Henry Shaw

Bio: Henry Shaw is an academic researcher from New Jersey Institute of Technology. The author has contributed to research in topics: Aqueous solution & Sodium chlorite. The author has an hindex of 4, co-authored 6 publications receiving 249 citations.

Simultaneous absorption and oxidation of no and so2 by aqueous solutions of sodium chlorite

Abstract: Complete and simultaneous removal of NO and SO2 is achieved in a laboratory bubble column reactor at about room temperature using aqueous solutions of NaClO2 buffered with Na2HPO4and KH2PO4The influence of reaction medium chemistry (pH and concentrations of buffer and NaOH) on NOx and SO2 removal efficiencies was also evaluated. The buffered NaClO2 solution is determined to be more effective in absorbing NOx and SO2 and in controlling chlorine dioxide (ClO2) leakage. The presence of SO2 greatly reduces the scrubbing solution absorption rate for NO as evidenced by shorter breakthrough times, irrespective of the absorbent solution used. The scrubbing solution pH is determined to be very critical in the simultaneous absorption and oxidation of NO and SO2. NO2 control is enhanced significantly as the buffer concentration increases from 0.1 M to 0.5 M, with no NO2 detected in the effluent gas at buffer concentration levels ≥ 0.5 M. Optimal removal efficiencies were observed at the following conditions...

Aqueous absorption of nitric oxide induced by sodium chlorite oxidation in the presence of sulfur dioxide

Abstract: The absorption of NO from a gas stream containing SO{sub 2} by aqueous solution of NaClO{sub 2} was studied in a bench scale scrubber. NO{sub x} removal of up to 95% was obtained using a packed bed scrubber. The corresponding SO{sub 2} removals were 100%. Experiments were also conducted in a bubble column and a spray chamber scrubber in order to obtain engineering data for scale-up and process design. A novel UV/Vis photodiode array (PDA) method was developed for real-time monitoring of oxychlorine compounds in the scrubbing solutions. As a consequence of the data obtained with the PDA system, a much better understanding of the chemistry of the scrubbing system has led to a simpler mass transfer model than is available in the literature. Absorption rates are reported in terms of overall reaction rates for a spray chamber scrubber and height of transfer units for a packed bed scrubber.

Absorption of no promoted by strong oxidizing agents: 1. inorganic oxychlorites in nitric acid

Abstract: Almost quantitative absorption of NO is achieved in nitric acid solutions containing sodium chlorite, sodium hypochlorite, or chlorine gas at temperatures up to 80°C and atmospheric pressure. Experiments are conducted by bubbling various mixtures of NO, NO2 and O2, with the balance N2 into varying volumes of scrubbing solutions up to one dm3. When scrubbing with acidic NaClO2, a greenish yellow color is observed in the solution when the gaseous mixture is bubbled into the liquid containing the oxidizing compound. The color is due to the presence of ClO2 gas, an intermediate active in the oxidation of NO. Results in acidic NaClO or Cl2 show similar results, except the intermediate that actually promotes the oxidation is HClO. These intermediates were identified spectroscopically. Material balances, determined using ion chromatography, show that the only anions in solution at NO breakthrough are NO3 − and Cl−.

Absorption of nitric oxide promoted by strong oxidizing agents: organic tertiary hydroperoxides in n-hexadecane

Abstract: The selective removal of nitric oxide from gas streams was investigated using 3,6-dimethyl-3-octyl hydroperoxide, p-menthanyl hydroperoxide, pinanyl hydroperoxide, and cumenyl hydroperoxide in solutions of n-hexadecane (cetane). The influence of different variables such as temperature, gas stream flow rate (or residence time), and concentration of hydroperoxide compounds on rate of NO removal was evaluated. The NO reacted with the hydroperoxides to produce allyl nitrates. These are easily hydrolyzed with ammonium hydroxide to ammonium nitrate and the alcohol

Application of a droplet column type two-phase reactor for the epoxidation of cyclooctene in water as an alternative solvent

Abstract: Droplet columns are used for their ability to greatly enhance liquid-liquid interfacial areas. The use of a droplet column for the two-phase epoxidation of cyclooctene by oxone in aqueous solution was studied as an application of pollution prevention, i.e., the replacement of hazardous solvents with water. The dispersion of alkene droplets in aqueous oxone solution was generated by pumping the organic phase through a sparger at the bottom of the column. Then, organic droplets rise to the top of the aqueous phase. As the alkene droplets rise, they are oxidized by the oxone solution to form epoxide. The study of aqueous epoxidation in a droplet column shows that the epoxidation of alkenes can be represented as a first-order reaction in alkene and a first-order reaction in oxone under mass transfer limiting conditions. By recycling the cyclooctene, over 60% yield of cyclooctene epoxide can be achieved in 3 h. However, due to epoxide crystals formation, a second reactor is needed to remove the solid and to bring the yield up to 80%. The authors found that a stirred tank reactor, which avoids the need to put the crystallized mixture through the small holes of a sparger, performed well in this applicationmore » as a second reactor.« less

Simultaneous Removal of SO2, NOX, and Hg from Coal Flue Gas Using a NaClO2-Enhanced Wet Scrubber

Abstract: A bench-scale study was conducted on the simultaneous removal of SO2, NOX, and mercury (both Hg0 and Hg2+) from a simulated coal flue gas using a wet calcium carbonate scrubber. The multipollutant capacity of the scrubber was enhanced with the addition of the oxidizing salt, sodium chlorite. The results showed a maximum scrubbing of 100% for SO2 and Hg species and near complete NO oxidation with about 60% scrubbing of the resulting NOX species. The chlorite additive was less effective as an oxidant in the absence of SO2 and NO in the flue gas. Oxidation of NO and mercury were only about 50% and 80%, respectively, in the case of no SO2 in the simulated flue gas. The mercury oxidation was similarly affected by the absence of NO in the flue gas.

Air-Soil Exchange of Organochlorine Pesticides in Agricultural Soils. 1. Field Measurements Using a Novel in Situ Sampling Device

Abstract: Initial results are presented for in situ measurements of soil−air partitioning for a range of organochlorine (OC) pesticides in two contaminated agricultural soils. A soil survey was conducted and used to identify high levels of several OC pesticides in two regions of southern Ontario that are known for their intensive agriculture, the Tobacco Belt and the Holland Marsh. Experiments were conducted at one field in each region by sampling air very close to the soil surface using a disc-shaped sampler. The equilibrium status of the sampled air was tested by comparing the chiral signature of the soil with the signature in air sampled by the device and ambient air. Although results showed that 104% of trans-chlordane (TC) and 96% of cis-chlordane (CC) in the air under the sampler originated from the soil, the propagated errors in these results (34% SD for TC and 26% SD for CC) are too large to provide conclusive evidence for equilibrium. Therefore, a soil−air quotient (QSA) is reported here instead of the soil−air partition coefficient (KSA). This value is an approximation of the “true” KSA. Results show a linear relationship between log QSA and log KOA and fit in with the relationship KSA = 0.411ρOCKOA where ρ is the soil density (kg L-1). Using this relationship, fugacities were calculated in air and soil. Results of this calculation identify a strong disparity that favors soil-to-air transfer. This gradient is confirmed by measurements at different heights over one of the fields. Soil−air exchange is a key process in the overall fate of OC pesticides. The results from this study will improve our ability to model this process and account for differences between soils.