| 摘要 |
<p>A method is disclosed for quenching the effluent from hydrocarbon pyrolysis units and removing resultant heavy oils and tars to prevent their accumulation in the recirculated quench water and excess quench water. Gaseous pyrolysis effluent is initially cooled to a target temperature close to or at the dew point of water at the pressure in the effluent stream. The gaseous effluent is then flashed upon entry into a separation vessel. Conditions in the separation vessel are such that any heavy oils and tars condense and are removed from the system as a substantially water-free concentrate. Following initial cooling, the gaseous effluent is largely free of the heavy oils and tars capable of forming a stable oil/water emulsion and the effluent is water quenched to complete the cooling process. By preventing the formation of a stable oil/water emulsion upon water quenching of the gaseous effluent, the disposal problems associated with a high volume stream of oil-contaminated water are eliminated. In addition, fouling in the recirculating quench water circuit and excess quench water system is reduced. The disclosed method is particularly applicable to removal of the heavy oils and tars produced when the pyrolysis products of mid-range hydrocarbons, such as liquefied petroleum gases and light naphthas, are quenched.</p> |
