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What heat and mass transfer technologies are helping the industry lower Opex?

Apr-2024

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Jesus Perez, Alfa Laval Packinox, jesus.perez@alfalaval.com

High efficiency heat exchangers such as welded plate exchanger technologies. Two particular ones were developed in the early 80's in France: Compabloc and Packinox. These are fabricated in state-of-the-art facilities incorporating robotic laser welding for high precision fabrication and are used by customers all over the world: US, China, India, Europe, Africa, Japan.

These products have gone through significant changes to improve operational reliability, robustness and clean ability. The use of corrugated plates provide a static mixer effect which increases fluid turbulence and surface shear stress resulting in less fouling compared to the hydraulic diameter of a circular tube.

Performance monitoring tools allow end users to predict fouling and plan outages minimizing economic impact.

May-2024
Kokil Jain, Advisian, kokil.jain.manchester@gmail.com

Following heat transfer technologies can reduce Opex in current context of high CO2 emission costs and avoided cost of CO2 capture investments:

1. Electric Heaters - low carbon, reduced distribution losses, faster response time, reduced fouling.

2. Vacuum based mechanical vapour recompression (MVRs) - Steam generation in vacuum would allow low grade waste heat (70-80°C+) to be economically converted into steam.

3. Polymer based air preheaters and economisers (e.g. from HeatMatrix) - allows heat recovery below acid gas dew point of flue gas (up to 90°C). Could improve furnace thermal efficiency by 3-5%.

Similarly, following mass transfer technologies would be relevant:

1. Membrane for oxygen enrichment from air (21% to 35% or 50%) - It can help in increasing CO2 concentration in flue gas and allow ambient air gasification of biomass waste sources.

2. Divided wall columns.

3. Use of N2 for Kerosene stripping - avoids downstream drying step.

3. Use of ultrasonic devices for fouling minimisation.

May-2024
Ujjal Mukherjee, Lummus Technology,

Some technologies that are especially useful include:
• New membrane technologies for separation and coil-wound heat exchangers.
• Air preheat systems that can significantly reduce energy consumption.
• Advanced integrated separation devices used in Lummus’ proprietary TC2C technology.
• The use of stripping media to eliminate expensive furnaces.

TC2C is a trademark of Lummus Technology.

Apr-2024
Jan Reneteau, Axens, Jan.RENETEAU@axens.net

Very high-efficiency heat exchangers are key to lowering the Opex of heavy energy consumption processes. While standard S&T technology can offer limited thermal performances, spiral tube heat exchanger technology greatly enhances thermal and hydraulic performances.
This technology has been used for many years in the cryogenic liquefaction industry. For more than 30 years, ZPJE has developed a unique state-of-the-art know-how of heat exchange calculation, hydraulic simulation, and mechanical modelling of spiral tubes design to enable this technology to be used in refining and petrochemical applications.

The design of spiral tube heat exchangers consists of many tubes arranged in multiple layers of helical coils, around a centre pipe. This tube bundle is enclosed in a cylindrical pressure vessel. The fluid on the tube side and shell side flows in opposite directions, making the equipment a true countercurrent heat exchanger, allowing a heat transfer efficiency two to three times higher than conventional S&T exchangers.

The minimum temperature difference between the two fluids can be as low as 2°C, permitting the unlocking of heat integration opportunities in demanding process services. Those exchangers can be applied in reforming, aromatics applications and also in hydroprocessing applications where their high performance and high tolerance towards fouling can drastically reduce the Opex, allowing, in some cases, the end user to operate the furnace only during start-up phases.

The newly created joint venture between ZPJE and Axens named Nectis aims to promote the application of spiral tube heat exchangers in the refining and petrochemical businesses to help the industry lower its carbon intensity.

Apr-2024
Caroline Bird, Solenis LLC, cbird@solenis.com

Heat exchanger efficiency is critical to the success of any industrial operation, yet many plants rely on outdated or inadequate data to assess the health of their heat exchanger networks. As digitalisation is slowly becoming accepted and explored in the industry, there are opportunities for refining and petrochemical operations to improve data management and lower operating expenses.

Digital monitoring of heat exchanger reliability and performance is allowing companies to identify problem heat exchangers and create appropriate action plans to optimise heat exchanger efficiency.

Solenis’ HexEval performance monitoring program for heat exchangers is an example of this digitalisation. The program allows plant operators to identify and monitor problem heat exchangers that are operating outside of set limits for fouling and scale. As a result, plant operators can address fouling and scale issues in real time to help avoid a plant shutdown or slowdown.

Additionally, Solenis’ HexEval program provides an online repository for all heat exchanger activity, allowing access to historical data when needed. This allows plant personnel to devise action plans to proactively address system issues, thereby maintaining plant productivity and generating operational savings. The utilisation of the HexEval program has enabled numerous Solenis customers to decrease corrosion and corrosion-related pitting, cleanings outside of turnarounds, and heat exchanger failures. Knowledge is power, and having the knowledge of their heat exchangers at their fingertips has enabled refining and petrochemical operations to significantly reduce their operating costs.

Apr-2024