| 摘要 |
An MP refining unit treats medium sweet charge oil with N-methyl-2-pyrrolidone solvent, hereafter referred to as MP, in a refining extractor to yield raffinate and extract mix. The MP is recovered from the raffinate and from the extract mix and returned to the extractor. A system controlling the refining unit includes a gravity analyzer, a refractometer and viscosity analyzer, all analyzing the medium sweet charge oil and providing corresponding signals, sensors sense the flow rates of the charge oil and the MP flowing into the refining tower and the temperature of the extract mix and provide corresponding signals. One of the flow rates of the medium sweet charge oil and the MP flow rates is controlled in accordance with the signals from all the analyzers and all the sensors, while the other flow rate of the medium sweet charge oil and the MP flow rates is constant.
|
