Hydrodynamic design of multiphase bubble-column reactors: An experimental and theoretical study

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1988

OSTI ID:7054871

Mikkilineni, S

An understanding of three phase flow hydrodynamics and flow pattern are necessary for the design and scaleup of bubble column reactors. Gas phase residence time is an important parameter that depends on superficial gas velocity and gas holdup in the bubble column. This work emphasized the study of three phase flow hydrodynamics including flow patterns and holdup of three phases and gas phase residence time. The effects of solid particle size, solid concentration, density of solids, viscosity of slurry, gas distributor and column diameter and height on hydrodynamics were studied. A key finding is that gas holdup increases with increasing solids concentration up to approximately three weight percent. As solid concentration increases further gas holdup steadily decreases. The residence time distribution using solids showed the same shape as in two phase flow for solid concentrations up to ten weight percent. Beyond ten weight percent, the shape of the residence time curve using a porous plate gas distributor is similar to that of sieve plate due to rapid coalescence of gas bubbles right at the gas distributor. Both linear and non linear regression analysis were performed on gas holdup and residence time as a function of superficial gas velocity and other variables in all three flow patterns. The outcome of this research will yield a better understanding of residence time, interfacial area, and the transition from one flow pattern to another in the operating region of interest to direct coal liquefaction reactors.

• Research Organization: Rhode Island Univ., Kingston, RI (USA)
• OSTI ID: 7054871
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010405* -- Coal
Lignite
& Peat-- Hydrogenation & Liquefaction
BUBBLES
CHEMICAL REACTORS
COAL LIQUEFACTION
DENSITY
DESIGN
DIMENSIONS
FLOW RATE
FLUID FLOW
FLUID MECHANICS
GAS FLOW
HYDRODYNAMICS
INTERFACES
LIQUEFACTION
MATHEMATICS
MECHANICS
MULTIPHASE FLOW
PARTICLE SIZE
PHYSICAL PROPERTIES
QUANTITY RATIO
REGRESSION ANALYSIS
SIZE
SOLIDS FLOW
STATISTICS
THERMOCHEMICAL PROCESSES
TIME DEPENDENCE
TWO-PHASE FLOW
VISCOSITY