Document Type
Working Paper
Date of this Version
5-25-2023
Abstract
Over the next decade, global electricity demand is forecast to rise by nearly two-thirds of current demand. Simultaneously, global Carbon Dioxide emissions are projected to increase by up to 9% annually. Green liquid Hydrogen, sourced by splitting water into Hydrogen and oxygen using renewable electricity, and condensed in a deep cryogenic refrigerator at 20 to 25 K, is a promising alternative to traditional fossil fuels. Yet, liquid Hydrogen as a fuel is prohibitively expensive. Between water electrolysis and liquefaction costs, current producers of green liquid Hydrogen must sell their product Hydrogen at a price of at least $9.20/kg to break even. Breakthroughs in electrolyzer efficiency and electrolyzer capital cost are likely to remedy these unfavorable economics. However, there remain many unknowns in Hydrogen liquefaction process design. We propose a green Hydrogen liquefaction plant that produces 45 metric tons per day (MTD) of liquid Hydrogen. Vapor feed Hydrogen to the liquefaction process will be sourced upstream by electrolytically splitting water into Hydrogen and oxygen. The electricity to split water and to operate the plant will come from a completely renewable power grid. Our plant design has three novel advantages to preexisting green Hydrogen liquefaction plant design. Namely: 1) A successful implementation of Large- scale Reverse Brayton refrigeration cycle, 2) Actualized Heat Exchanger Design, 3) A specific power of 6.24 kilowatt hours per kilogram of liquid Hydrogen, near the state-of-the-art in conceptual liquefiers. Assuming a cost of capital of 15%, a plant lifetime of 15 years, a sales price of $13 per kilogram of LH2, and 100% of vapor feed Hydrogen sourced via water electrolysis, a plant based on the process design detailed herein has an ROI of 16.57%, an IRR of 18.52%, and an NPV of $44,445,500.
Date Posted:25 May 2023