Abstract:
The present invention relates to the use of a compound of the general formula (I) wherein R1 is C1-C4-alkyl or —(C=0)—R3, R2 is hydrogen, C1-C4-alkyl or —(C=0)—R4, and R3 and R4, independently of one another, are selected from the group consisting of hydrogen and C1-C4-alkyl, a stereoisomer thereof or a mixture of stereoisomers thereof, as an aroma chemical, to aroma chemical compositions comprising at least one compound of the general formula (I), a stereoisomer thereof or a mixture of stereoisomers thereof, and to a method for preparing a fragranced ready-to-use composition, which comprises incorporating at least one compound of the general formula (I), a stereoisomer thereof or a mixture of stereoisomers thereof, into a ready-to-use composition. The present invention further relates to specific ethers and specific esters of the compounds of the general formula (I) and a method for their preparation.
Abstract:
A process for activating a fixed catalyst bed is disclosed. The fixed catalyst bed includes monolithic shaped catalyst bodies or include monolithic shaped catalyst bodies including at a first metal selected from Ni, Fe, Co, Cu, Cr, Pt, Ag, Au and Pd, and a second component selected from Al, Zn and Si. The fixed catalyst bed, for activation, is treated with an aqueous base having a strength of not more than 3.5% by weight. The base is selected from alkali metal hydroxides, alkaline earth metal hydroxides and mixtures thereof. The fixed catalyst bed has a temperature gradient during the activation and the temperature differential between the coldest point in the fixed catalyst bed and the warmest point in the fixed catalyst bed is kept at not more than 50 K.
Abstract:
The present invention relates to a process for preparing adipic acid or at least one conversion product thereof, in which muconic acid is hydrogenated with hydrogen in the presence of at least one transition metal catalyst C and of an aqueous liquid A in a reaction zone, wherein the muconic acid is at least partly insoluble in the liquid A under the hydrogenation conditions.
Abstract:
Process for the continuous hydrogenation of a carboxylic acid (I) to an alcohol (II) by means of hydrogen at a temperature of from 100 to 300° C. and a pressure of 10 to 33 MPa abs in a reactor tube through which axial flow occurs and which has a fixed-bed catalyst which is fixed therein and comprises at least one element from the group consisting of Re, Co and Cu, and in which the carboxylic acid (I) to be hydrogenated is present in a liquid mixture (Ill) comprising the carboxylic acid (I), water and alcohol (II), where the mixture (Ill) has an acid number of from 0.2 to 25 mg KOH/g and comprises at least 15% by weight of water and at least 20% by weight of alcohol (II) and the flow velocity of the flowing liquid calculated on the basis of the geometric cross-sectional area of the empty, catalyst-free reactor tube is from 10 to 50 m/h.
Abstract:
A process for decomposing formates in formate-containing compositions of matter comprises reacting formate-containing compositions of matter in the presence of at least one heterogeneous catalyst comprising lanthanum and at a temperature of from 80 to 180° C. and a pressure of from 0.1 to 60 bar, the formate-containing compositions of matter having a pH of from 6.5 to 10
Abstract:
The present invention relates to a process for purifying a crude nitrogen-containing, sulfur-containing, halogen-containing pyrolysis oil originating from the pyrolysis of plastic waste, comprising (i) subjecting the crude pyrolysis oil to a treatment with a trapping agent selected from (a) an elemental metal of group 1, 2, 6, 7, 8, 9, 10, 11, 12, 13 of the IUPAC periodic table, a mixture or an alloy thereof; (b) an oxide of metals of group 1, 2, 6, 7, 8, 9, 10, 11, 12, 13 of the IUPAC periodic table or a mixture thereof; (c) an alkoxide of metals of group 1, 2 of the IUPAC periodic table or a mixture thereof; (d) a solid sorption agent as defined in the claims; or a combination of at least two trapping agents (a), (b), (c) or (d); (ii) separating the product obtained into a purified pyrolysis oil fraction having a reduced nitrogen, sulfur and halogen content in relation to the crude pyrolysis oil and a fraction comprising the trapping agent which has bound at least a part of the sulfur, nitrogen, halogen present in the crude pyrolysis oil
Abstract:
The present invention relates to aroma chemical compositions containing 3,5-diethyl-2-propyl-tetrahydropyran, a 3,5-diethyl-2-propyl-dihydropyran or a 3,5-diethyl-2-propyl-pyran, a mixture of such compounds, a stereoisomer of one of these compounds, or a mixture of stereoisomers of one or more of these compounds. The invention further relates to a method for preparing such compounds, stereoisomers or mixtures thereof, to the composition obtainable by this method, to the use of such compounds as an aroma chemical or for modifying the scent character of a fragranced composition; and to a method for preparing a fragranced composition or for modifying the scent character of a fragranced composition using said compounds. Moreover, the invention relates to 3,5-diethyl-2-propyl-tetrahydropyran, to its stereoisomers and to mixtures of these stereoisomers.
Abstract:
Process for preparing monoethylene glycol (MEG) by metal-catalyzed reaction of a dialkyl oxalate of the formula I where R1 and R2 are each, independently of one another, methyl, ethyl, n-propyl or isopropyl, with hydrogen (H2), wherein the dialkyl oxalate (I) is used as melt or as a solution in a solvent, dialkyl oxalate (I) and H2 are used in a molar ratio of H2: dialkyl oxalate (I) in the range from 4.0 to 30 and the reaction is carried out continuously in a reactor at a cross-sectional loading of 10 m/s, a temperature in the range from 150 to 270° C., a pressure in the range from 150 to 390 bar and in the presence of a chromium-free heterogeneous catalyst comprising copper.