This article addresses the sustainable design of hydrogen (H2) production systems that integrate brown and blue pathways with green hydrogen infrastructure. We develop a systematic framework to simultaneously optimize the process superstructure and operating conditions of steam methane reforming (SMR)‐based hydrogen production systems. A comprehensive superstructure that integrates SMR with multiple carbon dioxide capture technologies, electrolyzers, fuel cells, and working fluids in the organic rankine cycle is proposed under varying operating conditions. A life cycle optimization model is then developed by integrating superstructure optimization, life cycle assessment approach, techno‐economic assessment, and process optimization using extensive process simulation models and formulated as a mixed‐integer nonlinear program. We find that the optimal unit‐levelized cost of hydrogen ranges from $1.49 to $3.18 per kg H2. Moreover, the most environmentally friendly process attains net‐zero life cycle greenhouse gas emissions compared to 10.55 kg CO2‐eq per kg H2 for the most economically competitive process design.

The world is facing a formidable climate predicament due to elevated greenhouse gas (GHG) emissions from fossil fuels. The preceding decade has also witnessed a dramatic surge in blockchain-based applications, constituting yet another substantial energy consumer. Nonfungible tokens (NFTs) are one such application traded on Ethereum (ETH) marketplaces that have raised concerns about their climate impacts. The transition of ETH from proof of work (PoW) to proof of stake (PoS) is a step toward reducing the carbon footprint of the NFT sector. However, this alone will not address the climate impacts of the growing blockchain industry. Our analysis indicates that NFTs can cause yearly GHG emissions of up to 18% of the peak under the energy-intensive PoW algorithm. This results in a significant carbon debt of 4.56 Mt CO 2 -eq by the end of this decade, equivalent to CO 2 emissions from a 600-MW coal-fired power plant in 1 y which would meet residential power demand in North Dakota. To mitigate the climate impact, we propose technological solutions to sustainably power the NFT sector using unutilized renewable energy sources in the United States. We find that 15% utilization of curtailed solar and wind power in Texas or 50 MW of potential hydropower from existing nonpowered dams can support the exponential growth of NFT transactions. In summary, the NFT sector has the potential to generate significant GHG emissions, and measures are necessary to mitigate its climate impact. The proposed technological solutions and policy support can help promote climate-friendly development in the blockchain industry.

Recent global logistics and geopolitical challenges draw attention to the potential raw material shortages for electric vehicle (EV) batteries. Here, we analyze the long-term energy and sustainability prospects to ensure a secure and resilient midstream and downstream value chain for the U.S. EV battery market amid uncertain market expansion and evolving battery technologies. With current battery technologies, reshoring and ally-shoring the midstream and downstream EV battery manufacturing will reduce the carbon footprint by 15% and energy use by 5 to 7%. While next-generation cobalt-free battery technologies will achieve up to 27% carbon emission reduction, transitioning to 54% less carbon-intensive blade lithium iron phosphate may diminish the mitigation benefits of supply chain restructuring. Our findings underscore the importance of adopting nickel from secondary sources and nickel-rich ores. However, the advantages of restructuring the U.S. EV battery supply chain depend on projected battery technology advancements.

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