High-Temperature Pressure Swing Adsorption Process for CO₂ Separation

This paper presents a novel pressure swing adsorption process and the development of specifically designed sorbents for the process. It is operated at high temperature (650–800 °C) using the reversible reaction of calcium oxide with CO₂, i.e., CaO + CO₂ ⇄ CaCO₃. The new process directly stores the reaction heat released from the forward reaction in the sorbent and then releases it for sorbent regeneration under reduced CO₂ partial pressure, so that the need of pure oxygen for oxy-fuel combustion is avoided. Two potential problems of the new process, namely, loss in capacity and slow and unmatched reaction rates of chemical-controlled carbonation and calcination, were discussed in detail. Three specifically designed calcium-based sorbents showed stable performance during 92 isothermal carbonation–calcination cycles at either 680 or 750 °C. The calcination rate was significantly enhanced by increasing the reaction temperature and the introduction of steam to match the reaction rate of chemical-controlled carbonation. This pressure swing adsorption process could be used for low-cost CO₂ separation using specifically designed sorbents under carefully selected operating conditions

Fabrication of CaO-Based Sorbents for CO₂ Capture by a Mixing Method

Three types of sorbent were fabricated using various calcium and support precursors via a simple mixing method, in order to develop highly effective, durable, and cheap CaO-based sorbents suitable for CO₂ capture. The sorption performance and morphology of the sorbents were measured in a thermogravimetric analyzer and a scanning electron microscopy, respectively. The experimental results indicate that cement is a promising low-cost support precursor for contributing to the enhancement of cyclic CO₂ sorption capacity, especially when organometallic calcium precursors were used. A sorbent (with 75% CaO content) made from calcium l-lactate hydrate and cement showed the highest CO₂ sorption capacity of 0.36 g of CO₂/g of sorbent and its capacity decreased only slightly after 70 cycles of carbonation and calcination

Behavior of CaO/CuO Based Composite in a Combined Calcium and Copper Chemical Looping Process

Integration of chemical looping combustion into calcium looping is an attractive approach to solving the problem of energy requirement for the regeneration of CaO-based sorbent. In this work, the behavior of MgO supported CaO/CuO composite in the new combined process (CaCuCL) was investigated. The composite was prepared via a simple wet mixing method and measured via a thermogravimetric analyzer for its chemical performance. It appears that the component of Cu/CuO has a significant influence on the cyclic performance of CaO, which is probably caused by the “wrapping” of Cu/CuO outside, due to its low melting point. However, this negative effect can be greatly reduced by using appropriate operating conditions in the successive reactions. When tested for 68 cycles, all synthetic sorbents showed good reactivity and stability of the Cu/CuO component, although loss-in-capacity of CaO was stilled observed

Structurally Improved, Core-in-Shell, CaO-Based Sorbent Pellets for CO₂ Capture

The pelletization of CaO-based sorbents is necessary for its practical application in the calcium looping process. In this work, three groups of composite pellets with different structures (non-shell pellets, core-in-shell pellets with inert shells, and structurally improved core-in-shell pellets with semi-reactive shells) were prepared from limestone powder and calcium aluminate cement. For the core-in-shell pellets, 2 wt % rice husks were added to the shells to enable the formation of relatively porous and strong shells. Both the CO₂ uptake and mechanical strength of the cement-bound pellets were investigated to find the promising structure for the pelletization of the CaO-based sorbent. Moreover, wet curing was used for the first time, and prolonging the curing time could be effective to enhance the mechanical strength of the pellets. It was found that the core-in-shell pellets with semi-reactive shells via adding a moderate amount of limestone to the outer shell was able to largely improve the overall CO₂ uptake capacity and, meanwhile, maintain the relatively good mechanical property. Particularly, when the limestone content of the core was fixed at 80 wt %, the pellets containing 60 wt % limestone in the shell exhibited a high total CO₂ uptake capacity of 2.97 g/g during 17 cycles, a value more than twice that of the pellets that did not have limestone in the shells. As a result of limestone addition, the average crushing force of the cured pellets decreased by only 11.8%. Comprehensively, considering the CO₂ uptake and mechanical strength, the core-in-shell pellets consisting of highly reactive cores and semi-reactive shells were the most promising to be used in the calcium looping process

Table_2_A new perspective on semen quality of aged male: The characteristics of metabolomics and proteomics.xlsx

BackgroundSemen quality is negatively correlated with male age and is mainly quantified by a routine semen analysis, which is descriptive and inconclusive. Sperm proteins or semen metabolites are used as the intermediate or end-products, reflecting changes in semen quality, and hold much promise as a new biomarker to predict fertility in advanced-aged males.ObjectivesIn this study, we sought to assess whether the semen metabolome and proteome of aged males can affect semen quality and serve as biomarkers for predicting semen quality.Materials and methodsWe retrospectively analyzed 12825 males that underwent semen routine analysis to understand the age-dependent changes in sperm quality. To identify the difference between aged and young adults, metabolomics (n=60) analyses of semen and proteomics (n=12) analyses of sperm were conducted. Finally, integrated machine learning of metabolomics was conducted to screen biomarkers to identify aging semen.ResultsWe discovered that male age was positively correlated with sperm concentration as well as DNA fragmentation index(DFI), and negatively with progressive motile sperm count, total sperm count, sperm volume and progressive sperm motility. The differential metabolites were significantly enriched in various metabolic pathways, and four of these differential metabolites (Pipamperone, 2,2-Bis(hydroxymethyl)-2,2’,2’’-nitrilotriethanol, Arg-Pro and Triethyl phosphate) were utilized to establish a biomarker panel to identify aging semen. Proteomic analysis showed that differential proteins were significantly enriched in protein digestion and absorption and some energy-related pathways. An integrated analysis of the metabolome and proteome identified differential energy metabolism and oxidative stress-related proteins, which could explain the decreased motility and the increased DFI of aging spermDiscussion and conclusionWe provide compelling evidence that the changes in semen metabolome and sperm proteome are related to the decline of semen quality in aged males. Moreover, a biomarker panel based on four metabolites was established to identify aging semen.</p

Table_3_A new perspective on semen quality of aged male: The characteristics of metabolomics and proteomics.xlsx

BackgroundSemen quality is negatively correlated with male age and is mainly quantified by a routine semen analysis, which is descriptive and inconclusive. Sperm proteins or semen metabolites are used as the intermediate or end-products, reflecting changes in semen quality, and hold much promise as a new biomarker to predict fertility in advanced-aged males.ObjectivesIn this study, we sought to assess whether the semen metabolome and proteome of aged males can affect semen quality and serve as biomarkers for predicting semen quality.Materials and methodsWe retrospectively analyzed 12825 males that underwent semen routine analysis to understand the age-dependent changes in sperm quality. To identify the difference between aged and young adults, metabolomics (n=60) analyses of semen and proteomics (n=12) analyses of sperm were conducted. Finally, integrated machine learning of metabolomics was conducted to screen biomarkers to identify aging semen.ResultsWe discovered that male age was positively correlated with sperm concentration as well as DNA fragmentation index(DFI), and negatively with progressive motile sperm count, total sperm count, sperm volume and progressive sperm motility. The differential metabolites were significantly enriched in various metabolic pathways, and four of these differential metabolites (Pipamperone, 2,2-Bis(hydroxymethyl)-2,2’,2’’-nitrilotriethanol, Arg-Pro and Triethyl phosphate) were utilized to establish a biomarker panel to identify aging semen. Proteomic analysis showed that differential proteins were significantly enriched in protein digestion and absorption and some energy-related pathways. An integrated analysis of the metabolome and proteome identified differential energy metabolism and oxidative stress-related proteins, which could explain the decreased motility and the increased DFI of aging spermDiscussion and conclusionWe provide compelling evidence that the changes in semen metabolome and sperm proteome are related to the decline of semen quality in aged males. Moreover, a biomarker panel based on four metabolites was established to identify aging semen.</p

Image_1_A new perspective on semen quality of aged male: The characteristics of metabolomics and proteomics.jpg

BackgroundSemen quality is negatively correlated with male age and is mainly quantified by a routine semen analysis, which is descriptive and inconclusive. Sperm proteins or semen metabolites are used as the intermediate or end-products, reflecting changes in semen quality, and hold much promise as a new biomarker to predict fertility in advanced-aged males.ObjectivesIn this study, we sought to assess whether the semen metabolome and proteome of aged males can affect semen quality and serve as biomarkers for predicting semen quality.Materials and methodsWe retrospectively analyzed 12825 males that underwent semen routine analysis to understand the age-dependent changes in sperm quality. To identify the difference between aged and young adults, metabolomics (n=60) analyses of semen and proteomics (n=12) analyses of sperm were conducted. Finally, integrated machine learning of metabolomics was conducted to screen biomarkers to identify aging semen.ResultsWe discovered that male age was positively correlated with sperm concentration as well as DNA fragmentation index(DFI), and negatively with progressive motile sperm count, total sperm count, sperm volume and progressive sperm motility. The differential metabolites were significantly enriched in various metabolic pathways, and four of these differential metabolites (Pipamperone, 2,2-Bis(hydroxymethyl)-2,2’,2’’-nitrilotriethanol, Arg-Pro and Triethyl phosphate) were utilized to establish a biomarker panel to identify aging semen. Proteomic analysis showed that differential proteins were significantly enriched in protein digestion and absorption and some energy-related pathways. An integrated analysis of the metabolome and proteome identified differential energy metabolism and oxidative stress-related proteins, which could explain the decreased motility and the increased DFI of aging spermDiscussion and conclusionWe provide compelling evidence that the changes in semen metabolome and sperm proteome are related to the decline of semen quality in aged males. Moreover, a biomarker panel based on four metabolites was established to identify aging semen.</p

Table_1_A new perspective on semen quality of aged male: The characteristics of metabolomics and proteomics.docx

BackgroundSemen quality is negatively correlated with male age and is mainly quantified by a routine semen analysis, which is descriptive and inconclusive. Sperm proteins or semen metabolites are used as the intermediate or end-products, reflecting changes in semen quality, and hold much promise as a new biomarker to predict fertility in advanced-aged males.ObjectivesIn this study, we sought to assess whether the semen metabolome and proteome of aged males can affect semen quality and serve as biomarkers for predicting semen quality.Materials and methodsWe retrospectively analyzed 12825 males that underwent semen routine analysis to understand the age-dependent changes in sperm quality. To identify the difference between aged and young adults, metabolomics (n=60) analyses of semen and proteomics (n=12) analyses of sperm were conducted. Finally, integrated machine learning of metabolomics was conducted to screen biomarkers to identify aging semen.ResultsWe discovered that male age was positively correlated with sperm concentration as well as DNA fragmentation index(DFI), and negatively with progressive motile sperm count, total sperm count, sperm volume and progressive sperm motility. The differential metabolites were significantly enriched in various metabolic pathways, and four of these differential metabolites (Pipamperone, 2,2-Bis(hydroxymethyl)-2,2’,2’’-nitrilotriethanol, Arg-Pro and Triethyl phosphate) were utilized to establish a biomarker panel to identify aging semen. Proteomic analysis showed that differential proteins were significantly enriched in protein digestion and absorption and some energy-related pathways. An integrated analysis of the metabolome and proteome identified differential energy metabolism and oxidative stress-related proteins, which could explain the decreased motility and the increased DFI of aging spermDiscussion and conclusionWe provide compelling evidence that the changes in semen metabolome and sperm proteome are related to the decline of semen quality in aged males. Moreover, a biomarker panel based on four metabolites was established to identify aging semen.</p

Mechanical Modification of Naturally Occurring Limestone for High-Temperature CO₂ Capture

The rapid decrease of CO₂ capture capacity is one of the most challenging problems hindering the use of naturally occurring limestone in the calcium looping process. In this work, the mechanical modification method (dry planetary ball milling) was used to improve the cyclic CO₂ capture performance of naturally occurring limestone. Low-cost Bayer aluminum hydroxide sourced from the industrial-scale production of alumina from bauxite ore was used as the precursor of the inert support to enhance the CO₂ sorption stability of the ball-milled sorbents. It was found that the CO₂ uptake of the milled sorbents could be further improved by increasing the ball-milling time because this generated more amounts of fine particles. Moreover, the pellets produced from ball-milled limestone powder possessed a relatively high CO₂ capture capacity of 0.252 g/g in the 25th cycle, which is nearly 1.3 times the capture capacity of naturally occurring limestone powder. This indicates that the combination of mechanical modification and pelletization is an effective approach to produce highly efficient CO₂ capture pellets from naturally occurring limestone

Enhancing Protein Solubility via Glycosylation: From Chemical Synthesis to Machine Learning Predictions

Glycosylation is a valuable tool for modulating protein solubility; however, the lack of reliable research strategies has impeded efficient progress in understanding and applying this modification. This study aimed to bridge this gap by investigating the solubility of a model glycoprotein molecule, the carbohydrate-binding module (CBM), through a two-stage process. In the first stage, an approach involving chemical synthesis, comparative analysis, and molecular dynamics simulations of a library of glycoforms was employed to elucidate the effect of different glycosylation patterns on solubility and the key factors responsible for the effect. In the second stage, a predictive mathematical formula, innovatively harnessing machine learning algorithms, was derived to relate solubility to the identified key factors and accurately predict the solubility of the newly designed glycoforms. Demonstrating feasibility and effectiveness, this two-stage approach offers a valuable strategy for advancing glycosylation research, especially for the discovery of glycoforms with increased solubility