The Infrared Absorption of Hydrogen Chloride in Nonionizing Solvents

1936 ◽  
Vol 50 (8) ◽  
pp. 719-722 ◽  
Author(s):  
Dudley Williams
Keyword(s):  
Hydrogen Chloride ◽  
Infrared Absorption ◽  
Absorption Of Hydrogen

Selective absorption of hydrogen chloride from flue gases in the presence of sulfur dioxide

1984 ◽  
Vol 3 (3) ◽  
pp. 183-187 ◽  
Author(s):  
W. S. Kyte ◽  
J. Bettelheim ◽  
N. E. Nicholson ◽  
J. Scarlett
Keyword(s):  
Sulfur Dioxide ◽  
Hydrogen Chloride ◽  
Flue Gases ◽  
Selective Absorption ◽  
Absorption Of Hydrogen

THE EFFECT OF INITIAL ACID CONCENTRATION ON THE LIGNIN ISOLATED BY THE ACIDOLYSIS OF ASPEN WOOD

1961 ◽  
Vol 39 (7) ◽  
pp. 1454-1461 ◽  
Author(s):  
J. M. Pepper ◽  
M. Siddiqueullah
Keyword(s):  
Hydrogen Chloride ◽  
Absorption Spectra ◽  
Acid Concentration ◽  
Infrared Absorption ◽  
Extraction Time ◽  
Extraction Temperature ◽  
Aspen Wood ◽  
Solvent Medium ◽  
Infrared Absorption Spectra ◽  
High Yields

A further study has been made of the isolation, by acidolysis, of lignin from aspen wood meal (Populustremuloides Michx.) using a dioxane–water (9:1) solvent medium containing hydrogen chloride and a low extraction temperature of 87 ± 2° for a short extraction time of 0.5 hour. Lignins so isolated included those: (a) under different initial acid concentrations of 0.0, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.8, and 1.7 equivalents of HCl/liter of solvent medium; (b) from successive extractions under increasing initial acid concentrations of 0.2, 0.4, 0.8, and 1.6 equivalents/liter; and (c) from successive extractions under constant initial acid concentrations of 0.2 equivalent/liter.All the lignin fractions so isolated were studied with respect to their yield, methoxyl content, infrared absorption spectra, and the yields of vanillin and syringaldehyde obtained from them by oxidation using alkaline nitrobenzene.Evidence is presented in support of the non-homogeneity of the whole protolignin. This may be the result of the presence of possibly two basic types. One fraction, comprising around 70–85%, is most readily extracted, has a consistently high methoxyl content (ca. 21%), and is capable of being oxidized to give high yields of syringaldehyde and vanillin in a ratio close to 2.5:1. The second fraction is characterized by a greater difficulty of extraction, lower methoxyl content, and significantly lower yields of the aldehydes in a ratio closer to 1:1.

PRESSURE-INDUCED INFRARED ABSORPTION OF HYDROGEN AND HYDROGEN – FOREIGN GAS MIXTURES IN THE RANGE 1500–5000 ATMOSPHERES

1958 ◽  
Vol 36 (1) ◽  
pp. 88-103 ◽  
Author(s):  
W. F. J. Hare ◽  
H. L. Welsh
Keyword(s):  
Absorption Coefficient ◽  
Infrared Absorption ◽  
Room Temperature ◽  
Pure Hydrogen ◽  
Vibrational Transition ◽  
Absorption Process ◽  
Quadrupole Interactions ◽  
Relative Kinetic ◽  
Very High ◽  
Absorption Of Hydrogen

The pressure-induced infrared absorption of hydrogen was studied in pure hydrogen and in hydrogen–helium, hydrogen–argon, and hydrogen–nitrogen mixtures at pressures up to 5000 atm. at room temperature. The integrated absorption coefficient can be expressed in the form α1ρaρp + α2ρaρp2 over the whole range of densities (ρa = density of H2, ρp = density of the perturbing gas, [Formula: see text] in the mixture experiments). The coefficient α2 is much smaller than predicted from the effect of finite molecular volumes; this is interpreted as a partial cancellation of the induced moments in ternary collisions. The splitting of the Q branch of the fundamental, which is due to the participation of the relative kinetic energies of the colliding molecules in the absorption process, increases linearly with the density because of ternary collisions; a more rapid increase observed at very high densities is not yet explained. The components of the overtone and double vibrational transition, like the QQ and S components of the fundamental, show no splitting or broadening with increasing density; these absorptions are believed to be due to quadrupole interactions while the QP and QR components of the fundamental are due to overlap interactions.

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