Synergistic sustainability: Future potential of integrating produced water and CO2 for enhanced carbon capture, utilization, and storage (CCUS)

CO2 geological storage site selection and long-term potential assessment framework based on TOUGH2/ECO2N

Carbon dioxide capture and storage (CCS) technology is considered a crucial tactic for achieving the "dual carbon" goals. However, current CCS technologies face several challenges, such as the absence of a comprehensive and systematic set of criteria for site selection, coupled with the lack of a universally applicable evaluation framework.To address these issues, this study proposes a regional-scale CO2 geological storage suitability assessment and potential estimation framework that can be adapted to similar regions. Using the Yellow River Delta as a case study, a geological storage site selection indicator system was developed, and a model for assessing site suitability was constructed.The model was employed to evaluate the appropriateness of CO2 geological sequestration sites within the study region, and numerical simulations of CO2 storage were performed utilizing the TOUGH2/ECO2N simulator for prospective target zones. This research examines the migration dynamics of CO2 in saline aquifers, the progression of storage mechanisms, and the carbon sequestration capacity of various storage configurations. The research addresses key questions such as: How can the optimal CO2 geological storage target area be selected? How can the best storage strategy matching the target area be determined? How can the migration and distribution characteristics of CO2 after storage be simulated? Are there potential risks in the future?

A green integrated process for phosphogypsum recycling: CO2 sequestration combined with SO2 recovery

An integrated process was constructed combining ammonia-enhanced CO2 sequestration and low-temperature preparation of SO2 to achieve efficient recovery and comprehensive utilization of the main element in phosphogypsum (PG). The entire integrated process could mitigate the environmental issue of PG stacking and the CO2 concentration, as well as yield high value-added product of SO2. PG obtained its maximum carbonation ratio of 91% within 40 min, and transformed to micro-sized fine CaCO3. The carbonation by-product of ammonium sulfate was used to stepwise recover NH3 and SO2, with the catalyze of iron scales. Under optimal conditions, SO2 recovery of 97% was attained and 84% of NH3 can be recycled for CO2 sequestration. Furthermore, the techno-economic efficiency was preliminarily assessed. During the entire process, the effective utilization rates of calcium and sulfur, the main elements of phosphogypsum, were 92% and 88%, respectively. Additionally, the recycling efficiency of ammonia water reached 84%. Furthermore, the techno-economic benefit was preliminarily assessed. Each ton of raw PG treated by the integrated process would capture 0.23 t of CO2 and yield economic benefit of 132 yuan, which has great advantages in industrial solid wastes with similar calcium content by direct wet mineralization. This integrated process offers a novel technological reference for current PG management and sulfuric acid manufacturing processes.

Estimation of CO2-Brine Interfacial Tension Based on an Advanced Intelligent Algorithm Model: Application for Carbon Saline Aquifer Sequestration

The emission reduction of the main greenhouse gas, CO2, can be achieved via carbon capture, utilization, and storage (CCUS) technology. Geological carbon storage (GCS) projects, especially CO2 storage in deep saline aquifers, are the most promising methods for meeting the net zero emission goal. The safety and efficiency of CO2 saline aquifer storage are primarily controlled by structural and capillary trapping, which are significantly influenced by the interactions between fluid and solid phases in terms of the interfacial tension (IFT) between the injected CO2 and brine at the reservoir site. In this study, a model based on the random forest (RF) model and the Bayesian optimization (BO) algorithm was developed to estimate the IFT between the pure and impure gas-brine binary systems for application to CO2 saline aquifer sequestration. Then three heuristic algorithms were applied to validate the accuracy and efficiency of the established model. The results of this study indicate that among the four mixed models, the Bayesian optimized random forest model fits the experimental data with the smallest root-mean-square error (RMSE = 1.7705) and mean absolute percentage error (MAPE = 2.0687%) and a high coefficient of determination (R2 = 0.9729). Then the IFT values predicted via this model were used as an input parameter to estimate the CO2 sequestration capacity of saline aquifers at different depths in the Tarim Basin of Xinjiang, China. The burial depth had a limited influence on the CO2 storage capacity.

Energy transition: Cap-and-trade and carbon capture and storage for achieving net-zero emissions with sustainable insurance

This paper introduces an energy transition model featuring a carbon-intensive manufacturer that adopts sustainable insurance, participates in a cap-and-trade scheme, and implements carbon capture and storage (CCS) transit, all aimed at achieving the net-zero carbon emission target. The model utilizes a down-and-out call (DOC) approach to evaluate the manufacturer's equity, considering the bankruptcy risk prior to maturity due to carbon intensity. The equity of the life insurer providing funds is assessed using a capped DOC method to address the capped credit risk from the manufacturer. The findings reveal that increased adoption of CCS transit diminishes manufacturer equity, heightens default risk, and reduces insurer equity, with these effects exacerbated by advanced CCS technology and stringent cap-and-trade caps. Both stringent cap-and-trade schemes and rapid advancements in CCS transit practices, particularly with the use of advanced CCS technology, deviate from the net-zero target. A critical policy implication is the necessity for the precise calibration of cap-and-trade schemes and the pace of CCS transit adoption to ensure alignment with net-zero targets.

Addressing Health Equity in the Context of Carbon Capture, Utilization, and Sequestration Technologies

PURPOSE OF REVIEW

To describe the role of health equity in the context of carbon capture, utilization, and sequestration (CCUS) technologies.

RECENT FINDINGS

CCUS technologies have the potential to both improve and worsen health equity. They could help reduce greenhouse gas emissions, a major contributor to climate change, but they could also have negative health impacts like air and noise pollution. More research is needed to fully understand the health equity implications of CCUS technologies. CCUS technologies have both health equity risks and benefits. Implementing misguided CCUS projects in vulnerable communities could exacerbate environmental injustice and health disparities and have the potential to increase carbon emissions. However, well-conceived projects could benefit communities through economic development. Governments, industry, and society should prioritize and expedite the reduction of CO2 emissions before considering carbon reductions via CCUS. Furthermore, CCUS projects must be thoroughly evaluated and should only proceed if they have demonstrated a net reduction in CO2 emissions and provide more benefits than risks to local communities. This underscores the importance of prioritizing health equity in the planning of CCUS projects.

Bioaerosol emissions from wastewater treatment process at urban environment and potential health impacts

The inlet of wastewater treatment plants (WWTPs) contains pathogenic microorganisms which during aeration and by mechanical mixing through wind typically aerosolized microbes into ambient air. Bioaerosol emission and its characterization (bacterial and fungal) was investigated considering low-flow and high-flow inlet of wastewater treatment plant. Generation of bioaerosols was found influenced by prevailing seasons while both during summer and winter, fungal concentration (winter: 1406 ± 517; summer: 1743 ± 271 CFU/m3) was higher compared to bacterial concentration (winter: 1077 ± 460; summer: 1415 ± 588 CFU/m3). Bioaerosols produced from WWTPs were predominately in the size range of 2.1-4.7 μm while fraction of fungal bioaerosols were also in ultra-fine range (0.65 μm). Bioaerosols reaching to the air from WWTPs varied seasonally and was calculated by aerosolization ratio. During summer, aerosolization of the bioaerosols was nearly 6 times higher than winter. To constitute potential health effects from the exposure to these bioaerosols, biological characterization, antibiotics resistance and the health survey of the nearby area were also performed. The biological characterization of the bioaerosols samples were done through metagenomic approach using 16s and ITS metagenomic sequencing. Presence of 167 genus of bacteria and 41 genus of fungi has been found. Out of this, bacillus (73%), curtobacterium (21%), pseudomonas, Exiguo bacterium, Acinetobacter bacillaceae, Enterobacteriaceae and Prevotella were the dominant genus (top 10) of bacteria. In case of fungi, xylariales (49%), Hypocreales (19%), Coperinopsis (9%), Alternaria (8%), Fusarium (6%), Biopolaris, Epicoccum, Pleosporaceae, Cladosporium and Nectriaceae were dominant. Antibiotics like, Azithromycin and cefixime were tested on the most dominant bacillus showed resistance on higher concentration of cefixime and lower concentration of azithromycin. Population-based health survey in WWTP nearby areas (50-150 m periphery) found several types of diseases/symptoms including respiratory problem, skin rash/irritation, change in smell and taste, eye irritation within the resident population and workers.