摘要:
A process for removing nitrogen from liquefied natural gas (LNG) using an enhanced surface, reflux heat exchanger is disclosed. A relatively warm high pressure LNG stream is directed countercurrently in heat exchange with a cool low pressure LNG stream to chill the high pressure stream and partially vaporize the low pressure LNG stream in the reflux heat exchanger. Vapor produced thereby strips the low pressure LNG stream of nitrogen. The cool low pressure LNG stream is produced by expansion of the chilled high pressure LNG stream. Vapor produced by the expansion is combined with the vapor produced in the exchanger and withdrawn overhead. Product LNG which is lean in nitrogen is withdrawn from the bottom of the exchanger.
摘要:
A process for removing nitrogen from liquefied natural gas (LNG) using an enhanced surface, reflux heat exchanger is disclosed. A relatively warm high pressure LNG stream is directed countercurrently in heat exchange with a cool low pressure LNG stream to chill the high pressure stream and partially vaporize the low pressure LNG stream in the reflux heat exchanger. Vapor produced thereby strips the low pressure LNG stream of nitrogen. The cool low pressure LNG stream is produced by expansion of the chilled high pressure LNG stream. Vapor produced by the expansion is combined with the vapor produced in the exchanger and withdrawn overhead. Product LNG which is lean in nitrogen is withdrawn from the bottom of the exchanger.
摘要:
A method for pretreating a natural gas stream using a single scrub column to remove freezable C₅₊ components and provide an LNG product which can be conveniently handled and shipped is disclosed. The method comprises feeding a natural gas stream to a feed point on a scrub column operated substantially as an absorption column wherein the heavy components are absorbed from the feed gas using a liquid reflux essentially free of such C₅₊ components. The feed can be vapor introduced at a low point on the column, or can be optionally split, cooled and/or expanded and introduced at one or more feed points on the column. The reflux stream can be overhead vapor condensate having a temperature of about -40°C, or methane-rich LNG or a combination of LNG and vapor condensate.