Seven Stages of Chemical Engineering Technology from Concept to Industrialization (Issue 57/100) -- Final Review of the Process Package

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The seven stages of chemical engineering technology from concept to industrialization (Issue 57/100) —— Technology finalization: Final review of the process package and delivery of documents. Dear friends: Hello everyone! In the previous issue, we discussed the integration of the process flow description and the general manual; all technical documents have been prepared and approved through internal review. This phase represents the final key task in the entire fourth stage of technology finalization: the final review and delivery of documents. At this point, the process package development team has been working on this set of process packages for a considerable length of time. The PFD and PID diagrams have been drawn, the equipment data sheets and instrument data sheets have been filled out, the interlock logic diagrams and safety valve calculations have been completed, and the process flow description has also been written. What needs to be done now is to invite representatives from all parties to spend one or two days going through this entire set of procedures in detail. The review was passed, the process package was signed and delivered, and the technical finalization phase was officially completed ； If the review is not approved, it will be returned for modification before re-review. This review is the final comprehensive technical inspection before the delivery of the process package. The quality of the review directly determines whether subsequent engineering design will deviate due to defects in the process package. I. Purpose of the final review What is the difference between the final review and the previous PFD review and PID review? PFD review is to confirm the viability of the process design, while PID review is to confirm the feasibility of its engineering implementation. The purpose of the final review is more comprehensive—it aims to verify the integrity, accuracy, and consistency of the entire process package as a basis for subsequent engineering design. Integrity refers to the completeness of all delivery documents for the process package, with no omissions in their content. Accuracy refers to the fact that every piece of data in each document has a reliable source and has been verified. Consistency refers to the absence of any contradictions among different documents – between PFDs and PIDs, between PIDs and instrument data sheets, and between equipment data sheets and port numbers. The approval of the final version review means that all parties acknowledge this process package as the sole technical benchmark for subsequent engineering design. The basic design and detailed design will be based on it, equipment procurement will be based on it, and performance evaluation will also be based on it. Any disagreements or disputes arising from subsequent work will ultimately be resolved by referring to this document. Therefore, the review is not a technical exchange, but a technical acceptance. II. Composition of the review team The team for the final review is more comprehensive than those for PFD and PID reviews. My suggestion is to invite the following people to attend. Owner’s representative. They are the ones who ultimately pay for the installation, and they are concerned about whether the investment is within acceptable limits, whether the consumption metrics are reasonable, and whether the installation is easy to operate and maintain. The opinion of the owner’s representative often determines whether the review can be approved. Representative of the technology provider. If the technology is introduced from outside, the technology provider must participate in the final review. They need to confirm whether the data in the pilot plant data package has been accurately transferred to the process package, and whether the design conditions for the core reaction and separation units fall within the operational range verified by the data package. Industry experts. Invite one or two experts with extensive experience in this industry to examine the process plan from a third-party perspective. Industry experts are often able to identify issues within a project team that are not easily noticed by the team members themselves—because we are too familiar with the solutions we have designed, which makes it easy for us to overlook certain potential problems. Core member of the process package development team. Project managers, process supervisors, equipment supervisors, and instrumentation supervisors – they are the key figures who are questioned during the review, and must be able to explain the rationale behind each design decision. Lead reviewers for each specialty. The equipment reviewer checks the equipment data sheet and the rationality of the selection ； The instrumentation control supervisor verifies the accuracy of the instrument data sheets and interlock logic diagrams ； The safety and fire protection supervisor reviews the HAZOP reports, SIL classifications, safety valve discharge capacities, and fire protection measures ； The operator reviews the operability and maintenance space from the perspectives of operation and maintenance. The review lead is responsible for facilitating the review meeting, controlling the pace, and signing the review report; this role is usually filled by a senior engineer with extensive experience who is independent of the development team. III. Review Content The final version review is usually scheduled to last one to two days. The focus on day one is design fundamentals and core drawings. In the morning, the fundamentals of design are reviewed: project definition, plant scale, product specifications, boundary conditions, and the standards and codes upon which the design is based. Review PFD in the afternoon — three balance data, material flow tables, equipment operating conditions, and key control schemes. If there are many PIDs, it may need to extend into the next morning as well. The focus on the second day was equipment, instruments, and safety. In the morning, review the equipment data sheets and equipment lists, and conduct spot checks to ensure that the selection calculations for key equipment are reasonable and that the data is traceable. Next, review the instrument data sheet and interlock logic diagram—the independence of the interlock circuits, the configuration of SIL levels, and the correctness of the interlock actions. In the afternoon, review of HSE and analysis testing – the completeness of waste discharge data, the operability of the sampling system, and the basis for calculating the discharge volume of safety valves. Finally, summarize the review comments to draw up a review conclusion. During the review meeting, each specialty examined each item carefully, using the process package documents along with the pilot plant data packages and calculation sheets. Randomly check the temperature data of key logistics processes, inquire about the basis for calculating heat balance, and verify the correspondence between interlock diagrams and instrument data sheets – the purpose of review is to identify issues and bring all hidden problems to light. Finding an issue on the drawing and changing a value results in almost zero cost. Problems are only discovered after the device is built, and the cost of rework is hundreds or even thousands of times higher. IV. Classification and Handling of Review Comments: The issues identified during the review meeting are, similar to those found in the previous PFD and PID reviews, classified into three levels—A, B, and C—based on their severity. Grade A issues are those that must be corrected, as they affect safety, compliance, or design accuracy; the process package cannot be delivered until such issues have been resolved. For example, there may be obvious errors in the calculations for selecting a certain critical piece of equipment; sensors in a certain interlock circuit might be shared with the DCS; or the data related to a key flow path might not match between the PFD and PID. Such issues affect the foundation of subsequent engineering design, and they must be corrected and verified properly. Grade B issues are those for which modifications are recommended; they can be used without changes, but have shortcomings or room for improvement. For example, a certain heat exchanger may have excessive margin, the elevation of a certain operating platform needs to be fine-tuned, or the wording of a certain section of the process description requires greater accuracy. Such issues are to be rectified by the responsible party within a specified time frame; once the rectification is completed and verified, the case is closed, without the need to hold another review meeting. Class C issues are advisory in nature, and it is up to the process package development team to decide whether to adopt them. The review experts may propose some optimization suggestions based on their experience—for example, the strategy for a certain control loop could be adjusted, or the location of a sampling point could be fine-tuned. These suggestions are not mandatory for modification, but they deserve serious consideration. All review comments must be recorded item by item, responded to item by item, and the corrections confirmed item by item. It’s not an oral response at the meeting; it’s a written response—in which the outcome for each suggestion is clearly stated: whether it was accepted and how it was modified ； Not adopted; why not? This review comment and response record are important attachments at the time of signing and delivery of the process package. If disputes arise during project execution due to some design issue in the future, this record can be reviewed to see whether the review experts raised that issue and how it was handled once it was brought up. V. Document signing: From \"materials\" to \"benchmarks\". Once all Class A issues have been resolved and the review team leader confirms that the process is complete, the document signing stage begins. Representatives of all parties sign the general instruction sheet and the relevant signing pages. Both the print version and the electronic version are archived simultaneously; the electronic version is usually provided in PDF format as well as in an editable source file format. The act of signing carries significant legal and liability implications. The compiler of the process package assumes design responsibility for the technical content in the documents – by signing their name, they commit to ensuring that the data contained in this process package is accurate, well-sourced, and verified, and that subsequent engineering designs based on this package will enable the plant to safely achieve its performance specifications. The owner’s signature confirming receipt and acceptance of the completeness of this technology signifies the official approval of the technical solution by the owner. The technology provider confirms that the technical information it provided has been correctly engineered and expressed, without any misunderstandings or distortions. From the moment it is signed, the process package changes from a \"set of documents\" to a \"baseline\". It is no longer a draft that can be modified at will, but rather the sole technical basis for all subsequent engineering design work. Any modification, regardless of size, must go through the formal change management process. This process is the core discipline of project technical management and serves as the first line of defense against discrepancies between drawings and actual conditions. VI. Several common issues in the final review After conducting process package reviews for so many years, there are several issues that keep reappearing during the final review; I’m mentioning them in advance for the reference of all colleagues. One is the break in the data traceability chain. The review experts asked where the heat load of a certain heat exchanger came from, and the preparation team searched through all the calculation documents but could not find the source. Such problems occur in many projects, and the root cause is often the loss of the calculation process during data transmission. The solution is to conduct a preliminary check of the entire data trail before the final review, starting from the PFD and verifying the source of each piece of data in order to fix any broken links in advance. Another issue is data inconsistency between different files. The operating pressure indicated on the PFD is 1.2 MPa; the equipment data sheet states 1.5 MPa, while the PID shows 1.3 MPa – the same parameter has three different values in these various documents. During the review, someone will definitely ask, “Which one should be taken as the standard?” ”If the development team cannot answer, it indicates a gap in data management. This issue should have been resolved during the integration of the 56th edition of the general instructions, but if it was overlooked, the final review becomes the last hurdle. Another one is the gap between the performance guarantee values and the actual design data. Is there any contradiction between the production and consumption targets promised in the technical annex and the actual design data in the process package? If the technical annex specifies a maximum allowable steam consumption, and the value calculated from the heat balance sheet exceeds this specified limit, then this is an issue that needs to be resolved immediately; it must be adjusted so that it meets the specified requirements before the process package is delivered. VII. Conclusion of the technology finalization phase: Once the final version of the process package is approved and the documents are signed and delivered, the technology finalization phase is officially completed. This is the longest phase in the seven-phase model, ranging from issue 34 to issue 57, and covering sixteen core tasks. This phase involves the greatest amount of work, as it requires transforming all the data and insights gathered earlier into a complete set of technical documents that can be handed over to the subsequent engineering design team for use. The quality of this set of documents directly determines whether the subsequent engineering design can proceed smoothly and whether the installed system can operate safely and stably once it is built. The technology finalization phase is now complete; the next step is the engineering translation phase – converting the technical language used in the process packages into an engineering language that the construction team can understand. But before entering the fifth phase, there are still two issues to be completed in the fourth phase—the 58th and 59th issues present two project cases, corresponding respectively to the scenarios of integrating international process packages and developing original innovative process packages, in order to see how the sixteen core tasks are implemented in different project contexts. Preview for the next issue: Issue 58 – MDI project case study: Standardized practices for international process package integration. The methods for Phase 4 have been covered. Starting from the next issue, we will use two real project cases to conclude the technology finalization phase. In issue 58, we will first discuss the MDI supporting projects — this is the first time the company has worked directly with world-class chemical companies on process packages. We will explore the challenges encountered in adapting international standards, converting equipment data, and developing interlock logic, as well as how these challenges were overcome. To be continued in the next issue.