Separation of Rhodium Catalyst in a Homogeneous System by using Nanofiltration

• Main Author: Nur Syafina binti Abdul Razak, Nur Syafina
• Format: Final Year Project
• Language: English
• Published: Unuversiti Teknologi Petronas 2010
• Subjects: TP Chemical technology
• Online Access: http://utpedia.utp.edu.my/1198/1/NUR_SYAFINA_A_RAZAK_9158_FINAL_DISSERTATION.pdf; http://utpedia.utp.edu.my/1198/

Nanofiltration process can assist the industry in recovering the catalyst in homogeneous system. The objective of this dissertation is to report the findings on the research of the separation for rhodium catalyst in a homogeneous system by using nanofiltration. The objectives of the research are to determine the solvent-membrane compatibility in a system, to study the solvent flux and rejection of catalyst in different solvent-membrane combination and to assess the effect of pressure and concentration towards the catalyst rejection. The research starts with the compatibility test which is conducted by soaking the membrane in solvent for 24 hours to observe any physical changes that occur. The solvents used are ethyl acetate and toluene while the membranes used are STARMEMTM 122 and STARMEMTM 240. The membranes used for soaking are taken for analysis using Field Emission Scanning Electron Microscopy (FESEM) to observe the changes on the surface and the cross section of the membrane after immersing into the solvents. Stable combinations are used for permeability and rejection study. METcell separation unit is used to conduct the research for the solvent flux. Three reading for pressure is used for flux and rejection study which are 10 bar, 15bar, and 25 bar while the concentration is varied at 0.5 mM, 0.8 mM and 1.0 mM. UV-Visible spectrophotometer is used to determine the concentration of permeate and the retentate solution for this research. STARMEMTM 122 and STARMEMTM 240 changed physically after 24 hours in Ethyl acetate and no changes observed for both membranes in toluene solvent. From the FESEM images, changes are observed as well as for all membranes with respect to the original membranes. During the flux study for pure solvent, it is proven that the flux declines with time to a steady level which is due to membrane compaction. As the pressure increases, the solvent flux also increases for both membrane but it is higher for STARMEMTM 240. Flux reduces with the increase of catalyst concentration which can be explained by the phenomenon of pore fouling. Rejection is reported high for both membranes which are around 0.8 to 0.95. In conclusion, nanofiltration is useful in producing green chemical process in industry especially in optimizing the purity of the products. Pressure and concentration affects the value of flux and rejection of a system. Prior to conducting the catalyst filtration, the membrane should be at steady flux condition to avoid unstable permeation. In obtaining, the right steady flux of system, the process should be done in continuous mode for more consistent result. The concentration of the rhodium catalyst in the permeate and retentate solution can be determined using various methods in order to obtain more accurate result.