Hydrogen Technology - Fewer References

Question 1

Physisorption

Broom and Book 2014

Answer 1

Isosteric Enthalpy of Adsorption. Hydrogen Uptake

See 7/7

Question 2

Physisorption

Ramirez-Vidal et al 2021

Answer 2

Gravimetric measure of absolute adsorption. Pore width Hydrogen density

See 7/10

Question 3

Hydrogen Storage - Porous Materials

Jankowska et al 1991

Answer 3

Porous Carbon Turbostratic structure

See 7/21

Question 4

Yang Xia Mokaya 2007

Answer 4

Carbon Zeolitic Framework

See 7/22

Question 5

Rosi et al 2003

MOF with…

Answer 5

Metal Organic Framework with Zinc Oxide and Organic molecular building blocks

See 7/27

Question 6

Explain Metal Organic Framework

Broom et al 2016

Answer 6

Small Particles –> High Surface Area –> Higher Hydrogen wt%

But higher gravimetric density –> lower volumetric density

See 7/31

Gravimetric density above 5.5%
Volumetric density above 40g/L
Use 77K for Liquid Nitrogen.
20,000 MOFs in Cambridge structural database

Question 7

Broom et al 2019

Answer 7

Stepped adsorption isotherms with flexible material

See 7/32

Question 8

Ahluwala and Peng 2009

Answer 8

Cryogenic Adsorption

See 7/39

Question 9

Thomas 2007 and Sandrock 2008

Graph for Temperature and Weight Capacity

Answer 9

Sweet Spot with High wt% and close to ambient temperature

See 7/12 - Porous Materials (and other places)

Question 10

MgH2 Ball Milling to 20nm

Hirscher 2003

Answer 10

Leads to smaller grain size and more grain boundaries. Hydrogen goes in (and comes out) much quicker and at lower temperature.
Smaller size ball milling leads to agglomoration.

See 6/53

Also Niemann (with Catalyst) and Hanada over 5% H wt%

Question 11

Destabilising MgH2

Zlotea et al 2015

Answer 11

Nanoparticles for Hydrogen storage. Chemical crystalisation. Embedded in microporous carbon. Under 2nm particles.
Lower temperatures

See 6/63

Also Orimo and Fuji - Binary phases of Mg with transition metals

Question 12

Complex Hydrides

Vajo et al 2007

Answer 12

Complex Hydrides. Lithium Borohydride. Destabilised intermediary with MgH2.
170 degrees 1 bar.
Reversible.

See A/26

Question 13

Separation: Grashoff et al 1983

Remember the curled up strip picture?

Answer 13

Paladium membrane for hydrogen separation.
Incorporate silver to reduce embrittlement.

See 8/17

Question 14

Weight of energy storage systems to take a car 500 km

Eberle et al 2009

Answer 14

Compressed 700bar
6kg (170L) Hydrogen
125kg (260L) system

Compared with ICE
33kg (37L) fuel
43kg (46L) system

Compared with Lithium
540kg(360L) “fuel” - batteries
830kg(670L) system

See 3/2

Weights and Volumes. ICE Fuel system considerably smaller. Under 50kg?

Question 15

PEM Fuel Cell - Catalyst functions

Answer 15

1. Gas transmission and distribution to electrolyte boundary layer
2. Electric current flow
3. Water (moisture) extraction/transport

Maybe some Oxygen related activity

Question 16

Fuel Cell vehicle transmission system
Hu and Egardt 2015

“Who has the heart to show tyres on their picture?”

Answer 16

Hydrogen tank
PEM? Fuel Cell
Energy Storage (battery)
Auxilliaries
Electric Motor
Transmission

See 3/3. Start with Transmission and work backwards

Question 17

Automotive PEM FC layout
Hu et al 2015

Answer 17

Compressor and Humidifier for air.
Control valve for Hydrogen (tank)
Cooling circuit
Recirculation and purge
STACK

Just the PEM - See Hu and Eghardt for Complete System

See 1/33

Question 18

Hydrogen storage mean distances between molecules/atoms

Answer 18

1bar ambient: 3.3nm
350bar ambient: 0.54nm
700bar ambient: 0.45nm
Liquid 20K: 0.36nm
Metal hydrides: 0.21nm (atoms) - Westlake

See 3/50 and ??

Question 19

Hydrogen Production techniques

Holladay et al 2009

Answer 19

SMR 70-85% Efficient. Commercial
Alkaline electrolyser 50-60%. Commercial
Biomass gasification 35-50%. Commercial
PEM 55-70%. Near term.

See 2/13

Question 20

Current Production and Prices

Vidal 2022

Answer 20

Current Hydrogen production:
48% Natural gas
30% Oil
18% Coal
4% Electrolysis and other!

Prices:
Wind: above $4
Solar electrolysis: near $4/kg

Onshore wind electrolysis: under $3/kg

NUCLEAR Electrolysis $2
SMR (with or without CCS): Under $2

Question 21

SMR methods

Enayatizade et al 2019
Shirasaki 2009

Answer 21

1. Desulpherise
2. Add Steam
3. Add Heat - Reformer
4. Shift Conversion (remove water)
5. PSA Pressure Swing Adsorption - purification

Reforming: CH4 + H2O –> 3H2 + CO (880 °C)
Water Gas Shift: CO + H2O <–> CO2 + H2 (~ 300 °C)

880 = 10 Back to the Futures
300 = Battle of Badr?

Shirasaki 2009 - SMR Membrane Reactor = TUBE with Pd

Question 22

Pressure Swing Adsorption

Cortes et al 2009

Answer 22

Passing a gas mixture through a high surface area adsorbent with the ability to adsorb impurity gases

Easily adsorbed to non adsorbed
(eg C3H6) – CO, CH4 – O2 – H2

Question 23

Metal Hydrides

Lototskyy et al 2014

Answer 23

Reversible Adsorption/Desorption
Metal or Alloy or Intermetallic Compound (LaNi5 TiFe etc)
and
Structure of Hydride: Parent alloy, Change in crystal volume

See 6/7 and 6/24

Question 24

Metal Hydride
Physics

Schlapbach 1988

Answer 24

Hydrogen disocciation and Potential Energy

See 6/10

Question 25

**Lots from Metal Hydrides** | Züttel 2003

Answer 25

Van't Hoff equation LaNi5 and FeTi Reversible! Thomas Sandrock Density graph. High G, v low temperatures | See 6/23 (with Schlapbach 2001) and 6/25

Question 26

Various Heat Exchanger concepts | Broom et al 2016 - Not the graph

Answer 26

1. Conventional Tube Fin 2. Aluminium Honeycomb 3. Carbon Foam 4. Aluminium Foam 5. Compacted and Augments MOF 6. Micro Channel Heat Exchanger (looks like Shivangi's PCM frame) | (Fish, Bee, 2 seas, Frame getting squashed, channel tunnel for ants)