H2Tech - Q2 2022 - 33

CAPITAL PROJECTS
Blue H2 co-generation with synthetic fuels
S. KRESNYAK, Rocky Mountain GTL Inc., Calgary, Alberta;
and J. WAGNER, Wagner Energy Consulting, Calgary, Alberta, Canada
H2 possesses a greater energy density
than natural gas, gasoline or diesel: with
the world moving increasingly towards decarbonization,
there is little doubt that H2
has a major role to play. Ultimately, the H2
economy is expected to rely on electrolytic
green H2
carbonization; however, green H2
, which will provide complete decannot
presently
compete economically with H2
derived from fossil fuels. Because of this,
the majority of H2
production now utilizes
While
from 10 kg-12 kg
.
a steam methane reforming (SMR) process
and a natural gas feedstock.1
this is unlikely to change before 2030, preand/or
post-combustion carbon management
systems can reduce the carbon intensity
(CI) of this H2
CO2e/kg H2
to low-emissions blue H2
to 3 kg-6 kg CO2e/kg H2
will provide
This transition from high-emissions gray
H2
an interim solution while zero-carbon
green H2
technologies mature. This article
alongside high-quality synSplit
natural gas into H2 and CO2
showcases a new method for co-generating
blue H2
thetic fuels, providing maximized energy
output with reduced carbon emissions
and need for carbon sequestration.
Production of syngas for blue H2
gas (H2
. Syn+
CO) feeds are necessary for a
number of chemical production processes
(e.g., methanol, synthetic fuels, ammoniabased
fertilizers).2
Any of three technolo:CO
ragies
can be used to generate syngas from
natural gas, depending on the H2
tio desired. The technologies available for
deployment and the syngas compositions
they produce are as follows:
* SMR: 3 H2
-5 H2 per CO,
but has ability to generate
a 2.4 H2
:CO ratio
* Autothermal reforming (ATR):
1 H2
-2.4 H2 per 1 CO
* Gasification/partial oxidation
reforming (POx): 1 H2
per 1 CO.
Steam
CO2 emitted in the atmosphere
FIG. 1. Types of H2
CO2 stored or reused
No CO2 emitted
Split natural gas into H2 and CO2
Split water into H2 by electrolysis
powered by water or wind
When the desired end product is H2
using a water-gas shift
,
the CO portion of the syngas is converted
to CO2
(WGS) reaction. The resulting CO2
then separated from the H2
is
and either
released or captured and sequestered.
Alternately, the WGS conversion process
can be omitted, and the raw syngas
synthesized into synthetic methanol,
Fischer-Tropsch (FT) diesel or jet fuel.
These synthesis conversion processes
require a syngas composition of ~2 H2
per CO mole ratio, meaning that syngas
generated via SMR would contain H2
in
Gray H2
Blue H2
excess of need. A membrane separation
process can be used to trim the syngas to
the desired composition, and the newly
separated H2
used as fuel for the process
or removed and utilized in other processing
units. This alternate method has
significant advantages for blue H2
production,
including:
* Produces blue H2
6 kg CO2e/kg H2
with a CI of
and without
immediate need for postcombustion
carbon capture
* Substantially all carbon from the
process inlet feed is fully converted
Green H2
.
H2/CO ratios of 1 to 5
produced depending on
fuel and syngas process
Purified H2 for
reuse, further
purification, or fuel
H2/CO ratios of 1 to 2
needed depending on
product
Syngas
production
(gasifier or
reformer)
Hydrocarbon feed (natural gas,
refinery waste, coal, etc.)
FIG. 2. Synthesis process flow schematic.
H2Tech | Q1 2021 33
Crude
syngas
Membrane
Adjusted
syngas
Syngas derivatives
MeOH production
Oxo-alcohols
Power turbine
GTL
H2Tech - Q2 2022

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