The resident time depends on the temperature you are carrying the process. First, you need to determine for a particular sample say 1 Kg of Biomass the time that gasification process starts ending time at a particular temperature. To achieve this, you need to introduce a pressure sensing device. Then this can be distributed over a wide range of temperature. I hope this gives you an insight to the solution of the problem

Thank you very much for your prompt reply Mr. Adeleke.

Here is a recent article on calculating residence time distribution of particles in a riser reactor.

Foust et al. (2017), "Predictive Model for Particle Residence Time Distributions in Riser Reactors. Part 1: Model Development and Validation", ACS Sustainable Chemistry & Engineering.

I hope it will be helpful.

Thank you very much dear

The resulting average residence times are correlated as function of gas velocity and solids circulation rate. Therefore, it is recommended to install pressure sensors along the riser. Then you can measure the pressure drop and the pressure fluctuations and later calculate your solids circulation rate and the residence time. And you must take into account that there are two regions in the riser (axial side) dense bottom and dilute top, also two regions in the radial side dilute core (moving upwar) and dense annulus near the wall (moving downward).

Thank you very much yousif. We have pressure tappings on the gasifier. Where can I find these correlations?

The residence time distribution of the gas phase is more tricky, the bulk mounting through as rising bubbles that gradually increase in size and then there is interstitial gas slowly exchanging with bubbles.

In my opinion, there is only one decent way: testing the residence time distribution by bringing in a pulse of inert tracer gas, such as helium, and measure mass 4 with a spectrometer, or thermal conductivity with a thermistor. Both will give accurate answers.

Thank you very much Alfons for answering.