Depolymerization capital costs

Other than for simple glycolysis, a substantial capital investment must be made to conduct commercial depolymerization of PET to regain PET monomers for repolymerization of PET. As the capital costs rise at roughly the 0.6 power of the relative volume [68], larger facilities are more economically attractive than smaller facilities. Besides the availability of capital to build very large depolymerization facilities, the limiting criterion has been and is likely to continue to be the sure supply of adequate PET feedstock at acceptable prices. 

Table 16.3 Capital costs for 22700 annual tonne depolymerization facilities (millions of US dollars, M )... 

For this study, an economic hurdle rate of 15 % before tax return on capital investment was used. This rate is higher than for the flake feed preparation facility because the depolymerization facilities cannot be as easily converted to other uses as can the flake preparation plants, which can be converted to produce mechanically cleaned PET for traditional post-consumer PET uses. Including the total capital return component, and a 12 year economic depreciation component, the total cost of the products are given in Table 16.4 as US 1.07/kg to US 1.32/kg. 

The commercial potential for recycling post-consumer PET is not limited by lack of depolymerizing technology. Many options are available with varying degrees of capital intensity. The technologies most probable to provide satisfactory quality product, suitable for reuse in food packaging, are likely to cost US 1.00/kg or more and require capacities of over 20000 annual tonnes. 

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