221results about "Refining by filtration" patented technology

The present invention belongs to the technical field of oil extraction and provides a sand fracturing wellhead device, comprising a main pipe, a branch pipe connected to the side of the main pipe, a mounting ring slidably installed in the branch pipe, and a second telescopic member fixedly installed in the branch pipe to drive the mounting ring to move, the mounting ring and the branch pipe are coaxially arranged and the outer side of the mounting ring is in sliding contact with the inside of the branch pipe, a first filter is fixedly installed in the mounting ring, and a temporary storage box is provided on the branch pipe, the temporary storage box is located on the outside of the branch pipe and a storage box and a connecting groove are fixedly installed at both ends of the temporary storage box, and the connecting groove is connected to the branch pipe. Compared with the prior art, the beneficial effects of the present invention are as follows: impurities on the first filter screen will fall off the first filter screen due to speed reasons, and at the same time, the oil flowing into the connecting groove will drive the impurities that have fallen off the first filter screen into the temporary storage box, thereby achieving the cleaning of impurities on the first filter screen, and the cleaning of the first filter screen can be achieved without stopping the transportation of oil.

Belonging to the field of petrochemical engineering, the invention discloses a catalytic slurry oil purification device, which comprises a tank body, and a feed end and a discharge end respectively arranged at two ends of the tank body. An upper partition plate and a lower partition plate are fixedly connected to the inner wall of the tank body, a discharging opening is formed in the upper partition plate, and a feeding opening is formed in the lower partition plate; the interior of the tank body is divided into three independent cavities by the upper partition plate and the lower partition plate; according to the scheme, the filter element is sleeved with the hollow cylinder, and the rotatable first spiral flow deflector is further arranged between the inner wall of the hollow cylinder and the outer wall of the filter element; a rotatable first spiral flow deflector is further arranged between the inner wall of the hollow cylinder and the outer wall of the filter element; a shear force generated by rotation of the first spiral flow deflector can prevent a filter cake on the surface of the filter element from forming a compact thick layer; a filter cake layer can be controlled within a relatively thin thickness range, and the rising speed of the pressure difference is delayed, so that the operation duration of a single filtering period is prolonged; and the single-time continuous treatment capacity of the device is greatly improved.

A filter and method for removing solids from FCC oil slurries and concentrates thereof is provided. The filter comprises a main tank (4), a first filter cylinder, a second filter cylinder and a third filter cylinder, each of which is composed of a main conduit and a number of secondary conduits with porous outer walls surrounding the main conduit, each of which is fitted with a single turn of first filter membrane around its outer periphery, a filter cake scraper (7) installed inside the main tank above the third filter cylinder, and a deslagging bin (8) installed at the bottom of the main tank. The present invention can achieve complete solid-liquid separation of FCC oil slurry and its concentrate, and fully automatic, intelligent operation.

The invention relates to the technical field of gas anchors, in particular to a variable pitch type spiral gas anchor. Comprising an anchor body, a sand prevention cylinder is installed on the lower side of the anchor body, a sand prevention hole is formed in the sand prevention cylinder, a spiral piece is fixedly connected into the anchor body, a center pipe fixedly connected with the anchor body is fixedly connected to the middle of the spiral piece, and the anchor body, the spiral piece and the center pipe are matched to form a spiral channel. A separation cavity is formed in the upper side of the spiral piece in the anchor body, the screw pitch of the lower side of the spiral piece is smaller than that of the upper side of the spiral piece, the screw pitch of the upper side of the spiral piece is gradually increased from bottom to top, and exhaust holes which are distributed in a spiral shape and located in the inner side of the spiral piece are formed in the center pipe. Petroleum pushes gas to the middle by setting the screw pitch of the spiral piece, the gas in the spiral channel is exhausted in advance in cooperation with the exhaust hole, the amount of the gas accumulated in the separation cavity is reduced, and it is guaranteed that the oil pumping process is conducted smoothly.

The invention provides a high-pressure crude oil filtering separator with a pressure self-adaptive adjustment function, and relates to the technical field of filtering and separating devices.The high-pressure crude oil filtering separator comprises a flow dividing pipe, filtering boxes are arranged at the bottoms of the two ends of the flow dividing pipe, connecting pipes are fixed to the tops of the filtering boxes, and propellers are rotationally installed in the connecting pipes through spokes; a flow dividing pipe is arranged at the bottom of the filter box, an oil inlet pipe is fixed to the top of the middle of the flow dividing pipe, an oil discharging pipe is arranged on one side of the bottom of the filter box, a separator is arranged at the rear end of the filter box, and a conveying pipe is fixed to the top of the oil discharging pipe. Crude oil is filtered and separated through the leakage frame and the conical filtering plate in the filtering box, comparison is conducted according to the crude oil output efficiency of the bottom of the filtering box, the situation that crude oil is insufficient or a filtering structure is blocked is distinguished, the filtering structure is cleaned or the rotating speed of a propeller is increased according to needs, and the passing rate of the crude oil is increased by improving pressure.

The present invention relates to a method for treating plastic pyrolysis oil, comprising: a) hydrogenating said feedstock in a mixture with at least a portion of the liquid effluent obtained from step c) in the presence of hydrogen and a catalyst at a temperature of 140-340° C.; b) hydrotreating said hydrogenated effluent in the presence of hydrogen and a catalyst; c) separating the hydrotreated effluent, said separation being carried out at high temperature and under high pressure to obtain a gaseous effluent and a liquid effluent, and recycling a portion of the liquid effluent upstream of step a); d) feeding at low temperature and under high pressure the other portion of the gaseous and liquid effluents obtained from step c) and an aqueous solution to carry out the separation and obtain a hydrocarbon-based effluent.

The utility model relates to the technical field of waste oil regeneration, and discloses a waste white oil alkali washing device which comprises a tank body, a heating assembly is installed on the periphery of the tank body, a sleeve, a servo motor and a feeding pipe are sequentially and fixedly connected to the top of the tank body from left to right, and a liquid discharging pipe is fixedly connected to the bottom of the tank body. A stirring assembly is installed in the tank body, a top ring is slidably connected to the middle of a sleeve, a filtering barrel is fixedly connected to the bottom of the top ring, a connecting pipe is fixedly connected to the top of the top ring, an elastic assembly is installed in the middle of the top ring, a clamping block is slidably connected to the middle of the top ring, and a clamping groove is formed in the middle of the sleeve; and the middle part of the sleeve is slidably connected with a push rod. According to the utility model, firstly, waste white oil is input through the connecting pipe, and larger impurities can be filtered under the action of the filtering barrel at the bottom of the connecting pipe, so that the mixing efficiency of the waste white oil and a sodium hydroxide aqueous solution is ensured, and the impurities are prevented from blocking the pipeline.

The invention relates to a method for treating a feedstock comprising a plastics-derived and / or tyre-derived and / or solid-recovered-fuel-derived pyrolysis oil, which method comprises: b) hydrogenation of the feedstock and a portion of the liquid effluent resulting from the separation step e1) to obtain a hydrogenated effluent; c) hydrotreatment of the hydrogenated effluent to obtain a hydrotreated effluent; d) hydrocracking of the hydrotreated effluent to obtain a hydrocracked effluent; e1) separation of the hydrocracked effluent at high temperature and high pressure to obtain a gaseous effluent and a liquid effluent, a portion of which is recycled upstream of step b); e2) a separation / washing step carried out at low temperature and high pressure, fed with the gaseous effluent and optionally the other portion of the liquid effluent resulting from step e1) and an aqueous solution, to obtain a hydrocarbon effluent freed of its impurities.

Aspects of the present disclosure generally relate to new processes for converting waste plastic. Aspects of the present disclosure also generally relate to new waste plastic conversion plants. In an aspect, a process for converting waste plastic is provided. The process includes heating a waste plastic feed with a dissolution medium to form a mixture comprising an insoluble component and a soluble component. The process further includes separating the soluble component of the mixture from the insoluble component of the mixture. The process further includes contacting the soluble component with a depolymerization catalyst to form a depolymerization product effluent. The process further includes separating a C12+ hydrocarbon from the depolymerization product effluent. The process further includes introducing the C12+ hydrocarbon to the dissolution unit.

The present invention relates to a method for pyrolysis of plastics, particularly waste plastics, comprising the steps of (a) pyrolysis of the plastic in a first pyrolysis reactor to obtain a first pyrolysis product, (b) separation of the pyrolysis residue from the first pyrolysis product in a first separation unit, (c) separation of the pyrolysis residue into a low-solid fraction and a high-solid fraction in a second separation unit, and (d) pyrolysis of the high-solid fraction in a second pyrolysis reactor to obtain a second pyrolysis product. The present invention further relates to a device for pyrolysis of plastics using the method.

The utility model provides an oil field filtering device which comprises a tank body, a filter screen is connected inside the tank body in a sliding mode, one end of the filter screen is fixedly connected with a connecting rod, one end of the connecting rod is fixedly connected with a vibration motor, the vibration motor and one end of the tank body are fixedly connected with a spring support, and one end of the filter screen is connected with a scraping plate in a sliding mode. One end of the tank body is fixedly connected with a stirring motor, one end of a power output shaft of the stirring motor is provided with a plurality of buffer grooves, one ends of the buffer grooves and the scraper blade are fixedly connected with springs III, one end of the scraper blade is slidably connected to the buffer grooves, one end of the stirring motor is rotatably connected with a limiting ring, and a limiting ring is fixedly connected in the tank body; sediment in crude oil can be filtered out through the filter screen, the rotating scraper blade can scrape away the sediment attached to the lower portion of the filter screen in the filtering process to keep the filter screen smooth, meanwhile, the vibration motor drives the filter screen to vibrate through the connecting rod at set intervals, vibration cleaning can be conducted, the filter screen is further prevented from being blocked, and the filtering effect is kept.

A process for reducing injector deposits in an internal combustion engine fuelled with a fuel composition, the process comprising contacting a fuel composition with a metal-selective membrane situated in the fuel delivery system. The reduction of such deposits provides an increase in fuel efficiency, fuel thermal stability, boost in engine cleanliness, improves fuel economy and enables the possibility of using a reduced amount of expensive detergent in the fuel composition.

The present invention relates to a method for treating a feedstock comprising pyrolysis oil from plastics and / or tires and / or solid recovered fuels containing halogenated compounds, said method comprising: a) a hydrotreating step to obtain a partially hydrotreated effluent having a reduced content of halogenated compounds; b) a separation step in which the hydrotreated effluent from step a) and an aqueous solution are fed to obtain a gaseous effluent, an aqueous effluent and a partially hydrotreated hydrocarbon effluent; and c) a step of fluidized bed catalytic cracking or hydrotreating of a petroleum feedstock and / or a feedstock resulting from biomass conversion, in which the partially hydrotreated hydrocarbon effluent is introduced as a co-feed without a prior separate hydrotreatment step at higher temperature and / or pressure, and the mixture of petroleum and / or biomass feedstock and the partially hydrotreated hydrocarbon effluent has a halogenated compound content of 10 ppm or less by weight.

The present invention relates to a method for producing an intermediate fraction and naphtha from a mixed raw material containing a heavy fraction of fossil hydrocarbons, wherein at least 50% by weight of the heavy fraction is a pyrolysis oil fraction of plastics and / or tires and / or recovered solid fuels, the initial boiling point of the compound being greater than 300°C and the final boiling point being less than 700°C, and less than 50% by weight is an aromatic compound content of more than 30% by weight, and the method comprises the following steps: a) a step of hydrogenating the mixed raw material to obtain a hydrogenated effluent; b) a step of hydrocracking the hydrogenated effluent to obtain a hydrocracking effluent; c) a step of separating the hydrocracking effluent to produce at least one gaseous effluent and at least one liquid effluent containing hydrogen; d) a fractional distillation step to produce a naphtha fraction and an intermediate distillate fraction.

The invention discloses a filtering device suitable for aviation kerosene and a filtering method thereof, and belongs to the technical field of aviation fuel purification and filtration. The cylinder shell, the annular supporting ribs and the main filter material form a filter cylinder, kerosene penetrates through the intervals of the annular supporting ribs from outside to inside and gathers in the central positioning shaft to be led out, in a quasi working state, the filter assembly is disassembled and transversely inserted into an inner cavity of the filter element socket, one end of the filter assembly is fixed in the inner cavity of the filter element socket, and the locking piece is driven to amplify thrust through the force amplifier; the pressing rod linearly extrudes the filter element, the threaded transmission sleeve is rotated through the spiral driving rod, so that the piston pressing disc compresses the cotton core at a constant speed, residual oil is recovered from the bottom liquid drainage hole in the axial direction, and the cotton core is taken out after squeezing; the filter element of the same cylinder is not replaced, only the inner-end fine filter layer is replaced by the reducing fine filter layer with a smaller inner diameter, the through-flow area is suddenly reduced, the local flow speed is increased, the surface of a main filter material is reversely washed, and impurities fall off; the reducing step generates secondary high pressure difference, the fiber gap is further compressed, and the precision is improved.

The method according to the invention for treating a starting substrate, which contains at least one solid substance and at least one high-boiling hydrocarbon, comprises the following steps: adding a liquid extractant (B) to the starting substrate (A, A') in a mixing stage (3); homogenizing the starting substrate-extractant mixture in a homogenizing stage (5); splitting the starting substrate-extractant mixture (C) drawn off from the homogenizing stage (5) into a solids fraction (E), containing predominantly solids, and a liquid fraction (F), containing predominantly liquid, in a solids separation means (8); splitting the solids fraction (E), in batches, into a solids residue (G) and a vapor fraction (H) by vacuum evaporation means (9); isolating the extractant from the liquid fraction (F), so as to form a hydrocarbon-containing residue (K), in a thermal separation stage (11); recirculating the extractant isolated in the thermal separation stage (11), together with extractant recovered from the vapor fraction (H) emerging from the vacuum evaporation means (9), in order to add said extractant to the starting substrate (A, A') again; and separately discharging the hydrocarbon-containing residue (K) and the solids residue (G) from the treatment plant.

A method of producing useful fuel fluids from solid plastic waste, including loading solid plastic waste matter into a reaction chamber to define a load, subjecting the load to HTP to extract hydrocarbon mixtures, filtering the hydrocarbon mixtures to extract solid matter, and separating the hydrocarbon mixtures into a light fraction (C1 to C25) and a heavy fraction (C26 to C31). The heavy fraction is directed to a first container and the light fraction is directed to a second container. The light fraction is separated into diesel (C8-C25), gasoline (C4-C12), and vapor (C1-C5), and the diesel is directed to a third container, the gasoline is directed to a fourth container, and the vapor is directed to a fifth container. The hydrocarbon mixtures have a carbon number distribution between C1 and C31. The pressure in the reaction chamber is typically between 0.1 and 10 MPa and the temperature in the reaction chamber is between 350 and 500 degrees Celsius. The plastic waste is selected from the group consisting of PS, PE, PP, and mixtures thereof.

The utility model discloses a petroleum filtering device for petroleum exploitation, belongs to the technical field of filtering equipment, and aims to solve the technical problems that a petroleum filtering device in the prior art is limited in filtering precision and difficult to meet the requirement of petroleum exploitation on high quality of petroleum. The petroleum filtering device for petroleum exploitation comprises a tank body, a feeding pipe is arranged at the top end of the tank body, an inner cylinder is vertically arranged in the tank body, the bottom end of the inner cylinder and the inner bottom wall of the tank body are sealed, a clamping cavity is formed between the inner cylinder and the inner side wall of the tank body, the top end of the inner cylinder is hermetically covered with a filtering cover, and a second filtering net is embedded in the filtering cover; and a filter cylinder is arranged in the inner cylinder. The petroleum filtering device for petroleum exploitation adopts double filtration, can effectively improve the filtering quality of petroleum, meets the requirements of petroleum exploitation on petroleum quality, has an impurity cleaning function, reduces the blocking frequency of the filter screen, ensures the filtering efficiency and the service life of the filter screen, and reduces the workload and the cost of manual cleaning.

The invention relates to the technical field of engines, in particular to a device for oil recovery treatment after engine testing. The recovery container comprises a box body, a magnetic filter plate and a flow baffle; the magnetic filter plate is mounted in the box body and is parallel to the bottom surface of the box body, and a set distance is formed between the magnetic filter plate and the bottom surface of the box body; the flow baffle comprises an upper-layer plate and a lower-layer plate, the upper-layer plate and the lower-layer plate are both perpendicular to the bottom surface of the box body, a set distance is formed between the upper-layer plate and the lower-layer plate, the lower edge of the lower-layer plate is attached to the bottom surface of the box body, the lower edge of the upper-layer plate is attached to the top surface of the magnetic filter plate, and the lower edge of the upper-layer plate is lower than the upper edge of the lower-layer plate. Through an optimized multi-stage filtering structure and reasonable flow field control, efficient purification of recycled diesel oil is achieved, it is ensured that the recycled diesel oil reaches the secondary use standard, and therefore the engine failure risk is reduced, the test run cost is saved, and meanwhile diesel oil waste and environmental pollution are avoided.

To provide a base oil production method, a base oil production apparatus, and a base oil production and logistics complex system with the same that can efficiently meet supply of various waste oils and recycled oils and demand for the various base oils.SOLUTION: A base oil production method comprises: a raw material oil storage step for distributing and storing at least one kind of raw material oils selected from waste oils and recycled oils in any one of a plurality of storage tanks based on properties of the raw material oils; and a base oil preparation step having at least one step selected from a step (1) for making a base oil without mixing the raw material oils distributed to the plurality of storage tanks with other raw material oils, and a step (2) for mixing at least two of the raw material oils distributed in the plurality of storage tanks to form the base oil. There are also provided a base oil production apparatus, and a base oil production and logistics complex system with the same.SELECTED DRAWING: Figure 1

This invention relates to the field of petroleum filtration, and particularly to an online backflushing wedge filter element filtration device for petroleum refining. It includes a tank with a through-type upper and lower section, with top covers installed at both ends. A through-pipe runs through both the upper and lower top covers. Several telescopic plates are installed on the lower top cover, with annular plates at the ends of the telescopic plates. A support shaft is installed on the annular plates, and another annular plate is installed on the top of the support shaft. Filtration units are installed between the annular plates. This invention uses a drive assembly to move an adjusting plate between the strip plates, adjusting the gap width between the adjusting plate and the strip plates. This allows it to adapt to different particle sizes and morphologies of impurities in petroleum, solving the contradiction between filtration accuracy and flow rate in traditional filtration devices, as well as the problem of fixed filter gaps in existing technologies that cannot be flexibly adapted.

The present invention relates to a process and system for forming a hydrocarbon feedstock from a biomass material, and the hydrocarbon feedstock formed therefrom. The biomass may be cellulose, hemicel

The utility model discloses an oil and gas gathering and transportation filtering device, which comprises a rectangular shell and a cover plate, the right side of the rectangular shell is provided with an opening, the cover plate is fixed on the right side of the rectangular shell, the bottom of the rectangular shell is sequentially communicated and fixed with a slag discharge pipe and an oil discharge pipe from left to right, and the left side of the top of the rectangular shell is communicated and fixed with an inlet pipe with the top end of a plugging structure; the top of the inlet pipe is fixedly communicated with an exhaust valve, the left side of the inlet pipe is fixedly communicated with an oil-gas inlet pipe, and a valve is installed on the oil-gas inlet pipe. By arranging a series of structures, solid residues in oil liquid can be filtered and intercepted when oil gas is introduced, the filter screen can be automatically cleaned and dredged at regular time, the solid residues can be conveniently discharged, manual cleaning and residue taking work is not needed, the use automation degree and convenience are improved, oil inlet and oil outlet work can be temporarily stopped during cleaning, and the use efficiency is improved. And after cleaning, dredging and deslagging, automatic unblocking can be carried out for continuous oil filtering work, unmanned automatic operation is facilitated, and the labor cost is saved.

The application discloses a self-cleaning crude oil wax removal filter system and belongs to the technical field of crude oil conveying and filtering. The system comprises a filter structure installed on a crude oil conveying pipeline. The filter structure comprises a plurality of groups of parallel filter pipe groups. Each group of filter pipe groups is composed of a communication pipe, a filter with an embedded filter screen, a pressure transmitter, a control valve group, a backwashing unit and / or a heating unit, and a control unit. The control unit determines the working condition based on the pressure conveying standard. If the pressure is qualified, the operation is maintained. If the pressure is unqualified, the control valve group is closed, the blowdown valve is opened, and the backwashing unit and the heating unit are started, so that the self-cleaning operation of the inside of the filter pipe group is realized. The application realizes intelligent self-cleaning, guarantees the continuity of crude oil conveying, improves the wax removal filtering efficiency, is suitable for various conveying scenes of waxy crude oil, and can solve the problems of manual cleaning, discontinuous conveying and poor wax removal effect of the traditional filter system.

The invention relates to the field of industrial white oil processing, in particular to an industrial white oil filtering device which comprises a rack, a filtering kettle is fixed to the rack, a sealing cover is arranged above the filtering kettle, a feeding pipe is arranged on the sealing cover, a discharging pipe is fixed to the bottom of the filtering kettle, a motor is further fixed to the sealing cover, and the motor is connected with the filtering kettle. The output end of the motor is fixed to a fixing rod below the sealing cover, a filtering barrel is fixed to the fixing rod, filtering holes are evenly formed in the filtering barrel, a fixing shaft is further fixed in the filtering barrel, and a supporting ring rotationally connected with the fixing shaft is arranged on the fixing shaft; a scraping plate matched with the inner wall of the filtering barrel for use is further fixed on the supporting ring, and a torsional spring is further fixed between the supporting ring and the fixing rod. According to the device, white oil is quickly filtered in a centrifugal manner, so that the filtering speed of the white oil is greatly improved.

This invention discloses a device for filtering catalytic oil slurry using ceramic membranes, relating to the field of filtration equipment technology. It includes multiple sets of ceramic membrane mounting assemblies arranged in a ring. Each ceramic membrane mounting assembly includes a ceramic membrane body and an outer cylinder. An upper connecting assembly and a lower connecting assembly are respectively installed at the upper and lower ends of the assembly. The lower connecting assembly is connected to a sinking control assembly. The side wall of the outer cylinder is connected to a filter collection pipe. An upper retainer and a lower retainer are provided between the outer cylinders, with the lower retainer sleeved to the outer cylinder. A rotation mechanism is provided at the center of the upper retainer, and a lifting mechanism is provided on the lower side of the upper retainer. The lifting mechanism drives the lower retainer to move up and down. By lifting the outer cylinder where the ceramic membrane body breaks, and combining this with the sinking control assembly to sink the lower connecting assembly, the ceramic membrane body can be quickly replaced, ensuring the filtration efficiency of the catalytic oil slurry.

The utility model discloses a separating device for removing solid particles in catalytic slurry oil. The separating device comprises a barrel body, a hollow shaft, a filtering membrane plate, a motor, a feeding pipe, a discharging pipe and a filtrate discharging pipe A, the hollow shaft is arranged in the barrel, the upper end of the hollow shaft is fixed at the top of the barrel through a sealing piece A and extends out of the top of the barrel to be connected with the motor, the lower end of the hollow shaft is fixed at the bottom of the barrel through a sealing piece B and extends out of the bottom of the barrel, and the bottom of the barrel is connected with a filtrate discharging pipe A through a flange; a plurality of layers of filtering membrane plates are arranged on the hollow shaft in sequence and are fixed through a sealing piece C; by adopting a rotary structure of the multiple layers of filtering membrane plates and the hollow shaft, solid particulate matters can be effectively prevented from depositing on the membrane surface and blocking membrane holes, the continuous and stable operation time is long, and the backwashing is easy; the device is simple in structure, easy to operate, high in separation efficiency, good in separation precision, low in production cost and good in economic benefit.

The utility model discloses a water bath heating and filtering device which comprises a water bath filtering box, a filtering funnel is connected to the top of the water bath filtering box in an inserted mode, a fixing assembly is arranged between the filtering funnel and the water bath filtering box, and an electric heating pipe is fixedly installed in the water bath filtering box. And four supporting mounting columns are fixedly connected to the bottom of the water bath filter box. According to the utility model, water is added into the water bath filter box through the water inlet pipeline, the water level submerges the conical part of the filter funnel, and the three groups of electric heating pipes are started to heat the water in the water bath filter box; crude oil is poured into the filtering funnel, filtered through the filtering paper and then flows into the material receiving beaker to be collected, a worker observes the speed of the crude oil flowing into the material receiving beaker and judges the fluidity of the crude oil, and convenience is brought to follow-up mining.

Water is combined with an oligomer product that contains an oligomer and an alkyl aluminum catalyst to deactivate the catalyst and form a treated product containing the oligomer and aluminum-containing solids. The aluminum-containing solids then can be separated from the treated product.

A method for treating a feedstock comprising pyrolysis oil of plastics and / or tires and / or recovered solid fuels containing halogenated compounds is disclosed, comprising: a) a hydrotreating step to obtain a partially hydrotreated effluent having a reduced halogenated compound content; b) a separation step feeding the hydrotreated effluent from step a) and an aqueous solution to obtain a gaseous effluent, an aqueous effluent, and a partially hydrotreated hydrocarbon effluent; and c) a petroleum feed steam cracking step in which at least a portion of the partially hydrotreated hydrocarbon effluent is introduced as a co-feed without previously being subjected to another hydrotreating step at a higher temperature and / or pressure, wherein the mixture of the petroleum feedstock and the partially hydrotreated hydrocarbon effluent from step b) has a halogenated compound content of 3 ppm or less by weight.