Chemical Engineering January 2022 - 27

Scale-up and production. The
Syntegra PUD family was commercially
launched in microfiber applications
in 2020, which has total addressable
market of 300,000 metric
tons (m.t.) in China.
Sapphire Technologies
tion and reduction of CO2 emissions.
Commercial implementation.
In
HONOR ACHIEVEMENT
Sapphire Technologies:
FreeSpin turboexpander
Sapphire Technologies, a subsidiary
of Calnetix Technologies, has
brought to market an axial flowthrough,
magnetic bearing, turboexpander
generator (Figure 5) for
pressure reduction energy recovery.
The FreeSpin In-line Turboexpander
(FIT) generator offsets carbon emissions
and improves the transmission
efficiency of natural gas pipelines by
recovering high-pressure energy at
pressure reduction stations (PRSs)
and converting it into electricity. A
single unit can offset up to 1,200
tons of CO2-equivalent (CO2e)
emissions and generate 2.5GW of
power per year. Market barriers of
entry for this technology have been
brought down by this invention for
its small footprint, non-contact operation
(magnetic bearings), zero
maintenance, hermetic sealing and
minimized capital cost.
Natural gas pipelines consume
energy by compressing natural
gas for high density, high efficiency
transport. A significant portion of
upstream compressor energy consumption
is recoverable through
a turboexpander generator downstream.
Expansion downstream is
achieved through a Joule-Thomson
(JT) valve, providing an adiabatic
pressure drop for the gas. To prevent
pipeline freezing from the JT effect,
gas pre-heating is implemented
upstream from decompression to
raise the gas temperature before JT
expansion,
an energy-consuming
process. Instead of losing pressure
reduction and heating energy to the
environment,
the
turboexpander
generator recovers the energy by reduction
of pressure and enthalpy.
Sapphire's FIT uses a radial inflow
expansion wheel to convert the gas
stream energy into rotating energy
and then transmits the energy to
the permanent-magnet rotor. The
generator then converts the rotaFIGURE
5. Shown here is Sapphire's FreeSpin Inline
Turboexpander (FIT) system
tional energy into electricity that is
transmitted to the variable-speed
drive (VSD). The VSD conditions the
electricity to match the voltage and
frequency of the local grid. The produced
electricity can then be used to
offset facility electrical burden or for
sale to the local electric utility.
In August 2019, outside of Bologna,
Italy, a partnership between
BHGE Nuovo Pignone and Calnetix
in the installation of first turboexpander
generator at a natural gas
PRS was the basis for forming Sapphire
Technologies. This installation
proved successful, producing 95%
of the designed power generation.
The installation paired a transcritical
CO2 heat pump for gas pre-heating
instead of a natural gas boiler, further
increasing the system efficiency. In
February 2021, the second and third
FIT systems were installed at a PRS
in Japan with a Japanese gas utility
within 1 week of delivery, proving the
ease of hardware installation.
An estimated 5,000 natural gas
pipeline PRSs exist in the U.S. alone,
all with the capability of FIT installation.
These PRSs have the capability
to produce power from several hundred
watts up to several megawatts.
Assuming a single FIT is installed at
each of these stations, 12,500 GW
of power can be recovered or 6M
tons of CO2e emissions reduced.
That's enough power for 1.17M U.S.
homes, according to the U.S. Energy
Information Admin. (EIA) 2019 average
residential home annual power
consumption, or to convert 370,000
people to net-zero CO2e emissions
per year according to " Our World In
Data 2019 " carbon footprint report.
With applicability to hydrogen and
other compressed gases, the FIT will
play a key role in maximizing efficiency
of consumer gas energy consumpCHEMICAL
ENGINEERING WWW.CHEMENGONLINE.COM
JANUARY 2022
2019, Calnetix and BHGE Nuovo
Pignone commissioned a 300kW
turboexpander generator designed
to recover energy during pressure
let down at a city gate station outside
of Bologna, Italy. Calnetix provided
the active magnetic bearing
system, PM generator, and power
electronics while BHGE provided
the turboexpander housing, aerodynamic
section, and skid. This was
the first natural gas turboexpander
project that sparked the interest in
developing a product.
From 2019 to 2021, amidst the
pandemic, Sapphire completed the
development, building and deployment
of the first FIT units to be installed
at a LNG terminal station in
Nagoya, Japan. Two units are currently
being commissioned: a 125
kW and a 280 kW, in parallel, producing
a total of 405 kW.
During the development of the first
FIT systems, Sapphire Technologies
was established with the intent of
delivering pressure to power solutions
for the pressure reduction industry.
Backed by Calnetix engineering
and 80+ patented technologies,
Sapphire's FIT product is poised to
provide a safe and reliable turboexpander
product for a broad scope of
pressure let down applications.
The FIT provides a way to capture
the energy lost in pressure reduction.
The FIT generator extracts kinetic
energy from the pressure reduction
and allows for the generation of electricity
with no added pollution.
The FIT consists of a high-performance,
high-speed permanentmagnet
generator with an integrated
radial in-flow expansion turbine and
low-loss active magnetic bearings
(AMBs). The FIT is designed to have
the process gas flow through the
system, which cools the generator
section and eliminates the need
for auxiliary cooling equipment. The
power electronics for FIT combine
the variable speed drive (VSD) and
magnetic bearing controller (MBC)
into one cabinet. The VSD allows
for a consistent and clean delivery
of generated power from the FIT to
the grid.
n
Edited by Gerald Ondrey
27
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Chemical Engineering January 2022

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