A system for continuously treating recycled polymeric material includes a hopper configured to feed the recycled polymeric material into the system. An extruder can turn the recycled polymeric material in a molten material. In some embodiments, the extruder uses thermal fluids, electric heaters, and/or a separate heater. The molten material is depolymerized in a reactor. In some embodiments, a catalyst is used to aid in depolymerizing the material. In certain embodiments, the catalyst is contained in a permeable container. The depolymerized molten material can then be cooled via a heat exchanger. In some embodiments, multiple reactors are used. In certain embodiments, these reactors are connected in series. In some embodiments, the reactor(s) contain removable static mixer(s) and/or removable annular inserts.

Oxidative dehydrogenation catalysts for converting lower paraffins to alkenes such as ethane to ethylene when prepared as an agglomeration, for example extruded with supports chosen from slurries of TiO.sub.2, ZrO.sub.2 Al.sub.2O.sub.3, AlO(OH) and mixtures thereof have a lower temperature at which 25% conversion is obtained.

Oxidative dehydrogenation of alkanes employs a catalyst, usually a mixed metal oxide, to convert, in the presence of oxygen, a lower alkane into its corresponding alkene. Continuous operation of an oxidative dehydrogenation process may result in a gradual decrease of catalyst activity and or selection, requiring downtime for regeneration. Provided herein is a process for regeneration of an oxidative dehydrogenation catalyst including initiating regeneration by passing a regeneration gas over the catalyst, monitoring regeneration by comparing the oxygen concentration of the regeneration gas before and after being passed over the catalyst, and ceasing regeneration when the oxygen concentration of the regeneration gas after passed over the catalyst is at least 90% of the concentration of the regeneration gas before being passed over the catalyst.

Oxidative dehydrogenation of alkanes employs a catalyst, usually a mixed metal oxide, to convert, in the presence of oxygen, a lower alkane into its corresponding alkene. Continuous operation of an oxidative dehydrogenation process may result in a gradual decrease of catalyst activity and or selection, requiring downtime for regeneration. Provided herein is a process for regeneration of an oxidative dehydrogenation catalyst including initiating regeneration by passing a regeneration gas over the catalyst, monitoring regeneration by comparing the oxygen concentration of the regeneration gas before and after being passed over the catalyst, and ceasing regeneration when the oxygen concentration of the regeneration gas after passed over the catalyst is at least 90% of the concentration of the regeneration gas before being passed over the catalyst.

The present invention provides a production method of a 3-cyanopyrrole compound possibly useful as an intermediate for pharmaceutical products. A production method of compound (II) including subjecting compound (I) to a reduction reaction, in which the aforementioned reduction reaction is continuous hydrogenation reaction in a fixed bed reactor filled with a supported metal catalyst. A production method of compound (III) including subjecting compound (I) to a reduction reaction followed by a cyclization reaction, in which the aforementioned reduction reaction is continuous hydrogenation reaction in a fixed bed reactor filled with a supported metal catalyst.

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A method of preparing hollow molybdate composite microspheres includes steps of: (1) dissolving 1-4 mmol of MCl.sub.2 in 20 ml of water to obtain a solution A and dissolving 1-4 mmol. of molybdic acid in 20 ml of water to obtain a solution B, followed by mixing the solution A and the solution B, in which M is Co, Ni, or Cu; (2) dissolving 10-40 mmol of urea in 40 ml of water, adding the mixed solution of step (1) and stirring uniformly; (3) placing the mixed solution of step (2) into a reaction vessel and reacting at 120-160 C. for 6-12 hours; (4) suction filtrating and water washing, followed by drying in a vacuum oven at 40-60 C.; (5) calcination at 350-500 C. for 2-4 hours in a Muffle furnace.

A method of preparing hollow molybdate composite microspheres includes steps of: (1) dissolving 1-4 mmol of MCl.sub.2 in 20 ml of water to obtain a solution A and dissolving 1-4 mmol. of molybdic acid in 20 ml of water to obtain a solution B, followed by mixing the solution A and the solution B, in which M is Co, Ni, or Cu; (2) dissolving 10-40 mmol of urea in 40 ml of water, adding the mixed solution of step (1) and stirring uniformly; (3) placing the mixed solution of step (2) into a reaction vessel and reacting at 120-160 C. for 6-12 hours; (4) suction filtrating and water washing, followed by drying in a vacuum oven at 40-60 C.; (5) calcination at 350-500 C. for 2-4 hours in a Muffle furnace.

A method for producing butadiene comprises a step of obtaining a product gas containing butadiene, by feeding a raw-material gas containing straight-chain butene and an oxygen-containing gas containing molecular oxygen to a reactor and performing oxidative dehydrogenation reaction in the presence of a catalyst, wherein the catalyst comprises a composite oxide containing molybdenum and bismuth, and the concentration of hydrocarbons having 5 or more carbon atoms in the raw-material gas is 0.05 mol % to 7.0 mol %.

A fluidized-bed catalyst suitable for the production of halogenated aromatic nitriles includes an active component and a support. The active component is a complex having the following composition expressed in atomic ratio:

VP.sub.aCr.sub.bA.sub.cM.sub.dO.sub.x, wherein A represents at least one metal selected from the group consisting of alkali metals and alkaline earth metals; M represents at least one element selected from the group consisting of Ti, Zr, Hf, La, Ce, Nb, Mo, W, Co, Zn, Fe, Ni, B, Sb, Bi, As, Ga, Ge, Sn, and In; in the XRD spectrum of the catalyst, diffraction peaks are present at 2=27.80.5 and 2=13.80.5, and the ratio of the height (I.sub.1) of the diffraction peak at 2=27.80.5 to the height (I.sub.2) of the diffraction peak at 2=13.80.5 is 3.5-6, i.e. I.sub.1:I.sub.2=3.5-6.

A fluidized-bed catalyst suitable for the production of halogenated aromatic nitriles includes an active component and a support. The active component is a complex having the following composition expressed in atomic ratio:

VP.sub.aCr.sub.bA.sub.cM.sub.dO.sub.x, wherein A represents at least one metal selected from the group consisting of alkali metals and alkaline earth metals; M represents at least one element selected from the group consisting of Ti, Zr, Hf, La, Ce, Nb, Mo, W, Co, Zn, Fe, Ni, B, Sb, Bi, As, Ga, Ge, Sn, and In; in the XRD spectrum of the catalyst, diffraction peaks are present at 2=27.80.5 and 2=13.80.5, and the ratio of the height (I.sub.1) of the diffraction peak at 2=27.80.5 to the height (I.sub.2) of the diffraction peak at 2=13.80.5 is 3.5-6, i.e. I.sub.1:I.sub.2=3.5-6.