Provide process design services in support of a new high-purity titanium tetrachloride (TiCl4) distillation train.
TITANIUM TETRACHLORIDE PURIFICATION SYSTEM PROCESS SIMULATION AND DESIGN
Process Engineering Associates, LLC (PROCESS) was contracted by the client, an engineering company, to provide process design and engineering services for a distillation train to produce high-purity (99.994%) titanium tetrachloride (TiCl4). The ultimate client, a titanium pigment producer, plans to sell high-purity TiCl4 as an intermediate chemical feedstock product to the paints and coatings industry. Specifically, PROCESS was contracted to complete the following project tasks: Task 1 – Develop a mass and energy balance for the new distillation train; Task 2 – Prepare process flow diagrams (PFDs) for the new system; and Task 3 – Design and size new distillation columns with their associated reboilers and condensers.
For Task 1, PROCESS' licensed computer process simulation software, CHEMCAD, was used to simulate the distillation columns. Pilot plant data, developed using actual feed from the existing titanium tetrachloride production facility, were used to develop and validate the column model. Sensitivity studies were performed to bound the possible operating conditions, including distillate temperature, feed location, reflux ratio, and number of trays for the design for normal operation. These results were also compared with simulation studies the ultimate client had done previously.
CHEMCAD was used to develop a complete mass and energy balance for the distillation train for three scenarios. The first scenario involved parallel operation of two columns with normal feed composition. The second scenario involved series operation of two columns when the feed contains double the normal contaminants. The third scenario involved operation with a product side draw in lieu of bottoms product in the event certain impurities are created in the process. The simulation models were used to determine the appropriate operating conditions for the columns in all of these modes of operation.
For Task 2, PFDs were prepared using AutoCad for the parallel, series, and side draw operations. The information generated during Task 1 was used to define the operating conditions shown on the PFDs. From this design information, process control requirements were developed, and a process control description was developed. The nature of the separation requires controls which are more complex than what is normally used for distillation columns.
For Task 3, design information from the previous tasks was used to complete a mechanical design of the distillation columns. Tray type and number were selected, and column vapor and liquid profiles from the simulation model were used to hydraulically size the columns and trays. A tray vendor was included in the final tray and column sizing. A detailed mechanical equipment specification for the column was then completed for a bid package sent to vendors.
The reboilers and condensers were sized and designed using CHEMCAD’s CCTHERM heat exchanger design software. The designs were checked for proper operation in all three operating scenarios. Detailed mechanical equipment specifications were then completed for a bid package sent to vendors.
In addition to these tasks, PROCESS also provided design information and physical properties from the model to allow sizing of other equipment, including pumps, control valves, and tanks. PROCESS also attended and assisted with the HAZOP study for the new process.
- Intermediate chemicals manufacturing
- Complex distillation system design
- Process design and bid package preparation
- Process simulation
- Process hazard analysis
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