Abstract: Spherical crystalline silica particles having a higher productivity, lower production cost, higher coefficient of thermal expansion, higher heat transmission rate, higher fluidity, higher dispersability, higher fill factor, low abrasiveness, and higher purity compared with the past and able to be applied in the semiconductor field and a process of production of the same are provided. Spherical crystalline silica particles containing 400 to 5000 ppm of aluminum and containing 80% or more of crystal phases are provided.

Abstract: The disclosure herein describes a method for producing ammonia by introducing N2, CO and water into a non-thermal plasma in the presence of a catalyst, the catalyst being effective to promote the disassociation of N2, CO and water to form reactants that in turn react to produce NH3 and CH4. This disclosure also describes producing a reactive hydrogen ion or free radical by the method comprising passing water through a non-thermal plasma in the presence of a catalyst, the catalyst being effective to promote the dissociation of water.

Abstract: Disclosed is a method of treating an acid gas stream through a series of process steps to provide an ammonium sulfphate stream. The method involves passing the acid gas stream to an incinerator to oxidize the H2S to SO2 to yield an incinerator flue gas stream. The incinerator flue gas stream is passed to a sulphuric acid unit that produces H2SO4 from the SO2 of the incinerator flue gas stream and to yield an aqueous sulphuric acid stream and a sulphuric acid unit off-gas stream. At least part of the aqueous sulphuric acid stream is passed to an ammonia scrubber wherefrom an aqueous ammonium suphate stream is yielded.

Abstract: Pyrogenically produced silicon dioxide powder in the form of aggregates of primary particles having a BET surface area of 150±15 m2/g, wherein the aggregates display an average surface area of 12000 to 20000 nm2, an average equivalent circle diameter (ECD) of 90 to 120 nm and an average circumference of 1150 to 1700 nm. It is produced by a pyrogenic process in which silicon tetrachloride and a second silicon component comprising H3SiCl, H2SiCl2, HSiCl3, CH3SiCl3, (CH3)2SiCl2, (CH3)3SiCl and/or (n-C3H7)SiCl3 are mixed with primary air and a combustion gas and burnt into a reaction chamber, secondary air also being introduced into the reaction chamber, and the feed materials being chosen such that an adiabatic flame temperature of 1670 to 1730° C. is obtained. Silicone sealing compound containing the pyrogenically produced silicon dioxide powder.

Abstract: A safe, economical and predictable process for producing ammonia from a urea solution, preferably where only a small amount of ammonia is required, (i.e. for SCR denitrification for small boilers, flue gas conditioning to enhance precipitator efficiency and/or alleviate plume problems, SNCR and the like), using an ultrasonic processor to cause “cold boiling” of portions of such solution and produce gaseous ammonia.

Abstract: A device for producing ammonia from urea pellets includes a pellet dispensing device, a pellet accelerator, a pellet shooting channel, and an ammonia reactor having a chamber or zone for shooting in urea pellets and a pellet deflector arranged on an end of the shooting path. The device further includes a urea pellet evaporation device and a hydrolytic catalytic converter. The urea pellets are removed from the reservoir in a regulated number/quantity by a dispensing device and transported to the accelerating device, where the pellets are moved from the pellet shooting channel into the ammonia reactor, where they are broken down into small pieces by impacting a pellet deflector at the end of the shooting path. The pieces are converted into a gas mixture containing ammonia and isocyanic acid by means of a urea evaporation device. The isocyanic acid is subsequently converted into ammonia and carbon dioxide.

Abstract: A safe, economical and predictable process for producing ammonia from a urea solution, preferably where only a small amount of ammonia is required, (i.e. for SCR denitrification for small boilers, flue gas conditioning to enhance precipitator efficiency and/or alleviate plume problems, SNCR and the like), using an ultrasonic processor to cause “cold boiling” of portions of such solution and produce gaseous ammonia.

Abstract: Processes and apparatus for quantitatively converting urea to ammonia on demand are disclosed. One process includes the steps of: receiving a demand rate signal for ammonia; feeding reactants including urea and water into a reactor to provide a reaction mixture; and controlling temperature and pressure in the reactor to produce a gaseous product stream including ammonia and carbon dioxide at substantially constant concentrations. Another process includes the steps of: feeding molten urea or solid urea to a reactor; feeding water (liquid or steam) to the reactor; and reacting the urea and water at elevated temperature and pressure to form a gaseous product stream including anmmonia and carbon dioxide.

Abstract: Methods and apparatus for continuously, quantitatively producing gaseous ammonia from urea, including the steps of: dissolving urea in water to form concentrated aqueous urea comprising at least 77 wt. % urea; continuously feeding the concentrated aqueous urea into a reactor; continuously feeding a separate, additional supply water into the reactor to form an aqueous urea reaction mixture; heating the aqueous urea reaction mixture; and continuously withdrawing a gas phase product including ammonia from the reactor, is disclosed. Also disclosed are methods and apparatus for continuous and batchwise dissolution of urea to form aqueous urea solutions.

Abstract: In many situations where the maximum NOx reduction capabilities of conventional SCR systems are not necessary, and alternative SNCR systems may not economically provide desired NOx reduction, a staged SCR/SNCR system is believed to be the most appropriate solution available. By means of the present invention, a system has been developed for delivering NOx reduction agents from a common urea feedstock, when it is appropriate to use combined NOx treatment stages (i.e. SNCR within the boiler followed by in-duct SCR and/or catalyzed air preheater elements). For the SNCR stage, the urea from the common feedstock is diluted prior to injection into the boiler and, for the SCR stage, the urea from the common feedstock is used to produce ammonia using hydrolysis. Urea solution which is not converted to ammonia in the hydrolyzer, is used for dilution of the solution being delivered to the SNCR system.

Abstract: Oligosiloxanes of the formula I ##STR1## where R.sup.1 is a C.sub.1 -C.sub.4 -alkyl andn is from 2 to 50,are chiefly used for fabricating fiber-reinforced composite and ceramic materials.

Abstract: A process for the removal of HCN from gaseous streams is described, the process being characterized by reaction of the HCN in the gaseous stream with an ammonium polysulfide solution and formation of ammonium thiocyanate in solution, precipitation and removal of sulfur from the ammonium thiocyanate-containing solution, and hydrolysis of the ammonium thiocyanate. Provision is made for recycle of hydrolysis products.

Abstract: A process for the removal of HCN from gaseous streams is described, the process being characterized by reaction of the HCN in the gaseous stream with an ammonium polysulfide solution, formation of ammonium thiocyanate in solution, decomposition of ammonium polysulfide and precipitation of sulfur from the ammonium thiocyanate solution in a stripping zone, and hydrolysis of the ammonium thiocyanate. Recycle or recovery of sulfur and hydrolysis products are contemplated.

Abstract: A process for the removal of HCN from gaseous streams is described, the process being characterized by reaction of the HCN in the gaseous stream with an ammonium polysulfide solution, formation of ammonium thiocyanate, and hydrolysis of the ammonium thiocyanate. Recycle of hydrolysis products is contemplated.

Abstract: The reaction off-gas from the synthesis of melamine consists, after separating off the melamine, mainly of ammonia and carbon dioxide, with traces of hydrogen cyanide, isocyanic acid, urea and residual melamine. To remove these trace components, the off-gas is passed over a catalyst, containing copper oxide and/or iron oxide, in the presence of steam at from 100.degree. to 500.degree. C.

Abstract: A process for the selective reduction of nitrogen oxide in a combustion effluent gas stream is disclosed wherein the gas stream is contacted with sulfur at a temperature of about 445.degree. C. to 2000.degree. C., therein converting the NO to N.sub.2 and the sulfur to SO.sub.2.

Abstract: Superfine amorphous, high structure silicic acid is made by subjecting the components in the precipitation reaction, that is, an acid or acidic substance and an alkali-metal silicate solution to a shearing force during the alkaline phase of the precipitation reaction, the shearing force being applied by passing the reaction mass in a continuous flow through a dispersing device and the dispersing device being operated with an hourly throughput frequency of at least 10h.sup.- .sup.1, the said frequency being determined as the ratio of the performance of the dispersing device to the initial volume of the reaction mass.The high structure silicic acid is particularly useful as carrier and filler for pesticides, animal feed additives and as matting agent for lacquers.

Abstract: A process is described whereby accumulated impurities, consisting mainly of sodium tiocyanate are continuously removed from scrubbing liquors used for removal of hydrogen sulphide from fuel gases and the liquors thereby regenerated and re-used in the hydrogen sulphide scrubbing operation. The thiocyanate is removed by contacting the used scrubbing liquor with an organic solvent, e.g. n-butanol, separating the thiocyanate-bearing solvent from the scrubbing liquor, re-using the treated scrubbing liquor, recovering the thiocyanate from the solvent and re-using the solvent. The extracted sodium thiocyanate can be converted to pure, saleable chemicals or converted to an alkali which can be re-used in the absorbing liquors, thereby producing a completely closed system with no effluent.

Abstract: Ammonia, hydrogen cyanide and hydrogen sulfide contained in gas streams are separated from the gas streams by contacting the gas stream with an aqueous solution containing free oxygen for a time sufficient for the ammonia, hydrogen sulfide and hydrogen cyanide to react with the oxygen present to form ammonium thiocyanate and water for further treatment or disposal.One method of treatment is to thermally and catalytically convert for the ammonium thiocyanate to ammonia or nitrogen and hydrogen sulfide in the form of a second gas stream which is processed for recovery of any formed ammonia and the hydrogen sulfide.

Abstract: In a process for the removal of hydrogen cyanide from raw gases containing at least one other acidic component selected from the group consisting of hydrogen sulfide, carbonyl sulfide and mixtures thereof comprising scrubbing said other components from the gases with a scrubbing agent, regenerating resultant loaded scrubbing agent, and recycling resultant regenerated scrubbing agent to the scrubbing step,The improvement wherein the hydrogen cyanide is scrubbed out simultaneously with the other acidic components, resultant loaded scrubbing agent is mixed with an aqueous alkali metal or alkaline earth hydroxide solution, and the thus-formed cyanide salt solution is thermally converted into ammonia and formate.