ENERGIX-Stort program energi

Project SiH2 presents a novel process concept for silicon (Si) production where hydrogen is used as reductant instead of solid carbon, and thus without CO2 emissions. The project will develop fundamental knowledge that can enable the silicon producing industry to reach their goal of zero CO2 emission in 2050. This will be an important step to reach the goals for the Paris climate agreement. Silicon is a main component in solar cells and thus required for the green shift. In addition, it is used in many areas important for our daily life, as in construction materials, silicones, and as additive in steel and aluminium used for instance in cars. Likely (25-50 % probability) there is silicon produced in Norway in your mobile phone and other electronic devices. But production of silicon requires substantial amount of energy 11MWh/ton and produces 5 kg CO2/kg Si. The industry is eager to reduce these numbers, but this is not easy. Hydrogen can not be used directly. Project SiH2 proposes to overcome this by a two-stage process where one of the oxygen atoms in the raw material, SiO2, is removed by reacting with some of the produced Si circulating in the process and the other oxygen atom is removed by hydrogen. There are several theoretical and practical challenges that must be overcome to realise such a process. These will be addressed by both theoretical simulation on an atom level and experimental investigations at temperatures as high as 2000 oC. This will provide fundamental knowledge needed for further technical development of a completely new process for silicon production and reveal the challenges that must be overcome in further development. To obtain competence about the reactions that are needed to develop the process from idea to reality, new laboratory equipment and new measurement methods must be developed in SiH2. Development of methods to model how SiO and H2 molecules will behave in these conditions are also needed. When SiO- gas is cooled down, it will become a sticky mass and is this difficult to investigate. To be able to study reactions with SiO-gas, SiH2 has developed equipment and methods both to generate SiO-gas under controlled conditions and to measure percentage of SiO in a gas at 1600-2000 °C. This is new methods that are now being tested. They are also of interest for other developments of Si-production outside SiH2. Combination of results from earlier research indicates that Si production by SIH2 process will be easier if it is no carbon present. Methods to investigate the reactions in a carbon free system are now being developed by the PhD candidate in the project. Modelling of reactions with the molecules involved in SiH2, indicate that hydrogen and SiO first combine to larger, more complex molecules, and that final release of oxygen from these is the step that requires most energy. Production of Si-hydrogen compounds might be a less energy demanding alternative to production of Si that will be further investigated in the project. The SiH2 process has been presented to national and international silicon producers and users on the biannually Si-conference and to CRU Silicon Market forum.

Project SiH2 presents a new process consept for silicon (Si) production where hydrogen is used as reductant instead of solid carbon, and thus without CO2 emissions. SiH2 will do the fundamnetal reserach required to obtain competence about the involved reactions and for clarifying the potentials for the proposed process. THe concept is based on reactions in two stages. First SiO-gas is produced by reaction between silica (SiO2) and Si. The produced SiO-gas is then reduced by hydrogen to Si and water vapour (H2O). Around half of the produced Si is recirculted back to the SiO generator and used there. In SiH2 the optimal conditions for the combined reactions in the system will be identified. Reaction mechanisma and kinetics for the two involved reactions will be determined by a combination of experimental investigations and theoretical modelling. The project includes a 3 year Post Doc. The project results will be open and shared both through publications and workshops. It is planned to arrange scientific workshop with international partners in INTPART Thanos and industrial workshop with Norwegian Si-producers.