PX oxidation produces 7.62 GJ of heat per tonne of PTA production and bottle-grade PET production also produces residual heat, mostly originating from its cooling processes. Currently, much of the residual heat is removed with cooling water. Recovering and utilizing this heat in the process would reduce overall energy needs and could contribute to decarbonisation. Incorporating the flow of cooling water into a heat network could recover the residual heat which is transported by the cooling water.
There are multiple possible destinations for this heat, but this is limited by the quality of the residual heat. The provided temperature of the residual heat and the availability of the recovered heat are crucial for implementation of this option. The residual heat could contribute to meeting the heat demand for bottle-grade PET and PTA production, which would require additional equipment and infrastructure at Indorama Rotterdam. The recovered heat could be used to decrease the fuel demand for both oil and steam heating. Techno-economic data for the required equipment is site-specific and not available publicly. Mechanical vapour recompression is a technology which increases the temperature of vapour by performing mechanical compression (Marsidi, 2018). This technology could allow Indorama Rotterdam to produce useful temperatures from the residual heat which is already produced on site. Table 14 gives the economic data of installing mechanical vapour recompression technology at the site.