Life cycle assessment of post-combustion carbon capture and storage for the ultra-supercritical pulverized coal power plant

In this paper, different emerging post-combustion technologies, i.e., monoethanolamine (MEA), aqueous ammonia, pressure swing adsorption (PSA), temperature swing adsorption (TSA), membrane and calcium looping, were applied to an ultra-supercritical coal-fired power plant for carbon capture. A 'cradle-to-grave' life cycle assessment (LCA) was conducted to evaluate the technical performance and environmental impacts of the power plant with six emerging carbon capture technologies. Carbon capture significantly influences the impact categories directly associated with flue gas emission. The application of carbon capture reduced the GWP in the range of 49-75 %. TAP also reduced in the range of 18-51 %. However, the human toxicity potential, eutrophication potential, ecotoxicity potential and particulate matter formation potential increased due to energy and resource consumption in the upstream and downstream processes. For the life cycle water consumption potential, it decreased by 8 % with calcium looping, whereas it increased in the range of 36-75 % with other post-combustion technologies. The highest reduction in GWP and the least reduction in power efficiency was observed in calcium looping because of the high-temperature heat recovery from flue gas and elimination of complex solvent manufacturing. The plant with aqueous ammonia and membrane separation had the second and third highest reductions in GWP. In addition, the lowest values for TAP, FEP, and MEP were obtained in the membrane system. With MEA for CO2 capture, the total GWP value of the plant is slightly higher than these three technologies mentioned above, and the highest HTPc, FETP, and METP can be observed in this case. TSA and PSA have the most significant environmental impacts in most categories due to higher energy requirements.

Comprehensive review and assessment of carbon capturing methods and technologies: An environmental research

A majority of the primary contributors of carbon dioxide (CO2) emissions into the environment have really been out of human-made activities. The levels of CO2 in the atmosphere have increased substantially since the time of the industrial revolution. This has been linked to the use of fossil fuels for energy production, as well as the widespread production of some industrial components like cement and the encroaching destruction of forests. An extreme approach is now necessary to develop the right policies and address the local and global environmental issues in the right way. In this regard, CO2 capturing, utilization, and storage are reliable options that industrial facilities can initiate to overcome this problem. Therefore, we have evaluated the two leading technologies that are used for carbon capture: direct (pre-combustion, post-combustion, and oxy-combustion) and indirect carbon (reforestation, enhanced weathering, bioenergy with carbon capture, and agricultural practices) capturing to provide their current status and progresses. Among the considered processes, the post-combustion techniques are widely utilized on a commercial scale, especially in industrial applications. Technology readiness level (TRL) results have showed that amine solvents, pressure-vacuum swing adsorption, and gas separation membranes have the highest TRL value of 9. In addition, the environmental impact assessment methods have been ranked to evaluate their sustainability levels. The highest global warming potential of 219.53 kgCO2 eq./MWh has been obtained for the post-combustion process. Overall, through this comprehensive review, we have identified some critical research gaps in the open literature in the field of CO2-capturing methods where there are strong needs for future research and technology development studies, for instance, developing stable and cost-effective liquid solvents and improving the adsorption capacity of commercialized sorbents. Furthermore, some research areas, like novel process design, environmental and economic impact assessment of capturing methods with different chemicals and modeling and simulation studies, will require further effort to demonstrate the developed technologies for pilot and commercial-scale applications.

Technological advancements in the use of ionic liquid- membrane systems for CO2 capture from biogas/flue gas - A review

Carbon capture has become a very important method for curbing the problems associated with the release of carbon dioxide into the atmosphere, which in turn has detrimental effects on the planet and its inhabitants. Ionic liquids and membrane separation have been explored in this review paper as effective means of capturing carbon dioxide. An innovative approach to CO₂ capture is the use of Ionic liquids (ILs) since they exhibit certain significant traits such as good stability (thermal, mechanical and chemical), inflammability and high absorptive capacities. Ionic liquids (ILs) are widely regarded as nontoxic substances. Viscosity and thermal degradation of ILs at temperatures slightly above 100 °C are the major disadvantages of ILs. Membrane separation is a technique used for the effective separation of substances by materials bearing holes in a continuous structure. Membrane technology has gained significant improvements, over the years. Several ILs and membrane systems were considered in this work. Their weaknesses, strengths, permeability, selectivity, operating conditions and carbon capture efficiencies, were all highlighted in order to gain a good perspective on ways by which the individual systems can be improved upon. The study considered several polymer-Ionic liquid hybrid materials as viable options for CO₂ capture from a post-combustion process. Different ILs were scrutinized for possible integration in membranes by taking full advantage of their individual properties and harnessing their tune-able characteristics in order to improve the overall carbon capture performance of the system. Several options for improving the mechanical, chemical, and thermal stabilities of the hybrid systems were considered including the use of cellulose acetate membrane, nanoparticles (graphene oxide powder) alongside potential ionic liquids. Doping membranes with ILs and nanoparticulates such as graphene oxide serves as a potential method for enhancing the CO₂ capture of membranes and this review provides several evidences that serve as proofs for this concept.

Potential matching of carbon capture storage and utilization (CCSU) as enhanced oil recovery in perspective to Indian oil refineries

Carbon capture storage and utilization is not a new technology, but its application to reduce CO2 emissions from the refinery sector is just now emerging as promising mitigation. This study will look closely at opportunities to match CO2 sources with potential sinks by matching carbon-capturing projects at Indian oil refineries with Enhanced Oil Recovery (EOR) operations at nearby oil fields in India. This study has identified four such pairings of source-sink matching along with the challenges the first of the kind implementation of CCSU technology in specific projects. The study concludes with a discussion on the way forward and policy implications for the commercial use of the CCSU in India.

GRAPHICAL ABSTRACT

CCS Carbon Capture Storage; CCU Carbon Capture Utilization, EOR . Source: Authors' design.

Post-combustion CO2 capture via a variety of temperature ranges and material adsorption process: A review

Carbon dioxide (CO₂) emissions from fossil fuel combustion have been linked to increased average global temperatures, a global challenge for many decades. Mitigating CO₂ concentration in the atmosphere is a priority for the protection of the environment. This is a comparison of the three main technological categories available for CO₂ capture and storage. They include: oxy-fuel combustion, pre-combustion, and post-combustion. Each capture technology has inherent benefits and disadvantages in cost, implementation, and flexibility, but post-combustion CO₂ capture has demonstrated the most promising results in typical power plant configurations. This paper presents a review of different post-combustion CO₂ capture materials; solvents, membranes, and adsorbents, focusing on economical and environmentally safe low to high temperature solid adsorbents. Furthermore, the authors summarize the advantages and limitations of the materials investigated to provide insight into the challenges and opportunities currently facing the development of post-combustion CO₂ capture technologies. The solid sorbents currently available for CO₂ capture are also reviewed in detail, including physical and chemical properties, reactions, and current research efforts on improvement.

Application of post-combustion ultra-low NOx emissions technology on coal slime solid waste circulating fluidized bed boilers

In order to achieve thermal treatment of coal slime and depth control of NO_x, a 75 t/h circulating fluidized bed (CFB) boiler arranging post-combustion air is constructed. In the experiment, the combustion atmosphere and the ratio of primary air and secondary air are adjusted to decrease the NO_x emissions below 50 mg/m³ (dry basis at 6% O₂). Compared with conventional CFB combustion, the post-combustion technology decreases the NO_x emissions from 92.9 to 65.4 mg/m³ by adjusting the combustion atmosphere. Then, the primary air volume is adjusted to decrease the NO_x emissions further. On the one hand, decreasing primary air volume contributes to inhibiting the NO_x generation in the dense phase. On the other hand, it is proved that the combination of the cyclone and a post-combustion chamber plays a crucial role in the de-NO_x process of post-combustion technology. More char particles are brought to the cyclone as the primary air volume decreases. The NO_x reduction in the cyclone and the post-combustion chamber is promoted. Finally, the NO_x emissions are decreased to 42.6 mg/m³ when the ratio of primary air and secondary air is 50.0%. In addition, the SO₂ emissions and the combustion efficiency during the ultra-low NO_x condition are 23.2 mg/m³ and 98.3%, respectively.

Technologies for the nitrogen oxides reduction from flue gas: A review

The required energy of the global industry is mostly generated from fossil fuel sources, such as natural gas, gasoline, diesel, oil, and coal. Nitrogen oxides are one of the main air pollutants that are produced from the combustion of fossil fuels in stationary and mobile sources. Development of new technologies to decrease the NO_x emission from exhaust gases is essential due to the harmful effect of NO_x on the environment and human health. Compared with pre-combustion and combustion methods (with <50% NO_x removal efficiency), the post-combustion methods with higher efficiency (above 80%) have attracted more attention in NO_x elimination. This review describes the currently used technologies of NO_x abatement. Different available post-combustion methods of NO_x removal, including selective catalytic reduction (using different types of reducing reagents, including ammonia, hydrogen, hydrocarbons, and carbon monoxide), selective noncatalytic reduction, wet scrubbing, adsorption, electron beam, nonthermal plasma, and electrochemical reduction of NO_x, are discussed.

Review of post-combustion carbon dioxide capture technologies using activated carbon

Carbon dioxide (CO₂) is the largest anthropogenic greenhouse gas (GHG) on the planet contributing to the global warming. Currently, there are three capture technologies of trapping CO₂ from the flue gas and they are pre-combustion, post-combustion and oxy-fuel combustion. Among these, the post-combustion is widely popular as it can be retrofitted for a short to medium term without encountering any significant technology risks or changes. Activated carbon is widely used as a universal separation medium with series of advantages compared to the first generation capture processes based on amine-based scrubbing which are inherently energy intensive. The goal of this review is to elucidate the three CO₂ capture technologies with a focus on the use of activated carbon (AC) as an adsorbent for post-combustion anthropogenic CO₂ flue gas capture prior to emission to atmosphere. Furthermore, this coherent review summarizes the recent ongoing research on the preparation of activated carbon from various sources to provide a profound understanding on the current progress to highlight the challenges of the CO₂ mitigation efforts along with the mathematical modeling of CO₂ capture. AC is widely seen as a universal adsorbent due to its unique properties such as high surface area and porous texture. Other applications of AC in the removal of contaminants from flue gas, heavy metal and organic compounds, as a catalyst and catalyst support and in the electronics and electroplating industry are also discussed in this study.

Suppression of dioxins after the post-combustion zone of MSWIs

Thiourea was selected as representative of combined S- and N-inhibitors and injected after the post-combustion zone of two full-scale municipal solid waste incinerators (MSWIs) using a dedicated feeder. Firstly, the operating conditions were scrutinised by monitoring the concentrations of SO2, NH3 and HCl in the clean flue gas. The suppression experiment showed that in MSWI A thiourea could reduce the total I-TEQ value in flue gas by 73.4% from 1.41ng I-TEQ/Nm(3) to 0.37I-TEQ/Nm(3), those in fly ash by 87.1% from 14.3ng I-TEQ/g to 1.84I-TEQ/g and the total dioxins emission factor by 87.0wt.%, with a (S+N)/Cl molar ratio of 9.4. The suppression efficiencies of PCDD/Fs in flue gas and fly ash in MSWI B could be up to 69.2% and 83.0% when the (S+N)/Cl molar ratio attained 7.51. Furthermore, the congener distributions of dioxins were also analysed in the flue gas and fly ash, before and after addition of thiourea, to find cues to some suppression mechanism. In addition, the filtered fly ash was explored by the Scanning Electron Microscope (SEM) and Energy Dispersive Spectrometer (EDS) analysis of fly ash. These results suggest that poisoning the metal catalyst and blocking the chlorination are most probably responsible for suppression.