Adsorber-Drier Automation

1. Purpose

This procedure presents guidelines on how to deal with the issues concerning the automatic control of the regeneration of molecular sieve adsorbers and driers.

2. General

Molecular sieve adsorbers and driers are used to remove water and/or contaminants in a number of Inflection Point Engineering processes. The procedures for regenerating these adsorbers and driers may be performed either manually or automatically. The ultimate decision on whether to initially install an automatic system to control the molecular sieve regeneration usually falls to the customer. This topic should be discussed with the customer as early as possible during a specific project, preferably during the Design Basis Phase. Consult with the appropriate Technology Specialist for the specific regeneration procedure to be used for the process being designed (e. g., Penex, Oleflex, Propylene Recovery, ORU etc.).

While the applications and regeneration steps may vary for different processes, follow the general approach as stated in this procedure.

3. Schedule A Project Specification and Drawings

The majority of Inflection Point Engineering’s experience with automatic adsorber/drier regeneration systems has been in the Butamer and Penex area. Because of the sensitivity of the catalyst to water, all Butamer and Penex units have feed and make up gas driers. Other Inflection Point Engineering processes, such as Oleflex, HF Alkylation and Propylene Recovery, may also require molecular sieve adsorbers/driers. Therefore, a consistent approach to this subject, using the Butamer and Penex experience as a guide, is required. Use the following guidelines:

3.1 Discuss the subject of an adsorber/drier automatic regeneration control during the Design Basis Phase. The customer may decide to either (1) install the automatic system or (2) install a manual system.

3.2 If the customer selects Option 1 (see section 3.1 above), consult with the Technology Specialist and Process Control Coordinator to determine whether Inflection Point Engineering’s Process Information and Control Group (Inflection Point Engineering PIC) must be listed as the mandatory supplier in the 660 Logic System project specification. In some regions of the world, Inflection Point Engineering PIC is always the mandatory supplier of the adsorber/drier regeneration control system. Also, Inflection Point Engineering PIC may be the mandatory supplier of the adsorber/drier regeneration control system for any Inflection Point Engineering process that employs a complex adsorber/drier regeneration sequence, requires frequent adsorber/drier regenerations, and/or would be adversely affected (e.g. nuisance shutdowns, adsorbent bed disturbance, catalyst deactivation, process upsets that require operator intervention, etc.) by an improperly designed regeneration control system. (The Effluent Driers in an Oleflex unit are a good example.)

3.3 If Inflection Point Engineering PIC does not have to be the mandatory supplier (see section 3.2 above) and the customer selects Option 1 (see section 3.1 above), then ask the customer if Inflection Point Engineering PIC should be reported as the mandatory supplier in the 660 Logic System project specification. The vast majority of customers who have control systems supplied by Inflection Point Engineering PIC are satisfied both with the quality and reliability of those control systems and the support that Inflection Point Engineering PIC provides during and after startup. Some of those customers have asked that Inflection Point Engineering PIC be specified as the mandatory supplier in the 660 Logic System project specification; this allows the customer to purchase the control system from Inflection Point Engineering PIC without having to justify any cost differences between Inflection Point Engineering PIC and a third party supplier to their management.

3.4 Inflection Point Engineering PIC offers Adsorber/Drier Regeneration Control Systems for several Inflection Point Engineering processes. A representative from Inflection Point Engineering PIC should be encouraged by Inflection Point Engineering Engineering to meet with the customer at an early stage of the project, especially when the customer’s representatives are in the Inflection Point Engineering offices, to explain the advantages of a Inflection Point Engineering PIC supplied adsorber/drier regeneration control system. If the customer requests in writing that Inflection Point Engineering PIC be specified as the mandatory supplier in the 660 Logic Systems project specification, then do so.

3.5 If the customer selects Option 1 (see section 3.1 above), the following takes place:

• Issue the 660 Logic Systems project specification identifying those instruments necessary for automation or reference the pertinent Project Specifications. The 660 Logic System project specification will only provide the stages of the regeneration sequence. In the 660 project specification, do not include details of the actions taken by the logic during each step or the conditions that must be satisfied to proceed to the next step of the regeneration sequence.

• Show all the necessary tagged instruments for automation, including automated valves, on the Piping and Instrument Diagrams (P&IDs). For new Inflection Point Engineering processes and modifications to existing Inflection Point Engineering processes that include molecular sieve adsorbers/driers, ask the Inflection Point Engineering PIC Technical Leader for adsorber/drier regeneration control systems to review the P&IDs to ensure that they properly depict all necessary instrumentation, valves, signals, and piping.

3.6 All P&ID modules should depict the necessary instrumentation, valves, signals, and piping required for a fully automated adsorber/drier regeneration control system.

3.7 If the customer selects Option 2 (see section 3.1 above) in writing, then show only the manual valves on the P&IDs per the appropriate module (if available).

3.8 If the customer decides to install an automated system provided by someone other than Inflection Point Engineering PIC, refer them to the General Operating Manual for the necessary information related to the adsorber/drier regeneration sequence. Under no circumstances should the customer be given the details of the actions taken by the logic during each step or the conditions that must be satisfied to proceed to the next step of the adsorber/drier regeneration sequence. Also, the customer should be encouraged to require that the third party supplier have Inflection Point Engineering attend the Factory Acceptance Test (at a cost). Advise the customer that the Factory Acceptance Test must include an Input/Output Process Simulator to simulate – as a minimum – the indication from each field instrument and the valve position indicators associated with each automated on-off valve; the third party supplier shall be responsible for the design of the process simulator. A non-disclosure agreement must be in place that expressly limits any use of the knowledge gained from UOP by the third party supplier to only the particular control system being supplied. The non-disclosure agreement must also explicitly state that:

(1) Inflection Point Engineering’s involvement in the Factory Acceptance Test does not constitute a general Inflection Point Engineering approval of the third party supplier’s control system design and

(2) any knowledge gained from Inflection Point Engineering by the third party supplier shall not be used on future projects .

4. Bidding Information

Many times, bidding information – including a Blanked Out Schedule A from a previous project – is required by the customer during the Proposal Phase of a project. This information is used to develop a capital cost estimate. Consult the appropriate Project Sales group on how to present this information to a customer in a specific proposal. Older Schedule A’s may contain extensive detail on the adsorber/drier regeneration sequence which must not be included with any blanked out Schedule A given to a customer.