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Task 3 -- Bench-scale char upgrading and utilization study

Description: This report describes the results of the bench-scale char upgrading study conducted as Task 3 of Development of an Advanced, Continuous Mild Gasification Process for the Production of Coproducts. A process where the char is gasified to produce methane in a first stage reactor was investigated. This methane is then decomposed to produce carbon and hydrogen for recycle in a second stage. The results indicate that both reaction steps are feasible using mild gasification char as the starting feedstock. Conditions for methanation are 700 to 800 C and 200 to 400 psig. Carbon formation conditions are 1,200 to 1,400 C at atmospheric pressure. The carbon produced has properties similar to those of carbons which are commercially marketed as carbon black.
Date: August 2, 1989
Creator: Jha, M.C. & McCormick, R.L.
Partner: UNT Libraries Government Documents Department

Enhanced durability and reactivity for zinc ferrite desulfurization sorbent

Description: AMAX Research Development Center (AMAX R D) has been investigating methods for enhancing the reactivity and durability of the zinc ferrite desulfurization sorbent. Zinc ferrite sorbents are intended for use in desulfurization of hot coal gas in integrated gasification combined cycle (IGCC) or molten carbonate fuel cell (MCFC) applications. For the present program, the reactivity of the sorbent may be defined as its sulfur sorption capacity at the breakthrough point and at saturation in a bench-scale, fixed-bed reactor. Durability may be defined as the ability of the sorbent to maintain important physical characteristics such as size, strength, and specific surface area during 10 cycles of sulfidation and oxidation.
Date: May 2, 1989
Creator: Silaban, A. & Harrison, D.P. (Louisiana State Univ., Baton Rouge, LA (United States). Dept. of Chemical Engineering)
Partner: UNT Libraries Government Documents Department

Enhanced durability and reactivity for zinc ferrite desulfurization sorbent

Description: AMAX Research Development Center (AMAX R D) has been investigating methods for enhancing the reactivity and durability of the zinc ferrite desulfurization sorbent. Zinc ferrite sorbents are intended for use in desulfurization of hot coal gas in integrated gasification combined cycle (IGCC) or molten carbonate fuel cell (MCFC) applications. For the present program, the reactivity of the sorbent may be defined as its sulfur sorption capacity at the breakthrough point and at saturation in a bench-scale, fixed-bed reactor. Durability may be defined as the ability of the sorbent to maintain important physical characteristics such As size, strength, and specific surface area during 10 cycles of sulfidation and oxidation.
Date: May 2, 1989
Creator: Jha, M.C. & Berggren, M.H.
Partner: UNT Libraries Government Documents Department

A Main Ring bunch length monitor by detecting two frequency components of the beam

Description: The bunch length is measured by detecting two revolution frequency harmonics of the beam and taking the ratio of their amplitudes. Two heterodyne receivers have been made to direct them, one at 53MHz and the other at 159MHz. These signals are picked-up by a stripline detector. An analog circuit provides a signal proportional to the bunch length. The monitor measures variation of the bunch length as a function of time in the Main Ring. The measured signal, which sometimes shows that the bunches are tumbling in phase space, can be damped by feedback to the RF amplitude modulator. 9 refs., 12 figs., 1 tab.
Date: June 2, 1989
Creator: Ieiri, T. & Jackson, G.
Partner: UNT Libraries Government Documents Department

The relation of electrode voltages to charge position in SLC arc and final focus beam position monitors

Description: The position of a charged particle beam can be measured with a Beam Position Monitor (BPM) by converting the voltages induced on its array of electrodes into a position offset from the array's center. Most of the BPMs in the Arcs and Final Focus of the SLC use four stripline electrodes arranged symmetrically around the beam; normalized voltage differences are calculated as the difference divided by the sum of voltages on opposite electrode pairs. The resulting number is multiplied by a conversion factor, denoted in this paper as S{sub b}, to give the offset (in millimeters) of the charge from the center of the BPM. Prior to installation in the beam line, the BPMs were calibrated with a charge pulse on a rod. Owing to geometric effects which will be discussed later, a different conversion factor had to be used for calibration. It will be denoted here by S{sub r}. This paper gives the results of calculations and measurements of S{sub r} and S{sub b} for Arc and Final Focus BPMs. This paper also describes the relevant physical properties of the several types of BPMs and calculations of the expected scale factors, the measurement methods used, and gives the results of measurements, which are compared with the theoretical expectations. 2 refs., 18 figs., 7 tabs.
Date: November 2, 1989
Creator: Fordham, C.
Partner: UNT Libraries Government Documents Department

Thermal regimes of major volcanic centers: Magnetotelluric constraints

Description: The interpretation of geophysical/electromagnetic field data has been used to study dynamical processes in the crust beneath three of the major tectono-volcanic features in North America: the Long Valley/Mono Craters Volcanic Complex in eastern California, the Cascades Volcanic Belt in Oregon, and the Rio Grande Rift in the area of Socorro, New Mexico. Primary accomplishments have been in the area of creating and implementing a variety of 2-D generalized inverse computer codes, and the application of these codes to fields studies on the basin structures and he deep thermal regimes of the above areas. In order to more fully explore the space of allowable models (i.e. those inverse solutions that fit the data equally well), several distinctly different approaches to the 2-D inverse problem have been developed: (1) an overdetermined block inversion; (2) an overdetermined spline inverstion; (3) a generalized underdetermined total inverse which allows one to tradeoff certain attributes of their model, such as minimum structure (flat models), roughness (smooth models), or length (small models). Moreover, we are exploring various approaches for evaluating the resolution model parameters for the above algorithms. 33 refs.
Date: October 2, 1989
Creator: Hermance, J.F.
Partner: UNT Libraries Government Documents Department

An alternative strategy for low specific power reactors to power interplanetary spacecraft, based on exploiting lasers and lunar resources

Description: A key requirement setting the minimum electric propulsion performance (specific power ..cap alpha../sub e/ = kW/sub e//kg) for manned missions to Mars is the maximum allowable radiation dose to the crew during the long transits between Earth and Mars. Penetrating galactic cosmic rays and secondary neutron showers give about 0.1-rem/day dose, which only massive shielding (e.g., a meter of concrete) can reduce significantly. With a humane allowance for cabin space, the shielding mass becomes so large that it prohibitively escalates the propellant consumption required for reasonable trip times. This paper covers various proposed methods for using reactor power to propel spacecraft. 7 refs., 6 figs., 1 tab.
Date: February 2, 1989
Creator: Logan, B.G.
Partner: UNT Libraries Government Documents Department