Expansion Planning of an Ideal Chemical Park’s Infrastructure Towards CO2 Neutrality: Comparing Multiple Investment Periods with a Simplified Greenfield Approach

Many processes in the chemical industry are fossil-based and require a reliable heat and power supply. This makes transforming the chemical industry towards CO2 neutrality challenging. Direct electrification, storage technologies, and renewable energy carriers could pave the way to a climate-neutral chemical industry. Energy system optimization is crucial in identifying economic transformation pathways towards CO2 neutrality. This study uses the open-source software PyPSA (Python for Power System Analysis) to implement a linear programmed model of an ideal chemical park’s infrastructure that covers electricity and steam demands. Various technologies, such as direct electrification, hydrogen, biomass, and fossil-based energy carriers, are considered. In addition, different storage systems and direct investment in renewables are also integrated. Two setups are implemented: First, considering a new investment period every 5 years, a brownfield setup covers an optimization span from 2019 to 2050. All investment periods are optimized with an hourly resolution. Second, a greenfield approach is implemented that only optimizes one key year in hourly resolution. From the results of the long-term brownfield optimization, it can be derived that direct electrification is immediately initiated in the first investment period and accompanied by significant investments in wind offshore capacities. Biomass-based onsite steam and electricity generation serve as transition technologies toward full electrification. From 2045, biomass utilization is reduced significantly. In addition, electricity storage combined with PV capacities are expanded massively in the last two investment periods. Steam production is mainly electrified using high-temperature heat pumps and electrode boilers. During the transformation towards CO2 neutrality, the total electricity demand of the chemical park is more than doubled from 1.997 TWh to 5.694 TWh. By comparing the results of the brownfield setup with the results of the greenfield setup, significant deviations can be noticed, indicating that the original starting setup still influences the expansion of subsequent investment periods even after the expiration of the default component’s lifetime. For both investment periods considered, this behavior leads to a higher total objective than the corresponding greenfield results. Even for the final investment period 2050, the expanded capacity of lithium-ion storage for the brownfield approach is still 362 MWh lower compared to the greenfield approach, indicating that further investment periods after 2050 may be relevant. Finally, a Morris screening sensitivity study was carried out for the greenfield approach, considering 113 input parameters. It was found that the most influential parameters are related to renewables’ maximum capacity or the system’s demands. Non-linear influences are particularly identified for OPEX-related parameters, whereas CAPEX-related parameters are rarely present in the top 30 most influential parameters. Subsequent studies will need to determine whether these findings can be directly transferred to a long-term multi-investment period approach.      «

Many processes in the chemical industry are fossil-based and require a reliable heat and power supply. This makes transforming the chemical industry towards CO2 neutrality challenging. Direct electrification, storage technologies, and renewable energy carriers could pave the way to a climate-neutral chemical industry. Energy system optimization is crucial in identifying economic transformation pathways towards CO2 neutrality. This study uses the open-source software PyPSA (Python for Power S...     »