Gases preparation

Cannon, R. E. (1998). The Gas Processing Industry Origins and Evolution, 2nd ed. Tulsa Gas Processors Association. Delucclii, M. A. (1998). LPG for Motor Vehicles A Total Fuel Cycle Analysis of Emissions of Urban Air Pollutants and Greenhouse Gases, prepared for the Propane Vehicle Council and the Propane Education Research Council, Washington, DC. 

The fact that practically all aromatic amines are readily converted into diazo compounds contributed greatly to Griess s success. The original method (Griess, 1858) by which he diazotized picramic acid (1.1 see Scheme 1-1) consisted of passing nitrous gases, prepared by the reduction of nitric acid with starch or arsenious acid, into an alcoholic solution of the amine. 

Chloroacetophenone was among the many samples of possible war gases prepared by E. Emmet Reid and sent to the Bureau of Mines in 1917. Because there were no testing facilities for lachryma-tors until the central laboratory was completed, the value of this compound as a tear gas went unnoticed. It was January, 1918, before the results of the physiological tests were reported which showed chloroacetophenone to be superior to any other tear gas in use at the time (23). The Johns Hopkins University branch laboratory, in cooperation with a unit at American University then developed a method of synthesis. Although chloroacetophenone was not produced in quantity before the war ended, it became the standard tear gas used by civilian police after the war (38). 

Ellerman, A. D., Joskow, P. L. and Harrison, D. (2003). Emissions Trading in the U.S. Experience, Lessons, and Considerations for Greenhouse Gases, prepared for the Pew Center on Global Climate Change. 

Laboratory experiments are generally carried out with pure, well-defined materials. Thus, the solvent selected for the absorption is used as received from the chemical stores. This differs, of course, from the subsequent situation, where the solvent must be recycled for cost reasons and inevitably becomes enriched with byproducts, some of which are unknown, however, at this point in time. The feedstock used is a synthetic mixture of gases prepared from pure materials which also does not contain byproducts. The experiment shows whether it is physically possible to absorb the useful product from the gas stream with reasonable amounts of solvent. 

As the basis for a reply to the Secretary of State, Mr. Stimson had access to a January 1942 study on toxic gases prepared by the War Plans Division of the General Staff. WPD had undertaken this study to determine existing capabilities of the United States in the event of gas warfare. In the course of preparing Mr. Stimson s reply, WPD had also consulted the Chief, CWS, and his views were subsequently expressed by the War Department. ... 

L,2-propadiene, allene, CH2=C = CH2, CjH4. Colourless gas prepared by the electrolysis of potassium itaeonate, or by the action of zinc and alcohol on 1,3-dibromopropane. It is easily isomerized to propyne (methylacetyl-ene), and is produced as a mixture with this substance from some reactions. 

Commercial production and utilization of ozone by silent electric discharge consists of five basic unit operations gas preparation, electrical power supply, ozone generation, contacting (ie, ozone dissolution in water), and destmction of ozone in contactor off-gases (Fig. 1). 

Synthesis Gas Preparation Processes. Synthesis gas for ammonia production consists of hydrogen and nitrogen in about a three to one mole ratio, residual methane, argon introduced with the process air, and traces of carbon oxides. There are several processes available for synthesis gas generation and each is characterized by the specific feedstock used. A typical synthesis gas composition by volume is hydrogen, 73.65% nitrogen, 24.55% methane, <1 ppm-0.8% argon, 100 ppm—0.34% carbon oxides, 2—10 ppm and water vapor, 0.1 ppm. 

Synthesis gas preparation consists of three steps ( /) feedstock conversion, (2) carbon monoxide conversion, and (2) gas purification. Table 4 gives the main processes for each of the feedstocks (qv) used. In each case, except for water electrolysis, concommitant to the reactions shown, the water-gas shift reaction occurs. 

It is also desirable to spot test the instrument s response between calibrations. For this purpose, several suppliers of compressed gas prepare cylinders containing almost any desired concentration of the gas or vapor of interest. If it is not practical... 

Ozonation systems are comprised of four main parts, including a gas-preparation unit, an electrical power unit, an ozone generator, and a contactor which includes an off-gas treatment stage. Ancillary equipment includes instruments and controls, safety equipment and equipment housing, and structural supports. The four major components of the ozonation process are illustrated in Figure 8. 

The carbon dioxide removed in synthesis gas preparation can be reacted with ammonia, to lonn urea CO(NH2)2- This is an excellent fertilizer, highly concentrated in nitrogen (46.6%) and also useful as an additive in animal feed to provide the nitrogen for formation of meat protein. Urea is also an important source of resins and plastics by reacting it with formaldehyde from methanol. 

Tile tartaric acid is finely powdered and mi.Ked with half the above quantity (80 c.c.) of absolute alcohol. The mixture is heated on the water-bath with upright condenser until dissolved. The flask is immersed in cold water, and the well-cooled solution saturated with dry hydrochloric acid gas (prepared in the usual way by dropping cone, sulphuric acid into cone, hydiochloric acid, see Fig. 65, p. 93). After standing for an... 

Nitrogen oxide (or nitrogen monoxide), NO (oxidation number +2), is commonly called nitric oxide. It is a colorless gas prepared industrially by the catalytic oxidation of ammonia ... 

M. Ahmad, N. Mohammad and J. Abdullah, Sensing material for oxygen gas prepared by doping sol-gel film with tris(2,2 -bipyridyl)dichlororuthe-nium complex, J. Non-Crystal. Solids, 290(1) (2001) 86-91. 

Even though the usual catalytic converter of the exhaust of the standard drive train is omitted, there are also net increases in the chemical industry. The increased demand is for the expensive coating of the electrode-membrane unit (MEA) and the catalysts needed for gas preparation (reformer). 

Contamination may result from incomplete evacuation of the vacuum system and/or from degassing of the sample. The system blank should be normally less than 1% of the amount of gas prepared from a sample for analysis. For very small sample sizes, the blank may ultimately limit the analysis. Memory effects result from samples that have previously been analyzed. They will become noticeable, when samples having widely different isotopic compositions are analyzed consecutively. 

The gas prepared by this process oontains ee hydrogen and the vapour of liquid phosphoretted hydrogen. 

The composition of the synthesis gas, particularly the concentrations of hydrogen, carbon monoxide, and carbon dioxide, affects the atmosphere throughout the reactor directly, and also indirectly by its effect on the composition of the recycle gas. Synthesis gas, prepared by partial combustion of methane or some less hydrogen-rich carbonaceous material, lacks sufficient hydrogen for the conversion of all the carbon monoxide to hydrocarbons, and in this sense the synthesis gas is deficient in hydrogen. Stoichiometrically methane has sufficient hydrogen to convert all its carbon to olefins by the two-step process ... 

Catalyst Poisons. Synthesis gas prepared by the partial combustion of sweet natural gas can be charged to the reactors directly without purification. However, synthesis gas containing more than 0.1 grain of sulfur per 100 cubic feet must be purified before use over fluidized iron catalysts. Other catalyst poisons are known, such as chlorine (14), but they are not likely to be encountered in the natural gas to gasoline process. 

Mamifitditrt.—Chlorate of potassa is now produced on a large ecolo by the following method, which has been found to answer bettor than any other,. One part of chloride of potassium and two parts of hydrate of lime are reduced with water to a thin cream, and chlorine gas—prepared in the ordinary way from binoside of manganese and hydrochloric acid—passed through the menstruum till it assumes a pinkish color, which is due to the formation of traces of hypermanganie acid, VOL. n. 

Fig. 4.29 A gas-preparation assembly for a chemical-vapor-deposition system.

Three 300-cc. gas-washing cylinders (Note 1) are connected in series, and the second and third cylinders are charged with 150 cc. each of dry acetone. Each of the three cylinders is immersed, in a thermos bottle, in sufficient Dry Ice-acetone cooling mixture to cover half of the cylinder. Ketene gas, prepared by the pyrolysis of acetone (Note 2), is passed through the system (Note 3) until a quantity of 2 moles has been introduced. This... 

The type of feed gas used, air or oxygen, determines the achievable ozone gas concentration and the gas preparation requirements. The higher the oxygen content, the higher the ozone concentration possible. Ambient air contains 02 in about 21 vol % (at STP) and is thus a cheap and ubiquitous resource for ozone production. Its main use and advantage is in applications where large mass flows are required at comparatively low ozone gas concentrations, e. g. in drinking water ozonation systems. 

An operating ammonia plant using the aforementioned improvements is shown schematically in Fig. 1. This plant8 has a capacity of 1000 short tons/day (900 metric tons/day) and uses natural gas as feedstock. The plant can be divided into the following integrated-process sections (a) synthesis-gas preparation (b) synthesis-gas purification and (c> compression and ammonia synthesis. A typical (Kellogg designed) ammonia plant is shown in Fig. 2. 

Synthesis Gas Preparation. The desulfurized natural gas mixed with steam is fed to the primary reformer, where it is reacted with steam in nickel-catalysl-lilled lubes to produce a major percentage of the hydrogen required. The principal reactions taking place are9... 

A prototype treatment system of NC consists of four 40-W fluorescent lamps which are radially equipped with four sheets of P i Ft, photocatalyst (total area of 18 m2) and shower nozzles over the lamps/reactors as well as a reservoir, which are used for washing the photocatalyst sheets periodically. A reaction gas prepared from diesel engine exhaust, containing about 2 ppir of NO is introduced into the reactors at a flow rate of 1.0 m s-1 for 10 hours. As shown in Fig. 8.25, although the NO removal ratio seemed to decline slowly after 6 h, the average NO removal ratio obtained was 77.7%. About 80% of NO was recovered as nitrate and nitrite ions by the catalysts using the shower systerr. 

J. Persoz said that nitrous oxide reacts with moist potassium hydroxide, forming nitric acid and ammonia, or ammonium nitrate, but later considered that these substances were derived from some ammonium nitrate mechanically mixed with the gas prepared from that salt. M. Berthelot could find no trace of ammonia... 

Figure 4.13 Schematic of the experimental system, including the gas preparation part and UV-PCO reaction cell.

The formula of carbon dioxide is C02, that of carbon disulphide CS2 and it is evident that an intermediate substance should exist of the formula COS. This substance is carbon oxysulphide. It is a gas, prepared by heating thiocyanic acid, HSCN, the ammonium salt of il which is produced when ammonia is passed through a mixture of carbon disulphide and alcohol CS2 + 2NHg.Alc = H2S + (NH4) SCN.Alc. On evaporation of the alcohol the ammonium thiocyanate crystallises out. This salt, distilled with sulphuric acid, yields in passing the acid HSCN, which, on account of the high temperature, reacts with water, forming ammonia (which yields ammonium sulphate with the sulphuric acid) and carbon oxysulphide, COS HSCN + H20 = NHS + COS. 

There were therefore no holes in the ceilings of these rooms through which the poison gas preparation could be introduced by means of wire mesh pillars or otherwise, as described by eyewitnesses. 

Ammonia synthesis is normally carried out at a pressure higher than that for synthesis gas preparation. Therefore the purified synthesis gas that is fed to the ammonia synthesis loop must be compressed to a higher pressure. Synthesis loop pressures employed industrially range from 8 to 45 MPa (80 to 450 bar). However, the great majority of ammonia plants have synthesis loops that operate in the range of 15 to 25 MPa (150 to 250 bar)74. 

Klumpp DA, Yeung KY, Prakash GKS, Olah GA, Preparation of 3,3-diaryloxyndoles by superacid-induced condensations of isatins and aromatics with a combinatorial approach, J. Org. Chem., 63 4481-4484, 1998. 

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