Abstract:
. É descrito um processo de produção de poli (ácido lático) de alta massa molar que compreende as etapas de: a) policondensação em reator (R1) de uma solução de ácido lático por aquecimento sob forma de rampas de temperatura e sob pressão controlada, obtendo oligômero de poli (ácido lático) na faixa de 300 a 5000 g/mol; b) conversão, em reator (200) na presença de catalisador de despolimerização, do poli (ácido lático) de baixa massa molar obtido na etapa a) em lactídeo; c) separação das frações voláteis; d) recristalização em etanol do lactídeo no vaso (R3); e) polimerização em reator tubular (300) do lactídeo recristalizado obtido na etapa d) via abertura de anel em presença de catalisador, obtendo poli (ácido lático) de elevada massa molar; f) devolatização em (400) da massa polimérica obtida na etapa e); e g) recuperação do produto final poli (ácido lático) com elevado grau de pureza, com massa molar entre 50.000 e 200.000 g/mol e conversão de reação entre 70% e 95%. Também são descritos os reatores de despolimerização (200), de polimerização (300) e de devolatilização (400) utilizados no processo da invenção.
Abstract:
Disclosed herein is an optimization method in a polymerization system in which heat is generated during the polymerization with an initiator. The optimization method includes the steps of measuring the heat generation amount based on the composition of the initiator in the polymerization system to previously set the relationship between the initiator composition and the heat generation amount, measuring the heat removal amount based on the temperature of a coolant in a cooling system of the polymerization system to previously set the relationship between the coolant temperature and the heat removal amount, calculating the initiator composition allowable at a predetermined coolant temperature to previously set the relationship between the coolant temperature and the initiator composition, and measuring the temperature of the coolant before and/or during the polymerization to adjust the composition of the initiator added at the measured temperature to the optimum condition, thereby decreasing the reaction time, and therefore, improving the productivity.
Abstract:
Die Erfindung betrifft eine Vorrichtung und ein Verfahren zum Auflösen von Festkörpern mit einer Flüssigkeit, insbesondere zum In-Kontakt-Bringen und Auflösen von vorwiegend sehr groben Festkörpern unterschiedlicher Form und Größe mit Flüssigkeiten zwecks Auflösung durch chemische Reaktion oder Dispergierung. Die Vorrichtung umfasst einen geschlossenen, teilweise mit der Flüssigkeit gefüllten Behälter (1), in den die Festkörper eingeschleust werden, bevor sie innerhalb des Behälters (1) von einem in Bezug zum Behälter (1) beweglichen Korb (2) aufgenommen und im Korb (2) mit der Flüssigkeit in Kontakt gebracht werden. Um die Festkörper zur Auflösung einfacher, schneller und auch gleichmäßiger in den im Behälter (1) befindlichen Korb zuführen zu können, ist der Korb (2) innerhalb des Behälters (1) pendelnd aufgehängt, so dass er mit einer Schüttung der Festkörper mit wechselnder Drehrichtung in Bezug zum Behälter (1) hin und her bewegt werden kann.
Abstract:
A method for microwave assisted chemical processes is disclosed that comprises applying sufficient microwave radiation (26) to a temperature-monitored mixture of reagents (22, 23), with at least one of the reagents (22, 23) being thermally responsive to electromagnetic radiation (26) in the microwave range, and based on the monitored temperature (21), to maintain the added reagents at or closely about a predetermined temperature while substantially avoiding thermal dilution (or before substantial thermal dilution can occur) that otherwise would have been caused by the addition of the reagents to one another.
Abstract:
The present invention relates to high-pressure melamine reactor characterized by at least one horizontal reactor body having a bottom and a top side with at least one dome integrally formed on the top side of the reactor body, wherein the at least one horizontal reactor body comprises at least two compartments separated by at least one baffle, in particular an overflow baffle. The present invention relates further to a process for obtaining melamine applying the reactor.
Abstract:
The invention relates to a process for the polymerisation of monomeric vinyl halides in a polymerisation reactor, especially using a reflux condenser, and also to a polymerisation reactor for carrying out the process according to the invention. As a result, the space-time yield (STY) of an exothermal reaction can be substantially improved whilst the product quality remains almost the same.
Abstract:
Die Anlage ist geeignet zum Durchführen einer diskontinuierlichen Rektifikation in einer Rektifikationskolonne (1) oder zum Durchführen einer chemischen Reaktion in einem Batchreaktor (35) mit einer aufgesetzten Rektifikationskolonne (1), wobei die Rektifikationskolonne (1) unter totalem Rückfluss betreibbar ist und mindestens einen Kolonnenabschnitt (5; 6; 7; 8) zum Stoffaustausch, mindestens einen unterhalb des Kolonnenabschnitts (5; 6; 7; 8) angeordneten Produktbehälter (3; 4; 35) zum Auffangen und Zwischenspeichern der durch den Kolonnenabschnitt (5; 6; 7; 8) nach unten geströmten Flüssigkeit und mindestens einen weiteren Produktbehälter (2) zum Auffangen und Zwischenspeichern des Kopfprodukts (2') aufweist. Eine Einrichtung (27, 28; 30 - 34) zum wahlweisen Lenken der Flüssigkeit in den unterhalb des Kolonnenabschnitts (5; 6; 7; 8) angeordneten Produktbehälter (3; 4; 35) oder an diesem Produktbehälter vorbei ist vorgesehen. Beim Betreiben der Anlage im industriellen Produktionsmassstab wird mit hoher Sicherheit eine hohe Reinheit der gewonnenen Produkte bei gleichzeitig grossen Produktionsausbeuten erzielt.
Abstract:
An improved condenser (16) system for condensing vapor (13) containing liquid or solid particles (15) to minimize contamination of the condenser system by such particles and to increase the efficiency of liquid processing systems, including means for efficiency of liquid processing systems, including means (100) for efficiently extracting particles from the vapor produced during processing and cooldown of the liquid and returning said particles to the processing container without fouling the condenser system or losing product. The system also includes design improvements and operation improvements for increasing the efficiency, safety and reliability of the condenser system used in the process of cooling and controlling the processing container.
Abstract:
A process for making a dialkyl carbonate which comprises reacting urea with a first alcohol in a carbamate reactor at a temperature and pressure sufficient to convert said urea to an alkyl carbamate; and reacting the alkyl carbamate with a second alcohol in the presence of a dialkyl isocyanato alkoxy tin catalyst or derivatives in a carbonate reactor at a temperature and pressure sufficient to convert the alkyl carbamate to a dialkyl carbonate, wherein the molar ratio of alkyl carbamate to second alcohol is in the range between about 2:1 to about 10:1 and wherein dialkyl carbonate is present within the carbonate reactor in an amount between about 1 to about 3 weight %, based on total alkyl carbamate and second alcohol content, and wherein the second alcohol is either the same as or different from the first alcohol or a mixture of alcohols.