Gas storage requirements in PtGsystem

NEO-CARBON ENERGY 1st researchers’ seminar

Matti TähtinenVTT Technical Research Centre of Finland

Boundaries of gas storagesGases at PtG systemEconomicsTechnologyAdditional things to keep in mindSafety and legislationSummary

Introduction

P2G concept

Economics Technology

Safety Legislation

Gas storages

Boundaries for gas storages

HydrogenOxygenMethaneCarbon dioxideSteamCarbon monoxideSulfur compoundsAmmonia?

Gases at PtG system

Needs to be store up

Depends on case!

HydrogenOxygenMethane

Carbon dioxideSteam

Ammonia

Time/size of storage highly dependable of the “mother process” or process integration

What is the product?Grid stabilization, gas (O2/H2/CH4), long term energy storage…Part of larger industrial process vs stand-alone

Size of storage to meet feasibilityInvestment vs use/sale

Type of storageInvestment

Modelling timescale is depending on product

Economics as driving force

Size of storage to meet process needsStart-up and shut-down cycleProcess instabilityProcess control system demands for buffer

Type of storageEnergy integration (especially with cryogenic storages)Time delay for accessible gasPurity of available gasCentralized vs de-centralized

Modelling should be made at steady-state and dynamically

Technology as driving force

Gaseous

Atmospheric Pressurized

Liquid

Atmospheric (cryogenic)

Pressurized (super critical)

Solid

Atmospheric

Phase of gas storage

Short term(0-1h)

Hydrogen

Mid-term(1-12h)

OxygenCarbon dioxide

Long term(12+h)

Methane

Types of storages and gases

Common storages at industry; commercially availableHighly regulated

Storage tanksActuatorsPressure reliefsEtc.

Trivial to increase capacity, modular

Characteristics of certain gas storages –pressurized gas storage

EN 13445 Unfired pressure vessels

1110/02/2016

Characteristics of certain gas storages –hydrogenLiquidNeed high purity hydrogen“Boil off” during longer

storage timeLiquefaction consumes

approx. 30% more energy than pressurization

PressurizedDegradation of steel

well documentedLeak detection

best practicesPressure varies up to350 and 700bar(ISO 11439 for natural gas; used also for hydrogen)

Seems to be most difficult gas to handle at process

Hydrogen transport/storage

Techno-economic assessment of hydrogen transmission & distribution systems in Europe in the medium and long term, European Communities, 2005

1310/02/2016

Characteristics of certain gas storages –Oxygen / Carbon dioxideLiquid“Boil off” during longer

storage time

PressurizedCO2 can be storage over

critical

O2 boiling point; 90.19 K = –183.0°C

CO2 triple point -56.6 °C / 0.518 MPaCO2 critical point 31.1 °C/ 7.39 MPa

Liquid“Boil off” during longer storage time

Approx. 5 days until need to release pressure (sea transport)Mainly atmospheric pressureStable

Characteristics of certain gas storages –LNG

EN 1473:2007Installation and equipment for liquefied natural gas

LNG storage

LNG tank (Kvaerner-Moss spherical cryogenic container)

Heating and prolonged storage of liquefied gas storage can cause turn overPossibility of incidentCan be prevented

Storage tanks should be possible to fill or unload controllable to transport or to flare

Impurities are always risk during storage

Can be prevented or stress tested with modelling(CFD/steady-state/dynamic)

Miscellaneous things to keep in mind

Size of storageSafety limits to environment

Type of storageSafety limits to environmentInsurancesTransport readiness

MiscellaneousRisk assessments of technologyATEX

Safety and legislation as driving force

“Storage is not simply a passive adjunct to the main process plant. It too is actively operated by filling and emptying. These operations have the potential to cause destructive overpressure or under pressure and to cause overfilling, and they need to be carefully controlled.”

EN 14197-3:2004Cryogenic vessels. Static non-vacuum insulated vessels. Operational requirements

Economics Technology

Safety Legislation

Gas storages

Boundaries for gas storages - summary

Gas truck size

Risk assessment

Insurance Transport

Intermittency

Gas trade Physical limitations

EU directives

Processintegration

Process dynamics

Economics Technology

Safety Legislation

Gas storages

Boundaries for gas storages - summary

Gas truck size

Risk assessment

Insurance Transport

Intermittency

Gas trade Physical limitations

EU directives

Processintegration

Process dynamics

NEO-CARBON ENERGY project is one of the Tekes’ strategic research openings.The project is carried out in cooperation between VTT, Lappeenranta University of Technology and University of

Turku / Futures Research Centre.