Polycarbonate Production from BPA and Phosgene | Economic Analysis
Polycarbonate Production — Technology Description & Economic Analysis
Polycarbonate Production from BPA and Phosgene
Polycarbonate is typically manufactured via the interfacial polymerization reaction of phosgene and bisphenol A. Other production processes include a non-phosgene process in which bisphenol A reacts with diphenyl carbonate (DPC). Production pathways may also differ by integrating bisphenol A or DPC production.
This article aims to present a brief process description and a condensed cost analysis of Polycarbonate Production from BPA and Phosgene.
Process Description
The process under analysis comprises three major sections: (1) Polymerization; (2) Purification; and (3) Finishing.
Polymerization. Initially, A caustic soda solution, 50 wt%, is mixed with the Bisphenol A and demineralized water, to create a solution of bisphenol-sodium salt, so Bisphenol A solubility in the aqueous phase increases. Phosgene is prone to suffer hydrolysis in an aqueous medium, so it is rather dissolved in an inert organic medium, in this process dichloromethane is used. The reaction is then conducted by mixing these two phases under severe turbulent flow. It is promoted by the addition of a phase transfer catalyst and alkaline medium. A chain stopper agent is added to control the polymer molecular weight. This reaction is conducted in two steps, first the reaction between the bisphenol-sodium salt and phosgene is favored, producing a variety of oligomers, primary chlorocarbonic esters. In the second step these oligomers are condensed into high molecular weight polycarbonate.
Purification. The final output from the polymerization reaction is then fed to a decanter, from which a dichloromethane phase rich in polycarbonate is recovered. This organic stream is then subjected to a series of washes to remove unconverted raw materials and other contaminants. Then, a series of drying operations are conducted to recover a dry polycarbonate solid. Aqueous stream from caustic wash are mixed with an an organic stream from drying operations and are fed to a distillation column, where a top product containing dichloromethane is obtained and recycled to oligomerization.
Finishing. The flakes are mixed with additives and fed to twin-screw extruder, where they are homogenized and pelletized. The pellets are homogenized, packed and stored.
Cost Analysis
The economic evaluation of industrial processes is a valuable support tool for a myriad of activities and studies, such as screening and assessment of investment options, preliminary evaluation of the economic potential of emerging industrial processes, rough assessment of the economic feasibility of industrial ventures, cost estimates double-checking, preliminary budget approval, research planning, and so on.
A detailed cost analysis for the manufacturing of Polycarbonate was developed by Intratec based on a plant constructed in 2018 Q1 in the United States with the capacity to produce 200,000 metric ton per year of Polycarbonate. The table below presents a few economic figures related to the process “Polycarbonate Production from BPA and Phosgene”.
Where,
“Net utilities costs” are costs related to a plant’s consumption of utilities, i.e., steam, electricity, fuel, and refrigeration.
“Corporate overhead costs” are the costs incurred by a company’s head office not directly related to the process operation, such as general administrative costs, information technology, marketing and advertising, and research and development activities.
Main Reference
[1] Intratec. 2018. Polycarbonate Production from BPA and Phosgene, Advanced Edition. Available at: www.intratec.us/analysis/pc-e11a
Polycarbonate Production Processes
To learn more about processes related to Polycarbonate production, visit: www.intratec.us/analysis/polycarbonate-production-cost
About Intratec Commodity Production Costs Reports
The report Polycarbonate Production from BPA and Phosgene is part of a series of reports prepared by Intratec approaching the production costs of commodities spanning a diverse range of industries: Oil & Energy; Fertilizers & Gases; Olefns & Derivatives; Aromatics & Derivatives; Alcohols & Organic Acids; Polymers; Inorganic Chemicals; Food & Nutrition; Metals & Mining; and Pharmaceuticals.
For information on all Intratec reports visit: www.intratec.us
