Nomenclature (Modeling OF Catalytic Hydrotreating)

a

Dimensionless number of Glaso’s correlation (Table 3.9) or constant of Eq. (3.3)

«L

Specific gas-liquid interface area

Liquid-solid interfacial area per unit volume of reactor

Aromatic compound

Lateral area of the geometric shape between lobes according to Table 3.5

Common area between each cylinder and each side of the shape between lobes, according to Table 3.5

API gravity

Asphaltenes

Bromide number

Mass heat capacity

Molar concentration of compound i

Molar concentration of compound i in liquid bulk phase

Molar liquid phase concentration of i at external surface of solid

Diameter of cylinder

Particle diameter

Equivalent particle diameter

Specific gravity at 15.6°C

Axial mass dispersion coefficient in the liquid phase

Molecular diffusion coefficient of compound i in phase f

Diaromatics

Activation energy

Gas mass flow rate of stream j

Liquid superficial flow

Gas hourly space velocity

Heat transfer coefficient for gas-liquid interface

Heat transfer coefficient for liquid film surrounding the catalyst particle

Hydrocarbon

Henry’s law constant for compound i

Hydrogen

Hydrogen sulfide

Hydrogen – to – oil ratio

j- factor for heat transfer

Forward rate constant

Apparent rate constant of reaction j

Thermal conductivity of liquid phase

Reverse rate constant

Frequency or preexponential factor

Adjustable parameters of Eq. (3.12)

Gas-liquid mass transfer coefficient for compound i

Liquid-solid mass transfer coefficient for compound i

Adsorption-equilibrium constant for compound i

Equilibrium constant

Liquid mass flow rate of stream j

Particle length

Catalyst bed length

Particle size, particle length

Liquid hourly space velocity

Reaction order for hydrogen

Monoaromatic

Molecular weight

Reaction order for compound i

Number of lobes

Naphthenes

Basic nitrogen compound

Nonbasic nitrogen compound

Ammonia

Partial pressure of compound i

Partial pressure of compound i in the j phase

Reactor total pressure

Polyaromatic

Peclet number for axial mass dispersion in liquid phase

Quench fluid mass flow rate

Radius of sphere

Radius of cylinder

Intrinsic rate of reaction j

Rate of reaction j

Radius of particle

Universal gas law constant

Total geometric external area of particle

Time

Temperature

Temperature of phase j

Mean average boiling point

Reference temperature or inlet reactor temperature

Superficial velocity of phase fin the reactor

Vapor fraction

Critical specific volume of the gaseous compounds

Molar volume of solute i at its normal boiling temperature

Molar volume of liquid solvent at its normal boiling temperature

Molar gas volume at standard conditions

Total geometric volume of catalyst

Vacuum gas oil

Weight fraction of catalyst in the reactor

Weight – average bed temperature

Weight hourly space velocity

Mass fraction of compound i

z

Axial position along the catalyst bed

Greek Letters

Fraction of the easy – to – react containing compounds

Adsorption enthalpy of H2S

Heat of reaction j

Pressure drop

Temperature correction of liquid density

Pressure dependence of liquid density

Bed void fraction or bed porosity

Particle porosity

Gas – phase fraction

Liquid holdup

Fractional volume of the catalyst bed diluted by inert particles

Catalyst effectiveness factor for reaction j

Solubility coefficient of compound i

Viscosity of phase f

Catalyst bulk density

Density of hydrogen

Density of oil

Liquid density at standard conditions (15°C, 1 atm)

Liquid density at 20 ° C

Stoichiometric coefficient of compound i

Subscripts

Aromatics

Gas phase

Hydrogen

Hydrogen sulfide

Hydrodearomatization reaction

Hydrodeasphaltenization reaction

Hydrocracking reaction

Hydrodemetallization reaction

Hydrodenitrogenation reaction of basic nitrogen

Hydrodenitrogenation reaction of nonbasic nitrogen

Hydrodeoxygenation reaction

Hydrodesulfurization reaction

Hydrogenation of olefin reaction

Inlet stream to the following catalytic bed

Liquid phase or gas-liquid interface

Basic nitrogen

Nonbasic nitrogen

Ammonia

Olefins

out

Outlet stream of the previous catalytic bed

q

Quench

S

Organic sulfur compound, solid phase or liquid-solid interface

G

Gas phase

L

Liquid phase or gas-liquid interface

^q

Quench fluid

S

Solid phase or liquid-solid interface