Novel reactor for producing MMA (methyl methacrylate) from methyl propionate

Abstract

The utility model relates to a novel reactor for producing methyl methacrylate (MMA) from methyl propionate. The novel reactor is characterized in that the novel reactor mainly comprises a reactor and a regenerator, the reactor and the regenerator are connected through an upper catalyst articulated chute and a lower catalyst articulated chute, online reaction and regeneration of the catalyst can be effectively realized, and the problem that a traditional tubular reactor can only stop after the catalyst is inactivated and can be regenerated after replacement is completed is solved. And continuous production of the methyl methacrylate device can be effectively guaranteed. The reactor mainly comprises a reactor outlet, a cyclone separator, a dipleg flap valve, a catalyst return pipe, a reactor inlet and a reactor inlet distributor. The regenerator is mainly composed of a regenerator outlet, a regenerator body and a regenerator inlet.

Description

Technical Field

[0001] The utility model relates to the field of chemical industry, and further relates to a novel reactor for producing methyl methacrylate (MMA) from methyl propionate and methanol. Background Art

[0002] Methyl methacrylate (MMA), also known as methyl methacrylate, is an organic compound. It is a colorless liquid, slightly soluble in water and soluble in most organic solvents such as ethanol. It is mainly used as a monomer for organic glass and is also used in the manufacture of other resins, plastics, coatings, adhesives, lubricants, impregnants for wood and cork, paper polishes, etc.

[0003] Methyl propionate is an organic compound commonly used as a solvent for nitrocellulose, nitro spray paint, coatings, varnishes, etc. It can also be used as a solvent for spices and condiments, and as an organic synthesis intermediate. The utility model is mainly used in the chemical industry to further synthesize methyl methacrylate (MMA) using methyl propionate.

[0004] Methanol is an organic compound and the simplest saturated monohydric alcohol. It is commonly used as a solvent, antifreeze, fuel, etc. In modern industry, methanol has become the main raw material for organic synthesis. The utility model uses methanol as the main raw material to synthesize methyl methacrylate (MMA).

[0005] In the production process of methyl methacrylate (MMA), the reactor is the most important equipment. In the past, the reactor mainly adopted a shell-and-tube fixed-bed reactor. However, the catalyst deactivates quickly during the production process, and the fixed-bed reactor needs to be shut down as a whole to replace the catalyst. Therefore, the utility model proposes a new reactor for producing methyl methacrylate (MMA) from methyl propionate and methanol. Utility Model Content

[0006] The utility model aims to provide a novel reactor for producing methyl methacrylate (MMA) from methyl propionate and methanol, capable of effectively achieving online catalyst reaction and regeneration. This solves the problem of conventional tubular reactors requiring shutdown and regeneration after catalyst deactivation. This reactor effectively ensures continuous production of methyl methacrylate.

[0007] The technical solution of the utility model is as follows:

[0008] A novel reactor for producing methyl methacrylate (MMA) from methyl propionate and methanol. The novel reactor mainly comprises a reactor (9) and a regenerator (11), wherein the reactor and the regenerator are connected by a catalyst upper chute and a catalyst lower chute. The reactor mainly comprises a reactor outlet (1), a cyclone separator (2), a feed leg flap valve (3), a catalyst return pipe (4), a reactor inlet (5), and a reactor inlet distributor (6).

[0009] The reactor (9) is made of carbon steel. The part of the reactor that contacts the catalyst locally adopts anti-wear and anti-coking coating. The methanol and methyl propionate mixed gas passes through the reactor inlet and is distributed inside the reactor through the reactor inlet distributor. Under the action of pressure, the catalyst inside the reactor is lifted. During the lifting process, a large amount of reaction materials pass through the catalyst surface and pass through the catalyst bed. Part of the catalyst moves upward along with the reaction material airflow, and the catalyst as a whole also moves upward. At this time, the catalyst gradually changes from a tightly packed state to a loosely packed state at the top layer, and then to a state of overall upward movement. When the catalyst at the top moves to the top of the reactor, the part connected to the cyclone separator at the top of the reactor enters the cyclone separator. Under the action of gravity, the cyclone separator rotates the catalyst downward and the reaction materials rotate upward. Finally, the reaction materials flow out through the top reactor outlet. Under the control of the material leg flap valve, when the catalyst reaches a certain weight, the material leg flap valve will open, and the catalyst flows out of the cyclone separator body. A part of it returns to the bottom of the reactor along the catalyst return pipe and continues to be mixed with the material for recycling. The other part of the catalyst slides along the catalyst upper slide pipe to the regenerator.

[0010] The main body of the regenerator (11) is made of carbon steel. The catalyst flows into the regenerator from the catalyst upper chute. The regeneration gas enters the regenerator through the regenerator inlet. After the regeneration gas contacts the catalyst, a regeneration reaction is carried out in the regenerator. After the reaction is completed, the gas flows out from the regenerator outlet, and the catalyst flows into the reactor from the regenerator lower chute. The material switching in the catalyst upper chute and the catalyst lower chute is controlled by a chute valve.

[0011] The cyclone separator (2) is inside the reactor. The number of cyclone separators is not limited and can be set according to actual needs. After the cyclone separator separates the catalyst in the reactor, the catalyst can be directly left in the reactor and the material gas can be directly produced. Compared with the traditional regeneration system, the traditional regeneration system uses a cyclone separator outside the reactor. The material gas and catalyst exit the reactor together and enter the cyclone separator. After separation, the catalyst is added to the reactor. The utility model can effectively reduce the flow distance and wear area of ​​the catalyst.

[0012] The catalyst return pipe (4) is outside the reactor. There is no limit on the number of such catalyst return pipes and they can be set according to actual needs. The catalyst return pipe outside the reactor affects the flow of catalyst and materials inside the reactor. At the same time, the return amount and return speed can be controlled by a valve according to the amount of catalyst returned, which can effectively control the number of times the catalyst is recycled.

[0013] The innovative features of this utility model are:

[0014] 1) A novel reactor for producing methyl methacrylate (MMA) from methyl propionate and methanol is provided, which can react methyl propionate and methanol to produce methyl methacrylate (MMA).

[0015] 2) The new reactor adopts the form of a combination of reactor and regenerator, which can realize the online regeneration of catalyst and return it for continued use, achieving the purpose of long-term stable operation.

[0016] 3) The reactor adopts the form of a circulating fluidized bed. The catalyst and the reaction materials flow together to the cyclone separator for separation and then regeneration, which solves the problem that the catalyst is fixed in the reactor and cannot be unloaded.

[0017] 4) The cyclone separator inside the reactor can effectively reduce the flow distance and wear area of ​​the catalyst. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Attachment Figure 1 Schematic diagram of a new reactor for producing methyl methacrylate (MMA) from methyl propionate

[0019] in:

[0020] 1: Reactor outlet 2: Cyclone separator 3: Die leg flap valve

[0021] 4: Catalyst return pipe 5: Reactor inlet 6: Reactor inlet distributor

[0022] 7: Catalyst lower slide 8: Catalyst upper slide 9: Reactor

[0023] 10: Regenerator outlet 11: Regenerator 12: Regenerator inlet DETAILED DESCRIPTION

[0024] The present invention will be further described below with reference to the embodiments, but the present invention is not limited by the embodiments.

[0025] Example

[0026] 10,000 tons / year methyl methacrylate (MMA) reactor

[0027] The reactor body is made of carbon steel, with a diameter of 1m, a total height of 6.8m, and an equipment wall thickness of 8mm. It uses 2 cyclone separators and 3 catalyst return pipes; the regenerator body is made of carbon steel, with a diameter of 0.6m, a height of 2m, and an equipment wall thickness of 8mm.

[0028] A mixture of methanol and methyl propionate passes through the reactor inlet and is distributed throughout the reactor via the reactor inlet distributor. Pressure lifts the catalyst inside the reactor. During this lift, a large amount of reactants passes over the catalyst surface and through the catalyst bed. Some catalyst moves upward with the reactant gas flow, leading the catalyst as a whole upward. The catalyst gradually transitions from a densely packed structure to a loosely packed structure at the top, and then to an overall upward movement. When the catalyst at the top reaches the reactor, it enters the cyclone separator through the portion connected to the reactor top. Gravity pulls the catalyst downward, while the reactants flow upward. Ultimately, the reactants exit through the top reactor outlet. Controlled by a dip leg flap valve, the dip leg flap opens when the catalyst reaches a certain weight, allowing it to flow outside the cyclone separator. Some catalyst returns to the reactor bottom along a catalyst return pipe to mix with the reactants for further recycling, while the remaining catalyst flows along the catalyst upper chute to the regenerator. The reaction temperature is 370°C, and the reaction pressure is 0.5 MPaG.

[0029] Regeneration gas enters the regenerator through the regenerator inlet. After contacting the catalyst, a regeneration reaction occurs in the regenerator. After the reaction is complete, the gas flows out of the regenerator outlet, and the catalyst flows into the reactor through the regenerator downpipe. The material switching between the catalyst uppipe and the catalyst downpipe is controlled by a slide valve. The regeneration temperature is 570°C and the regeneration pressure is 0.35MPaG.

[0030] The reactor and regenerator are in normal use, the reaction effect is good, the cyclone separator has a good separation effect, and the regenerator can effectively regenerate the catalyst and return it for use.

Claims

1. A novel reactor for producing MMA from methyl propionate, characterized in that The structure includes a reactor outlet, a cyclone separator, a feed leg flap valve, a catalyst return pipe, a reactor inlet, a reactor inlet distributor, a catalyst downpipe, a catalyst uppipe, a reactor, a regenerator outlet, a regenerator, a regenerator inlet, the reactor and the regenerator are connected by a catalyst uppipe and a catalyst downpipe, the cyclone separator is arranged inside the reactor, the regenerator body is made of carbon steel, and the material switching in the catalyst uppipe and the catalyst downpipe is controlled by a slide valve.

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