4.3. Reaction Mechanism 2373 4.4. Asymmetric Synthesis 2374 4.5. Outlook 2374 5. Alternating Polymerization of Oxiranes and CO2 2374 5.1. Reaction Outlines 2374 5.2. Catalyst 2376 5.3. Asymmetric Polymerization 2377 5.4. Immobilized Catalysts 2377 6. Synthesis of Urea and Urethane Derivatives 2378 7. Synthesis of Carboxylic Acid 2379 8. Synthesis of Esters and Lactones 2380 9. Synthesis of Isocyanates 2382 10. Hydrogenation and Hydroformylation, and Alcohol Homologation 2382

Transformation of carbon dioxide.

Over the course of the past decade, green chemistry has demonstrated how fundamental scientific methodologies can protect human health and the environment in an economically beneficial manner. Significant progress is being made in several key research areas, such as catalysis, the design of safer chemicals and environmentally benign solvents, and the development of renewable feedstocks. Current and future chemists are being trained to design products and processes with an increased awareness for environmental impact. Outreach activities within the green chemistry community highlight the potential for chemistry to solve many of the global environmental challenges we now face. The origins and basis of green chemistry chart a course for achieving environmental and economic prosperity inherent in a sustainable world.

https://www.qcc.cuny.edu/ehs/docs/WEEK_9a___paper_1.pdf

Origins, Current Status, and Future Challenges of Green Chemistry†

The increase in atmospheric carbon dioxide is linked to climate changes; hence there is an urgent need to reduce the accumulation of CO2 in the atmosphere. The utilization of CO2 as a raw material in the synthesis of chemicals and liquid energy carriers offers a way to mitigate the increasing CO2 buildup. This review covers six important CO2 transformations namely: chemical transformations, photochemical reductions, chemical and electrochemical reductions, biological conversions, reforming and inorganic transformations. Furthermore, the vast research area of carbon capture and storage is reviewed briefly. This review is intended as an introduction to CO2, its synthetic reactions and their possible role in future CO2 mitigation schemes that has to match the scale of man-made CO2 in the atmosphere, which rapidly approaches 1 teraton.

The teraton challenge. A review of fixation and transformation of carbon dioxide

https://eprints.ncl.ac.uk/file_store/production/162122/B5324BA5-F503-4BE9-947E-6F7ED01AAD04.pdf

Synthesis of cyclic carbonates from epoxides and CO2

The synthesis of organic carbonates from carbon dioxide.

A novel non-phosgene polycarbonate production process using by-product CO2 as starting material

PURPOSE: To obtain the objective aromatic polycarbonate by determining the ratio, etc., of hydroxy terminals to total terminals in a prepolymer in the reaction of a specific dihydroxydiaryl compound with a diaryl carbonate and additionally polymerizing the compound according to the determined result. CONSTITUTION: An aromatic polycarbonate having desired hydroxyl-terminal ratio and number-average molecular weight is produced in high efficiency by prepolymerizing (A) a dihydroxydiaryl compound composed of ≥60mol% of a dihydroxydiarylalkane of formula (Ar 1 and Ar 2 are arylene; Y is alkylene, etc.) and ≤40mol% of other dihydroxydiaryl compound and (B) a diaryl carbonate until the number-average molecular weight of the prepolymer reaches 1,000-10,000, determining the number-average molecular weight, the ratio of hydroxyl terminals and that of aryl carbonate terminals to total terminal groups, adding diaryl carbonate to the system when the hydroxyl terminal ratio is higher than the desired level or adding dihydroxydiaryl compound when the ratio is lower than the desired level and continuing the polymerization reaction. COPYRIGHT: (C)1991,JPO&Japio

Production of aromatic polycarbonate

This paper focuses on the world’s first non-phosgene process using CO2 as starting material succeeded in development and industrialization by Asahi Kasei Corp. The Asahi Kasei Process enables high-yield production of high-quality PC having excellent properties and high-purity monoethylene glycol (MEG), starting from ethylene oxide (EO), by-produced CO2 and bisphenol-A without waste and waste water. The innovative reactive distillation technologies in the monomer production and the innovative gravity-utilized, non-agitation polymerization reactor in the melt polymerization, led the new process to success. The monomer process consists of 3 production steps, ethylene carbonate (EC) from CO2 and EO, dimethyl carbonate (DMC) and MEG from EC and MeOH, and diphenyl carbonate (DPC) and MeOH from DMC and PhOH. All intermediates are recycled. The new type polymerization reactor perfectly overcomes the difficulty based on the extremely high viscosity in the melt polymerization of DPC with Bis-A. The by-produced PhOH is recycled to the monomer process. The reduction of CO2 emissions (0.173t/PC 1t) is also achieved, because CO2 used as raw material is utilized as the main chain components of the products. Four commercial plants (Taiwan: 150,000 t/y, Korea: 2 plants of 65,000 t/y, Russia: 65,000 t/y) using the Asahi Kasei Process are now successfully operating, and the plant of 260,000 t/y in Saudi Arabia will start in 2010.

A Novel Non-Phosgene Process for Polycarbonate Production from CO2: Green and Sustainable Chemistry in Practice

A porous, crystallized, aromatic polycarbonate prepolymer is disclosed, which comprises recurring aromatic carbonate units and terminal hydroxyl and aryl carbonate groups, wherein these terminal groups are in a specific molar ratio, and has specific number average molecular weight, surface area and crystallinity. The prepolymer can readily be converted by solid-state condensation polymerization to a porous, crystallized, aromatic polycarbonate having excellent properties. The porous, crystallized, aromatic polycarbonate of the present invention can readily be molded to obtain a shaped, porous, crystallized polycarbonate. The porous, crystallized, aromatic polycarbonate and the shaped, porous, crystallized polycarbonate of the present invention have excellent heat resistance and solvent resistance and exhibit advantageously low water absorption so that these are suited for use as a filter material, an adsorbent or the like. The porous, crystallized, aromatic polycarbonate and the shaped porous, crystallized polycarbonate of the present invention can also readily be molded by a melt process into an article useful as engineering plastics, such as an optical element and an electronic component, which is appreciated since it is free of impurities, such as chlorine-containing compounds, and has excellent properties.

Porous, crystallized, aromatic polycarbonate prepolymer, a porous, crystallized aromatic polycarbonate, and production methods

It is a task of the present invention to provide a method for producing a high quality, high performance aromatic polycarbonate (which is colorless and has excellent mechanical properties) from a molten aromatic polycarbonate prepolymer obtained by reacting an aromatic dihydroxy compound with a diaryl carbonate, wherein the polycarbonate can be stably produced on a commercial scale at 1 to 50 t/hr for a long time. In the present invention, this task has been accomplished by a method for producing an aromatic polycarbonate by the melt transesterification process, in which the prepolymer is polymerized by a guide-wetting fall polymerizer device having a specific structure, whereby a high quality, high performance aromatic polycarbonate as mentioned above can be stably produced on a commercial scale at 1 to 50 t/hr for a long time (more than several thousand hours, e.g., more than 5,000 hours) without fluctuation of the molecular weight thereof.

Kyosuke Komiya

Papers

A novel non-phosgene polycarbonate production process using by-product CO2 as starting material

Production of aromatic polycarbonate

A Novel Non-Phosgene Process for Polycarbonate Production from CO2: Green and Sustainable Chemistry in Practice

Porous, crystallized, aromatic polycarbonate prepolymer, a porous, crystallized aromatic polycarbonate, and production methods

Method for producing an aromatic polycarbonate