Develop simulation models for the liquid propane refrigeration section at an LNG liquefaction facility to determine the impact to the propane compressor horsepower using three different qualities of propane refrigerant.
Process Engineering Associates, LLC (PROCESS) was contracted by the client, a producer of light ends hydrocarbons, to model the liquid propane refrigeration section for the following LNG liquefaction processes:
- Phillips Optimized Cascade Process (OCP)
- APCI C3/MR process.
The Phillips OCP model included the propane compressor stages and associated chillers for three levels of refrigerant cooling (high, medium, and low pressures). The natural gas, ethylene, and methane streams for the LNG plant were included with UA (overall heat transfer coefficient area) models for the chillers. The APCI C3/MR model included the chillers and compressor stages for four levels of refrigerant cooling (high-high, high, medium, and low pressures). The model also included the natural gas and mixed refrigerant streams with UA models for the associated chillers.
The purpose of the models was to determine the impact to the propane compressor horsepower using three different qualities of propane refrigerant while keeping a constant temperature at each refrigerant level or a constant duty for each chiller. The composition of the propane was changed by adding a light (ethane) or heavy (isobutane) contaminant.
This above work resulted in the following study deliverables:
- Process simulations for propane refrigerant cycle of the LNG liquefaction process
- Report detailing study basis and results
- Heat and material balances for the three propane refrigerant composition points for light, heavy, and a 50/50 mixture of light and heavy contaminants.
Light-Ends Hydrocarbon Production
- Process simulation
- Process evaluation.