Lecture 10 – Power-to-X Technologies

Question 1

What is the main concern about the Power To Gas that is currently being discussed?

Answer 1

a Power To Gas Tech , such as Power yo Hydrogen by using the negativ residual load in the grid to first generate Hydrogen from water and than adding CO2 and generating methan in socalled “methanation” pricess in order to burn it afterwards to have a CO2 free gas to burn is compared with a direct power to heat technology.
in the power to heat we directly take the electricity generated and use for example electric heat pumps to generate heat. With this we have much better efficiencies and also the enviromental impact is lot less.

Question 2

Explain the chemical reaction forumula of the electrolysis on cathode and anode

Answer 2

2H2O + 2e -> H2 + 2OH-
6H2O ->O2 + 4H3O+ + 4e

Question 3

Which kind of hydrogen production do we have today?

Answer 3

Electrolysis
Steam Reforming
Partial Oxidation
Kvearner process ..

Question 4

Reaction of hydrogen atoms to molecule is ….
Hydrogen has a high reactivity with metal and non metals at high ….
Hydrogen cant be liquified when …., it needs to be cooled down to liqiufie it.
Hydrogen has ….. as energy density (LiIon 0,26kWh/kg, Diesel 11.8kWh/kg ) but in volumetric ED it has in standart conditions it has 3 Wh/l in liquid (-253K) 2,36kWh/l

Answer 4

exorthermic (heat comes out)
tempearture
compressing
33.3kWh/kg

Question 5

Gas Storage is very cheap from invesment but low efficiency, therefore you would use it with few cycles and long period of storage time.

Question 6

Which Fuel Cell is the most used Fuel Cell and how is its working princaple?

Answer 6

PEMFC
We have an ploymer membrane electrolyte, anode that splits the 2H2 to 4H+ and 4e to and Kathode that takes this 4H+ Ionen, which flows through the PEMFC to Kathode to form H2O with O2 and the electrons, which drives a load.

Clean Products

High Efficiency in Lower current rates

Low Efficiency in higher current rate

Question 6

Methan is a highly flammable gas and is the main source of natural gas.
It has a global warming potenial, that is 28 times more than the CO2, so any leakege in the pipelines could be catastrophic for the enviroment, even though its overall emmision in gas PPT are lot less then a lignite PPT.
It has a gravemetric Calorific Value: 50 (120 hyd)
It has a volumetric Calorific Value: 36 (11)

Question 7

Explain the AFC working princaple

Answer 7

Here we have an Electrolyte from potasium hydroxide , in Anode 2H2 and 4OH- (which comes from Kathode reaction) gets to build 4 H2O water and 4e, which than flow to cathode and form 4OH- from O2 and 2H2O and 4e-