A bio-renewable conversion process for making fuel from bio-renewable feedstocks is combined with a hydrogen production process that includes recovery of CO.sub.2. The integrated process uses a purge gas stream comprising hydrogen from the bio-renewable hydrocarbon production process in the hydrogen production process.

A process for producing liquefied natural gas and liquid carbon dioxide from a natural gas feed gas comprising at least the following steps: Separation of a natural gas feed gas into a CO.sub.2-enriched gas stream and a natural gas stream; Cooling of said natural gas in a heat exchanger; Purification of the in step 1 from compounds containing at least six carbon atoms; At least partial condensation of said gas stream resulting from step 3 to form a two-phase stream; Separation of said two-phase stream resulting from step 4 to form a gas stream and a liquid stream; Condensation of the gas stream resulting from step 5 to form a liquefied gas containing less than 5 ppm by volume of compounds containing at least six carbon atoms; Liquefaction of the CO.sub.2-enriched gas stream resulting from step 1 with a portion of the liquid stream resulting from step 5.

A system and method for cooling a gas using a mixed refrigerant includes a compressor system and a heat exchange system, where the compressor system may include an interstage separation device or drum with no liquid outlet, a liquid outlet in fluid communication with a pump that pumps liquid forward to a high pressure separation device or a liquid outlet through which liquid flows to the heat exchanger to be subcooled. In the last situation, the subcooled liquid is expanded and combined with an expanded cold temperature stream, which is a cooled and expanded stream from the vapor side of a cold vapor separation device, and subcooled and expanded streams from liquid sides of the high pressure separation device and the cold vapor separation device, or combined with a stream formed from the subcooled streams from the liquid sides of the high pressure separation device and the cold vapor separation device after mixing and expansion, to form a primary refrigeration stream.

A method and system for liquefying a natural gas feed stream and removing nitrogen therefrom.

A system and method for liquefaction of a natural gas stream utilizing a plurality of asymmetric parallel pre-cooling circuits. The use of asymmetric parallel cooling circuits allows for greater control over each refrigerant stream during the cooling process and simplifies process control by dedicating heat exchangers to performing similar duties.

A LNG liquefaction plant includes a propane recovery unit including an inlet for a feed gas, a first outlet for a LPG, and a second outlet for an ethane-rich feed gas, an ethane recovery unit including an inlet coupled to the second outlet for the ethane-rich feed gas, a first outlet for an ethane liquid, and a second outlet for a methane-rich feed gas, and a LNG liquefaction unit including an inlet coupled to the second outlet for the methane-rich feed gas, a refrigerant to cool the methane-rich feed gas, and an outlet for a LNG. The LNG plant may also include a stripper, an absorber, and a separator configured to separate the feed gas into a stripper liquid and an absorber vapor. The stripper liquid can be converted to an overhead stream used as a reflux stream to the absorber.

The invention relates to an integrated process and apparatus for liquefaction of natural gas and recovery of natural gas liquids. In particular, the improved process and apparatus reduces the energy consumption of a Liquefied Natural Gas (LNG) unit by using a portion of the already cooled overhead vapor from a fractionation column from an NGL (natural gas liquefaction) unit to, depending upon composition, provide, for example, reflux for fractionation in the NGL unit and/or a cold feed for the LNG unit, or by cooling, within the NGL unit, a residue gas originating from a fractionation column of the NGL unit and using the resultant cooled residue gas to, depending upon composition, provide, for example, reflux/feed for fractionation in the NGL and/or a cold feed for the LNG unit, thereby reducing the energy consumption of the LNG unit and rendering the process more energy-efficient.

A plant and process are used to liquefy and purify a high pressure ethane feed stream. The plant includes a cascaded refrigeration system that refrigerates the ethane feed stream. The refrigeration system includes a propylene circuit, an ethylene circuit and a mixed refrigerant circuit. The mixed refrigerant circuit includes a refrigerant that includes ethane and methane. The plant includes a demethanizer that is configured to remove methane and other natural gas liquids from the refrigerated ethane stream.

A method and system of controlling a temperature within a melt tray assembly of a distillation tower. The method may include determining a melt tray fluid composition of a melt tray fluid, determining a melt tray fluid temperature of the melt tray fluid, determining if the melt tray fluid temperature is within an expected melt tray fluid temperature range for the melt tray fluid composition, decreasing the melt tray fluid temperature if the melt tray fluid temperature is greater than an expected melt tray fluid temperature range upper limit, increasing the melt tray fluid temperature if the melt tray fluid temperature is less than an expected melt tray fluid temperature range lower limit, and maintaining the melt tray fluid temperature if the melt tray fluid temperature is within the expected melt tray fluid temperature range.

One or more specific embodiments disclosed herein includes a method for separating hydrogen from an olefin hydrocarbon rich compressed effluent vapor stream, employing a integrated heat exchanger, multiple gas-liquid separators, external refrigeration systems, and a rectifier attached to a liquid product drum.