SUSTAINABLE STEAM ON DEMAND FOR THE BAYER PROCESS

Bayon, A., Beath, A., Lovegrove, K.

In this work, we explore the coupling of Concentrated Solar Thermal to produce the steam required for the Bayer Process used for the conversion of bauxite to aluminium hydroxide. Specifically, we present the use parabolic trough and central receiver tower technologies to produce the required steam for the digestion and electricity demand of a commercial-scale Bayer Process plant. This work explores the integration of different configurations for the production of steam using annual simulations with real direct normal irradiation data. We studied the effect of the solar field size as a critical parameter towards the economic optimisation of the plant. In addition, we analyzed plausible sites based on physical and operational constraints. The results indicated that locations with higher direct normal irradiation deliver lower costs and higher net present value having the potential to incorporate a large amount of CST into the process. From all the sites analyzed, only Learmonth (Western Australia) showed positive NPV and large solar share. For central tower technology with an optimum NPV of M$24 and a solar share of 49.4% for a solar multiple 2.2 and 7.3 hours storage. The best scenario was obtained for parabolic trough, a maximum NPV value of M$51 and solar share of 35% were obtained for 2 solar multiple and 4 hours storage.