Evaluation, process improvements identification, and preliminary FEL-1 process design for a specialty silica manufacturing process.
SILICA POWDERS PROCESS DESIGN AND SAFETY REVIEW
The client is a global manufacturer of specialty chemicals, and this particular plant produces specialized (high value) highly porous micron size silica powders for analytical chemistry and pharmaceutical applications. Process Engineering Associates, LLC (PROCESS) was contracted to (1) document the design of an existing process, (2) conduct a process design and safety review of this process, (3) develop a preliminary design for an improved process, and (4) develop a proposal to perform the detailed process design for the improved process.
The process consists of two primary batch unit operations for processing Silica powder: (1) a Pfaudler glass lined stirred tank reactor with a refluxing condenser where the Silica is reacted with aqueous Hydrochloric Acid (HCl); and (2) a filter with three candles (filter elements) where the Silica is recovered from the slurry, washed to remove residual HCl, and air dried.
This process is a completely manual operation without any automatic valves or controls. All material transfer is by air driven diaphragm pumps through a mix of plastic piping, plastic hoses, and lined carbon steel piping.
The scope of work consisted of (1) documenting the existing “as built” process, (2) evaluating the design and safety aspects of the existing process with the objective of identifying areas for improvement, (3) developing the preliminary design for an improved process that incorporates significant automatic process control, automatic valves, and appropriate piping and auxiliary systems, (4) conducting a Process Hazard Analysis (PHA) of the improved process, and (5) generating a proposal to perform the detailed process design for the improved process.
PROCESS provided the following:
- Description of the existing “as built” process: block flow diagram (BFD), process flow diagram (PFD), piping & instrumentation diagram (P&ID), and a preliminary mass & energy balance (M&EB)
- A list of process improvement recommendations resulting from the site visit and process evaluation
- Preliminary design information for the improved process including: PFD with M&EB and process description; a P&ID depicting new equipment, piping, instrumentation, automatic valves, and controls; a process controls description; and a ±50% capital cost estimate (CAPEX) for the improved process
- Equipment and critical instrument duty specifications for new or modified process equipment and instruments, and preliminary pressure relief valve (PRV) sizing calculations
- A PHA report summarizing the design changes recommended by the PHA team
- A process modification work scope document outlining the scope of work required to fully implement the process improvement modifications identified in this project
- A proposal to perform the detailed process design for the improved process.
- Specialty Materials Manufacturing
- Process evaluation
- Process improvement
- Preliminary process design (FEL-1)