Enhanced Polypropylene Production with Amoco CD Catalyst: Organotitanium Complex on MgCl2 | Chapter 6 | Scientific Research, New Technologies and Applications Vol. 2

A MgCl2-supported catalyst with controlled particle size was developed specifically for the Amoco-Chisso gas phase process. Complete control of the final catalyst morphology and particle size is achieved by optimizing parameters such as precipitation temperature, THF/Mg mole ratio, aging conditions, chemical composition, stirring rate, and the choice of Mg compounds and electron donors. The resulting Amoco CD catalyst, based on anhydrous magnesium chloride and titanium compounds activated with triethylaluminium, exhibits excellent particle size distribution, high bulk density, good fluidity, and high activity. Both lab and pilot scale preparation methods are detailed, and polymerization tests in bench and pilot scale reactors demonstrate the catalyst’s effectiveness. The median particle size (d50) of the catalyst can be controlled within the range of 7-100 microns. Parameters influencing PS and PSD during catalyst support preparation include agitation speed, temperature, organic reagent to Mg ratios, morphology-controlling agents, and the deliberate spiking of the aromatic solvent with appropriate contaminants. Variations in particle shape, ranging from cubic to spheroidal, are affected by the reagents used, the ratios of reagents to Mg, the time/temperature profile of the procedure, and the sequence of reagent addition during catalyst support preparation. Catalyst activation occurs in several steps through thermal treatment of the support with TiCl4/toluene solutions. A cost-effective TiCl4/toluene reuse system from the activation streams has been implemented to significantly reduce waste material. The optimum activation temperature is approximately 120°C. Progress of activation and catalyst quality can be monitored by IR spectroscopy, with identifiable IR fingerprint patterns correlating well with catalyst performance. A new concept of organotitanium complexes as catalysts coordinated on MgCl2 support, operating independently, but in tandem with the traditional TiCl4 polymerization active centers has been introduced. The new catalysts with dual activity centers based on CD technology demonstrate improved performance and advantageous polymer product properties. We propose that the dual-activity concept applied to several organometallic complexes may herald a new era in MgCl2-supported polyolefin catalysis, including single-site catalysts activated by TEA and the production of advanced polyethylene copolymers. The success of the CD and Amoco-Chisso gas-phase process is illustrated by the two dozen commercial plants worldwide using the technology and the licensing advances by INEOS, the successor of Amoco, for this polypropylene technology.

 

Author (s) Details

Gregory G. Arzoumanidis
Oakwood Consulting, Inc., Naperville, Illinois, USA.

 

Please see the book here:- https://doi.org/10.9734/bpi/srnta/v2/1855

Visible Light-activated 2-Phenyl Indole (PI)/TiCl4 Complexes for Atmospheric CO2 Capture and C6-C17 Organic Synthesis via Hydroxyl Radical Synergism | Chapter 9 | Chemistry and Biochemistry: Research Progress Vol. 1

Preferred systems are catalysts that operate away from equilibrium, continuously supplied with energy and materials from inexhaustible sources such as sunlight, air, and water. This concept underpins artificial photosynthesis (AP). A novel self-organized chemical "living" system is presented that mimics natural photosynthesis by capturing CO₂ and H₂O from the atmosphere under ambient conditions. Using 2-phenyl indole (PI) and TiCl₄ complexes activated by visible light, this system autonomously reduces CO₂ with H₂O protons to produce long-chain oxygenated hydrocarbons up to C₁₇. The process begins with hydrolyzed PI/TiCl₄ complexes reacting with CO₂ to form organotitanium carbonates, with the 2:1 PI/TiCl₄ ratio proving most effective. Visible light reduces Ti+⁴ to Ti³⁺ and Ti²⁺, generating hydroxyl radicals, which play a critical role in the reduction of CO₂ to CO, H₂CO, and CH₃OH. These intermediate further couple to form C₆ to C₉ α-carboxylic acid-ω-aldehyde compounds, which serve as feedstocks for the subsequent synthesis of longer carbon chains (C₁₂ to C₁₇) through a radical mechanism. The system facilitates ligand exchange between PI and donor molecules, forming adducts involved in the photocatalytic process. Additionally, PI oligomerization contributes to the formation of functional oligomers. Over two dozen intermediates and products were identified using MALDI-TOF, ¹³C NMR, and IR spectroscopy, highlighting the complexity of the reaction network. This catalytic system uniquely integrates organotitanium chemistry and hydroxyl radical pathways, autonomously capturing CO₂ and humidity from the atmosphere while harnessing solar energy to produce valuable long-chain oxygenated hydrocarbons. This prototype offers a foundation for exploring broader applications and enhancements using other metals and ligands.

 

Author (s) Details

 

Gregory G. Arzoumanidis
Oakwood Consulting, Inc. Naperville, IL 60540, USA.

 

Michail Paraskevas
Guandong Technion Israel Institute of Technology, Jinping, Shantou, Guandong 515063, P. R. China.

 

Please see the book here:- https://doi.org/10.9734/bpi/cbrp/v1/3722