Study of hydrodynamics, mass transfer, energy consumption, and biomass production from natural gas in a forced-liquid vertical tubular loop bioreactor

A forced-liquid vertical tubular loop bioreactor (VTLB) has been used for the production of biomass from natural gas. Hydrodynamic characteristics and mass-transfer coefficients have been determined as functions of design and operational parameters. Energy consumption for different gas and liquid flow rates has been studied. Liquid flow rate was found to have a remarkable effect on gas hold-up and kLa due to its influence on mixing time. The values of kLa for gases have been determined for different geometrical and operational factors. New correlations for mixing time, gas hold-up, and kLa were obtained. A gas mixture of 40 vol% methane and 60 vol% air proved to be optimal for biomass production.