The selective dimerization of isoolefins, such as isobutene or isopentane, or mixtures thereof, may be conducted in a system including a series of fixed bed reactors and a catalytic distillation reactor. The system may provide for conveyance of the fixed bed reactor effluents, without componential separation, to a downstream reactor. It has been found that a high selectivity to the dimer may be achieved even though intermediate separation of the desired product from unreacted components between reactors is not performed. Further, embodiments provide for use of a divided wall column for recovery of a high purity dimer product, reducing unit piece count and plot size.

The present invention relates to a plant and a process for producing propylene at least one oxygenate, comprising a reactor for converting the reactant mixture into a product mixture which comprises propylene and also aliphatic and aromatic C.sub.5+ hydrocarbons, at least one distillation column for removing a C.sub.5+ stream, the C.sub.5+ stream comprising at least 90 wt % of the aliphatic and aromatic C.sub.5+ hydrocarbons of the product mixture, an extractive distillation column for separating the C.sub.5+ stream into an aromatics stream and an aliphatics stream, the aliphatics stream comprising at least 90 wt % of the aliphatics of the C.sub.5+ stream, and the aromatics stream comprising at least 90 wt % of the aromatics of the C.sub.5+ stream, and an aliphatics recycle line for at least partial recycling of the aliphatics stream to the reactor. According to the invention, an aromatics recycle line is provided which returns the aromatics stream at least partially as extractant into the extractive distillation column.

Methods and apparatuses are provided for producing hydrocarbons. A method for producing hydrocarbons may include two or more reactors having a distributed aromatic rich feed and hydrogen system. Using this configuration, the aromatic rich feed and hydrogen streams are split equally to all reactors wherein each reactor contains a catalyst. The outlet from the last reactor may include a recycle that may be injected into the inlet of the first reactor.

A catalyst for selectively oxidizing hydrogen sulfide to element sulfur, catalyst for burning tail-gas, and process for deeply catalytically oxidizing hydrogen sulfide to sulfur are disclosed. The catalyst for selectively oxidizing hydrogen sulfide to element sulfur is prepared by: 10-34% of iron trioxide and 60-84% of anatase titanium dioxide, and the balance being are auxiliary agents. Also a catalyst for burning tail-gas is prepared by: 48-78% of iron trioxide and 18-48% of anatase titanium dioxide, and the balance being auxiliary agents. The catalyst of the present invention has high selectivity and high sulfur recovery rate. An isothermal reactor and an adiabatic reactor of the present invention are connected in series and are filled with the above two catalysts for reactions, thus reducing total sulfur in the vented gas while having a high sulfur yield and conversion rate.

A trickle bed reactor, comprising a plurality of catalyst beds connected in series and progressively increasing in catalyst mass in a direction from upstream to downstream; and a plurality of heat exchangers, wherein each of the heat exchangers is located between two of the plurality of catalyst beds, and wherein each of the heat exchangers does not exchange heat with an outer surface of a vessel that contains any of the catalyst beds.

A process and device for reducing the environmental contaminants in a ISO 8217 compliant Feedstock Heavy Marine Fuel Oil, the process involving: mixing a quantity of the Feedstock Heavy Marine Fuel Oil with a quantity of Activating Gas mixture to give a feedstock mixture; contacting the feedstock mixture with one or more catalysts to form a Process Mixture from the feedstock mixture; separating the Product Heavy Marine Fuel Oil liquid components of the Process Mixture from the gaseous components and by-product hydrocarbon components of the Process Mixture and, discharging the Product Heavy Marine Fuel Oil. The Product Heavy Marine Fuel Oil is compliant with ISO 821 7 for residual marine fuel oils and has a sulfur level has a maximum sulfur content (ISO 14596 or ISO 8754) between the range of 0.05% wt. to 0.5% wt. The Product Heavy Marine Fuel Oil can be used as or as a blending stock for an ISO 8217 compliant, IMO MARPOL Annex VI (revised) compliant low sulfur or ultralow sulfur heavy marine fuel oil.

A two-reactor catalytic system including a catalytic membrane gasification reactor and a catalytic membrane water gas shift reactor. The catalytic system, for converting biomass to hydrogen gas, features a novel gasification reactor containing both hollow fiber membranes that selectively allow O.sub.2 to permeate therethrough and a catalyst that facilitates tar reformation. Also disclosed is a process of converting biomass to H2. The process includes the steps of, among others, introducing air into a hollow fiber membrane; mixing the O.sub.2 permeating through the hollow fiber membrane and steam to react with biomass to produce syngas and tar; and reforming the tar in the presence of a catalyst to produce more syngas.

A system for reducing dioxygen (O.sub.2) present in vapors from oil storage tanks. The system may include an inlet that receives vapors from the tanks; a heating device coupled with the inlet that heats vapors to a first temperature to form heated vapor; and a vessel coupled receiving heated vapor and containing at least one catalyst to reduce dioxygen from the heated vapor. The catalyst may include palladium, and the vessel may include zinc oxide to remove sulfur from the heated vapor. A compressor may be used to compress the vapors. A controller may be provided to monitor O.sub.2 concentration in heated vapor, and the controller directs flow of heated vapor to a gas pipeline if the O.sub.2 concentration is below a predetermined level; or if the O.sub.2 concentration is unacceptably high, the controller directs flow of vapor to be re-circulated within the system to further reduce O.sub.2 concentration therein.

This disclosure relates installed or new synthesis gas (Syngas) production units and potential modifications to those units to reduce the firing requirements and significant emissions of CO.sub.2 from those units with affordable capital expenditures.

The present invention is directed to improved methods and systems for increasing the efficiency of a dehydrogenation section of an alkenyl aromatic hydrocarbon production facility, wherein an alkyl aromatic hydrocarbon, such as ethylbenzene, is dehydrogenated to produce an alkenyl aromatic hydrocarbon, such as styrene. The disclosed methods are more energy-efficient and cost effective than currently known methods for manufacturing styrene. The methods and systems advantageously utilize multiple reheat exchangers arranged in a series and/or parallel configuration that result in an energy consumption reduction and, consequently, a utility cost savings, as well as a reduction in styrene manufacturing plant investment costs.