Advanced polymerization process with cogeneration and heat recovery

Considering energy requirements for major bulk polymer, low density polyethylene (LDPE) as an energy intensive process, the potential savings are proposed. The polymerization operations need electric and thermal energy in significant amounts. Usually in an conventional system, electric energy is supplied from grid, and thermal from boilers. The efficiency of such system could be improved by using simultaneous production of electric and thermal energy (CHP), as well as waste heat recovery. Considering the polymerization data in presented article a calculation methodology for evaluating the primary energy consumption for both options i.e. CHP and separate production of heat and power is presented. As a result of proposed combined heat and power scheme (CHP) achieved saving in purchased electric energy is 17.6%. Also, the waste heat streams has been recognized as a potential energy efficiency improving option. Therefore a thermodynamic analysis for conventional and CHP is carried out. The obtained results show savings in range of 5–7.3% for conventional and 16–24% for CHP scheme.