Restoring Pre-Industrial CO₂ Levels While Achieving Sustainable Development Goals

• Main Authors: Mark E. Capron, Jim R. Stewart, Antoine de Ramon N’Yeurt, Michael D. Chambers, Jang K. Kim, Charles Yarish, Anthony T. Jones, Reginald B. Blaylock, Scott C. James, Rae Fuhrman, Martin T. Sherman, Don Piper, Graham Harris, Mohammed A. Hasan
• Format: Article
• Language: English
• Published: MDPI AG 2020-09-01
• Series: Energies
• Subjects: sustainable development goals (SDGs); carbon dioxide removal (CDR); carbon sequestration (BECCS); renewable energy; waste-to-energy; Allam Cycle
• Online Access: https://www.mdpi.com/1996-1073/13/18/4972

Unless humanity achieves United Nations Sustainable Development Goals (SDGs) by 2030 and restores the relatively stable climate of pre-industrial CO₂ levels (as early as 2140), species extinctions, starvation, drought/floods, and violence will exacerbate mass migrations. This paper presents conceptual designs and techno-economic analyses to calculate sustainable limits for growing high-protein seafood and macroalgae-for-biofuel. We review the availability of wet solid waste and outline the mass balance of carbon and plant nutrients passing through a hydrothermal liquefaction process. The paper reviews the availability of dry solid waste and dry biomass for bioenergy with CO₂ capture and storage (BECCS) while generating Allam Cycle electricity. Sufficient wet-waste biomass supports quickly building hydrothermal liquefaction facilities. Macroalgae-for-biofuel technology can be developed and straightforwardly implemented on SDG-achieving high protein seafood infrastructure. The analyses indicate a potential for (1) 0.5 billion tonnes/yr of seafood; (2) 20 million barrels/day of biofuel from solid waste; (3) more biocrude oil from macroalgae than current fossil oil; and (4) sequestration of 28 to 38 billion tonnes/yr of bio-CO₂. Carbon dioxide removal (CDR) costs are between 25–33% of those for BECCS with pre-2019 technology or the projected cost of air-capture CDR.