last update: March 21, 2001
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STC-ERSP Program Details Principal Investigator: Yusuf G. Adewuyi Project Title: Benign Synthesis of Chemicals Using Novel Heterogeneous Catalysts in SC CO2 (Former Prog #23) Research Plan Connectivity Outreach Components Additional Comments Requested Budget Allocation - Year 1 Plans for Additional Funding Research Plan Overall objectives Adewuyi will synthesize selected zeolite catalysts (e.g., ZSM-5, Zeolite Beta, MCM-42) and use them to manufacture industrially-important specialty and commodity chemicals using supercritical CO2 as solvent. The goal here will be to optimize product selectivity, yields, and separation in traditional organic processes such as: aromatic alkylation, acylation and nitration; aliphatic alkylation; carbonylation; Fischer-Tropsch synthesis; indole synthesis; and selective catalytic hydrogenation in environmentally-friendly catalytic technologies. The catalysts synthesized will be characterized and adsorptive/catalytic processes taking place in the presence of supercritical CO2 studied. The products of reactions will also be analyzed (by GC/MS and/or NMR), quantified and characterized in an attempt to elucidate kinetics and reaction mechanisms. Relation to overall objectives of the Center The manufacture of fine and specialty chemicals in batch processes has commonly been associated with production of large quantities of toxic wastes due to the widespread use of traditional reagents such as mineral acids, strong bases, stoichiometric oxidants and toxic metal reagents. The practice also has other drawbacks including handling difficulties, inorganic contaminant of organic products, and poor reaction selectivity leading to unwanted isomers and side-products. The trend towards the integration of attractive economics with low environmental impact in chemicals manufacture (enviroeconomics) is expected to continue in the future as traditional, environmentally-unacceptable processes are replaced by cleaner alternatives. Hence, the widespread application of clean catalytic technologies will continue to play a pivotal role in the drive towards environmentally benign processes with minimal waste generation. Indeed, in this context we note that there is still a definite need for truly catalytic procedures for organic processes, e.g., using solid acid catalysts in benign solvent, that are both effective and broadly applicable. A key objective of this project is to investigate the tunability of supercritical CO2 to modify surface mediated reactions to maximize reaction yields and to simplify product recovery. Particular attention will focus on anticipated synergistic effects of the shape selectivity of selected zeolite catalysts and the ability of supercritical CO2 to tune solvent properties. Approach and Year 1-Year 5 timelines Years 1-2: Develop experimental and analytical protocol to enable the synthesis of shape selective zeolite catalysts and characterize properties of these novel materials. Also, obtain commercial grade zeolite catalysts from Engelhard Corporation (Ron Heck). Setup laboratory-scale apparatus for catalytic reactions in supercritical CO2 (e.g., autoclave reactors, fixed-bed flow reactors). Synthesize novel catalysts and use TGA, X-ray diffraction (XRD) and spectroscopic techniques to characterize and study their physicochemical properties. Years 2-3: Screen novel zeolitic catalysts for use in industrially-important organic processes such as selective catalytic hydrogenation, catalytic carbonylation, aromatic/aliphatic alkylation, Friedel Crafts acylation and Fischer-Tropsch synthesis in supercritical CO2 . Years 3-5: Conduct detailed studies on promising catalysts and processes, including product analysis, kinetics and reaction mechanisms. Extend studies to synthesis of other specialty chemicals. Seek new funding opportunities and expand collaborative efforts. Disseminate findings in national and international symposia and technical publications. Thrust area of this proposal Thrust Area D: Chemistry and Catalysis Connectivity Collaborators, multi-institutional, multi-disciplinary components These efforts will be in partnership with numerous groups. Adewuyi (NCA&T) will work with Kropp (UNC-CH) to explore the solvent effects on a variety of surface-mediated reactions using synthesized zeolitic catalysts. Adewuyi (NCA&T) will also work with Wallen (UNC-CH) and Fox (NCSU) in the use of UV-vis, Raman and FTIR spectroscopy and NMR to characterize the structure and surfaces of the catalysts and to study the adsorption/ desorption and catalytic processes involved in these surface-mediated reactions. Spectroscopic tools will also be used in situ to probe catalytic rates and mechanisms. Adewuyi will contact Engelhard Corporation and work with Ron Heck in the design and synthesis of novel zeolitic catalysts. Related work in other thrust areas The researchers in Thrust Area C (Rate Processes) will have the opportunity to collaborate with researchers in Thrust Area D (Chemistry and Catalysis) in designing novel separation techniques to simplify product recovery and separation on a number of industrially important organic processes. In addition, results obtained from various diffusion/mass transfer studies by researchers in Thrust Area C will be relevant to the development of detailed kinetic modeling needed to elucidate reaction mechanisms by researchers in Thrust Area D. Computational modeling and quantum chemistry tools that may accrue from the work of researchers in Thrust Area B (Molecular Thermodynamics and Computer Simulations) will be relevant to Thrust Area D in providing information about the controlling reaction mechanisms in the complex heterogeneous reaction network. Sharing of resources (students, supplies, equipment, etc.) The student responsible for this project will share catalysts and equipment with other groups outlined above. The student will also work closely with other PIs and their graduate/ postdoctoral students (especially Kropp's group at UNC-CH). Outreach Components Suggested K-12 Outreach Ideas Adewuyi and the student funded through this project would be available in teacher workshops to present topics such as "Pollution Prevention Through Materials and Process Substitution" and "Environmentally Benign Chemical Synthesis using Novel Heterogeneous Catalysts. Through the NASA SHARP Plus Apprentice Program, Adewuyi will mentor high school students and involve them in this research endeavor. The rewarding experience acquired through the NASA SHARP Plus Summer program in mentoring high school students in Adewuyi's other research programs in last two years will be useful here. This program (at NCA&T) is administered by Quality Education for Minorities (QEM) Network and will be at no additional cost to NSF. Additional comments: Adewuyi plans to discuss collaborative efforts with Engelhard Corporation (Ronald Heck) in catalyst design and synthesis. Adewuyi also plans to acquire Engelhard commercial-grade catalysts through Ron Heck. Requested Budget Allocation - Year 1 Personnel salaries
Plans for Additional Funding Funding agencies/programs and planned dates of submission: 1) EPA/NSF (Environmentally Benign Processing Initiative): Use of Shape Selective Zeolite Catalysts in Organic Catalysis with Kropp in Spring 2000. Return to top. |
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