Abstract: This invention relates to pollution control requirements for fossil fuel burning facilities such as power plants, and, more particularly, to an apparatus for providing a safe and economical supply of ammonia, from a urea feedstock, when ammonia is desired or necessary to initiate, cause and/or supplement the removal of one or more pollutants from an exhaust gas stream.

Abstract: A urea synthesis process starting from ammonia and carbon dioxide carried out under a pressure of 120×10 2 to 400×10 2 KPa and a temperature of 140 to 215° C., in which the reaction takes place in a reactor in which gaseous CO 2 is fed in the bottom of the reactor while liquid ammonia and the recycled ammonium carbamate aqueous solution are fed from the top of the reactor, and going downward the reactor, they meet in countercurrent the rising gaseous CO 2.

Abstract: This invention relates to pollution control requirements for fossil-fuel burning facilities, such as power plants, and, more particularly, to a method for providing a safe and economical supply of ammonia, from a urea feedstock, when ammonia is desired or necessary to initiate, cause and/or supplement the removal of one or more pollutants from an exhaust gas stream.

Abstract: An improved process for combustion flue gas conditioning in which ammonia is injected into a stream of said combustion flue gas, wherein urea is dissolved in water, forming a dissolved urea solution. The dissolved urea solution is heated and pressurized and the dissolved urea therein hydrolyzed, forming ammonia and carbon dioxide. The ammonia and carbon dioxide are then stripped from the resulting hydrolysis solution and injected into the stream of combustion flue gas to be treated. Water from the stripped hydrolysis solution is then recycled for use in dissolving fresh urea.

Abstract: Process for the hydrolysis of urea contained in the process water from plants for the synthesis of urea consisting of the thermic treatment of the water containing urea and of the removal by stripping of the compounds from decomposition of the urea (CO.sub.2 and NH.sub.3) in a series of stages in series with superimposed flow.The equipment is a vertical column with superimposed modules with weirs which penetrate in two successive modules and give the solution a rising movement.

Abstract: A system for the passivation of metal surfaces, and more especially those of stainless steel, titanium, etc., in equipment used for chemical processes, where elements and compounds are formed which have a corrosive action, in particular where temperature and pressure are higher than ambient conditions. In the system the main passivating agent is oxygen (air) combined with at least a second auxiliary agent, characterized by the fact that the latter is ozone (03).

Abstract: A method is described for preparing a high-concentration solids suspension, in particular coal or petroleum coke, which can be transported by pipe and be burnt with low emission of harmful substances, comprising crushing the solid to be suspended to a maximum particle size of 6 mm and then grinding it in the presence of additives in aqueous solution to a maximum solid particle size of 300 .mu.m, the method being characterized by adding, either before the crushing or immediately before the grinding, a desulphurizer chosen from CaCo.sub.3, MgCO.sub.3 and dolomite, either alone or in mixture, in a molar ratio to the sulphur contained in the solid of between 1.5 and 3, and adding immediately before or during grinding a desulphurizer also possessing stabilizing and anticorrosive properties and chosen from MgO, Mg(OH).sub.2, CaO and Ca(OH).sub.2, either alone or in mixture, in a quantity of between 0.04 and 0.4% by weight of the final suspension.

Abstract: Process for the psychrophilic biological purification of waste waters having medium-low concentrations of polluting substances. The process comprises a first anaerobic treatment step with an expanded mud bed of U.A.S.B. type at a low flow rate, a second treatment step comprising a fluid-bed treatment on a fine support at a high flow rate, and a final treatment step comprising anaerobic treatment for the nitrification and oxydation of the various substances reduced in the previous treatments. The flow is then recycled to the upstream steps for the removal of possible nutrients, such as nitrogen and phosphorus.

Abstract: A catalytic system and process for producing mixtures of methanol and higher alcohols from synthesis gas, the catalytic system comprising zinc, chromium, copper, one or more alkaline metals, and possibly one or more metals chosen from molybdenum, manganese, lanthanium, cerium, aluminium, titanium and vanadium, either all or only part of said elements being chemically bonded to oxygen and/or together.

Abstract: This invention relates to a process for the isothermal absorption of the ethylene oxide contained in the gas from an ethylene oxide production plant.This process is characterized in that the gas is firstly cooled to a temperature of between 5.degree. and 60.degree. C., and is then fed at a pressure which can vary from 1 to 30 atm. to a water-fed isothermal film absorber, from the bottom of which is obtained a high concentration ethylene oxide solution which can be fed directly to a glycol production plant after recovering the ethylene still in solution.By using this process, the absorption plant is simplified compared with known processes, and steam, electricity and cooling water consumption are considerably reduced.

Abstract: A catalytic system and process for producing mixtures of methanol and higher alcohols from synthesis gas, the catalytic system comprising zinc, chromium, copper, one or more alkaline metals, and possibly one or more metals chosen from molybdenum, manganese, lanthanum, cerium, aluminum, titanium and vanadium, either all or only part of said elements being chemically bonded to oxygen and/or together.

Abstract: A process for the production of urea starting from ammonia and carbon dioxide in a NH.sub.3 /CO.sub.2 molar ratio of from 5/1 to 8/1, comprising the synthesis and decomposition of the ammonium carbamate contained in the solution of urea, in two steps; the first of these provides for ammonia as the stripping agent and the second for carbon dioxide as the stripping agent.In the process of the invention the synthesis and the decomposition in the first decomposition step are carried out at an equal or substantially equal pressure comprised between 180 and 250 atm., while the decomposition in the second step is carried out at a pressure of from 30 to 50 atm. lower than the pressure in the first step.

Abstract: A process for the production of a mixture of methanol and higher alcohols of "fuel grade" from CO and H.sub.2.To reduce the water content in the mixture coming from the synthesis reactor of the synthesis of the alcohols, the reaction product is cooled down and is fed to a secondary reactor wherein the conversion reactionCO+H.sub.2 O.revreaction.CO.sub.2 +H.sub.2is carried on in conditions near to equilibrium.The further product of reaction is cooled in a more thorough manner so as to obtain a liquid phase constituted by the "fuel grade" mixture of alcohols and a gaseous phase which after the discharge of the inert substances and after elimination of the CO.sub.2 is recycled to the synthesis reactor.In the secondary conversion reactor operation is carried out with a temperature comprised between 150.degree. C. and 250.degree. C., at a pressure equal to that of the synthesis reactor and in the presence of a copper catalyst.

Abstract: This invention relates to a process for the isothermal absorption of the ethylene oxide contained in the gas from an ethylene oxide production plant.This process is characterized in that the gas is firstly cooled to a temperature of between 5.degree. and 60.degree. C., and is then fed at a pressure which can vary from 1 to 30 atm. to a water-fed isothermal film absorber, from the bottom of which is obtained a high concentration ethylene oxide solution which can be fed directly to a glycol production plant after recovering the ethylene still in solution.By using this process, the absorption plant is simplified compared with known processes, and steam, electricity and cooling water consumption are considerably reduced.

Abstract: A process for the production of a "fuel grade" mixture of methanol and higher alcohols from CO and H.sub.2.To reduce the amount of water contained in the mixture coming from the synthesis reactor of the alcohol synthesis the reaction product is cooled and fed to a secondary reactor wherein the reaction of conversion:CO+H.sub.2 O.revreaction.CO.sub.2 +H.sub.2is conducted in conditions near to equilibrium.The further reaction product is cooled down further so as to obtain a liquid phase constituted by the alcohols, and in which there are still dissolved some gases, and a gaseous phase containing the carbon dioxide produced in the secondary reactor together with the non-reacted gases. The gaseous phase is sent to a section of absorption of the CO.sub.2 wherein the absorbing liquid is constituted by the very alcoholic mixture produced; after removal of the CO.sub.2 the gas is partly recycled and partly let off in order to avoid the accumulation of inert gases contained in the feeding mixture.

Abstract: A process for recovering power is disclosed, by which excess electric power is exploited for electrolyzing alkali metal hydroxides (molten) and the thusly obtained pure alkali metals are stored. When the demand of electric power becomes critical, the alkali metals are reconverted into their hydroxides and the reaction heat, along with the hydrogen produced in the reaction, is recovered to produce steam: the latter can be used either to produce electricity, or to use its heat, or both.

Abstract: An improved process is disclosed for preparing gases containing hydrogen and nitrogen and which is especially suitable for the synthesis of ammonia. Using natural gas or virgin naphtha as the starting materials, the reforming reaction with steam takes place in two serially arranged stages, the first of which occurs at an inlet temperature of from 400.degree. C. to 650.degree. C. and an exit temperature of from 650.degree. C. to 750.degree. C., a conversion of from 20% to 50% being effected, the second stage working at an exit temperature of from 750.degree. C. to 850.degree. C. and the conversion being increased up to 70%. Air reforming is carried out under conditions at which the exit temperature of the gas is between 920.degree. C. and 1050.degree. C. and the sensible heat of the effluent gases from the air reforming at such temperature condition is employed to activate the second steam reforming stage. Tube bundle heat-exchangers, the tubes of which are filled with an appropriate catalyst, are used.

Abstract: Decarbonation of gases with solutions of alkali metal carbonates and with alkanolamine solutions is improved by exploiting the heat of the vapors exiting the head of the alkanolamine solution regeneration column and also the heat of fluids condensed at the head of the regeneration column for the alkali metal carbonate solution. A very favorable heat balance is achieved and considerable power savings.

Abstract: This invention relates to an apparatus for the desalination of sea water or brine. The apparatus comprises one or more vertical columns divided into a number of cylindrical portions. Each portion constitutes one stage comprising one or more film evaporators formed by vertical tubes, a single brine collection tank of circular section provided with upper lateral apertures, a throttle system, one or more syphon tubes and one or more preheaters having vertical tubes expanded into the same tube plates as the vertical tubes of the film evaporators. The apparatus also comprises pipes and water boxes located inside the tanks for connecting the preheaters of the several stages, connecting pipes between the stages and a final tube bundle condenser positioned below the last stage.

Abstract: A method is disclosed for reusing the processing condensates in a combined plant for the production of ammonia and urea. The condensates are combined into a single stream, filtered to remove the solid substances in suspension, if any, and fed to a boiler for the production of steam while exploiting the sensible heat. Pollution of sewage waters is prevented while obtaining a considerable economy in the running costs.