Abstract: The present invention is directed to a value chain return process for polyurethane and polyisocyanurate rigid foams containing at least one additive (A1) which is not chemically bonded to the polymer chain selected from the group consisting of phosphorous ester-based flame retardants, polymerization catalysts and surfactants comprising the steps of providing a composition comprising a comminuted polyurethane or polyisocyanurate rigid foam, wherein the comminuted foam has a content of intact cells of less than 10%, based on the number of intact cells of the not comminuted polyurethane or polyisocyanurate rigid foam, and extraction of the additive (A1) with a solvent at a temperature below 190° C.

Abstract: A process of separating phosgene and hydrogen chloride, comprises: conveying a mixed stream containing hydrogen chloride and phosgene into a distillation column; withdrawing from the distillation column a bottom stream containing phosgene; withdrawing a top stream containing hydrogen chloride; compressing at least a portion of the top stream and at least partially condensing the compressed top stream to form a liquid stream, decompressing at least a portion of the liquid stream to form a cooled liquid stream and a cooled gas stream; and recycling the cooled liquid stream to the top of the distillation column as a reflux; the process additionally comprising temporarily introducing an absorbing solvent into the distillation column, in particular during starting-up and/or shutting-down of the process. The process allows for safe operation even when hydrogen chloride production only gradually begins or decreases, without the necessity of storing hydrogen chloride.

Abstract: The present invention is directed to a value chain return process comprising the depolymerization of a polyurethane and polyisocyanurate rigid foam based on polymeric methylenediphenyl diisocyanate (pMDI) to give a mixture (M1); distillative removal of volatile compounds from mixture (M1) to give a mixture (M2) comprising pMDA and at least one polyol; dissolution of the mixture (M2) in an aprotic organic solvent (S1) with a dipol moment in the range from 0.5*10-30 Cm to 7.8*10-30 Cm; and subsequent addition of HCl and separation of the pMDA-HCl salt. The present invention is also directed to the polymeric methylene phenylene amine (pMDA) and the polymeric methylenediphenyl diisocyanate (pMDI) obtained or obtainable according to said process as well as the use thereof for the preparation of polyurethanes or polyisocyanurates.

Abstract: The invention relates to a process for the production of phosgene comprising a gas phase reaction of carbon monoxide and chlorine in the presence of a carbon catalyst in a multi-tubular reactor, wherein the carbon catalyst comprises an amount of mesopores having a pore diameter in the range of from 2 to 50 nm of at least 0.45 ml/g of the total pore volume and the use of a carbon catalyst comprising an amount of mesopores having a pore diameter in the range of from 2 to 50 nm of at least 0.45 ml/g of the total pore volume, for the production of phosgene and a reaction mixture for preparing phosgene, the mixture comprising a catalyst for preparing phosgene comprising a porous material comprising carbon, micropores and mesopores, wherein said micropores have a pore diameter of less than 2 nm and wherein said mesopores have a pore diameter in the range of from 2 to 50 nm, wherein the volume of the mesopores of the porous material is of at least 0.

Abstract: The invention relates to a process for producing phosgene by gas-phase reaction of carbon monoxide and chlorine in the presence of a catalyst in a reactor which comprises a plurality of parallel catalyst tubes which are filled with the catalyst and around which at least one fluid heat transfer medium flows, where a feed stream of a mixture of a chlorine input stream and a carbon monoxide input stream is fed into the catalyst tubes and is allowed to react to give a phosgene-comprising product gas mixture, wherein the reaction is carried out at an area load of more than 2.75 kg of phosgene/m2s. The invention also provides a reactor for carrying out the process.

Abstract: The present invention concerns a process for the preparation of isocyanates and/or polyisocyanates by reacting the corresponding amines with phosgene in a reactor, where isocyanates are obtained from a mixture of amines in gaseous or liquid form and phosgene in gaseous form, wherein no liquid solvents are used in the feeding, mixing, reacting, cooling, separating and purifying steps of the process.

Abstract: The invention relates to a process for preparation of chlorine from hydrogen chloride comprising circulating a liquid melt comprising copper ions Cun+ with n being a number in the range from 1 to 2, alkali cations and chloride ions Cl in a reactor system comprising three bubble lift reactors I, II and III, each comprising a reaction zone i, ii and iii respectively, wherein: ? (a) in the reaction zone i of the first bubble lift reactor I, a liquid melt comprising copper ions Cun+, alkali cations and chloride ions Cl? is contacted with oxygen at a temperature in the range from 395 to 405° C. so that the molar ratio Cun+:Cu+ in the liquid melt increases, obtaining a liquid melt having an increased molar ratio Cun+:Cu+ ? (b) the liquid melt obtained in (a) is circulated to the reaction zone ii in the second bubble lift reactor II, where the liquid melt is contacted with hydrogen chloride at a temperature in the range from 395 to 405° C.

Abstract: The present invention relates to a solvent-efficient process for recycling one or more polymers selected from the group consisting of polyurethanes, polyurethane ureas, polyisocyanurates, and a mixture of two or more thereof, said one or more polymers being contained in a solid material W.

Abstract: The present invention relates to a process for producing one or more polymers, selected from the group consisting of polyurethanes, polyurethane ureas, polyisocyanurates, and a mixture of two or more thereof, from a solid material W.

Abstract: The present invention relates to a process for recycling one or more polymers selected from the group consisting of polyurethanes, polyurethane ureas, polyisocyanurates, and a mixture of two or more thereof, said one or more polymers being contained in a solid material W.

Abstract: The invention relates to a process for producing phosgene by reacting carbon monoxide and chlorine in the presence of a heterogeneous catalyst, comprising: (a) feeding the chlorine and the carbon monoxide into at least one reaction tube which contains the catalyst; (b) reacting the chlorine and the carbon monoxide, thereby forming a phosgene containing reaction gas; (c) cooling the at least one reaction tube by indirect heat transfer to a heat transfer medium which flows through a space surrounding the at least one reaction tube; (d) withdrawing the phosgene containing reaction gas from the at least one reaction tube, wherein the heat transfer medium supplied to the space surrounding the at least one reaction tube has an entrance temperature which is increased from a starting temperature to a maximum temperature.

Abstract: The invention relates to a process for producing isocyanates by reacting the corresponding amines with phosgene in the liquid phase, comprising: (a) mixing an amine comprising feed stream, a phosgene comprising feed stream and optionally an inert solvent; (b) reacting the amine with phosgene in a first reaction section to obtain an intermediate reaction mixture comprising isocyanate, carbamoyl chlorides, amine hydrochlorides and unreacted phosgene; (c) cleaving the carbamoyl chlorides and remove phosgene from the intermediate reaction mixture in a second reaction section to obtain an isocyanate comprising crude product, (d) optionally working-up the crude product; wherein reacting (b) is carried out such that the intermediate reaction mixture comprises 1.7 to 5 mol-% solid amine hydrochlorides based on the molar amount of amine fed into the process.

Abstract: The invention relates to a process for storing a toluene diisocyanate and high boilers containing mixture by feeding the toluene diisocyanate and high boilers containing mixture into a storage vessel (23) and agitating the toluene diisocyanate and high boilers containing mixture.

Abstract: The present invention relates to a process for preparing phosgene by reacting chlorine with carbon monoxide over an activated carbon catalyst, wherein the content of chlorine oxides in the chlorine feed stream is low, to an apparatus for preparation of phosgene and to the use of the phosgene prepared by the process of the invention.

Abstract: The present invention relates to a process for preparing at least one polyisocyanate R(—NCO)x, the process comprising preparing a mixture R1 comprising at least one polyamine R(—NH2)x, with x=2 or more, in a first reaction zone Z1; passing at least a portion P1 of the mixture R1, P1 comprising R(—NH2)x, into a storing device D1 and storing P1 in D1 for a period of time ?t1; removing, after storing for ?t1, at least a portion P2 of P1, P2 comprising R(—NH2)x, from D1; passing P2 into a reaction zone Z2; and reacting, in Z2, R(—NH2)x comprised in P2 with phosgene, obtaining a mixture R2 comprising the at least one polyisocyanate R(—NCO)x; wherein ?t1 is in the range of from 1 minute to 7 d.

Abstract: The invention relates to a process for producing phosgene by conversion of chlorine and CO over an activated carbon catalyst, wherein the activated carbon catalyst is dried by reducing the water content, where the drying comprises the following steps: a) contacting the catalyst with an inert gas stream b) determining the residual moisture content of the catalyst by determining the moisture content in the offgas stream c) ending the drying process after attainment of the desired moisture content in the offgas stream by switching from the inert gas to the reaction gases and optionally d) heating up the catalyst bed and/or the inert gas during the drying process.

Abstract: A process of separating phosgene and hydrogen chloride, comprises: conveying a mixed stream containing hydrogen chloride and phosgene into a distillation column; withdrawing from the distillation column a bottom stream containing phosgene; withdrawing a top stream containing hydrogen chloride; compressing at least a portion of the top stream and at least partially condensing the compressed top stream to form a liquid stream, decompressing at least a portion of the liquid stream to form a cooled liquid stream and a cooled gas stream; and recycling the cooled liquid stream to the top of the distillation column as a reflux; the process additionally comprising temporarily introducing an absorbing solvent into the distillation column, in particular during starting-up and/or shutting-down of the process. The process allows for safe operation even when hydrogen chloride production only gradually begins or decreases, without the necessity of storing hydrogen chloride.

Abstract: The invention relates to a process for producing phosgene by gas phase reaction of carbon monoxide and chlorine in the presence of a solid-state catalyst in a shell-and-tube reactor (1) comprising catalyst tubes (3) which are surrounded by a reactor shell (23) and which accommodate the solid-state catalyst and around which a temperature control medium flows, and baffle plates (27) arranged at right angles to the catalyst tubes (3) in order to generate crossflow of the temperature control medium with respect to the catalyst tubes (3), comprising the following steps: (a) feeding a gas mixture comprising carbon monoxide and chlorine into the shell-and-tube reactor (1), such that the reaction mixture enters the catalyst tubes (3) at one end; (b) reacting the carbon monoxide with chlorine to give phosgene in the catalyst tubes (3) to give a phosgene-containing product stream; (c) withdrawing the phosgene-containing product stream from the shell-and-tube reactor (1), wherein the amount of liquid temperature cont

Abstract: The invention relates to a process for at least partially separating a light boiling component from a mixture containing said light boiling component and at least a heavy boiling component, the process comprising the steps of (a) feeding the mixture into a distillation column and withdrawing a distillate stream enriched in the light boiling component from the top section of the distillation column and withdrawing a bottom stream enriched in the heavy boiling component from the bottom section of the distillation column: and (b) transferring at least part of the distillate stream as a condensation stream to a condensation device wherein the condensation stream is at least partially condensed and recycled to the top section of the distillation column, wherein the condensation device comprises a pump and a de Laval nozzle having a throat, a converging zone before the throat and a diverging zone after the throat, the condensation stream being passed into the converging zone of the de Laval nozzle, the condensation

Abstract: The present invention relates to a continuous process for preparing phosgene as well as a production unit for carrying out said process.