Abstract: Disclosed are a fast fluidized bed reactor, device and method for preparing para-xylene and co-producing light olefins from methanol and/or dimethyl ether and toluene, with the reactor, device and method being capable of solving or improving the problem of competition between an alkylation reaction and an MTO reaction during the process of producing the para-xylene and co-producing light olefins from toluene and methanol, thus achieving a synergistic effect between the MTO reaction and the alkylation reaction. By controlling the mass transfer and reaction, the competition between the alkylation reaction and the MTO reaction is coordinated and optimized to achieve a synergistic effect, thereby increasing the conversion rate of toluene, the yield of para-xylene and the selectivity of the light olefins.

Abstract: A fast fluidized bed reactor, device and method for preparing para-xylene and co-producing light olefins from methanol and/or dimethyl ether and benzene, resolving or improving the competition problem between an MTO reaction and an alkylation reaction during the process of producing para-xylene and co-producing light olefins from methanol and/or dimethyl ether and benzene, and achieving a synergistic effect between the MTO reaction and the alkylation reaction. By controlling the mass transfer and reaction, competition between the MTO reaction and the alkylation reaction is coordinated and optimized to facilitate a synergistic effect of the two reactions, so that the conversion rate of benzene, the yield of para-xylene, and the selectivity of light olefins are increased.

Abstract: The present invention relates to a process for preparing phthalic anhydride by gas phase oxidation of aromatic hydrocarbons, in which a gas stream comprising at least one aromatic hydrocarbon and molecular oxygen is passed continuously over a thermostatted catalyst and the supply of the at least one aromatic hydrocarbon to the catalyst is temporarily interrupted after putting the catalyst on stream.

Abstract: A method for producing phthalic anhydride by catalytic gas-phase oxidation of o-xylene and/or naphthalene, carried out by means of a catalyst arrangement which has a first catalyst layer at the gas inlet side and at least one second catalyst layer after the first catalyst layer in the gas flow direction with different catalytic activity, wherein when the gas-phase oxidation is being carried out a lower maximum temperature is formed in the first catalyst layer than in the second catalyst layer. Furthermore, a method for producing the catalyst arrangement, as well as the catalyst arrangement itself.

Abstract: A method for producing phthalic anhydride by catalytic gas-phase oxidation of o-xylene and/or naphthalene, carried out by means of a catalyst arrangement which has a first catalyst layer at the gas inlet side and at least one second catalyst layer after the first catalyst layer in the gas flow direction with different catalytic activity, wherein when the gas-phase oxidation is being carried out a lower maximum temperature is formed in the first catalyst layer than in the second catalyst layer. Furthermore, a method for producing the catalyst arrangement, as well as the catalyst arrangement itself.

Abstract: The present invention relates to a process for gas-phase oxidation, in which a gaseous stream comprising an aromatic hydrocarbon and molecular oxygen is passed through two or more catalyst zones. Furthermore, the present invention relates to a catalyst system for gas-phase reaction using a preliminary zone.

Abstract: The present invention relates to a catalyst, in particular for the preparation of phthalic anhydride by gas phase oxidation of o-xylene and/or naphthalene, having an inert support and at least one layer which has been applied thereto and has a catalytically active composition comprising TiO2, characterized in that at least a portion of the TiO2 used has the following properties: (a) the BET surface area is more than 15 m2/g, (b) at least 25% of the total pore volume is formed by pores having a radius between 60 and 400 nm, and (c) the primary crystal size is more than 22 ångstrøm. Also described is a preferred process for preparing such a catalyst, and the preferred use of the titanium dioxide used in accordance with the invention.

Abstract: The present invention relates to a catalyst for preparing phthalic anhydride by gas phase oxidation of o-xylene and/or naphthalene, comprising at least three catalyst zones which have different compositions and, from the gas inlet side toward the gas outlet side, are referred to as first, second and third catalyst zone, the catalyst zones having in each case an active composition comprising TiO2, and the active composition content decreasing from the first catalyst zone disposed toward the gas inlet side to the third catalyst zone disposed toward the gas outlet side, with the proviso that (a) the first catalyst zone has an active composition content between about 7 and 12% by weight, (b) the second catalyst zone has an active composition content in the range between 6 and 11% by weight, the active composition content of the second catalyst zone being less than or equal to the active composition content of the first catalyst zone, and (c) the third catalyst zone has an active composition content in the rang

Abstract: The present invention relates to the use of titanium dioxide having a content of sulphur, calculated as elemental sulphur, of less than about 1000 ppm and a BET surface area of at least 5 m2/g for preparing a catalyst for gas phase oxidation of hydrocarbons, especially for gas phase oxidation of o-xylene and/or naphthalene. Also described is a preferred process for preparing such a catalyst.

Abstract: The present invention relates to a catalyst for preparing phthalic anhydride by gas phase oxidation of o-xylene and/or naphthalene, comprising at least three catalyst zones which have different compositions and, from the gas inlet side toward the gas outlet side, are referred to as first, second and third catalyst zone, the catalyst zones having in each case an active composition comprising TiO2 with a content of Na of less than 0.

Abstract: The present invention relates to a catalyst, in particular for the preparation of phthalic anhydride by gas phase oxidation of o-xylene and/or naphthalene, having an inert support and at least one layer which has been applied thereto and has a catalytically active composition comprising TiO2, characterized in that at least a portion of the TiO2 used has the following properties: (a) the BET surface area is more than 15 m2/g, (b) the primary crystal size is more than 210 ångstrøm. Also described is a preferred process for preparing such a catalyst, and the preferred use of the titanium dioxide used in accordance with the invention.

Abstract: The present invention relates to the use of a catalyst comprising at least one first catalyst zone located towards the gas inlet, a second catalyst zone located closer to the gas outlet and a third catalyst zone located even closer to or at the gas outlet for the preparation of phthalic anhydride by gas-phase oxidation of o-xylene and/or naphthalene, with the catalyst zones preferably each having an active composition comprising TiO2, characterized in that the catalyst activity of the first catalyst zone is higher than the catalyst activity of the second catalyst zone. Furthermore, a preferred process for the preparation of phthalic anhydride is described.

Abstract: The present invention relates to processes for improving or optimizing a catalyst for the preparation of phthalic anhydride by gas-phase oxidation of o-xylene and/or naphthalene, which comprises the following steps: a) provision of a starting catalyst (C) comprising at least one first catalyst zone located towards the gas inlet and a second catalyst zone located closer to the gas outlet, with the catalyst zones preferably each having an active composition comprising TiO2; b) replacement of part of the first catalyst zone by an upstream zone of a catalyst having a higher activity than the first catalyst zone in order to provide an improved catalyst. Furthermore, an improved catalyst obtainable by this process is described.

Abstract: A process for gas phase oxidation in which a gaseous stream which comprises at least one aromatic hydrocarbon and molecular oxygen is passed through one or more catalyst layers, wherein a moderator layer is arranged between two catalyst layers arranged in succession in flow direction of the gaseous stream, the moderator layer being less catalytically active than the catalysts adjacent upstream and downstream or being catalytically inactive. The desired oxidation products are obtained in high yield over prolonged periods.

Abstract: A multimetal oxide of the formula I, Aga-cQbMcV2Od*e H2O,??I where a is from 0.3 to 1.9, Q is an element selected from among P, As, Sb and/or Bi, is from 0 to 0.3, M is a metal selected from among Nb, Ce, W, Mn, Ta, Pd, Pt, Ru and/or Rh, c is from 0.001 to 0.5, with the proviso that (a-c)?0.1, d is a number which is determined by the valence and abundance of the elements other than oxygen in the formula I and e is from 0 to 20, and also precatalysts and catalysts produced therefrom for the partial oxidation of aromatic hydrocarbons are described.

Abstract: The invention relates to a process for preparing phthalic anhydride, in which the catalytic gas-phase oxidation of o-xylene and/or naphthalene is carried out over at least three zones of catalysts of increasing activity, with only the last zone of the catalyst system containing phosphorus and the last zone also comprising at least 10% by weight of vanadium (calculated as V2O5) based on the active composition of the catalyst and having a ratio of vanadium (calculated as V2O5) to phosphorus of greater than 35.

Abstract: A description is given of a process for preparing aldehydes, carboxylic acids and/or carboxylic anhydrides, in particular phthalic anhydride, in which a gaseous stream comprising an aromatic hydrocarbon and molecular oxygen is passed at elevated temperature over a bed of a first catalyst and a bed which is made up of a second catalyst having a higher activity than the first catalyst and is located downstream of the first catalyst in the flow direction of the gaseous stream, wherein the catalytically active composition of the first catalyst comprises at least vanadium oxide, titanium dioxide and antimony oxide and the ratio of vanadium, calculated as V2O5, to antimony, calculated as Sb2O3, in the first catalyst is from 3.5:1 to 5:1. The source of antimony oxide used for the first catalyst is preferably particulate antimony trioxide having a mean particle size of from 0.5 to 5 ?m. The process allows the desired oxidation products to be obtained in high yield over longer periods of time.

Abstract: Improved organophotoreceptor comprises an electrically conductive substrate and a photoconductive element on the electrically conductive substrate, the photoconductive element comprising: (a) a charge transport compound having the formula where R1 and R2 are, independently, hydrogen, an alkyl group, an alkaryl group or an aryl group; X is an aromatic group; Y is an (N,N-disubstituted)arylamine; Z is (CH2)m group where m is an integer between 0 and 30 where one or more of the methylene groups is optionally replaced by O, S, C?O, O?C—O, O?C—NR3, sulfoxide, sulfate, phosphate, an aryl group, urethane, urea, NR4 group, CHR5 group, or CR6R7 group where R3, R4, R5, R6, and R7 are, independently, H, hydroxyl, thiol, an amine group, an alkyl group, an alkaryl group, a heterocyclic group, or an aryl group, and E is a bond, O, S, C?O, NR8, CR9R10 group, a hetrocyclic group, or an aromatic group where R8, R9, and R10 are, independently, H, an alkyl group, an alkaryl group, or an aryl group; and (b) a charg

Abstract: A composition comprising at least one G protein inhibitor of the formula wherein the substituents are defined as in the specification and the salts thereof and at least one other antihypertensive agent for the treatment of arterial hypertension.

Abstract: A thermal cutoff member and compositions used to manufacture such members are described herein as including at least two organic compounds which, when sufficiently combined, give rise to a component which has a lower melt transition temperature than the initial organic compounds prior to combining the same. The thermal cutoff member is generally utilized in a thermal cutoff construction having an electrical switching unit that changes its operating condition when the member therein melts by being heated to a certain temperature for the particular material that forms the member being utilized.

Abstract: A process for cooling a hot reaction gas, as formed, in the preparation of phthalic anhydride by oxidation of o-xylene with hot air in a reactor (213), to a predetermined inlet temperature for introduction into a separator (221), in which the separation into crude phthalic anhydride and air is then effected, is described. A simple and economical design, which can be used for comparable processes, too, of a system for cooling the hot reaction gas, which simultaneously gives rise to low maintenance costs, is obtained by locating upstream of the separator (221) a heat exchanger (227) through which a cooling medium flows, the hot reaction gas being passed through the heat exchanger (227) for interaction with the cooling medium. Especially such a system comprises in addition to a main reactor (213) a downstream reactor (241), which my have a means for intermediate cooling (243), and the gaseous cooling medium leaving the heat exchanger 227 will be fed to the main reactor (213) as reactant.

Abstract: In a process for preparing phthalic anhydride by passing a gas stream comprising o-xylene, oxygen and sulfur dioxide at elevated temperature over a catalyst comprising heavy metals, the content of N-acyl compounds in the gas stream is restricted to less than 200 ppm, based on the weight of o-xylene.

Abstract: This invention relates to the vapor-phase oxidation of hydrocarbons by passing a gaseous mixture comprising of a molecular oxygen-containing gas and hydrocarbons which may contain substituents to a fixed bed of catalyst and provides a process for vapor-phase oxidation to be effected by passing a gaseous mixture of raw materials to a fixed bed of catalyst in which the void ratio of the catalyst layers increases by stages in one step or more from upstream downward in the flow of the gaseous mixture of raw materials. For example, the process can oxidize in vapor phase such hydrocarbons as naphthalene, xylene, benzene, toluene, durene, butene, acenaphthene, anthracene, indene and their derivatives in high yields with high productivity. Moreover, the process can prepare phthalic anhydride in high yields with high productivity by the vapor-phase oxidation of naphthalene or ortho-xylene.

Abstract: The invention relates to a heterogeneous vanadium-phosphorus oxide catalyst system for the selective oxidation of hydrocarbons, which may or may not be saturated, comprising a support based on one or more metal oxides, and vanadium-phosphorus oxide in an amount of from 0.01 to 45 wt. %, based on the weight of the catalyst and calculated as (VO).sub.2 P.sub.2 O.sub.7, to a process for the selective oxidation of an organic compound in the presence of a vanadium-phosphorus oxide catalyst, which process comprises an oxidation and a reduction phase, wherein a hydrocarbon is contacted with said catalyst in the reduction phase and in oxidized or non-oxidized form is adsorbed to the catalyst, whereafter the thus loaded catalyst is brought into the oxidation phase, the desired product is formed in the presence of gaseous oxygen and subsequently separated.

Abstract: A process for recovering phthalic anhydride as a liquid from a vapor phase oxidation product which comprises mixing the vapor phase oxidation product having a temperature of about 130.degree. C.

Abstract: A family of aza-ether based compounds including linear, multi-branched and aza-crown ethers is provided. When added to non-aqueous battery electrolytes, the family of aza-ether based compounds acts as neutral receptors to complex the anion moiety of the electrolyte salt thereby increasing the conductivity and the transference number of Li.sup.+ ion in alkali metal batteries.

Abstract: This invention is directed towards an improved process for the selective gas phase oxidation of a organic reactant using a metal oxide redox catalyst, wherein the organic reactant and air feeds are at a substantially continuous level, the improvement comprising adding a fluctuating flow of oxygen at alternating relatively high and relatively low levels. The invention also teaches means by which a gas may be provided to a reaction process on a fluctuating basis.

Abstract: The process for making phthalic anhydride by catalytic gas phase oxidation of o-xylene or naphthalene includes feeding a gas containing oxygen and the reactant to a first reactor; operating the first reactor to oxidize the reactant and obtain an effluent gas including the reactant, phthalic anhydride and/or maleic anhydride; adding the reactant or a gas containing the reactant to the effluent so that a molar ratio of moles of free oxygen to a sum of moles of the organic compounds in the effluent is less than 7, preferably from 3 to 6; after that, feeding the effluent into a second reactor; and operating the fixed bed reactor to at least partially convert the reactant in the effluent to phthalic anhydride.

Abstract: An improved process is provided for the production of a partial oxidation product by the vapor phase reaction of a hydrocarbon with substantially pure oxygen in the presence of a suitable catalyst. In the improved process, the partial oxidation product is removed, carbon dioxide and excess carbon monoxide, present in the reactor effluent as by-products, are also removed and the remaining gaseous effluent, comprised mainly of carbon monoxide and unreacted hydrocarbon, is recycled to the reactor. The concentration of carbon monoxide throughout the system is maintained sufficiently high to prevent the formation of a flammable mixture in the reactor or associated equipment.

Abstract: An improvement in the oxidation catalyst used for the partial oxidation of n-butane and containing vanadium and phosphorus, zinc and lithium mixed oxides which comprises adding a molybdenum compound modifier in an amount of from about 0.005 to 0.025/1 Mo/V to the catalyst during the digestion of the reduced vanadium compound by concentrated phosphoric acid. The addition of Mo produces a catalyst which is very stable more active system and longer lived than the unmodified catalyst.

Abstract: Petrochemicals are produced by the vapor phase reaction of a hydrocarbon with substantially pure oxygen in the presence of a suitable catalyst. In the improved process, the principal product is removed, carbon monoxide, present in the reactor effluent as a byproduct, is oxidized to carbon dioxide and part of the gaseous effluent, comprised mainly of carbon dioxide and unreacted hydrocarbon, is recycled to the reactor. Removal of carbon monoxide from the recycle stream reduces the hazard of a fire or explosion in the reactor or associated equipment. The use of carbon dioxide as the principal diluent increases heat removal from the reactor, thereby increasing the production capacity of the reactor.

Abstract: A process for the production of carboxylic anhydrides from aromatic hydrocarbons in gas phase oxidation by using a high activity and high selectivity fluid catalyst, comprising 50 to 95% by weight calculated as TiO.sub.2 +SiO.sub.2 +B.sub.2 O.sub.3 of component (A) which comprises titanium oxide, silicon dioxide and boron oxide and5 to 50% by weight calculated as V.sub.2 O.sub.5 +M.sub.2 O (M represents an alkali metal) +SO.sub.3 of component (B) comprising vanadium oxide, an alkali metal oxide and sulfuric anhydride, wherein weight ratios of B.sub.2 O.sub.3 to TiO.sub.2 and SiO.sub.2 to TiO.sub.2 in said component (A) are in the range of 0.02 to 0.5 and 0.25 to 1.0, respectively, is provided.

Abstract: A process for reacting a fluid phase (gaseous and/or liquid phase) in contact with a solid phase in a reaction zone, wherein the improvement in said process comprises reacting the fluid phase in contact with the solid phase in a horizontally-oriented fluidized bed vessel. The vessel includes at least two compartments or stages, and includes means for vibrating the vessel. The process of the present invention enables one to effect fluidization of the solid phase independently of the flow rate or velocity of the fluid phase, thus enabling proper contact time of the fluid phase with the solid phase and minimizing the amount of fluid phase reactant to be recycled.

Abstract: A method for reducing the formation of dust produced by solid aromatic anhydrides, and aromatic anhydride compositions that have a reduced tendency to emit aromatic anhydride dust, are disclosed. The method comprises treating the aromatic anhydride with low levels of suitable organic compounds.

Abstract: The invention relates to a catalyst for producing phthalic anhydride by gas phase catalytic oxidation of o-xylene and/or naphthalene with molecular oxygen or gas containing molecular oxygen and, to a process for producing phthalic anhydride by using said catalyst. The catalyst is made by supporting, on a heat-resistant inorganic carrier, a catalytic active substance which comprises: vanadium oxide; anatase type titanium dioxide having specific surface area of 10 to 60 m.sup.2 /g; niobium; at least one element selected from potassium, cesium, rubidium and thallium; phosphorus; and antimony. The catalytic active substance is prepared by using a five-valent antimony compound as an antimony source. The process for producing phthalic anhydride comprises use of said catalyst.

Abstract: The present invention relates to the oxidation of organic compounds in a non-uniform fluidized solid catalyst reaction system characterized in that a temperature profile is maintained in the reaction system such that a predominance of the oxidation occurs in a higher temperature zone, unreacted organic compound is adsorbed on the catalyst surface in a lower temperature zone, direct back-circulation of catalyst is restricted between zones and catalyst containing adsorbed organic compound is circulated from the lower temperature zone to the higher temperature zone.

Abstract: A high activity and high selectivity fluid catalyst for use in gas phase oxidation of aromatic hydrocarbons, comprising 50 to 95% by weight (calculated by TiO.sub.2 +SiO.sub.2 +B.sub.2 O.sub.3) of component (A) which comprises titanium oxide, silicon dioxide and boron oxide and 5 to 50% by weight [calculated by V.sub.2 O.sub.5 +M.sub.2 O (M represents an alkali metal)+SO.sub.3 ] of component (B) comprising vanadium oxide, an alkali metal oxide and sulfuric anhydride, wherein weight ratios of B.sub.2 O.sub.3 to TiO.sub.2 and SiO.sub.2 to TiO.sub.2 in said component (A) are in the range of from 0.02 to 0.5 and from 0.25 to 1.0, respectively, is provided.

Abstract: An improved process is provided for the production of a petrochemical by the vapor phase reaction of a hydrocarbon with an oxygen-containing gas in the presence of a suitable catalyst to produce a flammable gaseous product stream comprising the desired petrochemical, unreacted hydrocarbon, oxygen, carbon monoxide and carbon dioxide. In the improved process, a cooled or liquefied inert gas is injected as a quench fluid into the gaseous product stream exiting the hydrocarbon oxidation reactor, thereby cooling the stream to a temperature below the autoignition temperature of the flammable components of the stream, the petrochemical is recovered from the gaseous product and unreacted hydrocarbon is removed from the gaseous product and recycled to the reactor.

Abstract: This invention provides a process for the production of an anhydride by the vapor phase reaction of a hydrocarbon with substantially pure oxygen in the presence of a suitable catalyst. In the improved process, the anhydride product is removed, carbon monoxide, present in the reactor effluent as a by-product, is oxidized to carbon dioxide and part of the gaseous effluent, comprised mainly of carbon dioxide and unreacted hydrocarbon, is recycled to the reactor. Removal of carbon monoxide from the recycle stream reduces the hazard of a fire or explosion in the reactor or associated equipment. The use of carbon dioxide as the principal diluent increases heat removal from the reactor, thereby increasing the production capacity of the reactor.

Abstract: An improved process is provided for the production of anhydrides from hydrocarbons by reaction with an oxygen-containing gas comprising oxygen, air or a gas enriched in oxygen relative to air, in the presence of a suitable catalyst. In the process, a selective separator provides recycle of a substantial portion of the unreacted hydrocarbon as well as for a controlled amount of a gaseous flame suppressor in the system. The gaseous flame suppressor comprises a substantially unreactive hydrocarbon containing 1 to 5 carbon atoms, carbon dioxide, and nitrogen when present in the feed to the oxidation reactor. The use of air or oxygen-enriched air in the feed to the oxidation reactor is particularly advantageous from an economic view in combination with a pressure swing adsorption unit as the selective separator. The process is characterized by high selectively to the formation of the anhydride product.

Abstract: Catalyst compositions are disclosed containing potassium pyrosulfate, cesium pyrosulfate, supported on an inorganic oxide. The catalysts will selectively oxidize naphthalene and/or o-xylene to phthalic anhydride in a fluidized- or fixed-bed reactor system. Sulfur-containing gaseous promoter may be fed with the aromatic hydrocarbon to enhance selectivity.

Abstract: Catalyst compositions are disclosed containing potassium pyrosulfate, cesium pyrosulfate, supported on an inorganic oxide. The catalysts will selectively oxidize naphthalene and/or o-xylene to phthalic anhydride in a fluidized- or fixed-bed reactor system. Sulfur-containing gaseous promoter may be fed with the aromatic hydrocarbon to enhance selectivity.

Abstract: A process for the manufacture of phthalic anhydride by oxidation in the gas phase of an o-xylol naphthalene mixture. By producing a solution of 1 to 80 parts by mass naphthalene in 99 to 20 parts by mass o-xylol at a temperature of 0.degree. to 80.degree. C., storing the solution at that temperature, heating the solution only shortly prior to the reaction to 110.degree. to 180.degree. C., atomizing the heated solution into a hot airflow, passing the heated solution over metal oxide catalysts in the gas phase and collecting phthalic anhydride product, a problem-free manufacture of phthalic anhydride is attained.

Abstract: A method is disclosed for preparing titania-containing catalysts and catalyst supports that are fluidizable and attrition-resistant. By the method, a fluidizable substrate is impregnated with titanyl sulfate or a related compound. The compositions may be used to advantage in applications requiring titania-bearing catalysts or titania supports and are particularly useful in preparing fluid bed catalysts for the oxidation of o-xylene and naphthalene to phthalic anhydride.

Abstract: A mixture will involve a risk of explosion if a concentration limit is exceeded. For this reason only part of the liquid is admixed to the gas in a first mixing zone so that the concentration limit above which there is a risk of explosion will not be exceeded. In a second mixing zone, the remaining quantity of liquid is added to the mixture withdrawn from the first mixing zone and the explosive concentration is exceeded. That mixture, in which the gas and liquid are distributed as homogeneously as possible, is reacted in a reaction zone. The reaction zone directly succeeds the second mixing zone.

Abstract: Catalytic material is prepared by impregnating porous silica with an aqueous solution containing vanadyl oxalate (VOC.sub.2 O.sub.4), potassium sulfate (K.sub.2 SO.sub.4) and potassium bisulfate (KHSO.sub.4). A free-flowing dry-appearing powder is provided comprising particles having substantially all compounds deposited from the impregnating solution attached to the silica particles within pores of the particles. Subsequent calcining of the powder provides a mixture of compounds within the particle pores containing at least one oxide of vanadium and at least one sulfate of potassium. Catalytic material prepared by the disclosed process is characterized in having a substantially uniform concentration of deposited compounds within the pores of the silica support. The catalytic material is particularly useful in a process for fluid bed oxidation of naphthalene to phthalic anhydride, in which oxidation process the catalyst provides high product yield at a low catalyst attrition rate.

Abstract: A system for producing phthalic anhydride by the catalytic oxidation of naphthalene, wherein the system is characterized by reduced capital and operating costs due to lower operating pressures.

Abstract: A system for producing phthalic anhydride by the catalytic oxidation of naphthalene, wherein without creating a significant pressure drop in the system substantially all of the catalyst particles are removed from the product stream before the product stream is sent to a battery of switch condensers for recovery of the phthalic anhydride.

Abstract: A process for the preparation of phthalic anhydride (PA) of catalytic oxidation of naphthalene or o-xylene with air, a preheated mixture of air and naphthalene or o-xylene being passed into a reactor charged with the catalyst, and the reaction gas leaving the reactor being passed through a separator in which the PA is separated out as a solid, in which process the air fed to the reactor is preheated, before or after the admixture of naphthalene or of o-xylene, by using it to cool the reaction gas in the PA separator.

Abstract: The present invention is a reactor that consists of a single shell that contains a reaction zone and a regeneration zone. The reaction zone and regeneration zone are arranged in such a manner that (a) a particulate solid may be transferred by flow of gases from the regeneration zone to the reaction zone by a first route and then back to the regeneration zone by a second route; and (b) the gases passing through the regeneration zone are not transferred to the reaction zone and the gases passing through the reaction zone are not transferred to the regeneration zone.