摘要:
An exhaust gas purification apparatus for purifying exhaust gas exhausted from a diesel internal combustion engine and containing therein harmful substances including particulates, NOx, HC and CO, at least, comprises a removal part for trapping and removing particulates in the exhaust gas, a purification part for purifying NOx, HC and CO through contact, and a heat transfer part for transferring heat generated in the removal part to the purification part.
摘要:
An apparatus for purifying an exhaust gas of a diesel engine, characterized in that it has an NOx adsorption and reduction type catalyst and a diesel particulate filter for oxidizing and removing particulate matters in the exhaust gas, which are provided in the flow route for the exhaust gas and are arranged in the above described order from the upstream of the flow of the exhaust gas. The above arrangement allows the elevation of the temperature of the catalyst with ease and the precise control of the temperature and atmosphere therein, resulting in the achievement of satisfactory NOx purification performance, and the employment of the NOx adsorption and reduction type catalyst allows the enhancement of the rate of reduction of the NO2 captured, which shortens the time to keep a stoichiometric-rich atmosphere to a time of several seconds to several minutes.
摘要:
An object of the present invention is to provide a technology which can suppress the blockage and abrasion of pipes and devices caused by the production of by-products and stably synthesize acrolein at a high yield, under a condition in which energy efficiency is improved by an elevated concentration of glycerol in a reaction liquid, in a process for synthesis of acrolein by reacting supercritical water and an acid with glycerol. An embodiment of the present invention includes: setting a concentration of glycerol in the reaction liquid at 30% by weight or lower; also cooling the reaction liquid to a temperature between a temperature (300° C. or lower) at which the reaction stops and a temperature (100° C. or higher) at which tar contained in the reaction liquid can keep a state in which its viscosity is sufficiently low; then separating and removing carbon particles from the reaction liquid; subsequently cooling the reaction liquid to a temperature which is a boiling point of water or lower and at which the tar component in the reaction liquid does not adhere to devices; and then decompressing the cooled reaction liquid.
摘要:
An equipment for producing polyhydroxycarboxylic acid, includes a ring-opening polymerization apparatus, a liquid phase devolatilizing apparatus, and a drying apparatus, wherein an indirect heat exchanger is connected to a vent gas discharge path of the liquid phase devolatilizing apparatus. The indirect heat exchanger captures a dispersed in-process substance containing hydroxycarboxylic acid cyclic dimers and transfers the substance to the ring-opening polymerization apparatus; a wet condenser and a hot well are connected to a vent gas discharge path of the indirect heat exchanger and that of the drying apparatus, respectively. The wet condenser captures a dispersed in process substance containing the cyclic dimers with the use of a refrigerant containing hydroxycarboxylic acid corresponding to the cyclic dimers and transfers the substance to the hot well; the hot well causes hydrolysis of the cyclic dimers for generation of hydroxycarboxylic acid; the generated hydroxycarboxylic acid is mixed with a refrigerant and the mixture is circulated to the wet condenser; and hydroxycarboxylic acid is highly concentrated via circulation between the wet condenser and the hot well and then discharged.
摘要:
A method for purifying tetrahydrofuran from a liquid containing tetrahydrofuran and as impurities at least water, 2,5-dihydrofuran and butanol, the method comprising: a first distillation step in which the liquid is subjected to distillation using a distillation column to separate into a first bottoms product containing water as a major component and a first distillate containing tetrahydrofuran, 2,5-dihydrofuran and butanol as major components, a second distillation step in which the first distillate is subjected to distillation using a distillation column to separate into a second bottoms product containing tetrahydrofuran and butanol as major components and a second distillate containing 2,5-dihydrofuran as a major component, a third distillation step in which the second bottoms product is subjected to distillation using a distillation column to separate into a third bottoms product containing butanol as a major component and a third distillate containing tetrahydrofuran as a major component, and further comprising a recirculation step in which a part of the second top liquid is recirculated into the first distillation step as a recirculation liquid and the remaining part is discharged into the outside of the system.
摘要:
In a process of manufacturing polylactide, synthesis of high-quality polymers is achieved with a sufficient degree of vacuum secured. Provided is an apparatus for manufacturing polylactide which includes the steps of preparing lactide through oligomerization of lactic acid and depolymerization of the resulting oligomers, effecting ring-opening polymerization of the lactide, and removing unreacted lactide. The apparatus comprises an exhausting gas treatment device for reducing pressure in the step of removing unreacted lactide. The exhausting gas treatment device includes boilers (81-83) for generating water vapor; a pressure-reducing section having stages each including an ejector (71-73) driven with the water vapor, a condenser (61-63) connected downstream of the ejector, and a hot well tank (41-43) connected to the condenser; and a main condenser 60 and a main hot well tank 40 connected to the main condenser that are disposed on a pipe line through which a gas of the unreacted lactide is suctioned into the pressure-reducing section. The gas of the unreacted lactide is washed away in the main condenser using a liquid containing lactic acid as a main component that has been collected in the main hot well tank.
摘要:
A device and a method for producing high-quality polybutylene succinate are provided. The method for producing polybutylene succinate comprises the steps of: preparing a raw-material slurry by mixing succinic acid or a derivative thereof with 1,4-butanediol in a raw-material slurry preparation tank; storing the raw-material slurry in a raw-material slurry storage tank while maintaining flowability; carrying out an esterification reaction of the raw-material slurry in an esterification reactor; and synthesizing polybutylene succinate with a polycondensation reaction of the ester in a polycondensation reactor, in which the polycondensation reactor is divided, from the upstream side, into at least an initial polycondensation reactor, an intermediate polycondensation reactor, and a final polycondensation reactor, a catalyst is added in an amount from 1000 ppm to 3000 ppm in relation to succinic acid or a derivative thereof, the reaction time in the intermediate polycondensation reactor ranges from 0.25 hours to 0.75 hours, and the reaction temperature in the final polycondensation reactor ranges from 245° C. to 255° C.
摘要:
An object of the present invention is to provide a reasonable polycondensation step by which an appropriate molecular weight can be obtained and material decomposition associated with thermolysis can be suppressed, so as to contribute to production technology for PTT polymers. The production method for polytrimethylene terephthalate comprises an esterification step and a polycondensation step, wherein the polycondensation step is divided into multiple stages, polycondensation is performed using a polymerization vessel having a twin-shaft agitator in the final stage of the polycondensation step, and the polymerization temperature during the subsequent stage of the polycondensation step is less than the polymerization temperature during the former stage of the polycondensation step.
摘要:
An object of the present invention is to provide a technology which can suppress the blockage and abrasion of pipes and devices caused by the production of by-products and stably synthesize acrolein at a high yield, under a condition in which energy efficiency is improved by an elevated concentration of glycerol in a reaction liquid, in a process for synthesis of acrolein by reacting supercritical water and an acid with glycerol. An embodiment of the present invention includes: setting a concentration of glycerol in the reaction liquid at 30% by weight or lower; also cooling the reaction liquid to a temperature between a temperature (300° C. or lower) at which the reaction stops and a temperature (100° C. or higher) at which tar contained in the reaction liquid can keep a state in which its viscosity is sufficiently low; then separating and removing carbon particles from the reaction liquid; subsequently cooling the reaction liquid to a temperature which is a boiling point of water or lower and at which the tar component in the reaction liquid does not adhere to devices; and then decompressing the cooled reaction liquid.
摘要:
An object of the present invention is to provide a method for commercially manufacturing acrolein in a large flow rate by making supercritical water and an acid interact with glycerin, wherein by efficiently mixing high-concentration glycerin and supercritical water with each other, the method is made capable of making the synthesis stably proceed with a high yield while the occlusion and abrasion of the pipes and devices due to the generation of by-products are being suppressed. The method for synthesizing acrolein of the present invention is a method for synthesizing acrolein by making supercritical water and an acid interact with glycerin, the method using a reaction apparatus including: a cylindrical mixing flow path for mixing a fluid including glycerin and a fluid including supercritical water with each other; a first inlet flow path, disposed offset from the central axis of the mixing flow path, for making the fluid including glycerin flow into the mixing flow path; and a second inlet flow path, disposed offset from the central axis of the mixing flow path, for making the fluid including supercritical water flow into the mixing flow path, wherein the first inlet flow path and the second inlet flow path are each provided in a plurality of numbers in such a way that the first inlet flow paths and the second inlet flow paths are alternately arranged so as to encircle the central axis of the mixing flow path.