Treatment of streams containing hydrogen and/or hydrocarbons, and in one non-limiting embodiment refinery distillates, with alkyl carbonates, such as dimethylcarbonate, alone or together with at least one solvent results in reduction or removal of hydrogen sulfide (H.sub.2S) that is present to give easily removed alkyl sulfides and/or mercaptans. In one non-limiting embodiment, the treatment converts the original hydrogen sulfide into alkyl sulfides and/or mercaptans that can be extracted from the stream with caustic solutions, mercaptan scavengers, solid absorbents such as clay or activated carbon or liquid absorbents such as amine-aldehyde condensates and/or aqueous aldehydes.

The invention relates to a process for the manufacture of diesel range hydrocarbons wherein a feed is hydrotreated in a hydrotreating step and isomerised in an isomerisation step, and a feed comprising fresh feed containing more than 5 wt % of free fatty acids and at least one diluting agent is hydrotreated at a reaction temperature of 200-400 C., in a hydrotreating reactor in the presence of catalyst, and the ratio of the diluting agent/fresh feed is 5-30:1.

The present disclosure relates to processes that catalytically convert a hydrocarbon feed stream predominantly comprising both isopentane and n-pentane to yield upgraded hydrocarbon products that are suitable for use either as a blend component of liquid transportation fuels or as an intermediate in the production of other value-added chemicals. The hydrocarbon feed stream is isomerized in a first reaction zone to convert at least a portion of the n-pentane to isopentane, followed by catalytic-activation of the isomerization effluent in a second reaction zone with an activation catalyst to produce an activation effluent. The process increases the conversion of the hydrocarbon feed stream to olefins and aromatics, while minimizing the production of C1-C4 light paraffins. Certain embodiments provide for further upgrading of at least a portion of the activation effluent by either oligomerization or alkylation.

A method of hydroprocessing is performed wherein non-petroleum feedstocks, such as those containing from about 10% or more olefinic compounds or heteroatom contaminants by weight, are treated in a first reaction zone to provide reaction products. The process involves introducing the feedstock along with diluents or a recycle and hydrogen in a first reaction zone and allowing the feed and hydrogen to react in a liquid phase within the first reaction zone to produce reaction products. The reaction products are cooled and/or water is removed from the reaction products. At least a portion of the cooled and/or separated reaction product are introduced as a feed along with hydrogen into a second reaction zone containing a hydroprocessing catalyst. The feed and hydrogen are allowed to react in a liquid phase within the second reaction zone to produce a second-reaction-zone reaction product.

The present disclosure provides methods for hydroprocessing of heavy oils, such as pyrolysis tars. For example, a process for preparing a liquid hydrocarbon product includes providing a first process stream comprising a reduced reactivity tar, and blending the first process stream with a utility fluid to produce a second process stream comprising solids and a reduced reactivity, lower viscosity tar. The method can includes introducing the second process stream into a guard reactor without sulfiding the guard reactor catalyst(s) prior to introducing the second process stream into the guard reactor. The method includes hydroprocessing the second process stream in the guard reactor under mild hydroprocessing conditions to produce a third process stream. The method includes hydroprocessing the third process stream to produce a fourth process stream having a bromine number (BN) lower than 12 and comprising the liquid hydrocarbon product and the utility fluid.

The invention relates to a process for the manufacture of diesel range hydrocarbons wherein a feed is hydrotreated in a hydrotreating step and isomerised in an isomerisation step, and a feed comprising fresh feed containing more than 5 wt % of free fatty acids and at least one diluting agent is hydrotreated at a reaction temperature of 200-400 C., in a hydrotreating reactor in the presence of catalyst, and the ratio of the diluting agent/fresh feed is 5-30:1.

The present invention belongs to the field of petrochemical industry, and discloses a method for selective hydrogenation of butadiene extraction tail gas and a selective hydrogenation apparatus thereof. The method for selective hydrogenation of butadiene extraction tail gas comprises: (1) an alkyne-containing tail gas from a butadiene extraction unit is fed into a raw material tank, optionally impurities entrained in the alkyne-containing tail gas are removed before being fed into the raw material tank; (2) a C4 raw material in the raw material tank is pressurized by a feed pump to a pressure required for reaction, then merged with a circulated C4 stream from a first-stage reactor outlet buffer tank and fed into a first-stage mixer, wherein it is mixed with hydrogen gas, and fed into the first-stage reactor to undergo a first-stage hydrogenation reaction, and a first-stage reaction stream obtained by the reaction is fed into the first-stage reactor outlet buffer tank; the hydrogen gas required for the reaction in the first-stage reactor is fed through a first feeding mode or a second feeding mode: the first feeding mode comprises: all the hydrogen gas required for the reaction is fed through the first-stage reactor outlet buffer tank, and then fed into the first-stage reactor through a first route at an outlet of the first-stage reactor outlet buffer tank; the second feeding mode comprises: a part of the hydrogen gas required for the reaction is fed through the first-stage reactor outlet buffer tank, and then fed into the first-stage reactor through the first route at an outlet of the first-stage reactor outlet buffer tank; and the other part of the hydrogen gas is fed through the first-stage mixer, and then fed into the first-stage reactor; (3) there is no gas-phase discharge from the first-stage reactor outlet buffer tank, and a liquid-phase product is divided into at least two streams, the first stream is returned to the first-stage reactor as the circulated C4 stream, and the second stream is used as a feed to a stabilization tower or subjected to further hydrotreatment prior to being fed into the stabilization tower; (4) a C4 hydrogenation product is recovered after separation in the stabilization tower.

A system and a method for steam cracking hydrocarbons are disclosed. The system includes a steam cracking system comprising a first steam cracking furnace and a second steam cracking furnace. A hydrocarbon feed stream is fed into a convection section of a first steam cracking furnace. The preheated feed stream is mixed with steam and then separated into a light vapor stream and a heavy stream in a vapor-liquid separation unit. The light vapor stream is further steam cracked in a radiant section of the first steam cracking furnace. The heavy stream is further heated and steam cracked in the second steam cracking furnace.

Systems and methods for producing a wash oil using a light fuel oil (e.g., cracked distillate) are disclosed. The methods include hydrogenating the cracked distillate and separating the hydrogenated cracked distillate to remove C.sub.4 to C.sub.6 hydrocarbons to produce the wash oil.

System and method for producing olefins are disclosed. The method includes using a radial flow moving bed reactor system to catalytically crack paraffins, in multiple stages with continuous catalyst regeneration, to form olefins. The system includes inter-stage heaters to facilitate increase in yield of olefins.