Abstract: Methods for manufacturing brazed aluminum heat exchangers involved in boiling and condensing, including a high performance nucleate boiling surface bonded with the walls of fin-less boiling passages. One method includes providing a first heat exchanger core subassembly including a first joinable end, at least one cooling and one boiling passage, and a first partial finless passage arranged at the joinable end. A second heat exchanger core subassembly is provided similar to the first including a second joinable end. The first and second heat exchanger core subassemblies are brazed. The first joinable end is affixed, preferably by welding, to the second joinable end and the first partial finless passage is affixed to a second partial finless passage to form a coupled finless passage, and thereby a heat exchanger core.

Abstract: The selective saturation of unsaturated aliphatic hydrocarbons (e.g., diolefins) in a hydrogenation feed stream comprising an aromatic compound (e.g., benzene) and one or more nitrogen compounds renders it beneficial when the stream or a portion thereof is subsequently treated (e.g., with a zeolitic adsorbent) to remove nitrogen. In particular, the selective saturation of, for example, olefins and diolefins prolongs the life of the nitrogen guard bed. In a representative embodiment, the selective hydrogenation is applied to a recycle benzene-containing stream recovered in the separation section (e.g., from the benzene/toluene splitter overhead) of a styrene production process, prior to treatment with a nitrogen guard bed adsorbent.

Abstract: One exemplary embodiment can be a method for processing polyisopropylbenzene for producing cumene. The method can include passing a transalkylation feed stream to a transalkylation zone, and passing a reaction product to a separation zone. Typically, the separation zone produces a stream including di-isopropylbenzene, tri-isopropylbenzene, and one or more heavy compounds. Moreover, the stream may include at least about 0.7%, by weight, of the one or more heavy compounds based on the weight of the di-isopropylbenzene, tri-isopropylbenzene, and the one or more heavy compounds in the stream, and at least a portion of the stream is recycled to the transalkylation zone.

Abstract: A process for transalkylating aromatic hydrocarbon compounds, the process comprising introducing an aromatic hydrocarbon feed stream and a water source to a transalkylation zone. The feed stream contacts a catalyst in the transalkylation zone in the presence of water, and produces a reaction product stream comprising benzene and xylene. The invention includes methods to control the transalkylation process.

Abstract: A process for transalkylating aromatic hydrocarbon compounds, the process comprising introducing an aromatic hydrocarbon feed stream and a sulfur source to a transalkylation zone. The feed stream contacts a catalyst in the transalkylation zone in the presence of sulfur, and produces a reaction product stream comprising benzene and xylene. The invention includes methods to control the transalkylation process.

Abstract: One exemplary embodiment can be a process for removing one or more scale deposits formed on a surface. The process can include contacting the surface with a composition for a period of time sufficient to remove the scale deposits that comprise coke or metal sulfides or mixtures thereof. Generally, the composition includes an effective amount of an organic acid and/or a salt thereof, and an effective amount of an oxidizing agent.

Abstract: The apparatus includes at least two adsorptive separation zones to separate para-xylene from a feed stream comprising C8 aromatic hydrocarbons and at least one C9 aromatic hydrocarbon component. The first adsorptive separation zone delivers a raffinate stream to a raffinate distillation zone and an extract stream to an extract distillation zone. The raffinate distillation zone delivers a stream to the second adsorptive separation zone and at least one of the extract distillation zone and raffinate distillation zone delivers a recycle stream to the first adsorptive separation zone.

Abstract: The present invention comprises a hydrocarbon-conversion process using an improved MgAPSO-31 molecular sieve which demonstrates a favorable combination of conversion and selectivity in aromatics conversion. The sieve has a specific combination of crystal configuration, being limited in diameter and length, specified crystallinity as measured by an X-Ray Diffraction Index (XRDI), and a narrow range of magnesium content.

Abstract: Binderless BaKX zeolitic adsorbents, methods for their production, and processes for their use in a liquid phase adsorptive separation process are provided. An adsorbent includes a binder-converted zeolite portion formed from x wt % kaolin clay binder and (100-x) wt % unconverted Zeolite X with a silica:alumina molar ratio of about 2.5. The kaolin clay binder is in the range of about 10 to about 20 wt %. Ba and K occupy cationic exchangeable sites within the adsorbent. K is in the range of about 0.25 to about 0.9% by weight and Ba is greater than about 31.6% by weight of the binderless BaKX zeolitic adsorbent. Cornstarch may be added to the Zeolite X and kaolin clay binder to increase adsorbent macro-porosity and pore volume. Productivity of the adsorbent is improved decreasing process operating costs. The mechanical strength of the adsorbent is also improved.

Abstract: One exemplary embodiment can be a process for minimizing a solvent in a raffinate stream of an extractive distillation column. The process can include providing sufficient separation in the extractive distillation column between a reflux stream having an effective amount of water and a stream having an effective amount of solvent. Usually, the reflux stream has no more than about 2,000 ppm, by weight, solvent based on the weight of the reflux stream.

Abstract: The invention comprises an absorption heat pump to supply energy to a distillation process or an outside process. The streams used to effect the absorption heat pump are to be combined in any case as a feedstream to a conversion process, and energy thus is conserved by avoiding the necessity of reseparating the streams.

Abstract: A distillation column is disclosed. The column includes a plurality of rectification zones and corresponding stripping zones. Each rectification zone is linked to a heat pump or a stage of a heat pump. Overhead material from the top rectification zone is compressed and used to heat bottoms liquid from the bottom stripping zone. Similarly, overhead material from a lower rectification zone is compressed and used to heat liquid taken from the uppermost or top stripping zone. Optionally, overhead material from a middle rectification zone is compressed and used to heat liquid from a middle stripping zone. A single multiple stage heat pump compressor may be utilized as opposed to a plurality of heat pumps. Because the heat exchanger from each rectification-stripping zone pair has a lower duty, economical stab-in heat exchangers may be utilized.

Abstract: This invention is drawn to a process for isomerizing a non-equilibrium mixture of xylenes and ethylbenzene using a catalyst comprising a zeolite having specific particle-size characteristics, a platinum-group metal and a silica binder. A relatively minimal amount of hydrogen is supplied to the process on a once-through basis, resulting in low saturation of aromatics while achieving effective xylene isomerization with reduced processing costs.

Abstract: A distillation column is disclosed. The column includes a plurality of rectification zones and corresponding stripping zones. Each rectification zone is linked to a heat pump or a stage of a heat pump. Overhead material from the top rectification zone is compressed and used to heat bottoms liquid from the bottom stripping zone. Similarly, overhead material from a lower rectification zone is compressed and used to heat liquid taken from the uppermost or top stripping zone. Optionally, overhead material from a middle rectification zone is compressed and used to heat liquid from a middle stripping zone. A single multiple stage heat pump compressor may be utilized as opposed to a plurality of heat pumps. Because the heat exchanger from each rectification-stripping zone pair has a lower duty, economical stab-in heat exchangers may be utilized.

Abstract: A downcomer for a gas-liquid contacting device. The downcomer may include first and second spaced apart side walls, first and second end walls, a floor, and first and second opposing discharge walls. Generally, each end wall is coupled to a respective end of the first and second side walls. Typically, the floor is coupled to the side walls and end walls, and the floor has at least one section adapted for permitting the passage of liquid there-through. The first and second opposing discharge walls can be coupled to respective first and second side walls and having respective ends below the floor.

Abstract: A downcomer for a gas-liquid contacting device. The downcomer may include first and second spaced apart side walls, first and second end walls, a floor, and first and second opposing discharge walls. Generally, each end wall is coupled to a respective end of the first and second side walls. Typically, the floor is coupled to the side walls and end walls, and the floor has at least one section adapted for permitting the passage of liquid there-through. The first and second opposing discharge walls can be coupled to respective first and second side walls and having respective ends below the floor.

Abstract: A process for isomerizing ethylbenzene into xylenes such as para-xylene using a zeolitic catalyst system based on low Si/Al2 MTW-type zeolite that preferably is substantially free of mordenite. The catalyst may be bimetallic where the two metals are platinum and tin.

Abstract: A process for transalkylating aromatic hydrocarbon compounds, the process comprising introducing an aromatic hydrocarbon feed stream and a sulfur source to a transalkylation zone. The feed stream contacts a catalyst in the transalkylation zone in the presence of sulfur, and produces a reaction product stream comprising benzene and xylene. The invention includes methods to control the transalkylation process.

Abstract: A process for transalkylating aromatic hydrocarbon compounds, the process comprising introducing an aromatic hydrocarbon feed stream and a water source to a transalkylation zone. The feed stream contacts a catalyst in the transalkylation zone in the presence of water, and produces a reaction product stream comprising benzene and xylene. The invention includes methods to control the transalkylation process.

Abstract: Cumene production methods are disclosed, based on the alkylation of benzene with propylene, in which byproducts of the alkylation reaction are advantageously reduced to achieve a high cumene selectivity. This may be attained by (i) reducing the portion of the total alkylation effluent that is recycled, after cooling, to the alkylation reaction zone for quenching or direct heat exchange and/or (ii) reducing the benzene:propylene molar ratio of the alkylation feedstock. To manage the temperature differential across catalyst bed(s) in the alkylation reaction zone, indirect heat exchange may be used to remove heat.