Chemistry of trace element species in coal liquefaction processes
The following topics were discussed: (1) behavior of Hg, Se, As, Sb, Co, Cr, and Ni in the SRC II Process (solvent-refined coal process); (2) behavior of Hg in SRC II Process Waters; and (3) behavior of Ti in the SRC processes. Evaluation of trace element distributions in SRC process streams has shown that Hg, Se, As, and Sb are significantly volatile. High concentrations of these elements were found in certain liquid-liquid separator light oils and aqueous phases. It was also found that Cr, Co, and Ni were present in these materials at higher than normal concentration. Solids were analyzed by neutron activation analysis; mineralogical examination revealed unaltered coal minerals present; sulfide and non-sulfide minerals. Major non-sulfide minerals identified by x-ray diffraction, optical microscopy, microprobe and scanning electron microscopy-x-ray fluorescence were illite, kaolinite, quartz, rutile, siderite, barite, and wollastonite. Most of the minerals were identified in feed coals but some represented reaction products of the hydrogenation process. Analysis for pyrite and pyrrhotite grains were given. The volatility of Hg, Se, and As in the SRC II process was reflected in relatively high concentrations of these elements in condensate process waters. The approximate composition of SRC II process waters was given. In the SRC I process, most elements are efficiently removed in the mineral residue and are more than 98% depleted in product SRC I. However, Ti is an exception, in that the concentration of Ti remaining in SRC I may be as high as 88% of the Ti in the original coal. Several explanations were included for this depletion. The most concrete evidence for organic species of Ti being formed in the SRC processes was provided by recent x-ray absorption spectroscopy. 3 figures, 11 tables. (DP)
- Research Organization:
- Washington State Univ., Pullman
- OSTI ID:
- 6481515
- Journal Information:
- Fossil Energy I C Briefs; (United States), Vol. 3:3
- Country of Publication:
- United States
- Language:
- English
Similar Records
Solvent Refined Coal (SRC) process: trace elements. Research and development report No. 53, interim report No. 30. Volume III. Pilot plant development work. Part 6. The fate of trace elements in the SRC process. [111 references]
Solvent Refined Coal (SRC) process: trace elements. Research and development report No. 53, interim report No. 31, August 1976-July 1977. Volume III. Pilot plant development work. Part 6. [Fate of 36 trace elements]
Related Subjects
ANTIMONY
X-RAY DIFFRACTION
ARSENIC
CHROMIUM
COAL LIQUIDS
CHEMICAL ANALYSIS
COBALT
MERCURY
NICKEL
PROCESS SOLUTIONS
SELENIUM
CHEMICAL REACTIONS
SRC-II PROCESS
TITANIUM
COAL
OPTICAL MICROSCOPY
SCANNING ELECTRON MICROSCOPY
TRACE AMOUNTS
VOLATILITY
X-RAY FLUORESCENCE ANALYSIS
CARBONACEOUS MATERIALS
COAL LIQUEFACTION
COHERENT SCATTERING
DIFFRACTION
DISPERSIONS
ELECTRON MICROSCOPY
ELEMENTS
ENERGY SOURCES
FLUIDS
FOSSIL FUELS
FUELS
LIQUEFACTION
LIQUIDS
MATERIALS
METALS
MICROSCOPY
MIXTURES
NONDESTRUCTIVE ANALYSIS
SCATTERING
SEMIMETALS
SOLUTIONS
THERMOCHEMICAL PROCESSES
TRANSITION ELEMENTS
X-RAY EMISSION ANALYSIS
010600* - Coal
Lignite
& Peat- Properties & Composition
010405 - Coal
Lignite
& Peat- Hydrogenation & Liquefaction