Design and documentation issues of the process package

The low-temperature methanol washing process package is a process package jointly developed by Lurgi and Linde, with the main steps being condensation, absorption, and desorption. The task assigned to the design institute with the process package is to transform the theoretical chemical engineering concepts into engineering designs and produce the corresponding design drawings. If this process part is part of a process package, it should have been provided all at once; otherwise the process package would be incomplete. It depends on how it’s specified in the contract.

The process package provided by Luchi should be sufficient for basic engineering design, right? The design institute carries out detailed engineering design on this basis.

There is still much work that the process package design team needs to complete. The process package information is certainly provided in stages. Based on the date when the technical agreement is signed, details such as PFDs, PID diagrams, and information regarding the main equipment – like the number of towers and large pumps – are provided within two to three months. Once these details are established, there are usually no major changes; only minor adjustments may be made later. After another month, information regarding the remaining equipment such as heat exchangers, tank pumps, etc., along with layout plans and automation requirements, is provided in stages. The design team needs to refine the contents of the process package to provide the necessary information for other teams to carry out their work, as well as handle matters related to interface connections, among other things. The workload is quite substantial

Thank you so much. I now understand a bit better: the process package provides various parameter values for the main equipment and other items, and the design institute needs to take into account the actual parameters of the equipment purchased as well as the actual operating conditions in order to design appropriate margins in all aspects?

I would like to know that too; I hope for a more detailed answer.....................

This post was last edited by zhouhuahui on 2012-5-28 at 11:20. The three key requirements for process engineering are: equipment conditions, piping conditions, and automation control conditions. When it comes to equipment, there are generally no major issues with the calculations outlined in the process package, as extreme operating conditions have been taken into account. Nevertheless, the design institute still needs to evaluate each piece of equipment individually before specifying its requirements, after all, even foreigners can make mistakes. Regarding piping, the settings for PID controllers in some areas, as well as certain pipe diameters, may not be appropriate; further calculations are needed before specific requirements can be established for the piping. The same applies to automation control. The information contained in the process package actually reaches a level equivalent to that of basic or even detailed engineering designs. But even if it reaches the level of detailed design, the design institute still needs to re-evaluate many aspects. Moreover, this only covers the process package for one unit alone; coordinating it with upstream and downstream units also requires careful attention. There are also many pieces of equipment that need to be negotiated and purchased. So the workload for the design institute is quite substantial. It might seem like nothing much, but other departments and the client keep calling every day to confirm various details – it’s really annoying!!

Hehe, there are indeed a lot of things to take care of. Thank you for such a detailed answer!

To find a process package, in addition to some equipment calculations, PFDs, and PID files, are pipe characteristic tables and instrument specifications also included? Should we still wait for the design institute to handle it?

I know how the design institutes handle Linde’s methanol washing process package; I think Lurgi’s approach is similar! This process package is essentially detailed to the level of basic design. For PID, simply calculate the sizes of the inlet and outlet of the safety valve; after ordering the control valve, update the sizes of the inlet and outlet flanges. For the pump, calculate the NPSH using the data provided by the manufacturer. The other tasks mainly involve reviewing the process package, and then, in accordance with the requirements of that package, carrying out procurement or detailed design work for equipment, instruments, pipelines, mechanical devices, and electrical systems. If there is a conflict between the supplier’s documents and the PID in the process package, the PID is updated after evaluation.