Not Easy Technologies
Jim Metson is a MacDiarmid Institute Principal Investigator based at the University of Auckland.
I am currently spending a short period of leave at the Hydro Aluminium Research Centre at the Herøya (literally hare island) Industrial Park in Porsgrunn, Norway. The Research Centre is part of a much wider centre which covered all of Hydro’s research activities in oil (now StatoilHydro), fertilizer (now Yarra), Magnesium and Silicon. In 2007 the decision was taken to spin out each of these industries, which are large in their own right, and as a consequence, research activities have also been split up.
Hydro is world leading in a number of areas where we at Auckland University have research interests and we have worked together for more than a decade. Firstly we elucidated the processes by which HF is generated and collected in the process off-gas from aluminium smelters, secondly Hydro are at the forefront of work on concentrating this gas stream with the ultimate objective of CO2 sequestration. These are not easy technologies. The removal of HF from the process gas stream requires the gas to access transition alumina pores in the 2-10nm range. However the kinetics are also critical as the reactors in a typical plant will be handling gas volumes of up to 1000 m3 s-1.
Hydro was founded by a brilliant young chemist Kristian Birkeland (who now appears on the 200 Kronor banknote) and a brilliant industrialist Sam Edye. The chemist, of course, died young — likely as a consequence of his development work on mercury cells for the chlor-alkali process — while the industrialist prospered. Herøya (see http://en.wikipedia.org/wiki/File:Hydro_Heroya.jpg) is in many ways similarly a monument to the risks and rewards of industrial chemistry. It houses a massive fertilizer works, what was historically the world’s largest magnesium plant, a PVC plant and more recently a polycrystalline Si wafer facility. The top picture shows the preserved cap of one of the nitric oxide absorption towers from the fertilizer plant. 36,000 tonnes of granite was used in the 49 towers, each 30m in height and sealed with asbestos cement. The non-absorbed gas frequently wafted over the local community, while the nitric acid produced in these towers was neutralised with limestone to form calcium nitrate.
Herøya was of considerable strategic importance in the Second World War and a significant reason for the very early German push into Norway. I have a picture on the wall taken in 1943 from a Flying Fortress dropping its payload on the industrial park where the Research Centre now stands. The Germans had plans for both an Al and a Mg plant at Herøya. The electrolytic Mg plant, then under construction by I. G. Farbenindustrie, was largely destroyed with the loss of 55 lives. The facility was rebuilt by Hydro in the late 1940s and developed into the world’s largest Mg production facility until 2002 when the reduction cells were mothballed in the face of rising Chinese Pidgeon process production. With such a history, it is not surprising to see such a major emphasis here on very ambitious and “clean” technologies. The second photograph is of the Hydrogen filling station just outside the front door of the labs.