Studies have shown that online compressor washing of gas turbine engines slows down the rate of fouling deterioration during operation. However, for most operators, there is a balancing between the performance improvements obtained and the investment (capital and recurring cost). Washing the engine more frequently to keep the capacity high is a consideration. However, this needs to be addressed with expenditure over the life of the washing equipment rather than a simple cost-benefit analysis. The work presented here is a viability study of online compressor washing for 17 gas turbine engines ranging from 5.3 to 307 MW. It considers the nonlinear cost of the washing equipment related to size categories, as well as nonlinear washing liquid consumption related to the variations in engine mass flows. Importantly, the respective electricity break-even selling price of the respective engines was considered. The results show that for the largest engine, the return of investment (RoI) is 520% and the dynamic payback time of 0.19 years when washing every 72 h. When this is less frequent at a 480-h interval, the investment return and payback are 462% and 0.22 years. The optimization study using a multi-objective genetic algorithm shows that the optimal washing is rather a 95-h interval. For the smallest engine, the investment was the least viable for this type of application.

Although the chemical and petrochemical (C&P) industry is a cornerstone of the Italian and European economies, it is also an intensive energy consumer and a high emitter of greenhouse gases. Europe’s decarbonisation trajectory is often examined through the lens of individual countries, as key factors such as industry status, structure and resource accessibility may differ across nations. This study specifically examines the Italian C&P industry, with an emphasis on the basic chemicals sector. It reviews the current status of the production processes, technologies, energy consumption and carbon footprint in the sector, along with advancements towards decarbonisation. Key decarbonisation technologies are reviewed, highlighting their current use or research and development status. The primary barriers to the adoption of prospective decarbonisation solutions (e.g., increased costs and need for additional renewable capacity and infrastructure development) are discussed. While the Italian C&P sector has adopted strategies to enhance energy efficiency and waste recovery and utilisation, it is uncertain whether the industry will be able to meet the 2050 carbon emissions targets by relying on these two decarbonisation approaches alone. A combination of additional decarbonisation technologies, including electrification, green hydrogen and carbon capture utilisation and storage, will likely be necessary. However, technical challenges exist due to the maturity level of these technologies and their applicability to highly integrated processes. Appropriate, timely policy support will be crucial to aiding the green transition of the Italian C&P sector while safeguarding its significant role in the Italian economy.