Today we find ourselves in the midst of an energy revolution, with the general landscape of the industry changing and an increasing number of renewable energy, carbon capture and bio fuel sources entering the supply grid.

The energy industry’s move to greener solutions includes the global scale-up of green and blue hydrogen, LNG carbon capture possibilities, wind, solar, tidal and nuclear; all bringing new challenges and opportunities to the supply chain as we transition towards net-zero.

Global commitments to clean energy supply have had a significant impact on the supply chain.

Heat exchangers perform fundamental and essential heat transfer operations for numerous oil and gas applications.

To support the drive to net-zero the design requirements of this basic product have changed significantly. This is due to increasing demands for higher operating pressures and temperature resistance, coupled with requirements for new materials capable of withstanding harsher process conditions and new working fluids.

THE GREEN TRANSITION

Meggitt produces PCHEs using a compact diffusion bonded design

The supply chain has a growing responsibility to support the oil and gas majors as they transition towards decarbonisation and greener technologies. Public and government demand for solutions to climate change has never been so intense.

The range and rate of associated development and funding to find alternative ways of delivering ‘greener’ power or removing carbon from existing processes is growing exponentially, with increasing demand to supply clean energy systems with minimal environmental impact.

The variety of clean energy technologies under consideration has opened up many possibilities for the supply-chain to advance existing technologies and provide flexible solutions to support the variety of processes in scope.

Heat Exchangers are a key enabler for almost all of the available solutions and technologies.

Meggitt’s Heatric division produces Printed Circuit Heat Exchangers (PCHEs) using a compact diffusion bonded design, which is uniquely capable of meeting the evolving requirements of these new processes and applications, providing space and weight savings, high thermal effectiveness, low pressure drop and high design pressure capability.

In summary, Heatric’s PCHEs meet the needs of traditional applications, generating a reduction in topside space, weight and high thermal effectiveness, whilst also benefiting new applications such as carbon capture and cryogenic energy storage.

Investment and shared learning are the cornerstones for those engineers seeking to advance what was once impossible.

In pursuit of net-zero, oil and gas suppliers have found new ways to support the drive for cleaner energy by reducing emissions in traditional power generation.

One example is carbon capture utilisation and storage (CCUS), which makes use of captured carbon dioxide (CO2) from other processes to maximise resource recovery for existing oil and gas production. Additionally, waste output can be captured and sold to be used for other industrial applications.

Improving operating efficiency is another way of contributing to the net-zero agenda. Digitisation and improved health monitoring are leading the way in this area.

Optical sensing solutions have been designed to drive improvements in efficiencies and emissions through more accurate monitoring of static equipment, such as heat exchangers.

This enables energy producers and facility operators to make better informed decisions about existing processes, allowing them to spot areas for improvement and recognise potential issues before they become urgent, such as a fall in performance by monitoring pressure conditions. It also allows for the usage of predictive maintenance to identify potential failures to prevent leaks or damage.

BOOSTING POWER CYCLE EFFICIENCY

PCHEs are already well-established in the upstream hydrocarbon processing, petrochemical, and refining industries.

Customers such as Petrobras, BP, Shell, and ExxonMobil rely on Heatric PCHEs for a range of applications around the world. There are more than 3,000 PCHE units in operation, with some serving for nearly a quarter of a century.

The compact heat exchanger design is capable of operating at both high temperatures and high pressure with a very close temperature approach.

PCHEs have attracted the attention of many design engineers and research laboratories involved in the development of more efficient power conversion cycles including SCO2 Brayton Cycles, such as the Allam-Fetvedt Cycle.

In a traditional gas-powered energy plant, burning gas creates steam, which turns a power generating turbine. It’s a chemical process that results in an excess of harmful CO2 emissions.

In the Allam-Fetvedt Cycle, the super-critical CO2 (in liquid state) is used as the main fluid in the turbine rather than steam or air. This process effectively turns the problem of wasted emissions into a solution.

Super-critical CO2 is used to spin the power generating turbine as part of an entirely closed loop system. That means most of the high-pressure CO2 is reheated in the heat exchanger and returned to the combustor, where the whole cycle begins again.

It’s a recuperated, high-pressure, Brayton cycle employing trans-critical CO as the working fluid with oxy-fuel combustion. The carbon dioxide never enters the atmosphere and is captured for storage or use in other applications, increasing the routes to profitability for plant owners as waste materials can be sold on for other uses.

Several pioneering trials are underway to perfect this process to not only improve overall efficiency but also to maximise the cost-effectiveness of the technology.

OPTIMISING DESIGN & DEVELOPMENT

One of the keys to successful heat exchanger design for such applications is understanding the economics of developing a product that meets each market price point and technically allows the customer as broad a range of operating temperature to improve and optimise efficiency.

Current PCHE designs for such systems are made from an Inconel alloy capable of withstanding temperatures in excess of 750 deg C. Such materials are exotic by nature and, therefore, comparatively expensive compared to traditional material such as austenitic stainless steel. Different elements of the heat exchanger could be optimised using separate material.

To support design processes, 3D printing is rapidly becoming an established manufacturing technique in other industries such as aerospace, automotive and medical. However, the energy industry is relatively slow on the uptake.

Future designs could employ additive layer manufacturing (ALM) processes to meet developing customer requirements for producing heat exchangers in a more cost-effective way.

ALM heat exchangers would allow project owners, operators and governments alike to reach both their clean air and cost per kilowatt (kW) installed targets at a rate currently not available from existing technology.

One of the main barriers to this technology being deployed at scale is the lack of common accepted technical standards across the industry.

History shows the energy industry can be conservative in the face of such sudden technological change, but given the hunger for an available solution and the growing global emission targets, solution providers need to engage with the market quickly to meet demand and progress the journey to clean energy.

The oil and gas industry is facing a fundamental transition from traditional fossil fuels to nuclear, carbon capture, biofuels and renewable solutions. The demands of this green technology revolution will continue to drive the development of heat exchangers capable of operating at extremes for both conventional oil and gas applications but also to serve the increasingly growing needs of the net-zero revolution.