Kinetic enhancement of adsorbent for CO2 capture from atmosphere by porous material

Strategies for stabilizing atmospheric greenhouse gas concentrations will need to consider future CO2 emissions from an enormous resource of worldwide fossil fuel supplies and a diverse range of mitigation technologies. In 2013, global CO2 emissions due to fossil fuel use (and cement production) were 36 gigatonnes (Gt CO2), and are projected to increase by an additional 2.5% in 2014. Even if all emissions from large fixed sources could be captured, the roughly 30-50% of global emissions due to transportation and mobile sources would still be released into the atmosphere. To ensure the concentration of atmospheric CO2 in the scope of security, CO2 air capture, which offers the potential to be a truly carbon negative technology, is urgent. The design and preparation of porous materials with controlled structures and functionalities is crucial to low concentration CO2 capture. In this work, two preparation approaches of CO2 adsorbents are explored. One is heterogeneous membrane preparation using porous supporting materials through phase inversion method, which is relatively simple, rapid, and inexpensive, and the other is to directly prepare the porous adsorbents through grafting method using a novel material—cellulose. For phase inversion method, anion exchange resin, which can absorb low concentration CO2 after ion exchange treatment, is mixed with Polyethersulfone (PES), N-Methyl pyrrolidone (NMP) and Macrogol 400(PEG-400) to form casting solution, and finally, the heterogeneous membrane is prepared for CO2 adsorption. For grafting method, the cellulos anion exchange fiber used for CO2 adsorption, is prepared by alkali pretreatment of sodium hydroxide and the grafting of epichlorohydrin and ethylenediamine onto fiber, and finally ion exchange treatment is made to introduce basic groups, such as carbonate ions and hydroxide ion. The surface properties of the prepared adsorption materials are characterized by SEM and BET, as can be seen in Figure 1, and the results reveal that the materials are porous and have large specific surface area, which is beneficial to the kinetics of CO2 adsorption. The absorption performances of the two kinds of adsorbents are tested on a self-made rotating bed reactor, and the absorption capacity and kinetics are compared. To optimize the kinetics performance of CO2 adsorption, the modified shrinking core model (SCM) is used to analyze the resistance during the reaction process according to the test results. The resistance during the mass transfer process includes physical diffusion resistance and chemical reaction resistance. For the heterogeneous membrane, the results reveal that the resistance of physical diffusion and chemical reaction is comparable when the saturation of CO2 adsorption is low (less than 0.3), and the physical diffusion resistance increases greatly and controls the kinetics performance when the saturation of CO2 is high, as can be seen in Figure 2. The influence of temperature and humidity on CO2 adsorption kinetics is also studied and the diffusion coefficient and reaction rate constant are obtained, and the activation energy of reaction can be determined

Editorial: Immunological imbalance: What is its role in intervertebral disc degeneration?

Low back pain (LBP) is a major cause of disability worldwide (GBD, 2017 Disease and Injury Incidence and Prevalence Collaborators, 2018) and belongs to the most urgent priorities to identify novel therapies, especially for the elderly (Teichtahl et al., 2015; Chen et al., 2020; Lee et al., 2021). Global health costs are generally rising but in the field of orthopedics and mostly for spine, the costs are exploding in recent years compared to other diseases (Wieser et al., 2011; Martin et al., 2019). Surgical options to treat LBP efficiently are very limited; clinical outcome is often non-satisfactory for the patients with very high re-operation rates (Nachemson et al., 1996; Knezevic et al., 2021).

Sustainable Food and Fuel on Yongxing Island by Conversing the Carbon Captured from Ambient Air

AbstractSynthetic hydrocarbon fuel, derived from renewable energy and captured carbon dioxide from ambient air, can thoroughly close its carbon cycle and is a promising option for CCU and an important approach to sustainable energy. We investigate the Yongxing island in south China sea, which offers steady wind resources to provide continuous energy supply for plant factory and fuel synthesis. The energy consumption of MSAC and TSAC is compared and conversion of the captured CO2 to food and fuel are calculated. Powered by wind energy, 200 ton vegetables and 5.2*103 ton diesel will be produced per year, so self-sufficiency of vegetable and fuel demand can be achieved on Yongxing island. Our methodology could provide a new utilization mode for islands like Yongxing island

Electrochemical properties of roots determine antibiotic adsorption on roots

The adsorption behaviors and transfer pathways of antibiotics in plant–soil system are greatly influenced by the electrochemical properties of both soil particles and plant roots. However, the effects of roots electrochemical properties on antibiotic adsorption are largely unknown. Here, the fresh soybean, maize, and wheat roots with different electrochemical properties were obtained from hydroponic cultivation, and the adsorption processes and mechanisms of doxycycline, tetracycline, sulfadiazine, and norfloxacin on roots under various environmental conditions were investigated. Results showed that the adsorption amount of antibiotics on roots increased with the initial concentration of antibiotics. The coexisting low–molecular weight organic acids and anions inhibited the antibiotic adsorption on roots. The soybean roots performed strong adsorption ability compared with the maize and wheat roots driven by the variations in root electrochemical properties. This study demonstrates the significance of electrochemical interactions between antibiotics and roots in plant–soil system and can contribute to the more accurate risk assessment and effective pollution control of antibiotics

Mesenchymal Stem Cell in the Intervertebral Disc

Degeneration of the intervertebral disc (IVD) is a major spinal disorder that causes back pain. Nucleus pulposus (NP) in the central of IVD dehydrates and become more fibrous in the IVD degeneration. NP cells undergo apoptosis with the degeneration of extracellular matrix (ECM) components. To replenish the NP cells and core ECM, bone marrow mesenchymal stromal cells (BMSCs) have been highlighted in the regeneration of IVD degeneration. BMSCs differentiate into NP-like cells with the secretion of ECM components, which may not only replenish the number of NP cells but also stimulate NP reconstruction. This further maintains tissue homeostasis. Up to date, the disc progenitor cells (DPCs) have been identified with the characteristics of multidifferentiation and stem cell phenotype. These cells are involved in the IVD diseases and show regenerative potentials. However, the differences between the BMSCs and DPCs remain elusive, in particular, the cellular connection in vivo. As such, this chapter will discuss the findings of the two cell types and propose a novel concept in the understanding of the biology of IVD