Ronald W. Rousseau

Effects of bismarck brown R on the growth rates of large and small potassium alum crystals

Abstract Experimental data show that Bismarck Brown R, at a concentration of 10 ppm, substantially inhibited growth rates of potassium alum. All faces of the crystal were affected similarly, although there was some evidence that inhibition of the (111) faces was slightly greater. Growth rates of small crystals were inhibited more than larger crystals; this is explained using observations of growth rate dispersion believed due to variations in screw dislocation activities. Data showing time-dependent inhibition of growth was used to support the hypothesis that Bismarck Brown R forms complexes or chelates that completely inhibited growth.

The influence of quinoline yellow on potassium alum growth rates

Abstract The linear growth rate of the (111) face of potassium alum has been evaluated in the presence of quinoline yellow dye. Experimental conditions were such that surface incorporation was controlling the growth rate. The observed influence of the dye on the growth rate was attributed to a blockage of growth sites on the crystal face by adsorbed dye. Using an adsorption isotherm intermediate to those of Langmuir and Freundlich the growth rate was correlated with the dye concentration in parts per million by the equation (G − G ∞ ) (G 0 − G) = 6.76 × 10 5 c -3.41 .

Physical Absorption of CO2 and Sulfur Gases from Coal Gasification: Simulation and Experimental Results

Abstract High partial pressures of CO2, H2S and certain other constituents produced in coal gasification tend to make the use of physical solvents in associated acid gas removal systems more attractive than the use of chemical solvents. In the research program described in this paper operating data obtained on a pilot plant system employing refrigerated methanol as a solvent will be presented. A mathematical model of the packed absorber used in the process was developed. Predictions of system performance for a feed gas consisting of CO2 and nitrogen compared favorably to experimental data obtained on the system. In addition, there was very good agreement between predicted and observed distributions of nine of the major components in a feed gas synthesized in a coal gasification reactor. The results show the validity of the modeling procedure and may be used in understanding the general characterists of packed absorbers and strippers.

Conditioning coal gas with aqueous solutions of potassium carbonate: Model development and testing

Abstract A mathematical model describing the performance of an acid gas removal system that used hot potassium carbonate as a chemical solvent was developed and tested against operating data. The model has several parts, including algorithms for describing absorption, stripping and flash operations in which chemical reaction is occurring. The approach adopted rests on assumptions that allow the influence of chemical reactions on mass transfer coefficients to be calculated from correlations found in the literature. Predictions of the composition of the conditioned gas compared favourably with those obtained in experiments on an acid gas removal pilot plant. Although developed specifically for describing the performance of acid gas removal systems that utilize potassium carbonate solutions as a solvent, the approach can be extended to other chemical solvents.

CONDITIONING COAL GAS WITH REFRIGERATED METHANOL IN A SYSTEM OF PACKED COLUMNS

Experience with the operation of a pilot-scale unit is used to outline potential difficulties in the operation of acid gas removal systems on gases produced from coal. The pilot plant has been used to condition gases produced from subbituminous coal, devolatilized char, peat and lignite. The solvent used in the acid gas removal system has been refrigerated methyl alcohol. Data from this study document accumulation of hydrocarbons, sulfur and nitrogen compounds, and mercury in the circulating solvent.