The signals are everywhere that our planet is experiencing significant climate change. It is clear that we need to reduce the emissions of carbon dioxide and other greenhouse gases from our atmosphere if we want to avoid greatly increased risk of damage from climate change. Aggressively pursuing a program of emissions abatement or mitigation will show results over a timescale of many decades. How do we actively remove carbon dioxide from the atmosphere to make a bigger difference more quickly? As one of a two-book report, this volume of Climate Intervention discusses CDR, the carbon dioxide removal of greenhouse gas emissions from the atmosphere and sequestration of it in perpetuity. Climate Intervention: Carbon Dioxide Removal and Reliable Sequestration introduces possible CDR approaches and then discusses them in depth. Land management practices, such as low-till agriculture, reforestation and afforestation, ocean iron fertilization, and land-and-ocean-based accelerated weathering, could amplify the rates of processes that are already occurring as part of the natural carbon cycle. Other CDR approaches, such as bioenergy with carbon capture and sequestration, direct air capture and sequestration, and traditional carbon capture and sequestration, seek to capture CO2 from the atmosphere and dispose of it by pumping it underground at high pressure. This book looks at the pros and cons of these options and estimates possible rates of removal and total amounts that might be removed via these methods. With whatever portfolio of technologies the transition is achieved, eliminating the carbon dioxide emissions from the global energy and transportation systems will pose an enormous technical, economic, and social challenge that will likely take decades of concerted effort to achieve. Climate Intervention: Carbon Dioxide Removal and Reliable Sequestration will help to better understand the potential cost and performance of CDR strategies to inform debate and decision making as we work to stabilize and reduce atmospheric concentrations of carbon dioxide.

An automatically operated carbon dioxide reduction system was developed, fabricated and tested. The system was designed to reduce the carbon dioxide equivalent to that produced by one man, and to produce carbon and oxygen. A system such as this is required for providing respiratory support for man on extended space missions. The program was conducted in three phases: (1) development of system components, (2) experimental determination of system design parameters, and (3) fabrication and testing of an engineering model. Successful operation of the engineering model demonstrated the feasibility and ease of operation of the system. Recommendations are made for improving the system and for future work. (Author).

To achieve goals for climate and economic growth, "negative emissions technologies" (NETs) that remove and sequester carbon dioxide from the air will need to play a significant role in mitigating climate change. Unlike carbon capture and storage technologies that remove carbon dioxide emissions directly from large point sources such as coal power plants, NETs remove carbon dioxide directly from the atmosphere or enhance natural carbon sinks. Storing the carbon dioxide from NETs has the same impact on the atmosphere and climate as simultaneously preventing an equal amount of carbon dioxide from being emitted. Recent analyses found that deploying NETs may be less expensive and less disruptive than reducing some emissions, such as a substantial portion of agricultural and land-use emissions and some transportation emissions. In 2015, the National Academies published Climate Intervention: Carbon Dioxide Removal and Reliable Sequestration, which described and initially assessed NETs and sequestration technologies. This report acknowledged the relative paucity of research on NETs and recommended development of a research agenda that covers all aspects of NETs from fundamental science to full-scale deployment. To address this need, Negative Emissions Technologies and Reliable Sequestration: A Research Agenda assesses the benefits, risks, and "sustainable scale potential" for NETs and sequestration. This report also defines the essential components of a research and development program, including its estimated costs and potential impact.

An automatically operated carbon dioxide reduction system was designed, fabricated and tested. The system will reduce 0.365 pounds of carbon dioxide per hour, equivalent to a 3.2-man carbon dIoxide output, and is required for providing respiratory support for man on extended space missions. The program was conducted In three phases, analysis of a reactor developed on a previous contract, experimental determination of design parameters, and fabrication and testing of an improved engineering model. Operating characteristics, feed gas compositions, recycle flow rates, reaction temperatures and pressures, and catalyst composition and configuration were established and the effects of variations in these were determined. Recommendations are made for improving the system and for future work.

Methods suitable for use in a weightless environment for removing water and carbon from carbon dioxide reduction process systems were investigated. Water removal studies were conducted using a porous metal, plate-type, condenser-separator to remove the water from the exit gas streams of both Sabatier and Bosch type carbon dioxide reduction reactors. Water remaining in the effluent stream ranged from 0.97 to 2.08 percent by volume with the Sabatier reactor, and 0.78 to 0.92 percent with the Bosch reactor. A regenerative chemical dryer used to increase the reaction rate of the Bosch reactor, resulted in relatively minor changes in the reaction rate in steady state operation. Carbon flow pattern tests were conducted to determine design characteristics of a carbon separator-filter. A combination centrifugal separator and porous metal filter was used to remove carbon from the recycle flow stream and pass approximately 99 percent of the carbon to the carbon collector. Periodic back flow through the filter removes the remaining carbon from the filter. The Bosch reactor utilizes flat iron catalyst plates stacked on a hollow rotating shaft. Carbon is dislodged from the rotating plates by carbon removal fingers projecting between the catalyst plates. Reaction gases flowing through the reactor carry the carbon out of the reactor to the filter-separator. (Author).

Carbon Dioxide Reduction through Advanced Conversion and Utilization Technologies covers fundamentals, advanced conversion technologies, economic feasibility analysis, and future research directions in the field of CO2 conversion and utilization. This book emphasizes principles of various conversion technologies for CO2 reduction such as enzymatic conversion, mineralization, thermochemical, photochemical, and electrochemical processes. It addresses materials, components, assembly and manufacturing, degradation mechanisms, challenges, and development strategies. Applications of conversion technologies for CO2 reduction to produce useful fuels and chemicals in energy and industrial systems are discussed as solutions to reduce greenhouse effects and energy shortages. Particularly, the advanced materials and technology of high temperature co-electrolysis of H2O and CO2 to produce sustainable fuels using solid oxide cells (SOCs) are reviewed and the introduction, fundamentals, and some significant topics regarding this CO2 conversion process are discussed. This book provides a comprehensive and clear picture of advanced technologies in CO2 conversion and utilization. Written in a clear and detailed manner, it is suitable for students as well as industry professionals, researchers, and academics.

Homogeneous and Heterogeneous Catalysis