Renewable energy integration and waste heat valorization in aluminum remelting for co-producing kerosene and methanol

The aluminium sector relies on natural gas for the conversion of recycled scrap into new feedstock, which results in substantial atmospheric emissions. Hydric resources are also impacted, as they serve as heat sinks for the waste heat generated during the casting process. Other chemical industries are also responsible for a large production of waste heat, offgas and environmental emissions, which hinders efforts to decarbonize the sector that depend on them. Methanol and transportation fuels production are examples of those industries. Accordingly, there is a significant potential to decarbonize these productive activities via enhanced waste heat recovery and integration of renewable energy sources. The energy integration of aluminium, methanol and fuels production plants within urban areas also offers major advantages in terms of efficient energy utilization and reduced environmental impact, particularly in situations characterized by uncertain supply chains and fluctuating market prices. Biomass gasification offers an alternative carbon source to fossil fuels, and together with electrification, it may help to diversify and decentralize the energy inputs for industries traditionally dependent on natural gas, establishing resilient and sustainable energy pathways. Carbon abatement, power-to-gas and storage systems provide further advantages by mitigating the effects of seasonal availability and prices of electricity and fuel. Yet, the integration of the various energy technologies and industrial facilities calls for a systematic approach to identify optimal options for meeting the energy demands without significantly compromising the operational feasibility. Therefore, in this work, the most cost-effective technologies with minimum investment that meet the energy demands of the aluminium remelting, methanol and fuels production facilities are studied, aiming to upgrade the industrial waste heat available at low temperature to supply an urban center with variable energy needs. Implementing improved integration strategies shows the potential to reduce overall energy consumption, while achieving net-zero CO2 emissions compared to conventional scenario.