Typical Gross Energies for Polymer Production

Typical values for the production of a number of different polymers are given in Table 3.2. These values are based on practices in plants across Europe but, given the similarity of technologies used in polymer production worldwide, there is no reason to suppose that different results would be obtained elsewhere when a correction has been made for ihe fuel infrastructure. 

The actual values vary from plant to plant. In practice the direct energy consumption varies by 10% and, when ihe fuel infrastructure of the different countries is included, the variations in gross energies are of the order of 17%. These variations will include effects due to age and size of plant, level of maintenance, and variations in technology as well as accuracy of data reporting. 

When considering the variations in production energy, it is important to remember a number of points. 

Many polymer production units are part of larger chemical complexes. At such locations the goal is often the optimization of the whole site performance rather than individual plant performance. 

The data of Table 3.2 do not refer to the final production step alone but to all of the processes from the extraction of crude oil and gas through to the production of monomers and finally to polymerization. The final polymerization step commonly accounts for only around 10% of the gross energy. Most polymers are produced as powders or chips. However, some, such as viscose, are produced directly as the finished fiber, and so the spinning process is included in the data of Table 3.2. The data for nylon 66 and PET refer to granules but in practice these may also be produced at the site where they are converted to fiber. 

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