Chlorine Utilization Research Articles

Supersonic COIL with angular jet singlet oxygen generator

Supersonic Chemical Oxy-iodine Laser has been developed using a Singlet Oxygen Generator (SOG) with a novel approach. Generated singlet oxygen is taken out of the SOG at an angle of 40° to avoid the problem of carry over of droplets, which is one of the major drawbacks of horizontal system. The system has been operated up to 22 mmol/s chlorine flow rates. Chlorine utilization and singlet oxygen observed have been more than 90% and 60%, respectively. The observed maximum output power was 350 W , thus yielding a chemical efficiency of 17.5%.

Diode-laser-based absorption spectroscopy diagnostics of a jet-type O/sub 2/(/sup 1/Δ) generator for chemical oxygen-iodine lasers

Using diode-laser-based diagnostics, O/sub 2/(/sup 1//spl Delta/) yield and water vapor fraction were measured at the exit of a jet-type singlet oxygen generator (JSOG) for a chemical oxygen-iodine laser (COIL). Chlorine utilization and gas temperature at the generator exit were also measured, simultaneously. For conditions corresponding to the maximum chemical efficiency of the supersonic COIL energized by the JSOG, the O/sub 2/(/sup 1//spl Delta/) yield, water vapor fraction, chlorine utilization, and temperature at the generator exit are 0.65, 0.08 and 0.92, and 30/spl deg/C, respectively. Increase of the basic hydrogen peroxide temperature results in an increase of the water vapor fraction caused by an increase of the saturated water vapor pressure in the generator. As the pressure in the generator rises from 18 to 60 torr, the yield decreases from 0.65 to O.48. Dependence of the yield on the generator pressure is consistent with a rate constant for the O/sub 2/(/sup 1//spl Delta/) energy pooling reaction of 2.7/spl times/10/sup -17/ cm/sup 3//spl middot/S/sup -1/. The same rate constant explains the measured variation of the temperature along the flow in the diagnostic cell.

Complex processing of molten secondary aluminium

The paper describes a new in-line technology for complex treatment of secondary aluminium and aluminium alloys which combincs metal filtering, alkali removal and degassing operations into a single unit. Process hydrogen removal efficiencies are expressed as a percentage of original hygrogen content. The relationship between melt velocity and filtration efficiency, and height of filter and filtration efficiency were examined. The CTT system showed superior chlorine utilization efficiency compared to other comercialized in-line technologies. The CTT process offers superior secondary metal treatment performance in terms of inclusion removal and comparable hydrogen and alkali removal efficiencies

Chlorine utilization study for uniform-droplet singlet delta oxygen generators

A simple model incorporating gas-phase diffusion and surface reaction was used to investigate the effects of certain design parameters on the utilization of chlorine in uniform-droplet singlet delta oxygen generators. The results of this model compare favorably to experimental data for chlorine utilization. The effects of certain design parameters such as diluent ratio, gas temperature, gas pressure, droplet velocity, and droplet radius were studied.

Chlorination of commercial molybdenite concentrate in a fluidized bed reactor

Studies on recovery of molybdenum from commercial grade molybdenite using the technique of fluidized bed chlorination in the presence of oxygen are presented. Molybdenum recovery above 99 pct at a chlorine utilization efficiency of 84 pct has been achieved for a fluidizing gas flow-rate of 3 L/min of the gases Cl2, O2, and N2 mixed in the proportion of 2∶5∶23, respectively, at 300 °C. The investigations on kinetics showed that the overall oxychlorination reaction is controlled by chemical reaction and is of first order with respect to particle surface area.

Halogenated mobile phase additives for improved detection performance in liquid chromatography—negative chemical ionization mass spectrometry

The addition of 0.1–1% of chloroacetonitrile to an acetonitrile—water eluent can significantly improve the detection performance in column liquid chromatography—negative chemical ionization mass spectrometry (LC—NCI MS) using a direct liquid introduction interface. The addition of the chlorine-containing modifier does not change the retention times of the chlorophenols used as test compounds. However, the sensitivity for the lower chlorinated phenols is enhanced up to 30-fold. In addition, fragmentation is suppressed and the mass spectra are often characterized by only one main cluster over the whole 170–330°C temperature range studied. With most test compounds, so-called chloride attachment also occurs to some extent, especially at relatively low ion source temperatures. However, for phenol and mono- and dichlorophenol fairly intense [M + Cl] − clusters are even observed at source temperatures of 300°C. For a further evaluation two phenoxyacetic acids, lindane, l-leucine and l-ascorbic acid were studied, and the utilization of other chlorine-, bromine- and fluorine-containing additives was explored.

Chlorine utilization during trihalomethane formation in the presence of ammonia and bromide

The chlorination of humic substances in the presence of ammonia and bromide and the resultant formation of trihalomethanes (THM) are described. The presence of ammonia substantially reduced but did not eliminate THM production during the chlorination of waters containing humic substances. The presence of bromide ion in waters containing humic substances leads to increased THM formation, both in the presence and in the absence of ammonia. In waters containing ammonia, bromide, and humic substances, brominated haloforms can form upon chlorination. Brominated species comprise a larger portion of the total THMs at higher chlorine doses within the free chlorine region of the breakpoint curve than at lower dose in the subbreakpoint region. Although the THM formation reaction is slow and may not be complete even after 1 week of reaction time, the initial rate of formation is competitive with the relatively rapid reactions of bromide oxidation and chloramine formation. After free chlorine is converted to chloramines, THM production should theoretically cease. THMs will form in parallel with chloramine formation. This behavior has important implications for water utilities that use a raw water source containing low but significant levels of ammonia such as the Biscayne Aquifer, or are considering chloramine disinfection asmore » a THM control strategy.« less

炭素被覆アルミナの塩素化反応に影響を及ぼす諸因子

For the production of aluminum chloride, chlorination behaviors of sandy alumina coated with pyrolytic carbon have been examined by changing the amount of carbon coated, coating temperature, and specific surface area of alumina etc. The experimental results obtained are summarized as follows:(1) The chlorination reaction of alumina was affected by the characteristic of carbon pyrolytically coated and the crystallization of γ-alumina.(2) The chlorination reaction rate of alumina having the specific surface area of 100-200 m2/g was faster than that of 10-100 m2/g.(3) For the complete recovery of aluminum chloride at 600°C, it was required to deposit carbon of about 17.2wt% on alumina by thermocatalytic cracking. At temperature of 500°C600°C, the carbon consumption increased by 5wt% as the temperature increased by 25°C.(4) For the effective utilization of chlorine, the bed height of sample in chlorination reactor had to be adjusted by considering the chlorination temperature.(5) Chlorination reaction of alumina coated with pyrolytic carbon was accelerated by the addition of a small amount of NaCl or KCl. However, the chlorination reaction was decreased when these salts were excessively added because the contact of chlorine with alumina particle was prevented by NaAlCl4 or KAlCl4 formed.

Aspects of Chlorine Utilization in the United Kingdom

Annual U.K. production of chlorine stands at around 106 tonnes. Less than 1.5% (15,000 tonnes) finds direct application as a biocide, of which 10,000 tonnes (1976 estimate) is used by the C.E.G.B. (England and Wales) for the control of bacterial slimes and marine fouling in power station cooling circuits. This compares with 4000 tonnes used for treating domestic water supplies. Indirect biocidal application via chlorinated hydrocarbon pesticides never exceeded 300 tonnes per annum. It is not standard practice in the U.K. to use chlorine in sewage treatment.

The chlorination of lead + bismuth melts

Abstract An electrochemical kinetic model is described from which the rate of formation of lead chloride from a melt of lead and bismuth and bubbles of gaseous chlorine is calculated. The basic assumption of the model. is that the reaction rate is controlled by the electronic conductivity of the salt phase. Two periods of bubble history are recognized: (i) an inflation period and (ii) a rise period. The electrochemical rate equation and the mass balance equation are evaluated using published data for the ionic and electronic conductivity of the salt phase and information on bubble hydrodynamics. The calculated rates of formation of lead chloride and chlorine utilization are in broad agreement with laboratory-scale measurements. Agreement between the rate of chlorination as calculated from the model and as determined from industrial-scale studies is less good, probably due to uncertainties in the hydrodynamics of the relatively large bubbles involved. Resume Un modele electrochimique est propose a partir d...

Preparation of Oxides, Glycols and Polyglycols from Lower Olefins. II.

The authors contemplated to find the most suitable conditions to manufacture propylene oxide via chlorohydrine process.It was found that a high yield of propylene chlorohydrine is obtainable in circulating type reaction column.Further investigations were made on the condition for direct utilization of untreated gaseous chlorine from electrolysis of salt water, and 95% yield has been achieved.In manufacturing propylene oxide by the dehydrochloric acid of propylene chlorohydrine optimum conditions on holding time and were achieved when a horizontal type reactor having a providing net at the bottom was employed of the amount of direct blowing steam.

Chemical Hazards in Water Works Plants

Your committee promptly decided that for this first report the study would be limited to chlorine, first, because of the more universal use of chlorine, second, its relatively greater potential danger and, third, the greater amount of data regarding chlorine already available to your committee. It was also decided that the reactions from this first report would be of great assistance in determining the best procedure in the further study of this and other chemicals. Therefore, the attached report deals only with recommended practice in the handling and utilization of chlorine and the advisable first aid to be rendered those suffering from exposure to chlorine. We are indebted to Mr. L. L. Hedgpeth of the Pennsylvania Salt Company for special work in the first part of this report and to Mr. H. H. Gerstein, Department of Public Works, Chicago, for the special work in the second part of this report. Your committee will be glad to continue its work if deemed advisable. L. H. Enslow, Geo. H. Fenkell, H. H. Gerstein, A. E. Gorman, R. F. Goudey, Frank E. Hale, L. L. Hedgpeth, Norman J. Howard, H. S. Hutton, W. C. Lawrence, W. S. Mahlie, M. C. Smith, Chairman.