Start
Aug 19, 2013 - 17:00
End
Aug 19, 2013 - 18:00
Venue
Chemical Engineering room no 118
Event Type
Speaker
Dr. Rajesh Kumar completed his PhD with Professor Sanjay Mahajani
Title
Reactive Stripping for the Catalytic Exchange of Hydrogen Isotopes Speaker: Dr. Rajesh Kumar
Abstract: There has been considerable work on reactive separations especially for reactive distillation and reactive chromatography. Absorption accompanied by reaction is also the subject of classical multiphase gas-liquid reactions wherein reaction takes place between the liquid substrate and the dissolved gas. However an opposite case of reactive stripping wherein reaction taking place in the vapor phase between the stripped-off component and the gas is rare. An example of such reactive stripping process is hydrogen-water exchange used for the separation of hydrogen isotopes. The isotope exchange reaction is carried out in a trickle bed reactor (TBR) filled with a wet-proofed or hydrophobic catalyst. The TBR is commonly known as the catalytic chemical exchange (CE) column in which hydrogen and liquid water are contacted in countercurrent mode over the catalyst bed to transfer deuterium from liquid water to hydrogen through exchange reaction that takes place in the gas phase. In the present work a pilot scale counter-current trickle bed reactor (TBR) packed with an in-house developed water-repellent catalyst is investigated for deuterium exchange between water and hydrogen to be used for the production of heavy water. The reactant i.e. heavy water (HDO) from liquid phase is stripped by the gas phase wherein it undergoes an equilibrium limited exchange reaction with hydrogen over a solid catalyst. A two phase mathematical model is developed incorporating reaction kinetics mass transfer resistances and dispersion in liquid phase flow to simulate the reactor performance. Model parameters such as kinetic rate constant mass transfer coefficient etc. were determined by independent experiments. The reactor model is then experimentally validated by performing reactions in pilot scale column. The validated model is further used to arrive at a suitable design for the desired performance.About the speaker: Dr. Rajesh Kumar is a Scientist (F) at the Heavy Water Division of Bhabha Atomic Research Centre Mumbai. He received his Bachelor's degree in Chemical Engineering from the B.I.T. Sindri Dhanbad (1996) and joined BARC after completion of one year orientation course in Nuclear Engineering at BARC Training School under OCES scheme in 1997. He is associated with the process development section of the heavy water division and has made significant contribution in the R&D activities being pursued at the Division for the development of processes such as Hydrogen production by thermo-chemical splitting of water using Iodine- Sulfur cycle; manufacturing process for large size ultra-pure electronic grade mono-crystalline silicon wafers from metallurgical grade silicon and separation of hydrogen isotopes for heavy water production and up-gradation.