TU/e TechnischeUniversiteit Eindhoven University of Technology

TU/e Technische UniversiteitEindhovenUniversity of Technology

Lecture prof. Jacques DamMarch 31, 2015



The downstream LNG supply chain.

21 June 2019 Downstream LNG 2

Future LNG fuel chain

Upstream LNG chain


The Traditional LNG fuel supply chain.


Drivers for the LNG fuel supply chain.

Secondary LNG market. LNG is, or will be, delivered by the Upstream

Regasification terminals at a price concurrent to other fuels (oil and diesel).

System and component hardware “seems available”.

Engines can be converted relatively easy to run on LNG (+ Diesel) (gas, dual-fuel, turbine engines).

Effective reduction of all engine emissions other than CO2 and engine noise levels.

Problem of Methane Slippage must be solved. Availability of Natural Gas resources. Is introduced on a global scale. Safe.

Bio-LNG


The LNG fuel supply chain chalenges.


€ (CAPEX and OPEX)• Cost of the facility in general (investments, maintenance).• Storage LNG boil-off typically 0.1-0.3% of the stored volume per day.• Differences in LNG storage pressure and end-user LNG storage

pressure (typically 5bara for ships, 8 or 18bara for trucks)(complexity).• The cost of safety.• The cost of logistics (LNG delivery and retrieval, startup, maintenance).• Transfer is more complex than with traditional fuels.• Cost effective cooling for zero-boiloff.• Permits, regulations and standards.• User friendliness and operations.

Let us look at a typical LNG truck filling stationand the handling of LNG


Yes, partially, because it has a favorable emission profile in comparison with other fuels,

however:

• CO2 emission reduction is limited.• CH4 is an extreme greenhouse gas in

comparison with CO2.

and

From origin, LNG is a fossil fuel

But:

It is possible to give LNG fuel an betterenergy and CO2 neutral profile as Bio-LNGand through blending with bio-basedcomponents and Hydrogen.

LNG being a “Green” fuel?

21 June 20195

Downstream LNG


LNG use and world global warming (GWP).


Natural emission of Methaneas greenhouse gas

CH4 has a GWP100 factor 25 IPCC 2012).

The LNG fuel chain should therefore:

• Prevent the emission of CH4• Zero boiloff• Methane slippage.

• Minimize the energy requirement of the entire LNG fuel chain.

• Containment systems.• Cold Energy Recovery.• Inclusion in Hybrid Energy

Networks.• Development of more efficient

combustion platforms.


Introducing the renewable LNG fuel supply chain.

21 June 2019 LNG Systems 7

The Dutch approach towards a renewable LNG fuel.• Sensible use of fossil LNG (price and availability).• Does not depend on the upstream LNG quality.• Maximum use of Bio-LNG and bio-based and/or Hydrogen

additives.• The LNG fuel quality and quality spread is determined by the

maximum possible efficiency of combustion.• Maximal use of cold energy recovery processes.• Towards an energy neutral to produce and to distribute fuel.• Towards a CO2 neutral supply chain and combustion technology.• Is user friendly and safe.• Compliant with European and Dutch environmental targets.


Bio- Natural Gas pre-treatment.

21 June 20198

Biogas contains 50% of impurities, mostlyCO2 and therefore also requires extensivepre-treatment.• Fossil Natural Gas pre-treatment

technology.• Membrane technology.• Cryogenic pre-treatment.

Downstream LNG


Downstream LNG refrigerator options.


Open cycle

Closed cycle

Stored cryogenAmbient pres.

Low temp.

LiquidSolid Supercritical

Stored gasHigh pres.

Ambient temp.

Joule-ThomsonTurbine expansion

Static pressureDynamic pressure

Regenerative Recuperative

Valves

Gifford-McMahonPulse tube

Joule-ThomsonBraytonClaude

SorptionSolid-state Radiator

Sorptioncompressor

MagneticThermo-electric

Laser

Valveless

StirlingVuillemierPulse tube

Recuperative

Joule-ThomsonBrayton


Mid-Scale and Small-Scale LNG liquefaction cycles. (Summary)

21 June 2019 10

Small, Mid-Scale LNG liquefaction processes

Black & Veatch: Single-MR LNG process (Nitrogen, Methane, Ethane, Propane, iso-Pentane).Linde LE: Single-MR LNG process.Kryopak: Single-cycle turbo expander process; PCMR (pre-cooled MR, Methane, Ethane, Butane) or

SCMR (Nitrogen, Methane, Ethane, Butane, Pentane).Chart: Customer LNG process plant design.Mustang: Uses inlet gas as single refrigerant via compression and turbo-expansion.Hamworthy: Nitrogen expansion LNG process (mini-LNG plant using pipeline of landfill gas).ABB-Lummus: Ammonia bases absorption-refrigeration.Stirling: Stirling based refrigeratorsVarious: LNG production by heat exchange with LIN.

Downstream LNG


Cryogenic coolers efficiency overview

100 101 102 103 104

Compressor input power (W)

CO

P car

not(

%)


10

20


The Stirling cycle for small-scale LNG liquefaction.


LNG production at 1bar:Specific energy consumption: 0.90kWh/kg LNG

LNG production at 65bar:Specific energy consumption: 0.73kWh/kg LNG

This is worse by far in comparison with current industry best performance being production of upstream LNG at 0.27kWh/kg

Stirling refrigerator efficiency developments:

1. Reduction of regenerative loss: -0.21kWh/kg LNG2. Heat exchange with cycle over

the entire temperature range instead of only at TL: -0.10kWh/kg LNG

3. Mixed refrigerant instead of pure Helium -0.12kWh/kg LNG

Downstream LNG liquefaction at 0.30kWh/kg feasible.

Performance


Stirling-cycle cooling and cold energy recovery.

Differential equations describing the temperature of gas and matrix in a regenerator:

( ) ( ) ( )1 1p g g g gm mp m g r g g

m g m g

f C T T f T TV Vp pjC j V T T TV t l T l V T t l l

β κ − ∂ ∂ − ∂ ∂ ∂∂ ∂ ∂

= − − − + + − + ∂ ∂ ∂ ∂ ∂ ∂ ∂ ∂

( )r rr g r r

T TC T Tt l l

β κ∂ ∂∂ = − + ∂ ∂ ∂

Includes1. Convective heat transfer due to flow of gas in the presence of a

temperature gradient.2. Throttling of gas through the flow resistance of the matrix (Joule-

Thomson effect).3. Temperature change of the gas due to compression.4. Heat exchange between gas and matrix.5. Heat conduction through the gas and matrix.

β: Volumetric heat transfer coefficientTr: Matrix temperatureTg: Gas temperatureJ: Molar flux through the regenerator f:

Matrix filling factor



(Future) technology developments for the LNG fuel chain.

21 June 2019 LNG Systems 14

The responsible scientist contributes to the future ofthe LNG fuel chain through thorough theoretical andexperimental research within the environmentalcontext of the topic.

by

Introducing bio-componentsIntroducing Hydrogen

Introducing refrigerationIntroducing cold energy recovery

Improving storage and transfer systemsImproving the efficiency of combustion

Improving modeling and simulationTaking care of economics and legalization

Optimizing safety and process controlTaking care of standardization

Optimal logisticsGreen Deal 50-50-500(0)

TKI or other funded research

The LNG fuel chain evolves rapidly therefore:


LNG cold utilization benefits.– LNG boil-off gas reliquefaction utilizing LNG cold storage (100tons/h LNG for processing 15tons/h

BOG).– Cryogenic power generation (direct expansion 26-44kWh/t LNG, 20-37kWh/t LNG for mixed

refrigerant Rankine cycle, 35-56kWh/kg in a combination of both).– Air separation (0.4kWh/m3 against 0.8kWh/m3 conventional).– Production of liquefied CO2 and dry ice (0.08-0.11kWh/kg CO2 against 0.2kWh/kg conventional).– Cold warehouse refrigeration (0.2kWh/kW against 1.3kWh/kW conventional).– LNG cold for pulverizing waste.– Sea water desalinization.– Pre-cooling for the production of liquefied Hydrogen (4-5kWh/kg LHy against, 11.5-13.5kWh/kg LHy

conventional).– Cooling for HTS application as HTS electrical motors.– Improve the performance of active cycles by using waste heat (cooling water, exhaust heat etc.)

LNG cold utilization reduces the CO2 emissions with 50-75% depending on the application in which it is used!

Profits of LNG thermal energy management.


Power Generation

Seawater Desalination

Refrigeration

Dry Ice Production

Inlet Air Cooling of Gas Turbine Power

Generation

Cold Pulverization

Air SeparationHydrogen Production

Re-liquefaction of BOG of LNG


The role of LNG in a Hybrid Energy Network.


• Hybrid Energy Network definition.The total (thermal) components and processes that are required in any given energy network by means of (transient) energytransfer functions of those components and processes. This includes for instance heat pumps, heat storages, conversion to orfrom other energy carriers as well as more common components as heat exchangers, (isolated) pipe-line elements but alsocommand and control units as valves, expanders, sensors and so on. LNG gives a low temperature point in this network.

• Development approach.A generalized component/process network model approach and template that allows the coupling and use of thecomponents/processes and include suppliers of heat, users of heat and coupling elements for the coupling of the thermalnetwork with other energy networks (as gas, electricity etc.). Optimization of the thermal network in terms of energy efficiency,emission profile, economics and the required control & command structure that ensures the stability of the optimal setting ofthis heat network under steady-state and transient conditions.

With the power conversion from energy carrier α to energy carrier β with efficiency ηαβ defined as:

The energy hub shown on the figure on the left can be characterized by an input-output coupling as:


Application: The LNG filling station.

Basic LNG truck filling station.• Blow-off of pressure differences

between truck and dispenser (environmental & safety issues).

• LNG delivery saturated LNG at 1bara, LNG dispensed saturated at 9bara or 18bara.

• Ice-up of the system.• No simultaneous filling and

dispensing possible?• What to do with the boil off NG

when there is no dispensing possible?

• Dispenser transfer losses.• Typical thermal energy loss:

100kW during truck filling.

Concept LNG truck filling station.• Use of a thermal engine for the LNG energy

conversion.• Possible to use this concept for many

applications.• Generation of electricity during LNG delivery

(typically 50kW)


Mathematical dynamic simulation model of the LNG filling station.

Issue: LNG quality control


Application: LNG cooled HTS ship’s drive concept.


HTS motor

Air

Exhaust

HTS generator

LNG fuel pump

LNG111.5K

40K cooling

Thermal engine

Inlet air cooling


Application: The thermo-acoustic driven Stirling cycle.

21 June 201919

Performance

2000 l/day thermo-acoustic LNG liquefierSource: Praxair USA

Source: ECN

Downstream LNG

• Approximately 35% of the Natural Gas feed is burned to drive the resonator (40Hz).

• In comparison, the aero-derative turbine compressor burns 10% of the Natural Gas feed.

Therefore, use waste heat instead.(coupling with Hybrid Energy Networks)


LNG innovation topicsLNG still is a fossil fuel!...........Not a significant impact on CO2 reduction!..............Total waste of thermal energy!...............Methane slip!..................Does notcontribute to renewable energy ambition of the government!..........”Green” Bio-LNG is not a competitive option!................... Old technology instead of innovativetechnology!........Engines must work with relative large spread in LNG fuelquality!.............No 100% zero CH4 venting approach!... No relation between LNGfuel quality and optimal combustion efficiency!...........LNG supply is in control ofonly a few countries!..............LNG energy projects are the most expensive in allthe energy sectors!............Still no cost-competiveness!.........LNG is technically verychallenging so expensive!........... All components of the LNG fuel supply chainintroduce thermal energy and/or CH4 losses!.........LNG costs 0.3kWh/kg toproduce!...........Fewer km on a tank of fuel!..........Component lack on Intrinsicsafety properties!...........Shale gas needed to ensure long term delivery of LNGfuel!........Not convenient for private use!..........Large infrastructurefootprint!........Complex LNG handling and logistics!........... Insufficient knowledgeon downstream safety issues!........... Availability is coupled withOil!........Unburned CH4 is 20 times worse as greenhouse gas in comparison withCO2!...........Not sufficient trained technicians available!.......Make it an European development!.........Poor social acceptance andlegislation!..........................No flow measuring standard!.....No failure data!.

At the end of these lectures.

LNG will play an important role in our future energy mix but a significant

contribution requires innovations over the entire LNG chain.


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