Where the 𝐶 𝑝 factor is a function of the installed power in kW (𝐶 𝑝 = 𝑓(𝑃[𝑘𝑊]) . The process is operated with three reactive stages with intermediate condensation of the products, to achieve high conversion. The methanol reactors are modelled with a 1D pseudo homogeneous model as described by equations ( )-( ). The kinetic model is derived from Vanden Bussche and Froment . The cost of the methanol synthesis catalyst is set to 20 €/kg and it is exchanged every 2 years. The intermediate heat exchanger cost is determined with the formula , where the 𝐶 𝑝 factor is dependent on the surface area required (𝐶 𝑝 = 𝑓(𝐴[𝑚 2 ]).