International Benchmark of Energy Consumption for Alumina Production in Bayer Alumina Refinery

Hi Friends,

In earlier posts, we have covered various issues pertaining to design, engineering, execution and cost estimation of plant, equipment and facilities of Alumina refinery. In present post, we will discuss the International benchmark of energy consumption for production of Metallurgical grade calcined alumina.

As per the literature published by United Nations Industrial Development Organization (UNIDO) available on public domain, typical energy consumption data presented below clearly reveal that specific thermal energy consumption per tonne of alumina produced in various Alumina refineries across the globe ranges from 10.2 GJ/t to 24.5 GJ/t alumina. The thermal energy consumption figures for different regions are presented in following graph-

Data Source : International Aluminium Institute

It is evident from the above graph that specific energy consumption for production of calcined alumina in South America is the lowest at 10.2 GJ/t whereas it is highest in China at about 24.5 GJ/t of alumina. Reasons for wide range of variation in energy consumption figures have already been described in earlier posts. On comparative analysis of these figures, it can be concluded that Asian and American Alumina refineries have the potential to improve the performance of plants for reduction in specific energy consumption by 23 to 25% from the present level. However, Chines Alumina refineries have tremendous scope for further reduction in energy consumption by about 50% through modifications and modernisation in the existing plants. As such, many Alumina refineries under execution in the World have set their total thermal energy consumption target at 8.5 GJ/t alumina.

On critical analysis of plant efficiency figures, process control parameters of operative Alumina refineries and technological advancements in the World, the global benchmark for specific thermal energy consumption in new Alumina refinery has been set by the International Expert Committee as 7.80 GJ/t of calcined alumina.

It may be a little difficult to achieve the set benchmark figure in existing Alumina plants because of inefficient heat recovery system. However, it is challenging and achievable target for modern Alumina refineries with installation of efficient heat recovery system, high degree of automation and continuous monitoring of thermal energy consumed in various units of Alumina refinery. Let us join hands to save unwanted thermal energy and get additional advantage on production cost of alumina. 

Please put your views / suggestions / remarks / comments, if any.

Regards.

Rajendra Kunwar
rajendra@ceti.co.in
www.ceti.co.in