A new developed integrated process configuration for production of hydrogen chloride using geothermal and wind energy resources

Ethylene dichloride thermal cracking is one of the conventional methods for hydrogen chloride production. A critical issue concerned with this method is to provide thermal energy for cracking reaction, which is generally provided by the flammable gasses inside the furnace. Utilizing renewable energy sources can be an interesting topic in this case. Hence, in this paper, the thermal integration feasibility of an ethylene dichloride cracking unit with a hybrid renewable plant, based on geothermal and wind energies, is investigated, while the case study for wind turbines system (Alstom ECO 74/1670/ Class II model) is Meshkin Shahr, located in Iran. To utilize geothermal energy, a high-temperature heat pump cycle is developed to transfer heat energy from the heat source (geothermal reservoir) to the system. Moreover, the excess thermal energy produced by the geothermal heat pump cycle is used in an organic Rankine cycle to generate power. The parametric study's results show that the wind turbines and organic Rankine cycle generate 54532 kW and 19107 kW power, respectively. The geothermal plant provides 10490 kW and 103778 kW heat duty required by the cracking unit and organic Rankine cycle, respectively. Moreover, the integrated structure's main product is hydrogen chloride with a molar flow rate of 131.13 kgmole/h and a purity of 81.71%. The results of the economic analysis of the hybrid system illustrate that the period of return and additive value are 2.735 years and 0.0642 US$/kg HCl.