The M.w. Kellogg Company

Charles A Durr

Shanmuk Sharma

Donnie K Hill

Felix J Fernandez De La Vega

David B Manley

William C Petterson

David A Coyle

Ashutosh Rastogi

Robert L McKee

A process for liquefying natural gas containing mercaptans. Mercaptans are concentrated into a distillate stream by distilling the feed gas stream without specific pretreatment for mercaptans removal. Thus, the mercaptans removal equipment is much smaller since mercaptans treatment can take place at a point in the process where the flowrate is much lower. A portion of the treated distillate stream can be reinjected to the upstream distilling stage to facilitate mercaptan absorption.

Method for removing mercaptans from LNG

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 Vapor produced by the expansion is combined with the vapor produced in the exchanger and withdrawn overhead. Product LNG which is lean in nitrogen is withdrawn from the bottom of the exchanger.

Process for removing nitrogen from LNG

A process for recovering CO.sub.2 from a mixture of light hydrocarbons, e.g. light hydrocarbons produced from a CO.sub.2 injection enhanced oil recovery. The mixture is distilled in a distributive zone with CO.sub.2 produced overhead and in the bottoms. The overhead and bottoms produced from the distributive zone are then fed to first and second concentrating distillation zones, respectively. The first concentrating zone produces a bottoms product rich in CO.sub.2 and an overhead product rich in methane and lean in CO.sub.2. The second concentrating zone is refluxed with lean oil and produces a CO.sub.2 distillate and a CO.sub.2 -lean bottoms product. In various embodiments, at least a section of each of the concentrating zones are placed in a single column, the CO.sub.2 product streams are taken as a side draw, vapor from the first concentrating zone is used in an open cycle heat pump to heat the second concentrating zone, the distributive zone is thermally coupled with one or both of the concentrating zones, and the distributive zone and certain sections of the concentrating zones are physically integrated into a single column.

Carbon dioxide recovery process

A method for pretreating a natural gas stream using a single scrub column to remove freezable C.sub.5+ 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 C.sub.5+ 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.degree. C., or methane-rich LNG or a combination of LNG and vapor condensate.

Natural gas liquefaction pretreatment process

A method for sub-cooling normally gaseous hydrocarbon mixtures produced in a cryogenic process unit wherein the mixture is introduced to a gas/liquid separator, which may be a storage vessel, and vapor containing at least two components of the mixture is recovered as refrigerant, employed in an open cycle refrigeration system to sub-cool the hydrocarbon mixture, and returned to the separator. The system is particularly useful for sub-cooling a hydrocarbon product stream while, at the same time, recovering boil-off vapor from a cryogenic storage vessel.

Method for sub-cooling a normally gaseous hydrocarbon mixture

A process for separation of a high pressure gas stream such as refinery gas in which the starting gas mixture is cooled and separated into a first vapor portion and a first liquid portion which is expanded to an intermediate pressure. The first vapor portion is further cooled and separated into a second vapor portion which may be further processed for ultimate recovery of, for example, a methane-rich product gas and a second liquid portion which is expanded to essentially the same intermediate pressure and combined with the expanded first liquid portion. The resulting mixed intermediate pressure stream or a portion thereof is then employed as refrigerant.

Process for separation of hydrocarbon gases

A process for separation of a high pressure gas stream such as light refinery gases in which the gas mixture is expanded, preferably through a turbine, and separated into first vapor and liquid portions. The first vapor portion may be recovered as, for example, methane-rich product gas. The first liquid portion is raised to an intermediate pressure, revaporized, and introduced to a fractionator from which an ethane-containing stream is recovered. The ethane-containing stream is then cooled and separated into a second vapor portion and a second liquid portion which is then expanded and combined with the expanded starting gas mixture to increase the amount of refrigeration that may be recovered from the first liquid stream prior to its fractionation.

A process for separating gaseous or liquid hydrocarbons in first and second fractionation zones wherein the first fractionation zone employs a side reboiler discharging below the side draw point. A vapor sidestream is removed from the first fractionator below the side draw point and introduced to the second fractionator. The flow scheme permits control of the first fractionator bottoms temperature to match available low level waste heat which may therefore be used in fractionator reboiling duty.

Growing community of inventors

Houston, TX, United States of America

Charles A Durr