Abstract: A urea synthesis process with improved heat economy, wherein a urea synthesis solution obtained by removing most of the unreacted ammonium carbamate by stripping with carbon dioxide at a pressure approximately equal to a urea synthesis pressure is subjected to a high and low pressure decomposition. The gas mixture obtained from the high-pressure decomposition is condensed in at least two steps.

Abstract: An oil resistant rubber modified polystyrene composition comprises polybutadiene rubber particles having an average volume particle diameter of 6 to 13 &mgr;m dispersed in polystyrene. The oil resistant rubber modified polystyrene of the present invention has a gel content of 25 to 35% by weight, a degree of swelling of 13 to 22, a residual volatile content of 2000 ppm or less, and a total amount of dimer and trimer of 8000 ppm or less. The oil resistant rubber modified polystyrene composition may be prepared by polymerizing styrene in the presence of polybutadiene rubber, foaming a solution of the rubber modified polystyrene under a reduced pressure of 3 to 40 mm Hg, heating the solution in a tubular heater to a temperature of 190 to 230° C., and then flushing the heated solution into a gas-liquid separator to devolatilize an unreacted monomer and a solvent therefrom.

Abstract: A rubber modified polystyrene composition comprising polybutadiene particles dispersed in polystyrene, wherein the polybutadiene particles have an average volume particle diameter of 6 to 13 microns, and the composition has a gel content of 25 to 35% by weight and a degree of swelling of 13 to 22, is prepared by polymerizing the polybutadiene particles in the presence of styrene. The rubber modified polystyrene composition of the present invention may be used for components contacting flon compounds, such as components of refrigerators.

Abstract: A web server in a center device collects transaction conditions of materials via the Internet from a material-seller terminal which each of material sellers has, and the collected transaction conditions are assessed. Thereby, the best material-seller is selected, and sales conditions of the best material-seller selected are offered, via the Internet, to a material-buyer terminal which each of material buyers has. The material buyers buy desired materials via the Internet based on the sales conditions offered via the Internet.

Abstract: Stainless steels are welded using a shielding gas including 88 to 98.9 mole % Ar, 1 to 10 mole % H2, and 0.1 to 2.0 mole % CO2. The shielding gas permits low sulfur, high chromium, austenitic stainless steel pipes to be joined with welds having sufficient penetration, strength, corrosion resistance and durability for practical use.

Abstract: Urea is prepared by reacting ammonia and carbon dioxide in an apparatus comprising a vertical condensation and synthesis column and a stripper, to provide a urea synthesis solution comprising urea, unreacted ammonia, unreacted carbon dioxide and water. The urea synthesis solution is transferred from the top of the vertical condensation and synthesis column to the top of a stripper. Carbon dioxide is introduced into the bottom of the stripper and contacted with the urea synthesis solution, thereby separating the unreacted ammonia and the unreacted carbon dioxide from the urea, and providing a mixed gas comprising ammonia, carbon dioxide and water. The mixed gas is transferred into the bottom of the vertical condensation and synthesis column, where it is reacted with liquid ammonia injected into the bottom and a middle of the vertical condensation and synthesis column. The mixed gas and liquid ammonia are condensed and react to form urea.

Abstract: A catalyst for reforming of hydrocarbons with less reduction in activity. An improved steam-reforming catalyst for hydrocarbons, wherein the active component Ni is supported on an &agr;-Al2O3 or CaO—Al2O3carrier, a part of the active component Ni is combined with the carrier to form a compound NiAl2O4, and carbon is contained in both of the Ni and NiAl2O4 components, and the grating constant of Ni and the grating constant of NiAl2O4 in the catalyst are increased as compared with those of the catalyst before carbon is added to in both of the said components.

Abstract: There is disclosed an improved, energy-saving granulation method, wherein use is made of a granulator (1) having a bottom floor (9) of a granulation section whose bottom is a perforated plate, an upper air feed pipe (23) for feeding air for fluidization to the bottom floor of the granulation section, a lower air feed pipe (2), air feed pipes (3, 4, 5) branched from the lower air feed pipe for jetting air into the granulation section, and jetting nozzles (6, 7, 8) provided at the centers of the air outlets for jetting a molten raw material; which involves the steps of jetting a molten raw material from the jetting nozzles to approximately spherical nuclei in the granulation section, which have been fed after the particle diameter has been caused to be an average particle diameter of 0.4 to 3.0 mm, to form granules. There is also disclosed an improved granulator.

Abstract: A vertical condenser is installed on or above a urea synthesis column to condense the mixed gas from the stripper by bringing it into contact with an absorption medium under cooling. A first down pipe for making the top part of the condenser communicate with the bottom part of the synthesis column is provided to allow the resultant condensate to flow down to the bottom part of the synthesis column by gravity. The condensate is subjected to urea synthesis together with feed ammonia or a part of feed carbon dioxide supplied thereto. The urea synthesis solution thus formed is introduced into the stripper by gravity through a second down pipe having an opening in the top part of the synthesis column. Unreacted ammonia and carbon dioxide are separated as the aforesaid mixed gas by the rest of the feed carbon dioxide and introduced into the bottom part of the aforesaid condenser so as to be condensed.

Abstract: There is disclosed a process to produce fertilizer granules containing urea and ammonium sulfate with a high ammonium sulfate concentration of ≦60 wt. % in a fluidized bed granulator, which process comprises the steps of: a) a molten urea suspension consisting of ammonium sulfate having an average particle size of 30 to 300 &mgr;m and urea having a temperature range of 120 to 155° C. is produced, b) the molten urea suspension produced at the stage a) is then injected from below on the fine particles of urea/ammonium sulfate in a fluidized bed granulator by means of at least a nozzle, while the fluidized bed is loosened by a spouting air flow in the injection area, and subsequently, c) the fertilizer granules generated in the fluidized bed are separated and, if necessary, treated. Homogeneous urea/ammonium sulfate granules of an ammonium sulfate content between 30 and 60 wt.

Abstract: A method for removing volatile materials, comprises adding a blowing aid to a polymer composition containing volatile materials, mixing them in a static mixing apparatus, and extruding the resultant mixture by an extruding apparatus into a devolatilizing tank, thereby the mixture is made to be blown, to cause removal of the volatile materials. First, the blowing aid (6) is discharged with an addition nozzle apparatus (2), in a direction opposite to the direction of the flow of the polymer composition (1), to be added, and the polymer composition is introduced into the static mixing apparatus (3), at a pressure at which the blowing does not take place, thereby mixing them. Then, using the extruding apparatus (11), the resultant mixture is extruded into the devolatilizing tank (4), so that the polymer is made into a blown product at such a temperature and a pressure that the blowing coefficient B is 1.4 or more, thereby causing the removal of volatile materials.

Abstract: The present invention provides a process for producing methanol which gives reduced construction costs of plant and improved energy efficiency of the whole plant. According to this process for producing methanol, methanol is manufactured by subjecting a feedstock mixed gas comprising a feedstock gas and steam to primary reforming, to secondary reforming, and then to methanol synthesis reaction.

Abstract: The present invention provides an improved process for synthesizing urea from ammonia and carbon dioxide while preventing corrosion of sites, that are to be in contact with a condensate, of the joints of a tube plate and cooling tubes in a condenser installed vertically or horizontally. According to this process, the sites, that are to be in contact with the condensate, of the joints of the tube plate and the cooling tubes in the condenser are prevented from corrosion by enveloping the sites with liquid ammonia or a solution rich in ammonia in the synthesis of urea comprising separating unreacted ammonia and carbon dioxide as a gaseous mixture thereof from a urea synthesis solution at a pressure substantially equal to the urea synthesis pressure, bringing the gaseous mixture into contact with an absorption medium in the condenser to form a condensate, and recirculating the condensate to the synthesis column.

Abstract: Formation of calcium sulfite in a desulfurization column for desulfurizing flue gas is prevented by maintaining the pH of the sorption liquid in the column in the range of 5.5-7.0 and the chemical oxygen demand of the sorption liquid below an upper value determined by the concentration of magnesium sulfate. The upper value of the chemical oxygen demand of the sorption liquid can be controlled by maintaining the quantity of magnesium sulfate in an oxidization vessel arranged downstream of the desulfurization column. The oxidized liquid discharged from the oxidization vessel is neutralized in a double composition vessel, and the thus-obtained slurry is returned directly to the desulfurization column. By preventing formation of calcium sulfite, high-quality gypsum is formed in the double composition vessel.

Abstract: The present invention provides a process for preparing granular urea, which solves the problem of removing moisture in a prilling tower method and the problem of concentrating diluted formaldehyde in granulation by a fluidized, spouted bed method when urea is granulated in the presence of formaldehyde. That is, the present invention provides a process for preparing granular urea from liquid drops or sprayed drops of a urea solution, wherein the urea solution is divided into two portions of a urea solution A and a urea solution B, and a urea solution prepared by mixing an aqueous formaldehyde solution with the urea solution A, concentrating the above mixed solution and then mixing it with the urea solution B is used.

Abstract: There is disclosed a method for detecting clogging of air feed pipes, comprising air feed pipes (15), each having an outlet (13) for jetting air into a granulation section (1), and jetting nozzles (13), each situated at the center of the air outlet of a said air feed pipe for jetting a liquid of a molten raw material (e.g.

Abstract: A vertical condenser is installed on or above a urea synthesis column to condense the mixed gas from the stripper by bringing it into contact with an absorption medium under cooling. A first down pipe for making the top part of the condenser communicate with the bottom part of the synthesis column is provided to allow the resultant condensate to flow down to the bottom part of the synthesis column by gravity. The condensate is subjected to urea synthesis together with feed ammonia or a part of feed carbon dioxide supplied thereto. The urea synthesis solution thus formed is introduced into the stripper by gravity through a second down pipe having an opening in the top part of the synthesis column. Unreacted ammonia and carbon dioxide are separated as the aforesaid mixed gas by the rest of the feed carbon dioxide and introduced into the bottom part of the aforesaid condenser so as to be condensed.

Abstract: Disclosed is an automated pipe connection apparatus having an automated connection apparatus main body (1) capable of performing automated change-over between a group of pipelines and another group of pipelines, a washing/sterilizing utility block (2), and a drainage block (3). In particular, the automated pipe connection apparatus is provided with caps (111,112,114,115) for preventing intrusion of sundry bacteria into couplers (A1,A2,B1,B2) on standby and for performing washing and/or sterilization operation and also with washing- and/or sterilizing-purpose couplers (AWL,BWL).The apparatus according to this invention is superior in the operability for washing and sterilization and in the prevention of intrusion of sundry bacteria.

Abstract: A method of dissolving a rubber continuously to form a raw material for the production of rubber-modified polymer, by dissolving a rubber in a monomer liquid dissolving the rubber and capable of reacting with the rubber in the presence or absence of a solvent. Pieces of rubber are fed continuously to a dissolution tank to allow the dissolved rubber and the undissolved rubber to coexist in the dissolution tank, wherein the concentration of the dissolved rubber is the concentration at which the feeding to the reactor is made, and the quantity of the undissolved rubber present in the dissolution tank is at most the quantity that prevents pieces of the undissolved rubber from sticking to one another to form larger rubber masses. The time required for dissolution can be shortened, and the size of a dissolution tank can be made smaller, compared with the conventional methods.

Abstract: To provide an improved steam reforming catalyst for lower hydrocarbons which is highly active and has a high crushing strength. An improved steam reforming catalyst for lower hydrocarbons comprising a support constituted of CaO and Al.sub.2 O.sub.3 and an active component comprising nickel or a platinum-group metal. The content of CaO is 0.5 to 25 wt% based on the catalyst, and at least part of the CaO forms compounds with the A1.sub.2 O.sub.3. The support has a void fraction X of pores with a diameter of 0.5 .mu.m to 20 .mu.m of 0.08 or higher, a void fraction Y of pores with a diameter smaller than 0.5 .mu.m of 0.15 or higher, and a total void fraction Z of 0.23 to 0.8 (provided that Z.ltoreq.(X+Y)).