Abstract: In a urea synthesis process, temperature distribution in a submerged condenser is reduced. The process includes: synthesizing urea from NH3 and CO2 to generate a urea synthesis solution; by heating the solution, decomposing ammonium carbamate and separating a gaseous mixture containing NH3 and CO2 from the solution to obtain a solution higher in urea concentration than the solution obtained in the synthesizing; with use of a submerged condenser including a shell and tube heat exchange structure including a U-tube, absorbing and condensing at least a part of the gaseous mixture in an absorption medium on a shell side, and generating steam on a tube side with use of heat generated during the condensation; and recycling at least a part of liquid, obtained from the shell side, to the synthesizing, wherein water is supplied to the tube side of the condenser at a mass flow rate that is three times or more of the steam generation rate.

Abstract: The present invention provides a radial flow reactor with less uneven temperature even when an endothermic reaction is performed, small pressure loss, and easy maintainability as well, and also provides a method for producing an ammonia decomposition mixture using the same. The reactor according to the present invention is a so-called radial flow reactor having a cylindrical reaction vessel disposed in an upright position and a reaction region inside the reaction vessel, in which a chemical reaction is performed, wherein the reaction region has a catalyst member, having a heating part that generates heat by being energized and a catalyst disposed to be heated by the heating part, which is concentrically disposed in a cross-section perpendicular to an axial direction of the reaction vessel.

Abstract: Redox flow battery 1 includes cell stack 2, first positive-electrode tank 11, second positive-electrode tank 12, first negative-electrode tank 21, and second negative-electrode tank 22. Cell stack 2 is divided into a plurality of cell groups 3, each of which consists of a plurality of cells 4. The plurality of cell groups 3 are connected to first and second positive-electrode tanks 11, 12 such that a positive-electrode fluid containing positive-electrode active material flows in parallel through the plurality of cell groups 3, and are connected to first and second negative-electrode tanks 21, 22 such that a negative-electrode fluid containing negative-electrode active material flows in parallel through the plurality of cell groups 3. The plurality of cells 4 in each cell group 3 are connected to each other such that the positive-electrode fluid flows in series through a plurality of positive cells 5 and such that the negative-electrode fluid flows in series through a plurality of negative cells 6.

Abstract: Provided are urea manufacturing method and apparatus, which can increase the conversion ratio into urea and to reduce the consumption of steam. The temperature of the reactor is increased by introducing the entire amount of raw material ammonia and introducing a portion of the decomposed gas from the stripper into the reactor. The raw material ammonia is preferably heated using the steam condensate generated in the purification step, and/or the steam generated by the heat of condensation of the decomposed gas and the unreacted substances in the condensation step. The heating temperature is preferably between 70 and 140° C.

Abstract: Method and apparatus that enable the more efficient manufacture of urea are provided. Before unreacted substances are removed from a urea synthesis solution obtained from a stripper, the urea synthesis solution is placed under pressure reduced from the synthesis pressure. Thus, a gas-liquid mixture is obtained. The gas-liquid mixture is heated with a decomposed gas from the stripper using a shell-and-tube heat exchanger, and then introduced into a purification system. In the heating, the gas-liquid mixture is introduced into the shell of the heat exchanger while the decomposed gas is introduced into the tube side of the heat exchanger.

Abstract: A method for treating a urea aqueous solution includes a first stripping step of steam stripping an aqueous solution containing urea, ammonia and carbon dioxide at 0.2 to 0.6 MPaA in a first stripper to separate ammonia and carbon dioxide from this aqueous solution into a gas phase; a hydrolysis step of hydrolyzing urea in the solution obtained from the first stripping step at an LHSV of 10 to 20 h?1, at 1.1 to 3.1 MPaA and 180 to 230° C. in a catalytic hydrolyzer; and a second stripping step of steam stripping a liquid obtained in the hydrolysis step in a second stripper to separate ammonia and carbon dioxide from this liquid into a gas phase. The residual urea concentration can be reduced to 1 ppm or lower; the residual ammonia concentration can be decreased; LHSV can be increased; and an increase in apparatus size is minimized.

Abstract: An improved method for separating hydrocarbons for separating feed LNG into product LNG and a liquid fraction enriched in C3+ components is provided.

Abstract: The duty of internal heat exchange can be flexibly adjusted without impairing energy saving performance of a HIDiC. A method of adjusting the duty of heat exchange in a heat exchange structure of a HIDiC includes totally condensing a portion of the vapor fed to a heat exchange structure in a heat exchange structure; and providing a liquid control valve downstream of the heat exchange structure on the first line, without providing a control valve on a vapor-flowing part of first and second lines of the HIDiC, and adjusting a flow rate of a portion of the compressor outlet vapor flowing into the heat exchange structure by using the control valve, while compensating for a pressure loss needed for the control valve by using a liquid head of a condensate, and/or by using pressurization by a pump.

Abstract: Provided are urea manufacturing method and apparatus, which can increase the conversion ratio into urea and to reduce the consumption of steam. The temperature of the reactor is increased by introducing the entire amount of raw material ammonia and introducing a portion of the decomposed gas from the stripper into the reactor. The raw material ammonia is preferably heated using the steam condensate generated in the purification step, and/or the steam generated by the heat of condensation of the decomposed gas and the unreacted substances in the condensation step. The heating temperature is preferably between 70 and 140° C.

Abstract: Method and apparatus that enable the more efficient manufacture of urea are provided. Before unreacted substances are removed from a urea synthesis solution obtained from a stripper, the urea synthesis solution is placed under pressure reduced from the synthesis pressure. Thus, a gas-liquid mixture is obtained. The gas-liquid mixture is heated with a decomposed gas from the stripper using a shell-and-tube heat exchanger, and then introduced into a purification system. In the heating, the gas-liquid mixture is introduced into the shell of the heat exchanger while the decomposed gas is introduced into the tube side of the heat exchanger.

Abstract: A distillation apparatus of the present invention includes high-pressure column 1 corresponding to a region above a heat exchanging section located at a lowermost part of a region including a trayed section or a packed bed section, which is used as a rectifying section; and low-pressure column 2 that is located above as seen from high-pressure column 1, which integrates a region including a trayed section or a packed bed section which is used as a stripping section, with rectifying section corresponding portion 2g that corresponds to a region locating below the heat exchanging section located at the lowermost part in the rectifying section. Rectifying section corresponding portion 2g is located on top 2c of the stripping section in low-pressure column 2 so that rectifying section corresponding portion 2g continues to the stripping section.

Abstract: The present invention provides a solar heat collecting device having good heat collection efficiency. A uniaxial solar-tracking reflective mirror group is arranged such that each longitudinal axis thereof faces the same direction. A first biaxial solar-tracking reflective mirror group and a second biaxial solar-tracking reflective mirror group are arranged lined up in a direction orthogonal to the longitudinal axis direction of uniaxial solar-tracking reflective mirrors. The uniaxial solar-tracking reflective mirror group is arranged so as to be sandwiched on both sides by the first biaxial solar-tracking reflective mirror group and the second biaxial solar-tracking reflective mirror group. Each mirror group sends solar heat received during uniaxial or biaxial tracking in accordance with the position of the sun, to a heat collecting device.

Abstract: PROBLEM There is provided a method for producing polylactic acid, which is capable of obtaining polylactic acid at low cost, and having high molecular weight. SOLUTION A method for producing polylactic acid by polymerizing molten lactide using at least one reactor having plug flow characteristics with ?(?), calculated from the following FORMULA (1), of 0.3 or smaller: ?(?)=?0?(E(?)×ABS(1??))d???(1) in the Formula (1), E(?) is a residence time distribution function determined by impulse response by starch syrup having a viscosity of 3 Pa·s, and ? is ratio of elapsed time ? and mean residence time ?0.

Abstract: A granulator, having a granulation unit having a bottom floor with a perforated plate as its bottom part; an upper air-supplying pipe for supplying a fluidizing air to the bottom of the granulation unit; a lower air-supplying pipe; air-spouting pipes, each of which is branched from the lower air-supplying pipe, and has an opening in the bottom of the perforated plate, for jetting the air into the granulation unit; and spray nozzles for spraying a granulation raw material liquid, which each are provided in the center of an air outlet of the air-spouting pipe, or having: the bottom; the air-supplying pipe; and spray nozzles for spraying a granulation raw material liquid each of which are provided in an opening in the bottom of the perforated plate, and use a high-pressure atomizing air as an auxiliary gas, with the spray nozzles being provided in a triangular arrangement.

Abstract: A method of produced water treatment in an in-situ recovery method of producing bitumen from oil sand, the method has the steps of: separating bitumen from bitumen-mixed fluid so as to leave produced water, the bitumen-mixed fluid having been recovered from the oil sand wells; and filtering the produced water via a microfiltration membrane made of polytetrafluoroethylene.

Abstract: A process for separating hydrocarbons from an LNG, including the steps of: distilling a feed LNG in a first distillation column to separate it into a fraction enriched with methane and a fraction enriched with components heavier than methane; distilling the fraction enriched with components heavier than methane in a second distillation column to separate it into a fraction enriched with ethane and a fraction enriched with components heavier than ethane; recovering the cryogenic heat of the feed LNG to be fed into the first distillation column or of the liquid inside the first distillation column by using a heat transfer medium; and cooling the overhead gas of the second distillation column by using the heat transfer medium which has recovered the cryogenic heat to condense at least part of the overhead gas of the second distillation column. An apparatus for carrying out this process.

Abstract: An apparatus includes a first distillation apparatus for obtaining a fraction enriched in C8+ aromatics; a second distillation apparatus for obtaining a fraction enriched in C8 aromatics; an adsorption separation apparatus for obtaining an extract containing para-xylene and a raffinate containing xylene isomers; a third distillation apparatus for obtaining a fraction enriched in para-xylene; and a fourth distillation apparatus for obtaining a fraction enriched in xylene isomers. The second distillation apparatus includes a high-pressure part including a rectifying section; a low-pressure part including a stripping section; a line for directing overhead vapor of the low-pressure part to a column bottom of the high-pressure part; a line for directing a column bottom liquid of the high-pressure part to a column top of the low-pressure part; and a heat exchange structure for transferring heat from the rectifying section to the stripping section.

Abstract: The present invention provides a method for operating a stripper that is provided for a separating process in an aromatic component processing apparatus in which the stripper separates a component that is lighter than an aromatic component from the aromatic component via a distillation operation. In the method, using a HIDiC as the stripper, the pressure of the column top of rectifying section (201) of the HIDiC is determined, and the pressure of the column top of stripping section (202) of the HIDiC is set to be lower than the pressure of the column top of rectifying section (201).

Abstract: There are provided a method for analyzing an aqueous ammonium carbamate solution whereby the composition of an unreacted-gas absorber outlet liquid can be specified in real time, and a method for operating an unreacted gas absorber by use of the same.

Abstract: A piping system comprising: a main pipe; a first pipe member connecting an equipment nozzle and the main pipe via a first bellows; a second pipe member connected to a side part of the main pipe; a third pipe member connected to the other end of the second pipe member via a second bellows; first and second tie rod support members fixed to the first and third pipe members; tie rods that interconnect the tie rod support members; and an anchor that sets a portion of the main pipe as a fixed point. Lengths of the pipe members between the tie rod support members are determined so that the first bellows contracts by thermal expansion of the equipment nozzle, the first pipe member, and the pipe member of the main pipe below the anchor, and the second bellows contracts by an amount equally to that of the first bellows.