Abstract: A method for producing an oligomeric polyethylene terephthalate (PET) substrate for use in a recycled PET (rPET) manufacturing process comprises adding recycled bis-hydroxylethyleneterephthalate (rBHET) or a higher molecular weight oligomer derived from rBHET and water to a reaction zone and reacting the rBHET and water in the reaction zone to produce an oligomeric PET substrate represented by the Formula (I): wherein R1 is a carboxyl end group or a hydroxyl end group, R2 is a carboxyl end group or a hydroxyl end group, and n is a degree of polymerisation (Dp).

Abstract: A method for producing an oligomeric polyethylene terephthalate (PET) substrate for use in a recycled PET (rPET) manufacturing process, comprising (i) adding recycled bis-hydroxylethylenete rephthalate (rBHET) and an under-esterified purified terephthalic acid (PTA) oligomer to a reaction zone; and ii) reacting the rBHET and the under-esterified PTA oligomer in the reaction zone to produce an oligomeric PET substrate represented by the formula (I), wherein R1 is a carboxyl end group or a hydroxyl end group, R2 is a carboxyl end group or a hydroxyl end group, and n is a degree of polymerisation (Dp).

Abstract: A method for producing an oligomeric PET substrate for use in a rPET manufacturing process comprises reacting recycled bis-hydroxylethyleneterephthalate (rBHET) or a higher molecular weight oligomer derived from rBHET, with PTA to produce an oligomeric PET substrate represented by Formula (I), wherein R1 is a carboxyl end group or a hydroxyl end group, R2 is a carboxyl end group or a hydroxyl end group, and n is a degree of polymerisation.

Abstract: The invention relates to a thermosiphon esterifier design comprising a riser baffle in the vapor separator. Advantageously, the thermosiphon esterifier design can provide an economic benefit as compared with traditional thermosiphon esterifier designs. Methods of using the thermosiphon esterifier design in a system for the production of polyethylene terephthalate are also described.

Abstract: The invention relates to recycling steam at elevated temperature and/or pressure generated within a thermosiphon esterifier design comprising a riser baffle in the vapor separator. Advantageously, the thermosiphon esterifier design can provide steam that can be employed in various additional processes and can thus provide an overall energy savings in operating the thermosiphon esterifier. Methods of using the steam are also described.

Abstract: Polyester is depolymerized by methanolysis and methanol is recovered in a process that uses methyl benzoate and/or p-methyltoluate as an azeotropic agent while the methanol is present.