Temperature determination of shock layer using spectroscopic techniques

Shock layer temperature profiles are obtained through analysis of radiation from shock layers produced by a blunt body inserted in an arc jet flow. Spectral measurements of N2(+) have been made at 0.5 inch, 1.0 inch, and 1.4 inches from the blunt body. A technique is developed to measure the vibrational and rotational temperatures of N2(+). Temperature profiles from the radiation layers show a high temperature near the shock front and decreasing temperature near the boundary layer. Precise temperature measurements could not be made using this technique due to the limited resolution. Use of a high resolution grating will help to make a more accurate temperature determination. Laser induced fluorescence technique is much better since it gives the scope for selective excitation and a better spacial resolution

LIF and emission studies of copper and nitrogen

A technique is developed to determine the rotational temperature of nitrogen molecular ion, N2(+), from the emission spectra of B-X transition, when P and R branches are not resolved. Its validity is tested on simulated spectra of the 0-1 band of N2(+) produced under low resolution. The method is applied to experimental spectra of N2(+) taken in the shock layer of a blunt body at distances of 1.91, 2.54, and 3.18 cm from the body. The laser induced fluorescence (LIF) spectra of copper atoms is analyzed to obtain the free stream velocities and temperatures. The only broadening mechanism considered is Doppler broadening. The temperatures are obtained by manual curve fitting, and the results are compared with least square fits. The agreement on the average is within 10 percent

MAGNETO-CHEMICAL CHARACTER STUDIES OF NOVEL Fe CATALYSTS FOR COAL LIQUEFACTION

The objectives of the present study are: (1) To synthesize iron catalysts: Fe/MoO{sub 3}, and Fe/Co/MoO{sub 3} employing two distinct techniques: Pyrolysis with organic precursors and Co-precipitation of metal nitrates; (2) To investigate the magnetic character of the catalysts before and after exposure to CO and CO+H{sub 2} by (a) Mossbauer study of Iron (b) Zerofield Nuclear Magnetic Resonance study of Cobalt, and (c) Magnetic character of the catalyst composite; (3) To study the IR active surface species of the catalyst while stimulating (CO--Metal, (CO+H{sub 2})--Metal) interactions, by FTIR Spectroscopy; and (4) To analyze the catalytic character (conversion efficiency and product distribution) in both direct and indirect liquefaction Process and (5) To examine the correlations between the magnetic and chemical characteristics. This report presents the results of our investigation on (a) the effect of metal loading (b) the effect of intermetallic ratio and (c) the effect of catalyst preparation procedure on (i) the magnetic character of the catalyst composite (ii) the IR active surface species of the catalyst and (iii) the catalytic yields for three different metal loadings: 5%, 15%, and 25% (nominal) for three distinct intermetallic ratios (Fe/Co = 0.3, 1.5, 3.0)

MAGNETO-CHEMICAL CHARACTER STUDIES OF NOVEL FE CATALYSTS FOR COAL LIQUEFACTION

The primary objectives of research during this period were: (1) To prepare iron-cobalt-molybdenum trioxide catalysts using co-precipitation method; (2) To examine the surface character of these catalysts with CO and Syngas as probe molecules by FTIR spectroscopy; and (3) To examine the magnetic properties of these catalysts using NMR and Magnetization techniques

Quarterly Technical Progress Report - Investigation of Syngas Interaction in Alcohol Synthesis Catalysts

This report presents the work done on " Investigation of Syngas Interaction in Alcohol Synthesis Catalysts" during the last quarter. The major activity during this period is on FTIR absorption studies of Co/Cr catalysts using CO as a probe molecule. Transition metals cobalt and copper play significant roles in the conversion of syngas (CO + H2 ) to liquid fuels. With a view to examine the nature of interaction between CO and metal, the FTIR spectra of CO adsorbed on Co-Cr2 O3 composites were investigated. The results indicate that as cobalt loading increases, the intensity of the CO adsorption bands increase and several vibrational modes seem to be promoted. Heat treatment of the sample revealed two distinct processes of adsorption. Bands due to physisorption disappeared while bands due to chemisorption not only increased in intensity but persisted even after desorption. It seems that the physisorption process is more active when the catalyst is fresh and is hindered when carbidic/carbonyl formations occur on the metal surfaces

MAGNETO-CHEMICAL CHARACTER STUDIES OF NOVEL FE CATALYSTS FOR COAL LIQUEFACTION

Co-precipitation is the major method proposed for synthesis of molybdenum oxide supported Fe, Fe/Co, and Fe/Cu catalysts. However, many variables may effect the particle size and surface properties of the synthesized catalysts, such as pH of molybdate solution, precipitation temperature and pH, Fe/Mo atomic ratio, pH of the washing solution, aging of the freshly prepared samples, and the length and temperature of calcination. In this period, we have been working on precipitation between iron(III) nitrate solution and ammonium para-molybdate solution under controlled pH condition, and with different Me/Fe atomic ratio. The effect of aging time on the property of the samples was also studied. The samples with the ratio of Fe/MoO{sub 3}: 6.5%, 20%, 26%, and 30% were prepared using above mentioned method. The samples with 6.5% and 26% were characterized with thermal analysis, infrared spectroscopy, magnetization, Moessbauer and X-ray diffraction before and after calcination at 400 C. FTIR was examined on precipitate, calacined and reduced samples as well as CO adsorbed and desorbed samples. Magnetization Studies were made on precipitated, calacined, and reduced samples. Their synthesis and characterization are presented in this report

Quarterly Technical Progress Report - Investigation of Syngas Interaction in Alcohol Synthesis Catalysts

This report presents the work done on " Investigation of Syngas Interaction in Alcohol Synthesis Catalysts" during the last quarter. The major activity during this period is on FTIR absorption studies of Co/Cr catalysts using CO as a probe molecule. Transition metals cobalt and copper play significant roles in the conversion of syngas (CO + H2 ) to liquid fuels. With a view to examine the nature of interaction between CO and metal, the FTIR spectra of CO adsorbed on Co-Cr2 O3 composites were investigated. The results indicate that as cobalt loading increases, the intensity of the CO adsorption bands increase and several vibrational modes seem to be promoted. Heat treatment of the sample revealed two distinct processes of adsorption. Bands due to physisorption disappeared while bands due to chemisorption not only increased in intensity but persisted even after desorption. It seems that the physisorption process is more active when the catalyst is fresh and is hindered when carbidic/carbonyl formations occur on the metal surfaces

Quarterly Technical Progress Report

This report presents the work done on " Investigation of Syngas Interaction in Alcohol Synthesis Catalysts" during the last quarter. FTIR absorption studies on Cu/Co/Cr catalysts using CO as a probe molecule are presented in this report. A comprehensive FTIR investigation on the catalysts was undertaken to unfold the picture of the gas - metal interactions. Our magnetization studies have provided valuable information on the changes in the magnetic character of the ferromagnetic metal due to CO adsorption. The FTIR results showing the effect of the adsorbate-adsorbent interactions on the stretching frequencies of the CO vibrational modes are presented in this report