Abstract: A plant for providing purified hydrogen gas comprises a dehydrogenation unit for releasing a dehydrogenation mixture comprising hydrogen gas and at least one impurity from an at least partly laden hydrogen carrier medium, a separation/purification unit fluidically connected to the dehydrogenation unit, for removing the hydrogen gas from the dehydrogenation mixture, a purge gas feed fluidically connected to the separation/purification unit, for feeding purge gas into the separation/purification unit (6), a thermal conversion unit fluidically connected to the separation/purification unit, for thermally converting a tail gas mixture comprising the purge gas and at least one impurity, and a heat transfer unit for transferring heat generated in the thermal conversion unit to the dehydrogenation unit.

Abstract: A method for storing hydrogen gas includes the process steps pre-heating of an at least partially dehydrogenated hydrogen carrier material, storing the hydrogen gas in chemically bound form on the hydrogen carrier material as well as cooling and conditioning of the at least partially hydrogenated hydrogen carrier material.

Abstract: A method for storing hydrogen gas includes the process steps pre-heating of an at least partially dehydrogenated hydrogen carrier material, storing the hydrogen gas in chemically bound form on the hydrogen carrier material as well as cooling and conditioning of the at least partially hydrogenated hydrogen carrier material.

Abstract: A method for providing hydrogen gas includes the process steps pre-heating of an at least partially hydrogenated hydrogen carrier material, release of hydrogen gas by at least partial dehydrogenation of the hydrogen carrier material, purification of the released hydrogen gas as well as cooling and conditioning of the at least partially dehydrogenated hydrogen carrier material.

Abstract: In a practicable continuous or batchwise process for the preparation of a crystallizable polylactic acid mixture, lactic acid may be polycondensed to yield an oligomer, which may then be depolymerized to yield a crude lactide. The crude lactide may be purified to yield a pure lactide, wherein fractionation may be carried out in the purification into an L- or D-lactide-rich fraction and also a meso-lactide-rich fraction. Subsequently a separate ring-opening polymerization of the resulting lactide fractions can be carried out. The individual polylactic acid batches or streams generated by the ring-opening polymerization may then be mixed. The present disclosure further relates to apparatuses for carrying out such processes and polylactic acid mixtures.

Abstract: A process for preparing a high molecular weight heteraromatic polyester or copolyester is disclosed. A process for preparing a high molecular weight heteroaromatic polyester or copolyester includes the steps of: (a) processing comonomers by mixing together to form a homogeneous solution (1) at least one heteroaromatic dicarboxylic acid having 2-12 carbon atoms or a diester or an acid anhydride derived therefrom, or a mixture thereof; (2) at least one alcohol having 2 to 12 carbon atoms and at least two hydroxyl functionalities; and (3) optionally aromatic or aliphatic dicarboxylic acids or diesters or acid anhydrides derived therefrom; (b) converting the paste/solution obtained in step a) into an esterification product containing at least one diester or at least one oligoester formed from the at least one heteroaromatic dicarboxylic acid and the at least one alcohol; and (c) polycondensing/copolycondensing the reaction product obtained from step b) under reduced pressure.

Abstract: A process for preparing a high molecular weight heteraromatic polyester or copolyester is disclosed. A process for preparing a high molecular weight heteroaromatic polyester or copolyester includes the steps of: (a) processing comonomers by mixing together to form a homogeneous solution (1) at least one heteroaromatic dicarboxylic acid having 2-12 carbon atoms or a diester or an acid anhydride derived therefrom, or a mixture thereof; (2) at least one alcohol having 2 to 12 carbon atoms and at least two hydroxyl functionalities; and (3) optionally aromatic or aliphatic dicarboxylic acids or diesters or acid anhydrides derived therefrom; (b) converting the paste/solution obtained in step a) into an esterification product containing at least one diester or at least one oligoester formed from the at least one heteroaromatic dicarboxylic acid and the at least one alcohol; and (c) polycondensing/copolycondensing the reaction product obtained from step b) under reduced pressure.

Abstract: In a practicable continuous or batchwise process for the preparation of a crystallizable polylactic acid mixture, lactic acid may be polycondensed to yield an oligomer, which may then be depolymerized to yield a crude lactide. The crude lactide may be purified to yield a pure lactide, wherein fractionation may be carried out in the purification into an L- or D-lactide-rich fraction and also a meso-lactide-rich fraction. Subsequently a separate ring-opening polymerization of the resulting lactide fractions can be carried out. The individual polylactic acid batches or streams generated by the ring-opening polymerization may then be mixed. The present disclosure further relates to apparatuses for carrying out such processes and polylactic acid mixtures.

Abstract: The present invention relates to a method for the production of cyclic carboxylic acid esters, in particular intramolecular lactones, such as e.g. dilactide, the production of these cyclic esters from oligomeric carboxylic acids being effected by cyclizing depolymerization. During this reaction, a condensation product of these oligomeric carboxylic acids is produced as by-product, i.e. a mixture of higher-molecular oligomeric carboxylic acids which are hydrolyzed in a further step and hence recovered. This hydrolysate can be added again to the cyclizing depolymerization which is implemented in the first step.

Abstract: The present invention relates to a method for the production of cyclic carboxylic acid esters, in particular intramolecular lactones, such as e.g. dilactide, the production of these cyclic esters from oligomeric carboxylic acids being effected by cyclising depolymerisation. During this reaction, a condensation product of these oligomeric carboxylic acids is produced as by-product, i.e. a mixture of higher-molecular oligomeric carboxylic acids which are hydrolysed in a further step and hence recovered. This hydrolysate can be added again to the cyclising depolymerisation which is implemented in the first step.

Abstract: A process for preparing a high molecular weight heteraromatic polyester or copolyester is disclosed. A process for preparing a high molecular weight heteroaromatic polyester or copolyester includes the steps of: (a) processing comonomers by mixing together to form a homogeneous solution (1) at least one heteroaromatic dicarboxylic acid having 2-12 carbon atoms or a diester or an acid anhydride derived therefrom, or a mixture thereof; (2) at least one alcohol having 2 to 12 carbon atoms and at least two hydroxyl functionalities; and (3) optionally aromatic or aliphatic dicarboxylic acids or diesters or acid anhydrides derived therefrom; (b) converting the paste/solution obtained in step a) into an esterification product containing at least one diester or at least one oligoester formed from the at least one heteroaromatic dicarboxylic acid and the at least one alcohol; and (c) polycondensing/copolycondensing the reaction product obtained from step b) under reduced pressure.