    • PhD Student Audun Aspelund at MIT Fall 2006 & Spring 2007

  • Four Results have emerged in Parallel

    • A Liquefied Energy Chain (LEC) for Stranded Natural Gas

    • An Extended Pinch Analysis and Design (ExPAnD) Procedure

    • A Math Progr. Model for Optimizing Temperatures and Pressures

    • A Simulation-Optimization Approach for Entire LNG Chains

  • Publications

    • 1 Patent on the LEC (industrialization attempted through TTO)

    • Journal Papers:

      • 1 published (ExPAnD), 4 (series) accepted (LEC), 1 drafted (Opt. P/T)

    • Conference Contributions:

      • CHISA/PRES 2006, ESCAPE 2007, AIChE Mtg 2007, INFORMS 2007

      • 1st Gas Symposium, Qatar, 2009 (2 papers accepted)

Paul I. Barton

& Truls Gundersen


Slide11 l.jpg

OXYFUEL Process

CO

2

LNG

LNG

LNG

Water

NG

Power

S

Process

NG

LNG

LNG

t

Electricity

The

o

The

Offshore

r

Onshore

O

2

N

2

LIN

LIN

Process

a

Process

g

CO

2

LCO

2

LCO

2

N

2

e

ASU

Argon

LIN

LCO

2

LCO

2

AIR

The Liquefied Energy Chain (LEC)- Utilize Stranded Natural Gas for Power Production- Combined with CO2 Capture and Storage- Enhanced Oil Recovery using CO2- Combined Liquid Carrier

Paul I. Barton

& Truls Gundersen


The expand methodology l.jpg
The ExPAnD Methodology

  • Extended Pinch Analysis and Design

  • Currently focusing on Subambient Processes

  • A new Problem Definition has been introduced:

    • ”Given a Set of Process Streams with a Supply and Target State (Temperature, Pressure and the resulting Phase), as well as Utilities for Heating and Cooling  Design a System of Heat Exchangers, Expanders and Compressors in such a way that the Irreversibilities (or later: TACs) are minimized”

  • Limitations of the Methodology (at present)

    • Relies Heavily on a Set of (10) Heuristics, 6 different Criteria (Guidelines) and suffers from a rather Qualitative Approach

    • Strong need for Graphical and/or Numerical Tools (Optimization) to replace or assist Heuristic Rules and Design Procedures

    • Using the Concept of Attainable Region is a small Contribution towards new Graphical and Quantitative ExPAnD Tools

Paul I. Barton

& Truls Gundersen


Temperature enthalpy tq route from supply to target state is not fixed l.jpg

Target

State

Supply

State

Temperature/Enthalpy (TQ) ”Route”from Supply to Target State is not fixed

The Route/Path from Supply to Target State is formed by Expansion & Heating as well as Compression & Cooling

a) Hot Streams may temporarily act as Cold Streams and vice versa

b) A (Cold) Process Stream may temporarily act as a Utility Stream

c) The Target State is often a Soft Specification (both T and p )

d) The Phase of a Stream can be changed by manipulating Pressure

The Problem is vastly more complex than traditional HENS

Paul I. Barton

& Truls Gundersen


How can we play with pressure l.jpg

Heating

before

Expansion

Expansion

before

Heating

Heating

only

How can we Play with Pressure?

Given a ”Cold” Stream with Ts = - 120ºC, Tt = 0ºC, ps = 5 bar, pt = 1 bar

Basic PA and the 2 ”extreme” Cases are given below:

159.47ºC

-176.45ºC

Paul I. Barton

& Truls Gundersen


How can we play with pressure15 l.jpg
How can we Play with Pressure?

Given a ”Cold” Stream with Ts = - 120ºC, Tt = 0ºC, ps = 5 bar, pt = 1 bar

Attainable Region with One Expander:

Paul I. Barton

& Truls Gundersen


Slide16 l.jpg

O2

Air Separation

ASU

Oxyfuel

Power Plant

W

Air

NG

LNG

LIN

H2O

NG

LNG

Natural Gas

Liquefaction

CO2

Liquefaction

CO2

LCO2

Sub-processes in the LEC

Illustrate how ExPAnD is used

to design the Offshore Process

Paul I. Barton

& Truls Gundersen


Base case for the offshore process using basic pinch analysis l.jpg
Base Case for the Offshore Process- using basic Pinch Analysis

Heat Recovery first,

Pressure Adjustments subsequently

Paul I. Barton

& Truls Gundersen


Base case composite curves l.jpg

Seawater

NG

CO2

ex = 49.7 %

LNG

N2

Base Case Composite Curves

External Cooling required for Feasibility

External Heating is ”free” (Seawater)

Paul I. Barton

& Truls Gundersen


After several process modifications l.jpg

ex = 85.7 %

After several Process Modifications

The Composite Curves have been ”massaged”

by the use of Expansion and Compression

Paul I. Barton

& Truls Gundersen


A novel offshore lng process l.jpg

N

2

-

7

EXP

-

101

K

-

101

N

2

-

8

N

2

-

9

N

2

-

4

EXP

-

102

N

2

-

5

N

2

-

10

N

2

-

12

N

2

-

11

N

2

-

6

N

2

-

3

CO

2

-

4

N

2

-

2

N

2

-

1

CO

2

-

3

CO

2

-

2

NG

-

5

NG

-

2

NG

-

3

NG

-

4

NG

-

PURGE

P

-

101

P

-

102

NG

-

1

NG

-

6

K

-

100

V

-

101

LIQ

-

EXP

-

101

LIQ

-

EXP

-

102

CO

2

-

1

P

-

100

LNG

A novel Offshore LNG Process

Self-supported w.r.t. Power

& no flammable Refrigerants

Paul I. Barton

& Truls Gundersen


Slide21 l.jpg

The Nitrogen ”Path”

Paul I. Barton

& Truls Gundersen


The onshore process regasification l.jpg

ex = 71.2 %

The Onshore Process (Regasification)

Paul I. Barton

& Truls Gundersen


Slide23 l.jpg

More new Process Concepts?

  • The LNG Industry is facing several Challenges

  • We will Challenge established ”Truths” about LNG

  • The Trend has been to shift from Cascaded Single Component Refrigerants to Mixed Refrigerants

    • Cascade Liquefaction Processes

    • Mixed Refrigerants

  • Mixed Refrigerants cause Flow Distribution Problems in Heat Exchangers Onshore, even more so Offshore

  • We have shown that Multicomponent Behavior can be achieved by Single Components playing with Pressure

    • Expansion & Compression

Paul I. Barton

& Truls Gundersen


Slide24 l.jpg

Cascade Liquefaction Process

Paul I. Barton

& Truls Gundersen


Slide25 l.jpg

Combining Mixed and Pure Refrigerants

APCI’s C3-MR dominates (≈ 87%)

Paul I. Barton

& Truls Gundersen


Slide26 l.jpg

N

2

-

7

EXP

-

101

K

-

101

N

2

-

8

N

2

-

9

N

2

-

4

EXP

-

102

N

2

-

5

N

2

-

10

N

2

-

12

N

2

-

11

N

2

-

6

N

2

-

3

CO

2

-

4

N

2

-

2

N

2

-

1

CO

2

-

3

CO

2

-

2

NG

-

5

NG

-

2

NG

-

3

NG

-

4

NG

-

PURGE

P

-

101

P

-

102

NG

-

1

NG

-

6

K

-

100

V

-

101

LIQ

-

EXP

-

101

LIQ

-

EXP

-

102

CO

2

-

1

P

-

100

LNG

Pure Refrigerants & Expansion/Compression

Paul I. Barton

& Truls Gundersen


Slide27 l.jpg

ex = 85.7 %

Pure Refrigerants & Expansion/Compression

Q: Can these Results from the Offshore Process be utilized in Onshore LNG Applications ?

Paul I. Barton

& Truls Gundersen


Slide28 l.jpg

Why do we need Optimization?

  • The Heuristics of ExPAnD coupled with Domain and Engineering Insight can produce Thermodynamically “sound” and “near-optimal” Processes, however . . .

  • Multiple Economic Trade-offs requires Optimization

  • Optimization can be used in a number of Ways

    • At the total Energy Chain Level (including Ship Utilization)

    • At the Level of the individual Processes of the Chain

      • Optimize Decisions at the Flowsheet Level (structure)

      • Optimize Operating Conditions (flows, compositions, P and T)

  • Different Optimization Algorithms can be used

    • Deterministic Methods (Mathematical Programming)

    • Stochastic Methods (Simulated Annealing, Genetic Algorithms, etc.)

Paul I. Barton

& Truls Gundersen


Slide29 l.jpg

and

by that

it is time

to introduce

my Project Partner

Prof. Paul I. Barton

Paul I. Barton

& Truls Gundersen


Slide30 l.jpg

Paul I. Barton

& Truls Gundersen


ad