Abstract: A process and apparatus for the liquefaction of natural gas including an improved heavy hydrocarbon removal column with overhead condensing and refluxing. Particularly, a methane-rich stream exiting a propane refrigerant cycle is delivered to a heavies removal column, and the heavies depleted vapor from the column is at least partially condensed and the liquid portion provided as reflux to the heavies removal column.

Abstract: Natural gas liquefaction system employing a turboexpander to convert excess pressure within a predominantly methane stream into work useable in another location within the liquefaction system. Primarily, the turboexpander is used to compress a refrigerant used in at least one of the refrigeration cycles within the liquefaction system.

Abstract: Natural gas liquefaction system employing an enhanced nitrogen removal system capable of removing nitrogen from a relatively warm natural gas stream.

Abstract: Natural gas liquefaction system employing an open methane cycle wherein the liquefied natural gas is flashed immediately upstream of the liquefied natural gas storage tank and boil off vapors from the tank are returned to the open methane cycle.

Abstract: A method and apparatus for enhancing the power output and operational efficiency of a combustion turbine system using a combined refrigerant substantially comprising a first refrigerant and a second refrigerant, whereby the combined refrigerant exhibits a total pressure substantially greater than each respective first and second refrigerant at a temperature inside an evaporative chiller. In a preferred embodiment, the combined refrigerant cools turbine inlet air through the exchange of heat from the inlet air, in an air chiller, with a coolant which is cooled by the combined refrigerant in the evaporative chiller. The combined refrigerant, after it is used to cool the coolant in the evaporative chiller, is separated through the use of a liquid absorbent which absorbs the second refrigerant to form a solution pair. The non-absorbed first refrigerant is compressed, condensed and then recirculated to eventually join the second refrigerant which is desorbed from the solution pair in a regenerator.

Abstract: A process for enhancing the recovery of less volatile components, from a multi component gas mixture, in a cryogenic distillation column, which involves withdrawing a stream from the cryogenic distillation column and processing it to yield a stream leaner in the component to be recovered, which will be cooled and fed to the cryogenic distillation column as a reflux. The processing step may include heating or cooling the side draw and then further contacting the side draw with another stream which is substantially condensed.

Abstract: The present invention is directed to methods and apparatus for improving the recovery of the relatively less volatile components from a methane-rich gas feed under pressure to produce an NGL product while, at the same time, separately recovering the relatively more volatile components which are liquified to produce an LNG product. The methods of the present invention improve separation and efficiency within the NGL recovery column while maintaining column pressure to achieve efficient and economical utilization of the available mechanical refrigeration. The methods of the present invention are particularly useful for removing cyclohexane, benzene and other hazardous, heavy hydrocarbons from a gas feed. The benefits of the present invention are achieved by the introduction to the NGL recovery column of an enhanced liquid reflux lean on the NGL components. Further advantages can be achieved by thermally linking a side reboiler for the NGL recovery column with the overhead condenser for the NGL purifying column.

Abstract: A process for enhancing recovery of ethylene, ethane and heavier components using a cryogenic distillation column which involves dividing the feed gas into a first gaseous stream and a main gaseous stream. The first gaseous stream is compressed and cooled, and then expanded and introduced into the cryogenic distillation column as main reflux stream, or is further processed to generate at least one reflux stream to the cryogenic distillation column.

Abstract: A process for enhancing the recovery of less volatile components, from a multi component gas mixture, in a cryogenic distillation column, which involves withdrawing a stream from the cryogenic distillation column and processing it to yield a stream leaner in the component to be recovered, which will be cooled and fed to the cryogenic distillation column as a reflux. The processing step may include heating or cooling the side draw and then further contacting the side draw with another stream which is substantially condensed.

Abstract: A simple, efficient, and cost effective process for separating components of a feed gas, e.g., containing methane and heavier hydrocarbons has been devised. First, feed gas is condensed to provide a vapor component and a liquid component. The vapor component is divided into at least a first, major portion a second portion, and a remaining portion. The second portion is directed to a lean reflux absorber, and the remaining portion is condensed and fed to the top of the lean reflux absorber. A bottom fluid stream, generally a liquid intermediate product, is recovered from the bottom of the lean reflux absorber, and lean vapor is recovered from the top of the lean reflux absorber. The liquid component, the first, major portion of the first vapor component, the liquid product from the bottom of the lean reflux absorber, and the lean vapor from the top of the lean reflux absorber are all fed to different feed points on a cryogenic distillation column.

Abstract: The present invention is directed to methods for separating and recovering propane, propylene and heavier hydrocarbons, i.e., the C.sub.3 + hydrocarbons, from a gas feed, e.g., raw natural gas or a refinery or petroleum plant gas stream. These methods employ sequentially configured first and second distillation columns, e.g., a de-methanizer tower followed by a de-ethanizer tower. A cooled gas feed condensate is separated in the first column into methane and a liquid phase comprising ethane and heavier hydrocarbons. The liquid phase is separated in the second column into a gas phase primarily comprising ethane and a second liquid phase primarily comprising the desired C.sub.3+ hydrocarbons. At least a portion of the second gas phase is introduced into the first distillation column as an overhead reflux to improve the separation of C.sub.3+ hydrocarbons. The methods of the present invention permit separation and recovery of more than about 99% of the C.sub.

Abstract: A process and associated apparatus for removing aromatics and/or higher molecular weight hydrocarbons from a methane-based gas stream comprising the steps of (a) condensing a minor portion of the methane-based gas stream thereby producing a two-phase stream, (b) feeding said two phase stream to the upper section of a column, (c) removing from the upper section of the column an aromatic- and/or heavies-depleted gas stream, (d) removing from the lower section of the column an aromatic- and/or heavies-rich liquid stream, (e) contacting via indirect heat exchange the aromatic- and/or heavies-rich liquid stream with a methane-rich stripping gas thereby producing a warmed liquid stream and a cooled stripping gas stream, (f) feeding said cooled stripping gas stream to the lower section of the column; and (g) contacting said two-phase stream and the cooled stripping gas stream in the column thereby producing the aromatic- and/or heavies-depleted gas stream and the aromatic- and/or heavies-rich liquid stream.

Abstract: This invention concerns a method and an apparatus for removing nitrogen and other low boiling point inorganic components from pressurized LNG-bearing streams and streams produced therefrom. The removal of such components is accomplished via a novel pressure reduction/stripping methodology thereby producing at least one low BTU nitrogen-rich gas stream and at least one high BTU methane-rich stream which is suitable for recycle to an open methane cycle liquefaction process and/or employment as a high quality fuel gas.

Abstract: The present invention is directed to methods for improving the efficiency and economy of processes for the recovery of natural gas liquids (NGL) from a gas feed, e.g., raw natural gas or a refinery or petrochemical plant gas stream. These methods may be employed with most, if not all, conventional separation methods using a distillation tower, e.g., a demethanizer or deethanizer column. In the methods of the present invention, a portion of a hydrocarbon liquid condensed on a chimney tray disposed below the lowest feed tray of the column is withdrawn from the tower. This withdrawn liquid hydrocarbon is expanded and heated to produce a two-phase system for separation into a heavy, liquid hydrocarbon product and a vapor phase for recycle to the column, preferably as a stripping gas. The withdrawn hydrocarbon liquid is preferably heated by indirect heat exchange with the inlet gas, thus reducing or eliminating the external refrigeration requirements of the process.

Abstract: A process and associated apparatus for removing aromatics and/or higher molecular weight hydrocarbons from a methane-based gas stream comprising the steps of (a) condensing a minor portion of the methane-based gas stream thereby producing a two-phase stream, (b) feeding said two phase stream to the upper section of a column, (c) removing from the upper section of the column an aromatic- and/or heavies-depleted gas stream, (d) removing from the lower section of the column an aromatic- and/or heavies-rich liquid stream, (e) contacting via indirect heat exchange the aromatic- and/or heavies-rich liquid stream with a methane-rich stripping gas thereby producing a warmed liquid stream and a cooled stripping gas stream, (f) feeding said cooled stripping gas stream to the lower section of the column; and (g) contacting said two-phase stream and the cooled stripping gas stream in the column thereby producing the aromatic- and/or heavies-depleted gas stream and the aromatic- and/or heavies-rich liquid stream.

Abstract: A process and apparatus for improving the efficiency of an open-cycle cascaded refrigeration process. Process efficiency is improved by the manner in which the compressed recycle stream is combined with the main process stream in the open refrigeration cycle.

Abstract: Nitrogen and methane are separated in a nitrogen-methane cryogenic fractionator operating at a temperature between the boiling points of nitrogen and methane. A distillative aid or absorbent is injected into the nitrogen-methane cryogenic fractionator for enhancing separation, for enabling an increase in operating pressure, and for enabling a high separation rate at relatively high temperature.

Abstract: Disclosed is a method and apparatus for separating and purifying carbon dioxide and natural gas contained in the associated gas of an oil well. Feed containing hydrocarbons, carbon dioxide, water and hydrogen sulfide, is fed to a stabilizer column where heavy hydrocarbons and water are removed. Hydrogen sulfide is then stripped from the gas in a carbon dioxide fractionator using a solvent which absorbs H.sub.2 S and increases the relative volatility of carbon dioxide to hydrogen sulfide. Overhead from the CO.sub.2 fractionator contains carbon dioxide and light hydrocarbons, which are then separated in a demethanizer column which produces liquid carbon dioxide as a bottoms product. The invention is particularly useful in recovering carbon dioxide from the associated gas of oil produced from enhanced oil recovery processes using carbon dioxide injection.