This document summarizes hydrogen production through solid oxide electrolysis. It discusses how solid oxide electrolysis cells (SOECs) can efficiently produce hydrogen or syngas from electricity and unused heat. SOECs operate at high temperatures and can take advantage of excess renewable energy through water electrolysis, storing the energy as hydrogen. The document outlines the key materials used in SOECs, including yttria-stabilized zirconia as the electrolyte and lanthanum strontium manganite and nickel cermet as the oxygen and hydrogen electrodes. Co-electrolysis of steam and carbon dioxide via SOECs is also presented as a method to produce syngas for liquid fuels while recycling carbon dioxide.

1. ESSAY ON:
Hydrogen Production from Water and
Air Through Solid Oxide Electrolysis
To fulfill B.Sc. Degree of Science
Prepared by:
Haytham Ayman Nasser
4th Year Special Chemistry
Supervised by:
Dr. Mohamed Ismael Mohamed

2.  Introduction
 Hydrogen plays an important role in the energy sector and is one of
the most important feedstocks for the production of hydrocarbon
fuels and chemicals.
 hydrogen does not exist in its pure state in nature, like oxygen.
 Hydrogen has high energy density and environmental friendliness .
 Hydrogen is an ideal energy carrier for renewable energy storage.
 Currently, about 96 % of hydrogen is produced from fossil fuels .
 The industrial processes produce significant amounts of CO2, which
is a major green-house gas (GHG) and has a strong impact on
global warming. Due to the depletion of fossil fuels

3. Schematic representation of the energy cycle using water splitting to store
excess solar electrical energy and fuel cells to provide the electricity during
the low peak period
 Hydrogen is an ideal energy carrier for renewable energy storage

4.  Classification of water electrolyzers

5.  Solid Oxide Electrolysis Cells
 High-temperature solid oxide electrolyzers (SOEs) or solid oxide
elec-trolysis cells (SOECs) are electrochemical devices for the
efficient production of hydrogen or syngas as feedstock for liquid
fuels such as methanol, gasoline, and diesel using electricity and
unused heat from nuclear plants,steelmakers, or renew-able
energy sources.
Schematic diagrams of the operation principles of (a) solid oxide fuel cell
(SOFC) and (b) solid oxide electrolysis cell (SOEC)

6.  Effect of temperature on thermodynamic properties
of the water electrolysis process.

7.  Co-electrolysis of Steam and CO2 Via SOECs
Schematic of the proposed CO2-recycled synthetic fuel production process. –
CH2-represents a hydrocarbon. HX heat exchanger
 produces syngas (CO/H2 mixture) . Syngas is feedstock of liquid fuel
such as gasoline or diesel production by Fischer-Tropsch synthesis
route.

8.  Co-electrolysis of Steam and CO2
Continued

9.  Key Materials for SOECs
1)Electrolyte
The 8 mol% Y2O3-stabilized ZrO2 “yttria-stabilized zirconia” (YSZ) is
a commonly used high-temperature electrolyte material
2)Oxygen Electrode
Sr-doped LaMnO3 “lanthanum strontium manganite” (LSM)
perovskite oxide is a common oxygen electrode for high-
temperature SOECs
3) Hydrogen Electrode
Ni cermet is a state-of-the-art hydrogen electrode of SOECs