New LNG Processes & LNG Chains 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 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 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 Coal Oil Paul I. Barton & Truls Gundersen

LNG increases even more Ref.: http://www.cedigaz.org/Fichiers/PREstimates2006.pdf Paul I. Barton & Truls Gundersen

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

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

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 ”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 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

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 OXYFUEL Process LIN LCO 2 LNG The Offshore Process S t o r a g e Onshore NG CO N ASU Power O Argon Water Electricity AIR Paul I. Barton & Truls Gundersen

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 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? 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: Heating before Expansion 159.47ºC Expansion before Heating Heating only -176.45ºC Paul I. Barton & Truls Gundersen

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

Sub-processes in the LEC Oxyfuel Power Plant CO2 Liquefaction Natural Gas Air Separation ASU NG Air LIN LNG W LCO2 O2 H2O 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 Heat Recovery first, Pressure Adjustments subsequently Paul I. Barton & Truls Gundersen

Base Case Composite Curves Seawater CO2 N2 NG LNG ex = 49.7 % External Cooling required for Feasibility External Heating is ”free” (Seawater) Paul I. Barton & Truls Gundersen

After several Process Modifications ex = 85.7 % The Composite Curves have been ”massaged” by the use of Expansion and Compression Paul I. Barton & Truls Gundersen

A novel Offshore LNG Process K - 100 P 102 V 101 NG 2 LIQ EXP 1 3 4 5 6 PURGE LNG N 10 11 CO 9 8 12 7 Self-supported w.r.t. Power & no flammable Refrigerants Paul I. Barton & Truls Gundersen

The Nitrogen ”Path” Paul I. Barton & Truls Gundersen

The Onshore Process (Regasification) ex = 71.2 % Paul I. Barton & Truls Gundersen

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

Cascade Liquefaction Process Paul I. Barton & Truls Gundersen

Combining Mixed and Pure Refrigerants APCI’s C3-MR dominates (≈ 87%) Paul I. Barton & Truls Gundersen

Pure Refrigerants & Expansion/Compression K - 100 P 102 V 101 NG 2 LIQ EXP 1 3 4 5 6 PURGE LNG N 10 11 CO 9 8 12 7 Paul I. Barton & Truls Gundersen

Pure Refrigerants & Expansion/Compression Q: Can these Results from the Offshore Process be utilized in Onshore LNG Applications ? Paul I. Barton & Truls Gundersen

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

my Project Partner Prof. Paul I. Barton and by that it is time to introduce my Project Partner Prof. Paul I. Barton Paul I. Barton & Truls Gundersen

Paul I. Barton & Truls Gundersen