Carbon Removal to the Rescue?

This article looks at the current state of carbon removal approaches and some of the politics that surround them. It outlines what carbon removal is, charts some of the major challenges and controversies, and sketches some of the work needed to ensure that carbon removal developments are attentive to environmental sustainability and social justice. It also examines some of the major carbon removal options that are either in development or in discussion, starting with biological approaches and then looking at engineered options.

Technology for Upgrading the Tailwater of Municipal Sewage Treatment Plants: The Efficacy and Mechanism of Microbial Coupling for Nitrogen and Carbon Removal

The efficient removal of carbon (COD) and nitrogen (NH3-N) is vital to improving tailwater from municipal wastewater treatment plants. In this study, denitrification and decarburization bacteria with stable removal efficiencies were introduced into a membrane bioreactor (MBR) for 45 days of field experiments in a QJ Wastewater Treatment Plant (Hangzhou, China) to enhance carbon and nitrogen removal. After adding the decarbonization microorganisms into the denitrification reactor, COD removal increased from 31.2% to 80.2%, while compared to the same MBR with only denitrification microorganisms, the removal efficiency of NH3-N was greatly increased from 76.8% to 98.6%. The results of microbial analysis showed that the cooccurrence of Proteobacteria and Bacillus with high abundance and diverse bacteria, such as Chloroflexi, with autotrophic decarburization functions might account for the synchronous high removal efficiency for NH3-N and COD. This technology could provide a reference for industrial-scale wastewater treatment with the goal of simultaneous nitrogen and carbon removal.

Exploring the Thermodynamic Limits of Enhanced H2 Recovery With Inherent Carbon Removal From Low Value Aqueous Biomass Oxygenate Precursors

Rational integration of chemical pathways at the molecular scale to direct thermodynamically favorable enhanced H2 production with inherent carbon removal from low-value substrates can be guided by exploring the thermodynamic limits of feasibility. The substrates of interest are biomass oxygenates that are water-soluble and uneconomical for separation from water. In this study, we investigate the thermodynamic feasibility of recovering H2 with inherent carbon removal from biomass oxygenates such as ethanol, methanol, glycerol, ethylene glycol, acetone, and acetic acid. The influence of biomass oxygenate-to-water ratios, reaction temperature of 150°C–325°C, and CaO or Ca(OH)2 as the alkalinity source on the yields of H2, CH4, CO2, and Ca-carbonate are investigated. By maintaining the fluids in the aqueous phase under pressure, energy needs associated with vaporization are circumvented. The hypothesis that enhanced alkalinity favors the preferential formation of CO (precursor for CO2 formation) over CH4 and aids the formation of calcium carbonate is investigated. The findings from these studies inform the feasibility, design of experiments, and the tuning of reaction conditions for enhanced H2 recovery with inherent carbon removal from biomass oxygenate sources.

XPRIZE Carbon Removal: largest incentive prize in history

XPRIZE Carbon Removal is a 4-year global competition that invites innovators and teams from anywhere on the planet to create and demonstrate solutions that can pull carbon dioxide directly from the atmosphere or oceans, and sequester it.

Report to boost climate action calls globally

Significance Drawing on more than 14,000 peer-reviewed studies, the report summarises contemporary science on climate change and finds that it is unequivocal that human influence has warmed the atmosphere, oceans and land. The report will underpin climate negotiations and policymaking, and place increased pressure on governments and businesses to act. Impacts Governments will face pressure to make climate targets more ambitious ahead of COP26. Increasing numbers of climate litigation cases from environmental campaigners will be filed against governments and businesses. Carbon removal technology threatens to give excuses to those reluctant to act on reducing emissions.