The study of redox-active inorganic substituents of cellulase enzymes. Quarterly report, 25 August--25 November 1993 (open access)

The study of redox-active inorganic substituents of cellulase enzymes. Quarterly report, 25 August--25 November 1993

Cellulase (CBHI) was modified by bis (2,2- bipyridine) ruthenium (II) and the modified enzyme was assayed for cellulase activity using p- nitrophenyl beta-D-cellobioside as substrate. Absorption spectroscopy of native and modified CBHI was also conducted.
Date: December 31, 1993
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Chemically Assisted in Situ Recovery of Oil Shale (open access)

Chemically Assisted in Situ Recovery of Oil Shale

The purpose of the research project was to investigate the feasibility of the chemically assisted in situ retort method for recovering shale oil from Colorado oil shale. The chemically assisted in situ procedure uses hydrogen chloride (HCl), steam (H{sub 2}O), and carbon dioxide (CO{sub 2}) at moderate pressure to recovery shale oil from Colorado oil shale at temperatures substantially lower than those required for the thermal decomposition of kerogen. The process had been previously examined under static, reaction-equilibrium conditions, and had been shown to achieve significant shale oil recoveries from powdered oil shale. The purpose of this research project was to determine if these results were applicable to a dynamic experiment, and achieve penetration into and recovery of shale oil from solid oil shale. Much was learned about how to perform these experiments. Corrosion, chemical stability, and temperature stability problems were discovered and overcome. Engineering and design problems were discovered and overcome. High recovery (90% of estimated Fischer Assay) was observed in one experiment. Significant recovery (30% of estimated Fischer Assay) was also observed in another experiment. Minor amounts of freed organics were observed in two more experiments. Penetration and breakthrough of solid cores was observed in six experiments.
Date: December 31, 1993
Creator: Ramierz, W. F.
Object Type: Report
System: The UNT Digital Library
Waste minimization opportunities at the U.S. Uranium Mill Tailings Remedial Action (UMTRA) Project, Rifle, Colorado, site (open access)

Waste minimization opportunities at the U.S. Uranium Mill Tailings Remedial Action (UMTRA) Project, Rifle, Colorado, site

At two uranium mill sites in Rifle, Colorado, the US Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project is removing uranium mill tailings and contaminated subgrade soils. This remediation activity will result in the production of groundwater contaminated with uranium, heavy metals, ammonia, sulfates, and total dissolved solids (TDS). The initial remediation plan called for a wastewater treatment plant for removal of the uranium, heavy metals, and ammonia, with disposal of the treated water, which still includes the sulfates and TDSS, to the Colorado River. The National Pollutant Discharge Elimination (NPDES) permit issued by the Colorado Department of Health for the two Rifle sites contained more restrictive discharge limits than originally anticipated. During the detailed review of alternate treatment systems to meet these more restrictive limits, the proposed construction procedures were reviewed emphasizing the methods to minimize groundwater production to reduce the size of the water treatment facility, or to eliminate it entirely. It was determined that with changes to the excavation procedures and use of the contaminated groundwater for use in dust suppression at the disposal site, discharge to the river could be eliminated completely.
Date: December 31, 1993
Creator: Hartmann, George L.; Arp, Sharon & Hempill, Hugh
Object Type: Report
System: The UNT Digital Library
Direct Conversion of Methane to Methanol in a Non-Isothermal Catalytic Membrane Reactor (open access)

Direct Conversion of Methane to Methanol in a Non-Isothermal Catalytic Membrane Reactor

The direct partial oxidation of CH{sub 4} to CH{sub 3}OH has been studied in a non-permselective, non-isothermal catalytic membrane reactor system. A cooling tube introduced coaxially inside a tubular membrane reactor quenches the product stream rapidly so that further oxidation of CH{sub 3}OH is inhibited. Selectivity for CH{sub 3}OH formation is significantly higher with quenching than in experiments without quenching. For CH{sub 4} conversion of 4% to 7% CH{sub 3}OH selectivity is 40% to 50% with quenching and 25% to 35% without quenching.
Date: December 31, 1993
Creator: Noble, R. D. & Falconer, J. L.
Object Type: Article
System: The UNT Digital Library