Assist with completion of the front-end engineering design (FEED) and provide process engineering oversight through detail design for a pilot-scale specialty metal flame salt encapsulation process.
METAL FLAME SALT ENCAPSULATION PILOT SYSTEM FRONT-END ENGINEERING DESIGN (FEED) PACKAGE PREPARATION
The client, the corporate office of a specialty metals production company, contracted Process Engineering Associates, LLC (PROCESS) to assist with completion of the front-end engineering design (FEED) for a pilot scale specialty metal flame salt encapsulation process. The pilot system is an innovative high temperature gas phase metal reduction process used to produce a high grade specialty metal powder. Unit operations for the process included raw materials feed systems, an argon delivery system, a high temperature gas phase metal reduction reactor, a high temperature metal product filtering system, an excess metal reactor with offgas scrubbing system, and a product finishing system that includes ultra-filtration, centrifuge, and drying.
PROCESS was contracted to assist with the FEED documents after completing the preliminary process design package for the system during a separate previous project. Specifically, PROCESS was to act as the process lead during detailed design and was contracted to complete the following project tasks:
- Finalize the heat and material balance (H&MB) data for the process and prepare final issued for design process flow diagram (PFDs). The H&MB data was developed using PROCESS‘ licensed commercial process simulation software (CHEMCAD). A total of 6 PFDs were issued that depicted all unit operations and process and utility streams.
- Evaluate alternative methods for safely handling any excess metal in the process exhaust and scrubbing the remaining off-gas. This evaluation involved the review of technically feasible alternatives to capture and/or react the excess metal carried over from the process and scrub the resulting particulate constituents. Two options were selected for detailed review that included a sodium/air reactor chamber or a quench chamber/high-efficiency fiber bed filter system. The focus of the detailed review was primarily on process safety and system performance (no economics). The wet system had to be designed for physical isolation from the process to eliminate the potential for water egress to the upstream unit operations.
- Complete a detailed issued for bid specification for the selected submicron sodium oxide particulate scrubbing system. The scrubbing system included quench chamber and high efficiency fiber bed filter system with integral water recirculation loop.
- Complete issued-for-design piping and instrumentation diagrams (P&IDs) for the process. These drawings were issued to the detailed design firm for mechanical and electrical design.
- Size all pressure relief devices (PRDs) associated with the system. PROCESS sized a total of twelve (12) relief devices for the process. The system presented some challenges due to the presence of a raw material with limited vapor pressure data as well as chlorides in a high temperature application (>1,000 oF). Some of the PRDs required specialty materials of construction and low relief tolerances.
- Facilitate and document a process hazards analysis (PHA) for the system. PROCESS performed both a preliminary HAZOP in the early stage of design to identify any issues that needed to be resolved during the FEED and a final HAZOP after completion of the FEED documents.
- Interface with an air permitting consultant to develop all detailed information needed for the plan approval application. This included annual average and peak hourly emissions estimates, stack configuration, system block flow diagram, and detailed system description.
- Provide process engineering oversight during the course of detailed design. This involved on-going review of engineering design documents, vendor bid submittals, and cost estimation information prepared by the detail design firm during the course of the FEED development.
Execution of the project involved interfacing with corporate R&D staff, the Capital Engineering group, and the detailed design firm. The system design was completed and the client was waiting on plan approval (state permitting agency). Once the plan approval is received, the client will move ahead with installation of the innovative process.
- Specialty Metals Production
- FEED packaged development
- Process alternatives evaluation
- Vendor bid specification preparation
- Air permitting support
- Process engineering oversight during detail engineering