J. HOOPER, Senior Vice President, Electrification,
Automation, Digitalization, Siemens Energy
Like all process industries, the chemical sector is under
intense pressure to drastically reduce its carbon footprint and reach net-zero
emissions by 2050. While decarbonizing the process industries is critical to
resolving the energy trilemma—energy transition, security and affordability—achieving
this will be no easy task. Among all industrial sectors, the chemicals industry
is the largest energy consumer. Additionally, at 923 MMtpy of carbon dioxide (CO2)
emissions, it is third in direct carbon emissions (only the cement and steel
industries have a higher carbon footprint).1
In the medium to long term, transitioning from traditional
fossil fuel-based energy sources in favor of renewables and other low-carbon
alternatives will be critical to meet emissions targets outlined by the
International Energy Agency (IEA) and other organizations. However, this shift
cannot happen overnight. To this end, operators must begin looking at what
actions they can take to prepare their businesses for success in a
Enhancing the energy efficiency of existing assets via
modernization has proven to be one of the fastest ways to reduce a facility’s
emissions profile incrementally. Modernization projects can have a positive
impact, with many delivering CO2 reductions at costs as low as €10/t–€30/t.
This article highlights some of the specific technologies and
concepts the author’s company are seeing with its customers deploying and
discussing how the broader chemicals industry can benefit by embracing a more
collaborative engagement model regarding decarbonization.
exchanges (BEXs). Power generation and heat production are typically
among the largest sources of emissions for chemical facilities that do not
utilize grid electricity. This is particularly the case for sites with power or
cogeneration plants commissioned decades ago. BEX projects focus on replacing
obsolete equipment in these plants (e.g., gas turbines) to reduce emissions
while avoiding significant production disruptions.
In recent years, the author’s company has performed major BEXs
for industrial customers worldwide. One notable project commenced in a 2019
agreement with BASF to upgrade a combined-cycle (gas-fired) power plant at a
chemical production site in eastern Germany. The project aimed to reduce
overall emissions from the power plant and enable BASF to expand its onsite
production capacities sustainably. Another objective was to provide the basis
for future integration with renewable energies.2
The project involved replacing a decades-old gas turbine on one
power line with a more fuel-efficient unit: in this case, the SGT-800
industrial gas turbine. This enabled BASF to increase the plant’s output from
45 MW to 52 MW. In addition, the existing generator in the plant was
modernized. The author’s company also installed a battery energy storage system
for emergency power supply and to enable the black start of the power plant
without relying on external sources.
Together, the combination of the new gas turbine and refurbished
generator, along with other facility upgrades, resulted in a 10% increase in
the efficiency of the power plant. This translated into lower fuel costs per
kilowatt-hour (kWhr) and greenhouse gas (GHG) emissions reductions of
approximately 16%. All of this occurred without interrupting production at the
surgery of sorts.
For many facilities, replacing aging gas turbines
also opens additional opportunities for emissions reductions by burning
residual gases such as hydrogen (H2) in combination with natural gas
The SGT-800, for example, is already capable of burning fuel streams with up to
75 vol% H2. By 2030, the author’s company intends to have gas
turbines operating on 100% H2 fuel. This includes installed units, designed
to allow for future conversion to 100% H2 if/when it becomes
Use of industrial
heat pumps. Over the next three decades, industrial heat demand
is projected to grow by nearly 30% above its current level. Today, most heat generated for chemical production processes is produced via natural
gas-fired boilers, resistive heaters, or extracted from hot exhaust streams of
gas or steam turbines in combined heat and power plants.
While these equipment setups are proven and often highly
efficient, modern heat pumps can sometimes represent an even more efficient
option—with coefficients of performance (COP) > 4. This means four times as
much heat energy is provided to the heat sink than the electricity
industrial-scale heat pumps (FIG. 2) can achieve temperatures
of up to 150°C with pressure ranges of up to 5 bar. Temperatures as high as
300°C and pressure levels up to 85 bar are possible when combined with steam
compression. These capabilities are well within the range of many batch
processes’ heat demands. Real-world installations have demonstrated that even
with steam compression, which reduces efficiency, an overall COP of 3 can still
By replacing traditional boilers with modern electrically driven
heat pumps, the need to burn gas is significantly reduced, resulting in a
corresponding decrease in direct plant emissions. In some cases, operational
expenditure (OPEX) is also reduced because electricity can be purchased at a
lower cost than gas.
with hybrid drives. Generating the necessary horsepower for process
compressors can significantly reduce emissions and OPEX for a chemical
facility. Selecting the type of machine to perform this duty has historically
been a choice between an electric motor- or a mechanical-drive solution, such
as a gas turbine. In certain cases, a compelling case can be made for combining
one or more mechanical drive components with an electric motor (or motor generator)
into a single hybrid/dual-drive train.
A hybrid/dual-drive provides added operational flexibility by
allowing producers to use either grid electricity or gas as an energy source
for compression, whichever is more beneficial at the time. Many oil and gas
facilities already capitalize on this concept by installing two separate compression
trains (one motor-driven and one mechanically driven). A hybrid system serves
the same purpose, often with a corresponding reduction in capital expenditure (CAPEX)
because the requirement for ancillary infrastructures, such as foundations,
piping, wiring, cabling, electrical systems and balance of plant, is
One example where a hybrid drive can be especially impactful in
terms of emissions reductions is when renewables make up a large part of the
grid’s power generation mix. In such cases, the use of electric motor-driven
compression is attractive. However, the inherent intermittency and instability
of the grid means that some form of reliable backup is needed. Electricity
costs during peak hours can also be extremely high.
With a hybrid drive, an operator can use the electric motor to
drive the compression train during off-peak hours, presumably when the grid is
stable and prices are low. If electrical power is unavailable or becomes
cost-prohibitive, the mechanical drive gas turbine installed on the opposite
shaft end of the compressor can be started up. In this way, plant operators can
ensure that contractual obligations for production are never in jeopardy.
The electric motor can be designed to dually work as a generator,
which means that any extra energy from the gas turbine after compression duties
are met can produce electricity. The electricity can be used onsite if needed,
or it can be sold back to the grid.
In recent years, the author’s company has installed hybrid
drives for oil and gas customers, including upstream production sites, liquified
natural gas (LNG) plants, pipeline stations and refineries. The concept can
also be applied to exothermic chemical processes that utilize steam turbines
and hot gas expanders.
utilization and storage (CCUS). If boosting plant efficiency helps decrease a
facility's emissions, CCUS offers a way to avoid them altogether.
Much of the chemical industry’s carbon emissions stem from steam
methane reforming (SMR), where syngas (H2 and carbon monoxide) is
produced from natural gas at high temperatures and 20 bar–30 bar pressures.
This is still the most widely used method of producing H2—gray H2—if the CO2 is
released directly into the atmosphere. However, the emissions can also be
compressed and sequestered for storage underground or reclaimed for further
usage. H2 produced via this method is often referred to as blue H2.
In certain areas, there may be opportunities to combine captured
CO2 with zero-emissions green H2 to produce
climate-neutral eFuels, such as eMethanol or eAmmonia. However, because green H2
production depends on low-cost renewable electricity, eFuel plants are only
commercially viable in very select regions where conditions are favorable.
The author’s company is involved in developing several such
projects, such as a partnership with Sweden-based Liquid Wind AB to develop an
eMethanol plant in Sweden (FIG. 3). The plant will use an electrolyzer powered by
renewable energy to split water into green H2 and oxygen. The green H2
will be combined with CO2 captured from the flue gas of a nearby biomass plant
to yield carbon-neutral methanol.3
As much as 70,000 tpy of CO2 will be captured at the
facility and combined with green H2. The plan is to produce 50,000 tpy
of carbon-neutral eMethanol. Methanol will replace hydrocarbon fuels in
shipping operations, preventing the emissions of approximately 100,000 tpy of CO2.4
As global demand for eFuels and other feedstocks derived from CO2 increases, it
is likely that similar opportunities for sector coupling in the chemicals
industry will emerge.
partnerships. Successfully navigating the energy transition and
achieving deep decarbonization is not something any single company can achieve.
Instead, it will require a long-term vision and collaboration from many
stakeholders across process industries.
In improving energy efficiency, the chemical industry can
benefit from forming strategic partnerships with suppliers and original
equipment manufacturers (OEMs) that fully utilize each respective party’s
strengths. Producers certainly possess the engineering and project management
experience to drive successful modernization projects; however, the expertise
of technology providers is also needed to identify synergies and optimize systems
around any potential constraints.
The energy transition is the most effective investment program
since the dawn of industrialization. Co-creation is needed to achieve the best
possible outcome. If governments, businesses and society work together, energy
transition represents a great opportunity. HP
JENNIFER HOOPER is the SVP for Siemens Energy’s
Electrification, Automation and Digitalization group for the Transformation of
Industry Business. She joined Siemens Energy in 2020. Prior to this, Hooper
held positions of increasing responsibility with TechnipFMC (formerly FMC
Technologies Inc.). She earned an MBA from the University of Saint Thomas in
Houston, Texas, U.S.