Light spectrum regulation is an effective way to promote carbon fixation of haematococcus pluvialis. The carbon fixation capacity of haematococcus pluvialis was compared under different light conditions, and the effects of the mixed red and blue light with different spectral ratios on the carbon fixation performance of haematococcus pluvialis were studied. Gene expressions at different vegetative stages were compared to figure out the dynamic changes of haematococcus pluvialis metabolism on the time scale. The results show that, the carbon fixation rate in red light was 40% higher than that in blue light. By comparing the whole-genome transcriptome of the haematococcus pluvialis, the metabolic responses of the haematococcus pluvialis to different light qualities, including biomass accumulation, energy transfer, photosynthesis, stress and transcription, were analyzed at the molecular level. The metabolism and energy transfer of the haematococcus pluvialis were more active in red light than that in blue light. At the early growth stage, cells under the red light dominant condition tended to accumulate regulatory substances rather than energy storage substances, and genes involved in glycolysis/ gluconeogenesis pathway, tricarboxylic acid cycle (TCA) and AMP-activated protein kinase (AMPK) pathway were up-regulated. Cells under the blue light dominant condition performed better in stress response.

Due to the low-carbon transformation requirement of domestic coal power units in the “carbon peak and carbon neutrality” situation, exploring a new industrialization way in solid adsorption CO₂ capture technology on CCUS, and developing a new solid chemical sorbent to capture CO₂ from coal-fired flue gas, are important for realizing large-scale application of such technology. Current researches on solid adsorption CO₂ capture technology in China mainly focus on the theory level. This study systematically reviews and analyzes the research progress on solid sorbent materials at low, medium and high temperatures, points out the directions for further research, and identifies the research content needed for scaled application. A typical high-temperature calcium-based sorbent is used as an example to analyze the industrial applications of the entire process, including the sorbent preparation, sorbent scaling up, sorbent granulation and molding, reactor design, and CO₂ capture system verification for calcium looping. This study can provide references for aspects including further key technology research and breakthroughs, the construction of a full process for solid adsorption CO₂ capture with high activity and low energy requirement, and the realization of the large-scale application of solid adsorption CO₂ capture technology.

In post-combustion CO₂ capture, organic amine absorbents are prone to degradation, forming heat-stable salts (HSS) that impair absorption performance and accelerate equipment corrosion. Electrodialysis (ED), operating under ambient conditions with high HSS removal efficiency, has emerged as a promising technology for amine recovery. This review systematically summarizes recent advances in ED for amine solvent recovery, covering the configurations of different ED systems and the mechanisms by which key process parameters (voltage, current density, initial HSS concentration, CO₂ loading, etc.) affect removal efficiency, amine loss, and energy consumption. It highlights process optimization strategies such as multi-stage membrane stacks and ED coupling with resins or bipolar membranes, and compares industrial performance data across different applications. Finally, challenges related to membrane stability, energy consumption, and cost control are discussed, with perspectives on future development directions for ED-based amine recovery in carbon capture systems.

The TiO₂ surface is functionalized with different concentrations of K₂CO₃ and polyethyleneimine (PEI), and in-depth research on CO₂ adsorption performance and mechanism is conducted. CO₂ low-temperature adsorbent was successfully prepared by ultrasonic impregnation method using K₂CO₃ and PEI as functionalized materials and commercial selective catalytic reduction (SCR) catalyst white embryo (porous TiO₂) as carrier. The physicochemical properties of the modified adsorbents were characterized using X-ray diffraction (XRD), differential thermogravimetry (DTG), Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The results indicate that, K₂CO₃ and PEI activate the porous structure of TiO₂, enhancing the density of surface alkaline active sites. This enhancement facilitates the accommodation of PEI and K₂CO₃, exposes adsorption active sites, and promotes CO₂ diffusion and CO₂ adsorption. 50%PEI@TiO₂ introduces numerous active functional groups and alkaline amine sites, achieving a CO₂ adsorption capacity of 2.11 mmol/g. By measuring the CO₂ adsorption by 50%PEI@TiO₂ adsorbent and fitting to Langmuir and Freundlich adsorption isotherm models, it finds that CO₂ is mainly adsorbed physically, and van der Waals force plays a major role during adsorption. The optimal adsorption and desorption temperatures for CO₂ are 50 ℃ and 110 ℃, respectively. The cyclic experiment showed that, compared with PEI, K₂CO₃-loaded adsorbents exhibit greater stability, with a decrease in adsorption capacity of less than 10% after 30 cycles. These findings suggest that functionalized materials based on commercial SCR catalyst TiO₂ pellets hold promise for low-temperature CO₂ capture in industry flue gases.

As the global climate change intensifies, carbon capture, utilization and storage technology (CCUS) has become a crucial means to achieve the goal of carbon neutrality. Focusing on addressing the issues of poor operational stability and high regeneration energy consumption in conventional absorption agents, a new water-poor compound absorption agent was developed, which is mainly composed of tert-butyl aminoethanol (TBAE). The absorption agent was optimized by combining different ratios of amines and stabilizers and was mixed at a total amine mass fraction of 30%. The CO₂ absorption-desorption performance, corrosion situation, and small-scale upscaling experiment were tested and investigated using 30% (mass fraction) conventional absorption agent ethanolamine (MEA) as a reference standard. The aim is to enhance the CO₂ absorption capacity and desorption rate while reducing regeneration energy consumption and improving the stability of the solvent in the device. The experimental results indicate that, when the formula is 20% TBAE + 10% 3-methyl-1-propanol + 50% N-methylpyrrolidone, the saturated CO₂ absorption capacity is 3.10 mol/L, the cyclic absorption capacity is 2.97 mol/L, the corrosion rate is 0.016 2 mm/a, and the regeneration energy consumption is 4.00 GJ/t. Compared with the 30% MEA absorption agent, the saturated CO₂ absorption capacity increases by 12.3%, the cyclic capacity rises by 22.7%, the corrosion rate reduces by 60.3%, and the regeneration energy consumption decreases by 36%. The excellent basic performance of the new water-poor compound absorption agent and its long-term stable and low-energy operation in a 10 t/a carbon capture small-scale pilot plant have laid a solid foundation for its future industrial application.

Carbon capture, utilization and storage technology is an important way to realize the carbon peaking and carbon neutrality goals in China. Among them, the non-aqueous phase absorbents have great energy-saving potential, and it is suitable for the existing mixed amine reactor, which has a large development potential. However, there are still problems such as high viscosity of CO₂ saturated solution and low circulating load. In this regard, a non-aqueous absorption system with low viscosity and regeneration temperature was constructed using secondary amine MCA as the absorbing component and EG as the organic solvent. The absorption and regeneration performance of MCA/EG was investigated. The results showed that, the absorption load of 3 mol/L MCA/EG solvent was up to 2.14 mol/L, and the viscosity was only 44.19 mPa∙s. Under the condition of absorption at 40 ℃ for 30 min and regeneration at 80 ℃ for 25 min, the cyclic load was as high as 0.98 mol/L, which is 1.46 times of the cyclic load of 30% MEA/H₂O solution at 105.5 ℃. The reaction heat of the absorbent was measured to be -82.85 kJ/mol by C80 microcalorimeter, which was lower than that of the MEA/H₂O solution. The reaction mechanism of CO₂ capture by MCA/EG was explored by ¹³C NMR and quantum chemical calculations. It was found that the stability of the reaction products was reduced for the steric hindrance effect of MCA. The carbamates transform into alkyl carbonate by reacting with EG to realize the regeneration at low temperatures. MCA/EG can realize the stable operation of non-aqueous phase absorbent and expand the scope of waste heat utilization in absorbent regeneration, which has a great advantage of energy reduction.

By taking a 150 000 tons/year carbon dioxide capture system in a power plant as the research object, a comprehensive analysis was conducted for its water usage, water consumption and water balance. Moreover, the water balance of the carbon capture system was experimentally studied and compared under different loads. The experimental results show that, the main problem in the current capture system’s water balance is that the outlet temperature at the top of the absorption tower is higher than the inlet flue gas temperature. Under high-load conditions, the reaction heat inside the absorption tower is relatively large, resulting in an excessively high exhaust steam temperature and a significant increase in system water consumption. After the outlet temperature of the absorption tower was reduced from 54 ℃ to 43 ℃, the system water consumption reduced by approximately 86.7%, demonstrating remarkable energy-saving effects. In light of this, combined with the actual operation situation, suggestions are put forward to further improve the temperature field of the absorption tower and reduce the outlet temperature of the absorption tower by adjusting the circulating water volume and enhancing the heat transfer efficiency of the lean solution cooler and the tail gas scrubber. The experimental results can provide guidance for efficient and economical operation of carbon capture systems.

To investigate the dominant role and mechanism of solid particles in enhancing mass and heat transfer and catalytic effects during CO₂ desorption from rich liquids, nano-titanium dioxide (TiO₂) and zeolite (HZSM-5) are selected as representative particles to represent the enhancement of heat and mass transfer and chemical catalytic effects, respectively. A continuous stirring reactor was set up, and the ratio of CO₂ desorption rate from rich liquids with and without particle addition was defined as the desorption enhancement factor. The effects of varying particle mass fraction, particle size, stirring speed, CO₂ loading of the rich liquid, and absorbent type on the CO₂ desorption enhancement were systematically investigated. The results show that, the HZSM-5 particles achieve a higher desorption enhancement factor compared with the TiO₂ particles, this is primarily due to the higher micropore surface area and Brønsted acid site coupling parameters of HZSM-5 particles. Additionally, the desorption enhancement factor for TiO₂ is less affected by operational conditions, fluctuating between 1.00 and 1.20. In contrast, increasing the particle mass fraction and CO₂ loading in the rich liquid significantly enhances the desorption effect of HZSM-5, with the desorption enhancement factor reaching up to 2.25. A linear relationship was observed between the HCO₃^– concentration in the rich liquid and the desorption enhancement factor for HZSM-5, indicating that HZSM-5 particles promote the CO₂ desorption process by enhancing the reaction pathway related to HCO₃^–. This finding provides a theoretical basis for further optimizing the design of solid particles and improving CO₂ desorption efficiency from rich liquids.

Post-combustion capture is a bottom-up technology for achieving carbon neutrality, but the high costs associated with carbon capture are detrimental to the application of this technology. In order to investigate the sensitivities to changes in the cost of carbon capture, compression and liquefaction, the costs incurred by different process parameters and absorbent types were modelled. The results show that, increasing the number of plates in the absorption tower promotes the efficiency of CO₂ capture by absorbent, with a corresponding rise in investment costs. The increase of absorber temperature at the inlet of the absorber tower does not show a significant decrease in capture rate, but the reduction of coolant and water usage reduces the operating cost to a certain extent. In addition, the reboiling ratio has the greatest influence on the CO₂ capture rate and cost, which may be the key factor for cost reduction. At the same time, the energy consumption of the system with different liquefaction pressures and different numbers of compression stages was compared, and it is found that the lower the liquefaction pressure and the higher the number of compression stages, the higher the total cost, and the equipment investment cost and operation and maintenance cost changes more obviously, while the utility costs are less affected.

Taking CO₂ absorption by amine solutions in industrial-scale spray towers as the research object, a computational fluid dynamics (CFD) model is established to describe the gas-liquid two-phase flow, interphase heat and mass transfer, and chemical reaction process in industrial-scale spray scrubber, based on the Euler-Lagrange method. The reliability of the CFD model is validated by experimental data of CO₂ absorption by monoethanolamine (MEA) solution. On this basis, the fundamental laws of heat and mass transfer and chemical reactions accompanying the CO₂ absorption process, as well as the effects of the absorbents’ chemical composition, gas-liquid phase flow characteristics, and operating pressure on the efficiency of CO₂ removal in a spray tower were investigated. The numerical results indicate that, the volume fraction of CO₂ in flue gas decreases with the increase of scrubber height, while both the gas temperature and water vapor pressure firstly increase and then decrease with the increase of elevation. With the increase of CO₂ load in lean solution from 0.1 to 0.4, the highest gas temperature in the scrubber declines from 70 ℃ to 54 ℃. The overall decarbonization efficiency for the spray scrubber significantly decreases when the load of lean solution is greater than 0.25. When the superficial gas velocity is greater than 2.5 m/s, the enhancement of increased mass transfer specific interface area on CO₂ absorption is restricted ascribed to the declines of gas residence time and mass transfer coefficient. For the decrease of operating pressure in spray scrubber from 101 kPa to 70 kPa, the CO₂ removal efficiency decreases by about 15.9 percentage points.