Patent GB-777038-A (GB)
Title: Improvements in or relating to method of carrying out homogeneous vapor phase reactions
IPC: B01J8/34
Filed: 1953-07-21
Abstract: <PICT:0777038/IV(b)/1> A non-catalytic homogeneous vapour-phase reaction, e.g. the partial oxidation of hydrocarbons, is carried out by passing the reactants alternately through reaction zones, which contain substantially no solid particles, and quenching zones which are contiguous with the reaction zones and which contain a dense fluidized mass of inert solid particles.  The alternate reaction and quenching zones may be formed by producing slug flow in the reactor, i.e. by passing the reactants upwardly through the mass of finely divided inert solids at such a velocity with respect to the particle size and density of the solids and the diameter of the reaction vessel that the mass is continuously maintained in the form of a fluidized bed comprising bubbles of appreciable size bounded at their vertical extremities by a fluidized mass of the finely divided solids and surrounded at their horizontal extremities by a wall of the reaction vessel or by a substantially vertical baffle within the reaction vessel; the gases react within the bubbles and the reaction products are quenched by passing into the surrounding fluidized solids.  Alternatively, the alternate reaction and quenching zones may be formed by separate dense fluidized beds and substantially solid-free spaces above the beds. In the apparatus shown, preheated and vaporized hydrocarbon is introduced at 20 and passes through grid 23; oxygen enters via pipes 21 and perforations 21a, 21b . . .  The reactants and inert solids pass upward in slug flow through vertical tubes 27 provided in the reaction vessel.  The fluidized solids descend through regions 28 without slug flow.  Pipes 26 are provided for circulation of a cooling medium, e.g. water, steam, or oil. Reaction products are withdrawn at 22.  In Fig. 2 (not shown), the reaction vessel contains a plurality of shallow dense fluidized beds on superimposed trays separated by gas-phase zones where reaction takes place; the fluidized beds do not form bubbles and are used for quenching the reaction products; the oxidizing gas may be introduced into the fluidized beds for preheating and distribution.  Suitable contact times are 0.1-10 seconds, and the preferred oxygen to hydrocarbon mol. ratio is 0.3-1.5; reaction temperature may be 275-480 DEG  C. and reaction pressure 0.15 p.s.i.g. or higher; steam or nitrogen may be present as a diluent.  Suitable inert solids are sand, glass beads, clays, alumina, coke, carbon powder or granules, powdered copper, nickel or aluminium and steel or iron spheres; the diameter of the particles may be 40-1000 microns, and when bubbles are to be formed, preferably 40-220 microns.  Specified hydrocarbon reactants are n-heptane, light and heavy naphthas, normal or monomethyl substituted paraffins of 5-16 carbon atoms, lower paraffins, olefins, octene-2, cyclohexane, methylcyclopentane and methylcyclohexane.  The process results in the upgrading of the hydrocarbons for fuel purposes, or the formation of C1-C3 aldehydes, acrolein, ketones, alcohols, monocyclic ethers, and olefins.  In the production of oxygenated compounds, the reaction product is cooled and forms a water layer and a hydrocarbon layer; gum-forming aldehydes in the hydrocarbon layer may be converted by light hydrogenation to alcohols or by dehydration to olefins; aldehydes and ketones in the water layer may be hydrogenated to alcohols.  Examples and tables give details of the oxidation of n-heptane and solvent and heavy naphtha using sand and glass beads as the inert solids.  The process may also be used for the selective oxidation of alcohols, ketones, aldehydes and aliphatic amines, ethers and esters, and for halogenations such as chlorinations, oxidations using nitrogen tetroxide as oxygen carrier, decomposition of peroxides and hydroperoxides, sulphurizations involving gaseous sulphur and hydrocarbons, and reactions involving acetylene.  When using a plurality of shallow fluidized beds separated by reaction zones, different reactions may be carried out in sequence, e.g. oxidation in the lower stages and dehydrogenation or dehydration in the upper stages using an alumina or chromia catalyst.ALSO:<PICT:0777038/III/1> A non-catalytic homogenous vapour-phase reaction, e.g. the partial oxidation of hydrocarbons, is carried out by passing the reactants alternately through reaction zones, which contain substantially no solid particles, and quenching zones which are contiguous with the reaction zones and which contain a dense fluidized mass of inert solid particles.  The alternate reaction and quenching zones may be formed by producing slug flow in the reactor, i.e. by passing the reactants upwardly through the mass of finely divided inert solids at such a velocity with respect to the particle size and density of the solids and the diameter of the reaction vessel that the mass is continuouly maintained in the form of a fluidized bed comprising bubbles of appreciable size bounded at their vertical extremities by a fluidized mass of the finely divided solids and surrounded at their horizontal extremities by a wall of the reaction vessel or by a substantially vertical baffle within the reaction vessel; the gases react within the bubbles and the reaction products are quenched by passing into the surrounding fluidized solids. Alternatively, the alternate reaction and quenching zones may be formed by separate dense fluidized beds and substantially solid-free spaces above the beds.  In the apparatus shown, preheated and vaporized hydrocarbon is introduced at 20 and passes through grid 23; oxygen enters via pipes 21 and perforations 21a, 21b...  The reactants and inert solids pass upward in slug flow through vertical tubes 27 provided in the reaction vessel.  The fluidized solids descend through regions 28 without slug flow.  Pipes 26 are provided for circulation of a cooling medium, e.g. water, steam, or oil.  Reaction products are withdrawn at 22.  In Fig. 2 (not shown), the reaction vessel contains a plurality of shallow dense fluidized beds on superimposed trays separated by gas phase zones where reaction takes place; the fluidized beds do not form bubbles and are used for quenching the reaction products; the oxidizing gas may be introduced into the fluidized beds for preheating and distribution.  Suitable contact times are 0.1-10 seconds, and the preferred oxygen to hydrocarbon mol ratio is 0.3-1.5; reaction temperature may be 270-480 DEG C. and reaction pressure 0-15 p.s.i.g. or higher; steam or nitrogen may be present as a diluent. Suitable inert solids are sand, glass beads, clays, alumina, coke, carbon powder or granules, powdered copper, nickel, or aluminium, and steel or iron spheres; the diameter of the particles may be 40-1000 microns, and when bubbles are to be formed, preferably 40-220 microns.  Specified hydrocarbon reactants are n-heptane, light and heavy naphthas, normal or mono-methyl substituted paraffins of 5-16 carbon atoms, lower paraffins. olefins, octene-2, cyclohexane, methylcyclopentane, and methylcyclohexane. The process results in the upgrading of the hydrocarbons for fuel purposes, or the formation of C1-C3 aldehydes, acrolein, ketones, alcohols, monocyclic ethers, and olefins.  In the production of oxygenated compounds, the reaction product is cooled and forms a water layer and a hydrocarbon layer; gum-forming aldehydes in the hydrocarbon layer may be converted by light hydrogenation to alcohols or by dehydration to olefins; aldehydes and ketones in the water layer may be hydrogenated to alcohols.  Examples and tables give details of the oxidation of n-heptane and solvent and heavy naphtha using sand and glass beads as the inert solids.  The process may also be used for the selective oxidation of alcohols, ketones, aldehydes, and aliphatic amines, ethers, and esters, and for halogenations oxidations using nitrogen tetroxide as oxygen carrier, decomposition of peroxides and hydroperoxides, sulphurizations involving gaseous sulphur and hydrocarbons, and reactions involving acetylene.  When using a plurality of shallow fluidized beds separated by reaction zones, different reactions may be carried out in sequence, e.g. oxidation in the lower stages and dehydrogenation or dehydration in the upper stages using an alumina or chromia catalyst.