Nov-2022

Hydroprocessing catalysts sulphiding with DMDS: Carelflex® Connect brings more than IIoT (ERTC)

Two years after the launch of its new digital Carelflex® service, Arkema has greatly improved the content of its digital platform known as Carelflex® Connect. An intuitive design eases its use, and a private instant messaging service has reinforced communication between the on-site Arkema team and refinery representatives.

Francis Humblot
Arkema

Article Summary

Catalyst sulphiding with DMDS and Carelflex® service
Hydrotreating (HDT) catalysts must be converted to their sulphide forms to get the desired activity. This is traditionally carried out during unit start-up by injecting a sulphiding agent into the feedstock called dimethyl disulphide (DMDS). DMDS has 68 wt% sulphur and is efficiently converted to hydrogen sulphide (H₂S) on the hydrotreating catalyst under standard sulphiding conditions. H₂S reacts immediately with HDT catalysts that become increasingly active until all active metals are fully sulphided. Over the years, DMDS has shown superior performance and has become the industry standard solution.

For the last 30 years, Arkema has supported the development of DMDS refinery applications by offering a service to safely handle and carefully inject the DMDS, following the procedure of the hydrotreating catalyst manufacturer. A major improvement has also been achieved with the use of in-line H₂S analysers (see previous articles in ERTC newspapers in 2017 & 2018) that address a safety concern on the use of a reactive tube that would otherwise create a potential for exposure to H₂S for workers. Moreover, Arkema’s H₂S analysers offer a continuous H₂S measurement that allows the refinery to anticipate the DMDS flow rate and reactor temperature changes, saving time and significant DMDS volumes.

Why offer a digital Carelflex service?
Previously, DMDS data (H₂S concentration, flow rate, and cumulated amount injected) were shared by the Carelflex® operator with the refinery regularly and on demand. However, thanks to the latest advances in data management and communication, it is possible to collect all these data, format them, and make them available to the refinery on a real-time basis (see Figure 2). This advanced service was introduced in Europe two years ago (See 2020 ERTC newspaper) and has grown quickly. Within less than two years, 50% of European refineries have shifted to real-time data transmission and communication using Carelflex® Connect, improving their sulphiding time by up to 20%.

A full digital project to meet refinery expectations
While real-time access to key data of DMDS catalyst sulphiding has been a great success, Arkema rapidly understood that the catalyst sulphiding and unit start-up would benefit from a more advanced communication tool between the experienced on-site Carelflex® team and the refinery production team. As a result, in 2021 Arkema launched a secured and temporary instant messaging service (see Figure 3) for each Carelflex® Connect operation that includes:
• Secured access: a list of users is agreed with the refinery one week before and cancelled two weeks after completion of the operation. Catalyst supplier representatives may be given the same access when requested by the refinery.
• Artificial Intelligence (BOT): The BOT uses the Chat function to send the latest value of DMDS and H₂S concentration data on demand. The refinery team use the BOT to send instructions to the Carelflex® team, who acknowledge receipt from their tablets on site. Moreover, any DMDS flow rate change is automatically reported to the refinery team on the Chat by the BOT.
• User-friendly platform: the instant messaging service provider Citadel™ is available through a web page or mobile phone app and can be checked at anytime. Any member of the user group can check the entire Chat at anytime: it enables, for example, any refinery team member to track and understand the history of DMDS flow rate changes and related instructions upon the start of their shift.

“Arkema’s H₂S analyser and digital platform greatly improved the efficiency of hydroprocessing units’ start-up sulphiding operations. These elements streamlined the process engineer’s focus and resources on critical unit parameter adjustments. Looking forward to these proven value-adds for future sulphiding operations.”

These positive comments and the success of the advanced digital service have prompted Arkema to pursue investments in additional digital features that will ease the information exchange to prepare the on-site service, collect refinery feedback, and promptly issue the final mission report. At the same time, in 2022 Carelflex® Connect has been introduced in other parts of the world, such as the Middle East, North America, and Asia, where refiners welcome the application and adopt it rapidly.

This short article originally appeared in the 2022 ERTC Newspapers, which you can view HERE