Elkem, a global leader in silicon-based advanced materials, will test the world’s first carbon capture pilot for silicon smelters at its plant in Rana, Norway. The project has received financial support from Gassnova CLIMIT and is a follow-up to the company’s recently launched climate roadmap to reduce emissions towards net zero while growing supplies to the green transition.
The carbon capture pilot is a collaboration between Elkem and Mo Industripark, SINTEF, Alcoa, Celsa, Ferroglobe, SMA Mineral, Norcem, Norfrakalk, Arctic Cluster Team and Aker Carbon Capture.
The test unit will be installed at Elkem’s plant in Rana, which produces high purity ferrosilicon and Microsilica. In addition, emissions from SMA Mineral will also gradually enter the treatment plant. Aker Carbon Capture delivers the test unit, which is the only one of its kind in Norway.
Silicon is extracted from quartz rock—which consists of silicon and oxygen—in a chemical process at high temperatures in which the oxygen in the quartz is bound to carbon, thus freeing the silicon from the oxygen. The smelting furnace is fed with quartz and various types of carbonaceous materials: coke, coal, charcoal and wood chippings. Electrodes made from a carbonaceous material are lowered into this mixture. Elkem Carbon is the world’s leading producer of such electrodes and supplies Elkem’s silicon plants.
When the current is turned on a powerful electric arc is formed between the electrodes. This causes the oxygen in the quartz to react with the carbon in the carbonaceous material and form CO2. The CO2 rises and the silicon can be tapped from the bottom of the furnace. CO2 is therefore always formed when silicon and ferrosilicon is produced.
Ferrosilicon is an alloy of iron and silicon. The ferrosilicon is divided in different classes or families of materials based on silicon content and types of additional alloying elements (magnesium (Mg), aluminum (Al), calcium (Ca), barium (Ba), strontium (Sr), cerium (Ce), zirconium (Zr), manganese (Mn)). Ferrosilicon is produced in a furnace similar to a silicon furnace, but with iron-containing raw materials as part of the charge mix added in the smelting furnace.
CLIMIT is Norway’s national program for research, development and demonstration of CO2 capture and storage technology. The main goal of the project is to verify the technology on real industrial exhaust gases from smelters, in order to prepare a full-scale plant for industrial carbon capture. The program runs over the course of two years.
Elkem recently launched a global climate roadmap detailing how the company plans to reduce its total CO2 emissions by 28% from 2020-31 while growing its supplies to the green transition, thereby delivering 39% improvement of its product carbon footprint in the same period.
As a part of this work towards carbon-neutral materials production, Elkem has conducted a feasibility study for the establishment of carbon capture and storage (CCS). The purpose of the study has been to assess the technical and economic feasibility of installing carbon capture at its Norwegian plants in Bjølvefossen, Bremanger, Rana, Salten and Thamshavn.
In total the partners have identified 1.5 million tonnes of potential CO2 capture in the region. This corresponds to three percent of Norway’s total emissions, and almost one third of the emissions from the metal industry.—Jack Ødegård, Vice President Research in SINTEF
The project has a total budget of NOK 23.6 million (US$2.8 million), of which Gassnova CLIMIT will contribute 13.8 million (US$1.7 million) and the industry will contribute with the remaining amount.