DESIGN OF POLYURETHANE PLANT FROM POLYOLS AND ISOCYANATES

Abstract

Polyurethane is a versatile polymer widely used as foam in furniture and automotive seating, insulation, coatings, adhesives and as elastomers. It is preferred over other polymers due to its exceptional properties such as resilience, �lexibility, and resistance to abrasion and chemicals. The annual worldwide production of polyurethane is around 26 million metric tons, and it is primarily produced by the polyaddition reaction of polyols and isocyanates. Triethylamine is used as a catalyst to enhance reactivity between polyols and isocyanates and to allow the reaction to take place at room temperature. Water is used as a blowing agent during the preparation of polyurethanes to provide foams. Despite the large number of applications and huge market for polyurethanes, certain issues such as sustainability concerns and toxicity are associated with polyurethanes. Isocyanates, which are the key component in the production of polyurethane, are highly toxic compounds that pose several health and safety concerns. Moreover, the conventional phosgenation route for isocyanate production requires phosgene as a raw material which is a highly toxic compound and have signi�icant adverse effects on the environment such as water pollution, climate change, and ozone depletion. This process involves reaction of phosgene and toluene diamine at elevated temperature (~300oC) producing toluene diisocyanate and hydrogen chloride. To address these issues, the objective is to come up with a more suitable and environmentally friendly alternative method for toluene diisocyanate synthesis. One such method is to use a phosgene free process for toluene diisocyanate production which involves oxy-carbonylation reaction of toluene diamine, oxygen, and carbon monoxide, producing carbamate which then decompose thermally to produce toluene diisocyanates. This continuous process is carried out in two packed bed reactors for effective utilization of reactants. This continuous production and utilization of toluene diisocyanate reduces storage and handling problems. iv TABLE OF CONTENTS LIST OF TABLES ....................................................................................................