Abstract: Provided a method for separating PHA and PHA prepared therefrom. The method comprises the following steps: subjecting a PHA fermentation broth to solid-liquid separation to obtain a thallus precipitate; breaking cell walls of the thallus precipitate, and subjecting obtained wall-broken products to a plate and frame filtration to obtain PHA; a filter cloth for the plate and frame filtration is pre-coated with a PHA layer. The method adopts a plate and frame separation to replace the traditional centrifugal separation to prepare PHA, and the PHA layer is pre-coated on the filter cloth for the plate and frame filtration, thereby overcome the defects in the prior art such as high cost and operational difficulty caused by adopting multiple centrifugal separations; in addition, the method of the present disclosure also exhibits the advantages of high recovery rate of PHA and high purity of the prepared PHA product.

Abstract: Provided a method for separating PHA and PHA prepared therefrom. The method comprises the following steps: subjecting a PHA fermentation broth to solid-liquid separation to obtain a thallus precipitate; breaking cell walls of the thallus precipitate, and subjecting obtained wall-broken products to a plate and frame filtration to obtain PHA; a filter cloth for the plate and frame filtration is pre-coated with a PHA layer. The method adopts a plate and frame separation to replace the traditional centrifugal separation to prepare PHA, and the PHA layer is pre-coated on the filter cloth for the plate and frame filtration, thereby overcome the defects in the prior art such as high cost and operational difficulty caused by adopting multiple centrifugal separations; in addition, the method of the present disclosure also exhibits the advantages of high recovery rate of PHA and high purity of the prepared PHA product.

Abstract: A method for efficiently producing PHA comprising: inoculating PHA fermentation strains into a fermentation medium for fermentation under the condition of being capable of producing PHA through fermentation; subjecting the fermentation broth to a solid-liquid separation to obtain fermentation supernatant and thallus precipitate; breaking the cell walls of the thallus precipitate, and subjecting the wall-broken products to a plate and frame filtration to prepare PHA; pre-coating a filter cloth for the plate and frame filtration with a PHA layer; at least part of the water of the fermentation medium is PHA process wastewater. The method utilizes the PHA process wastewater as at least part of the water of the fermentation medium, and filters and separates the broken thallus with the plate and frame filtration equipment pre-coated with PHA layer to prepare PHA, thereby recycling the high-salt wastewater, reducing costs, and potentially separating PHA on a large scale for industrial production.

Abstract: The present disclosure relates to the technical field of polymer material, and discloses a device and method for online preparation of a modified polylactic acid material with a polylactic acid melt. The device comprises a twin-screw extruder, a first solid modifier hopper, a polylactic acid melt pipeline and a polylactic acid melt feedstock metering pump, wherein the first solid modifier hopper is connected with Zone I of the twin-screw extruder, the polylactic acid melt pipeline is connected with Zone IV of the twin-screw extruder. The method for online preparation of modified polylactic acid material with the device can avoid degradation of the polylactic acid caused by the secondary processing, improve mechanical property of the prepared polylactic acid and reduce production cost.

Abstract: The present invention relates to the technical field of polylactic acid preparation, and discloses polylactic acid polymerization reaction apparatus and system. The polylactic acid polymerization reaction apparatus comprises a polymerization reactor and an agitating assembly arranged in a flow channel of the polymerization reactor, wherein the agitating assembly comprises an electromagnetic winding mechanism and a magnetic induction element, the electromagnetic winding mechanism is arranged along the inner wall of the polymerization reactor around the magnetic induction element, with clearance formed between the electromagnetic winding mechanism and the magnetic induction element, so that the magnetic induction element and the electromagnetic winding mechanism can induce electromagnetic induction, and thereby the magnetic induction element can rotate around its own axis; a threaded groove is formed on the magnetic induction element.

Abstract: The present invention relates to the field of devolatilization, and discloses a polylactic acid devolatilization evaporator, which comprises: a container comprising a cylinder; an agitating shaft coaxial with the cylinder; an agitating belt connected to the agitating shaft and arranged in a spiral shape around the central axis of the cylinder, comprising an outer belt surface facing the inner circumferential surface of the cylinder and spaced apart from the inner circumferential surface of the cylinder. With the above technical scheme, the agitating belt makes the materials distributed more uniformly on the inner circumferential surface of the cylinder and form a thin layer in uniform thickness, thereby avoids agglomeration of the materials, facilitates uniform heating of the materials, avoids deterioration (e.g., darkened color) of the materials owing to non-uniform heating of the materials and excessive retention time in a high-temperature environment, and improves product quality.

Abstract: The present invention relates to a method for obtaining a fraction oil yield from petroleum hydrocarbons in a distillation column, wherein said distillation column comprises a fractionation stage, a vaporization section and a stripping stage from the top to the bottom of the distillation column. The method comprises preheating and sending a feedstock oil of petroleum hydrocarbons through a pressure-feeding system at a pressure of 100-1000 kPa higher than the vaporization section pressure of the distillation column, wherein said preheating is conducted in a heating furnace, wherein said heating furnace has an outlet pressure of 100-1000 kPa higher than the vaporization section absolute pressure, and an outlet temperature of 360-460° C.

Abstract: A method for improving yield of petroleum hydrocarbon distillate in a distillation tower (6) comprises: preheating raw oil of petroleum hydrocarbon ready for fractionation; feeding it to a vaporization section (11) through a pressure feed system (3) under a pressure 100-1000 kPa higher than the vaporization section (11) of the distillation tower (6) for simultaneous atomizing and vaporizing; then feeding it to a fractionation section (13) for distillation-separation; and finally, discharging distillate product from the top and/or side of the tower and unvaporized heavy oil from the bottom. A distillation tower (6) for improving yield of petroleum hydrocarbon distillate comprises a vaporization section (11) and a fractionation section (13), and further comprises a pressure feed system (3) for feeding the raw oil of petroleum hydrocarbon ready for fractionation under a pressure 100-1000 kPa higher than that in the vaporization section (11) of the distillation tower (6).

Abstract: A conversion apparatus for catalytic cracking a hydrocarbon feed to light hydrocarbon comprises at least one riser reactor, a dense bed reactor, a disengager, and a stripper. A dense bed reactor which is separated from disengage, is employed to enforce further cracking hydrocarbon to light olefins, with low methane yield. Moreover, the spent catalysts discharged from the outlet of the dense bed reactor can be introduced into the stripper via a specific catalyst transporting channel, to maintain catalyst concentration in the dense bed reactor that can be advantageous to deeper cracking of the intermediate products to produce more light olefins, particularly propylene.

Abstract: The present invention relates to a catalytic conversion apparatus, characterized in that said apparatus comprises at least one feed oil cracking riser reactor, a dense bed reactor, a disengager, and a stripper, wherein said stripper locates below said dense bed reactor and communicates directly with the lower part of the dense bed reactor or through a fluid-communicating channel, the outlet of at least one of said riser reactor(s) communicates with the lower part of said dense bed reactor or any part of said fluid-communicating channel, the outlet of said dense bed reactor communicates with the inlet of a gas-solid separating apparatus located in said disengager through said disengager and/or through an optional transporting channel, the catalyst outlet of said disengager communicates with at least one position selected from the upper part of said stripper, any part of said fluid-communicating channel, and the lower part of said dense bed reactor, through at least one catalyst transporting channel.

Abstract: A downflow catalytic cracking reactor, comprising the following components: catalyst delivery pipe (1), reactor top cover (2), feed nozzle (3), reactor vessel (6), downflow reaction pipe (9), the upper end of the outer body is close connected to top cover (2) along the direction of circumference; the bottom of the outer wall body is close connected to the outer wall of the downflow reaction pipe; the upper section of the downflow reaction pipe is located inside the reaction vessel, while the lower section extends from the bottom of the outer body; feed nozzle (3) is located on the top cover (2) and/or side wall of the reactor vessel (6) with the outlet of the feed nozzle being above the inlet of the downflow reaction pipe; catalyst delivery pipe (1) is fixedly joined to the reactor vessel and in communication with catalyst lifting zone (7) formed by the reaction vessel and the downflow reaction pipe.

Abstract: A downflow catalytic cracking reactor, comprising: one or more catalyst delivery pipes, reactor top cover, one or more feed nozzles, reactor vessel, downflow reaction pipe, the upper end of the reaction vessel is close connected with top cover along the direction of circumference; the bottom of the reactor vessel is close connected with the outer wall of the downflow reaction pipe; the upper section of the downflow reaction pipe locates inside the reactor vessel, while the lower section extends from the bottom of the reactor vessel; feed nozzle locates on the top cover and/or side wall of the reactor vessel with the outlet of the feed nozzle being above the inlet of downflow reaction pipe; catalyst delivery pipe is fixedly jointed with the reactor vessel and communicated with catalyst lifting zone formed by the reactor vessel and the downflow reaction pipe. Besides, the present invention also provides the use of the reactor.

Abstract: The present invention discloses a catalytic cracking process of petroleum hydrocarbons and a tube-in-tube riser reactor used therein. In the present invention, a catalyst is fed via an inlet conduit to an inner tube and an annular space between the inner and outer tubes of the tube-in-tube riser reactor to contact a hydrocarbon feedstock, and the hydrocarbon feedstock is cracked under FCC conditions, then a reaction stream thus produced flows into a separation apparatus via a confluence tube to separate a hydrocarbon product stream from a spent catalyst, the spent catalyst is stripped and regenerated, then a regenerated catalyst is recycled for reuse. The process of the present invention can improve both product distribution and product properties.