Integration of bio-carbon in the formulation of carbon electrodes for metallurgical processes- Al smelting process

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This research program aims at developing a process for substituting biochar for petroleum coke in production of carbon electrodes in metallurgical operations, especially in manufacturing of anodes for aluminum electrolysis. Implemented in Canada more than a century ago, aluminum industry today is one of the major Canadian industries, producing 3 Mt/y of primary metal, securing more than 10000 direct and 20000 indirect jobs, and contributing more than 3 B$/y to the economy of the country. Aluminum is conventionally produced by the Hall-Héroult process, involving the electrolysis of alumina, dissolved in molten cryolite. Although the technology is now more than one hundred years old and total aluminum production has grown more than one hundred times within the past fifty years, the process has not changed substantially and carbonaceous materials are still the main ingredients of both anode and cathode. Anode is essentially made of anode grade petroleum coke, and is consumed during the electrolysis process. The spectacular increase of global aluminum production and the shortage of anode grade coke push the industry for seeking alternative carbon sources. At a first glance, biomass-based carbon seems to be a natural solution for this issue, however it does not meet the very strict specifications required for anode. In this research program we intend to explore the possibility of using biochar in anode recipe and to develop an appropriate process in order that biochar meet the industry specifications and eventually be used as an anode ingredient.***The escalating production capacity of Al and shortage of petroleum coke as well as the tightening environmental regulations will, sooner or later, force the technology to go toward bio-carbon sources. This implies a deep understanding of biomass structural features and development of appropriate process parameters, making them suitable for anode. This program could provide such an opportunity for the Canadian industry; first by training the HQP and second by providing required knowledge for replacing pet-coke by bio-coke. The latter, with zero carbon footprints, will remove the financial pressure of the carbon tax, while providing an abundant and local source of carbon thus reducing the dependence of the industry to foreign carbon sources.***At a time when the price of electricity and environmental issues are major factors influencing the location of new aluminum plants, any technology, which improves the specific energy consumption and GHG footprint of aluminum production, will give a competitive advantage to the country that owns the technology. This fact is even more pronounced if we consider the progressive carbon tax program, approved by the Canadian government. A targeted carbon tax of 50 $/ton CO2 will increase the cost of anode by 180 $/ton. Replacing pet-coke by bio-coke will give a tremendous advantage to the Canadian Aluminum industry.