The kinetics of catalytic hydrogenation of pyrene-implications for direct coal liquefaction processing

Conference · Sat Jan 01 04:00:00 EST 1983 · Prepr. Pap., Am. Chem. Soc., Div. Fuel Chem.; (United States)

OSTI ID:6655417

Stephens, H P; Chapman, R N

Although recycling heavy solvents has recently re-emerged as a key to cutting the cost of direct coal liquefaction, little data for the hydrogenation of heavy solvent donors have been reported. This study addresses the kinetic and thermodynamic aspects of catalytic hydrogenation of pyrene, a donor solvent precursor thought to play an important role in coal liquefaction processes that use heavy recycle solvents. In the presence of a catalyst, pyrene (Py) is hydrogenated to di- (H/sub 2/Py), tetra- (H/sub 4/Py), hexa- (H/sub 6/Py), deca- (H/sub 10/Py) and perhydro- (H/sub 16/Py) species via a complex mechanism involving a network of reversible parallel and series reactions. Though several studies have dealt with aspects of pyrene hydrogenation, including hydrocracking reactions, reaction product distributions and thermodynamic properties, the kinetics of hydrogenation have not been previously reported. Ultimate application of kinetic and thermodynamic data to direct coal liquefaction must take into consideration the conditions imposed by the particular process used. However, two generalizations may be made regarding hydrogen supplied by the dihydropyrene component of donor solvents: (1) Increasing hydrogen partial pressure increases both the rate at which H/sub 2/Py is formed and the equilibrium concentration of H/sub 2/Py. Therefore, pyrene rehydrogenation should be done at as high a pressure as is cost effective. Although an increase in temperature favors the rate of attainment of equilibrium between Py and H/sub 2/Py, the position of the equilibrium is shifted toward pyrene. Temperature must therefore be adjusted to achieve an optimum trade-off between rate of formation and maximum possible concentration of H/sub 2/Py.

• Research Organization: Sandia National Laboratories, Albuquerque, NM
• OSTI ID: 6655417
• Report Number(s): CONF-830814-
• Conference Information: Journal Name: Prepr. Pap., Am. Chem. Soc., Div. Fuel Chem.; (United States) Journal Volume: 28:5
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010405* -- Coal
Lignite
& Peat-- Hydrogenation & Liquefaction
AROMATICS
CATALYSIS
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
COAL LIQUEFACTION
CONDENSED AROMATICS
HYDROCARBONS
HYDROGEN TRANSFER
HYDROGENATION
KINETICS
LIQUEFACTION
ORGANIC COMPOUNDS
ORGANIC SOLVENTS
PRESSURE EFFECTS
PYRENE
REACTION KINETICS
RECYCLING
SOLVENTS
TEMPERATURE EFFECTS
THERMOCHEMICAL PROCESSES