Differential scanning calorimetry studies on coal hydrogenation. [4 refs. ; 800 psig; temp. to 570/sup 0/C]

Conference · Wed Jan 01 04:00:00 EST 1975 · Am. Chem. Soc., Div. Fuel Chem., Prepr.; (United States)

OSTI ID:7354293

Mahajan, O P; Tomita, A; Nelson, J R; Walker, Jr, P L

Differential scanning calorimetry in conjunction with the thermogravimetric analysis technique has been used to determine quantitatively thermal effects involved during hydrogenation of 21 U.S. raw coals of varying rank at 800 psig and temperatures up to 570/sup 0/C. The heat of hydrogenation decreases with increase in coal rank; exothermic heats vary from 153 cal/g for lignites to 6.9 cal/g for anthracite. Transition temperature, that is the temperature corresponding to the onset of exotherms, is markedly dependent on coal rank, varying from about 250/sup 0/C for lignites to 540/sup 0/C for anthracite. A sharp increase in transition temperature occurs for coals having a carbon content, on a dry-ash-free basis, in the 75 to 80 percent range. In most cases, demineralization of coals decreases the heat of hydrogenation. However, in the case of medium volatile and HVA bituminous coals, exothermic heats increase upon demineralization. There is some indication that pyrite, or pyrrhotite produced during reduction of pyrite, may have a beneficial catalytic effect on coal hydrogenation. Reaction rate constants have been estimated in some cases. In general, demineralization causes a decrease in rate constant and an increase in activation energy for hydrogenation.

• Research Organization: Pennsylvania State Univ., University Park
• OSTI ID: 7354293
• Conference Information: Journal Name: Am. Chem. Soc., Div. Fuel Chem., Prepr.; (United States) Journal Volume: 20:3
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010403* -- Coal & Coal Products-- Hydrogenation-- (-1987)
ANTHRACITE
BLACK COAL
BROWN COAL
CALORIMETRY
CARBONACEOUS MATERIALS
CHEMICAL REACTIONS
COAL
COAL RANK
ENERGY SOURCES
ENTHALPY
FOSSIL FUELS
FUELS
HIGH TEMPERATURE
HYDROGENATION
LIGNITE
MEDIUM PRESSURE
PHYSICAL PROPERTIES
REACTION HEAT
THERMODYNAMIC PROPERTIES