As part of the German coal phase-out, the decision was made to decommission the coal-fired boilers at EnBW‘s Stuttgart-Münster site in 2026. To compensate for the loss of district heating capacity, we implemented two heat recovery steam generators (HRSG) with a total capacity of 180 MWth as part of a state-of-the-art combined heat and power plant (CHP). Designed as a mid-load plant, it is used to reliably supply electricity and district heating, whereby the entire power plant with its new CHP is primarily operated with heat control. In addition, the CHP is H2-ready, i.e., hydrogen content of up to 30 % by volume can be burned in the future. The CHP is prepared for 100 Vol.% hydrogen, whereby only a short standstill is required for the adaptation. The HRSGs use duct burners to increase output. An SCR is used to achieve the required emission values.
One particular feature is that the HRSGs do not have their own stacks. Instead, the exhaust gases are discharged via the gas turbine stacks. As a result, the number of externally visible stacks could be reduced by half, helping to preserve the cityscape. Noise emissions are carefully considered due to nearby residential areas. The combined steel construction for the gas turbine and boiler house and HRSGs reduced steel mass, building height, and overall costs compared to the original design. Additionally, around 150 m of BoP pipelines were routed to the existing plant.