Alternative fuels, also known as non-conventional and advanced fuels, are fuels derived from sources other than petroleum. Alternative fuels include gaseous fossil fuels like propane, natural gas, methane, and ammonia; biofuels like biodiesel, bioalcohol, and refuse-derived fuel; and other renewable fuels like hydrogen and electricity.
Climate engineering is an umbrella term for both carbon dioxide removal and solar radiation modification, when applied at a planetary scale. However, these two processes have very different characteristics. For this reason, the Intergovernmental Panel on Climate Change no longer uses this overarching term. Carbon dioxide removal approaches are part of climate change mitigation. Solar radiation modification is reflecting some sunlight back to space. Some publications place passive radiative cooling into the climate engineering category. This technology increases the Earth's thermal emittance. The media tends to use climate engineering also for other technologies such as glacier stabilization, ocean liming, and iron fertilization of oceans. The latter would modify carbon sequestration processes that take place in oceans.
Flue gas is the gas exiting to the atmosphere via a flue, which is a pipe or channel for conveying exhaust gases, as from a fireplace, oven, furnace, boiler or steam generator. It often refers to the exhaust gas of combustion at power plants. Technology is available to remove pollutants from flue gas at power plants.
Coal pollution mitigation, sometimes labeled as clean coal, is a series of systems and technologies that seek to mitigate health and environmental impact of burning coal for energy. Burning coal releases harmful substances that contribute to air pollution, acid rain, and greenhouse gas emissions. Mitigation includes precombustion approaches, such as cleaning coal, and post combustion approaches, include flue-gas desulfurization, selective catalytic reduction, electrostatic precipitators, and fly ash reduction. These measures aim to reduce coal's impact on human health and the environment.
Carbon capture and storage (CCS) is a process in which carbon dioxide (CO2) from industrial installations is separated before it mixes with the atmosphere, then transported to a long-term storage location. In CCS, the CO2 is captured from a large point source, such as a natural gas processing plant and typically is stored in a deep geological formation. Around 80% of the CO2 captured annually is used for enhanced oil recovery (EOR), a process in which CO2 is injected into partially-depleted oil reservoirs in order to extract more oil and then is left underground. Since EOR utilizes the CO2 in addition to storing it, CCS is also known as carbon capture, utilization, and storage (CCUS).
Douglas Patrick Harrison is a professor emeritus of chemical engineering from Louisiana State University's Gordon A. and Mary Cain Department of Chemical Engineering, where he taught undergraduate and graduate classes and served as a dissertation advisor to Ph.D. and M.S. students.
The Virgin Earth Challenge was a competition offering a $25 million prize for whoever could demonstrate a commercially viable design which results in the permanent removal of greenhouse gases out of the Earth's atmosphere to contribute materially in global warming avoidance. The prize was conceived by Richard Branson, and was announced in London on 9 February 2007 by Branson and former US Vice President Al Gore.
A carbon dioxide scrubber is a piece of equipment that absorbs carbon dioxide (CO2). It is used to treat exhaust gases from industrial plants or from exhaled air in life support systems such as rebreathers or in spacecraft, submersible craft or airtight chambers. Carbon dioxide scrubbers are also used in controlled atmosphere (CA) storage and carbon capture and storage processes.
Carbon dioxide removal (CDR) is a process in which carbon dioxide is removed from the atmosphere by deliberate human activities and durably stored in geological, terrestrial, or ocean reservoirs, or in products. This process is also known as carbon removal, greenhouse gas removal or negative emissions. CDR is more and more often integrated into climate policy, as an element of climate change mitigation strategies. Achieving net zero emissions will require first and foremost deep and sustained cuts in emissions, and then—in addition—the use of CDR. In the future, CDR may be able to counterbalance emissions that are technically difficult to eliminate, such as some agricultural and industrial emissions.
Bioenergy with carbon capture and storage (BECCS) is the process of extracting bioenergy from biomass and capturing and storing the carbon dioxide (CO2) that is produced.
Enhanced weathering, also termed ocean alkalinity enhancement when proposed for carbon credit systems, is a process that aims to accelerate the natural weathering by spreading finely ground silicate rock, such as basalt, onto surfaces which speeds up chemical reactions between rocks, water, and air. It also removes carbon dioxide from the atmosphere, permanently storing it in solid carbonate minerals or ocean alkalinity. The latter also slows ocean acidification.
A carbon carousel is made of CO2-sorbent panels that are spun around in the air to remove carbon dioxide. After spinning the panels are placed in a regeneration chamber where the carbon dioxide is desorbed.
Carbon-neutral fuel is fuel which produces no net-greenhouse gas emissions or carbon footprint. In practice, this usually means fuels that are made using carbon dioxide (CO2) as a feedstock. Proposed carbon-neutral fuels can broadly be grouped into synthetic fuels, which are made by chemically hydrogenating carbon dioxide, and biofuels, which are produced using natural CO2-consuming processes like photosynthesis.
Christopher W. Jones is an American chemical engineer and researcher of catalysis and carbon dioxide capture. In 2024 he is the John Brock III School Chair and Professor of Chemical & Biomolecular Engineering and adjunct professor of chemistry and biochemistry at the Georgia Institute of Technology, in Atlanta, Georgia. Previously he served as associate vice president for research at Georgia Tech (2013-2019), including a stint as interim executive vice-president for research in 2018.
Calcium looping (CaL), or the regenerative calcium cycle (RCC), is a second-generation carbon capture technology. It is the most developed form of carbonate looping, where a metal (M) is reversibly reacted between its carbonate form (MCO3) and its oxide form (MO) to separate carbon dioxide from other gases coming from either power generation or an industrial plant. In the calcium looping process, the two species are calcium carbonate (CaCO3) and calcium oxide (CaO). The captured carbon dioxide can then be transported to a storage site, used in enhanced oil recovery or used as a chemical feedstock. Calcium oxide is often referred to as the sorbent.
The Center for Negative Carbon Emissions (CNCE) is led by Director Matthew Green, and was founded by Klaus S. Lackner in the School of Sustainable Engineering and the Built Environment (SSEBE) at Arizona State University in 2014. CNCE is advancing carbon management technologies that can capture CO2 directly from ambient air in an outdoor operating environment. CNCE aims to demonstrate systems that over time increase in scope, reliability and efficiency while lowering the cost of carbon dioxide capture from air.
Direct air capture (DAC) is the use of chemical or physical processes to extract carbon dioxide directly from the ambient air. If the extracted CO2 is then sequestered in safe long-term storage, the overall process will achieve carbon dioxide removal and be a "negative emissions technology" (NET).
Climeworks AG is a Swiss company specializing in direct air capture (DAC) technology. The company filters CO2 directly from the ambient air through an adsorption-desorption process. At its first commercial direct air capture and storage plant, Orca, in Hellisheidi, Iceland, the air-captured CO2 is handed over to storage partner Carbfix, who injects it deep underground where it mineralizes and turns into stone. Climeworks's machines are powered by renewable energy or energy-from-waste, with a carbon dioxide re-emission rate of less than 10%.
Sorption enhanced water gas shift (SEWGS) is a technology that combines a pre-combustion carbon capture process with the water gas shift reaction (WGS) in order to produce a hydrogen rich stream from the syngas fed to the SEWGS reactor.
