الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
 |  | from | 220 |  |  |
| | | from | 220 | | |
Abstract
Liquid-phase catalytic oxidation of p-xylene (PX) is an important process for the terephthalic acid (TPA) production, which is widely used in the commercial production of polyesters fiber and polyester film that commonly used in packaging and containers manufacturing. Only Asia’s TPA capacity has reached 55.7 m ton/year by the end of 2013.
The industrial catalytic oxidation of PX was carried out by air with cobalt acetate and manganese acetate as the reaction catalysts which promoted either by bromine (Br2) or hydrogen bromide (HBr) in acetic acid as solvent. The used reaction conditions were a temperature range of 175–225 °C and an air pressure is up to 30 atm in autoclave.
This process has met some industrial problems that acetic acid and bromine cause corrosions in equipments when used at high temperatures. Therefore, expensive special corrosion resistant equipment was required for the process, and this is economically unfavorable. In addition to, acetic acid gives different reaction by-products including methanol, methyl acetate and methyl bromide also, carbon oxides are produced by partial combustion of the solvent and the aromatic compounds. Furthermore, the use of bromine will have many limitations in the future, because bromine is very harmful and cause serious environmental pollution.
The thesis introduce an active strategy to overcome the industrial drawbacks; three different categories of heterogeneous catalysts were synthesized as single and mixed nano-metal oxide and metal (II) Schiff base complex grafted nano-γ-alumina. These catalysts are confirmed by many analytical techniques such as x-ray diffraction (XRD), specific surface area (SBET), high resolution transmission electron microscopy (HRTEM) and Proton nuclear magnetic resonance (1H NMR).
The catalytic oxidation activity for PX were examined by using all prepared catalysts through studying different parameter including; catalyst weight, reaction time, solvent, pressure and temperature in presence of a promoter (N-hydroxysuccinimide, NHS) rather than bromine gas or bromide compounds in varied solvents rather than acetic acid to determine the optimum conditions for achieving maximum values of conversion, yield and selectivity percentages of TPA.
Finally, the superior oxidation activity was accomplished especially by using CuMn11 and VMn11 at moderate conditions rather than industrial process with appropriate environmentally and economically favorable method.