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Abstract: An industrial coal char from coal pyrolysis was used for simultaneous preparation of hydrogen-rich gas and porous carbon by catalytic steam gasification. The effects of K2CO3 as a catalyst under varying steam flow rates, reaction temperatures, mass ratios of CC:K2CO3 and reaction times were investigated on hydrogen output and textural properties of the produced porous carbons. The suitability of CaO and the packing pattern were also examined for CO2 capture, thereby promoting hydrogen content in the outlet gas. The results show that in a single operating system and process, stable and consistent hydrogen-rich gas and porous carbon can be simultaneously produced by partial or incomplete gasification. At the optimized gasification conditions, hydrogen output can be up to 3.2–3.5 mmol/(min•gCC). H2 and CO2 were the dominant species sharing around 65% and 30% of the produced gas (dry basis), respectively, while only small CO and CH4 fractions were observed. The surface area and total pore volume of the produced porous carbon can reach up to 812 m2/g and 0.473 cm3/g, respectively. The maximum hydrogen content of 95 vol.% (dry basis) can be achieved at the initial stage with some additional CaO by using either homogeneous or heterogeneous configuration.Graphical Abstract: [ABSTRACT FROM AUTHOR]

Chemical looping partial oxidation of methane using a sole CO2 oxidant (CL-POM-CO2) is an emerging technology for synthesis gas generation and CO2 utilization, which is highly dependent on an oxygen carrier (OC). In this work, Fe-substituted La-hexaaluminate as the OC was found to exhibit good reactivity and stability during 50 periodic CH4/CO2 redox cycles due to the formation of magnetoplumbite La-hexaaluminate structure with the introduction of La. Deeper reduction for synthesis gas generation did not destroy the La-hexaaluminate structure via a charge compensation mechanism, which increased CH4 reactivity and further improved CO2 utilization under subsequent re-oxidation. In the La-hexaaluminate structure, O6-Fe3+(Oh) was highly active for the total oxidation of methane, while O5-Fe3+(Tr) and O4-Fe3+(Th) selectively oxidized CH4 to synthesis gas. The sole CO2 oxidant only selectively recovered O5-Fe3+(Tr) and O4-Fe3+(Th), and thus is more favorable for improving synthesis gas selectivity than O2/air, which offers an attractive opportunity for CO2 utilization. © 2017 American Institute of Chemical Engineers AIChE J, 64: 550-563, 2018 [ABSTRACT FROM AUTHOR]

A >300°C distillation fraction (300F) from low-temperature coal tar was reacted with formaldehyde. Residual oil (RO) and residual solid (RS) were collected. RO was detected by gas chromatography-mass spectroscopy (GC-MS) and shows that it mainly contains alkanes and polycyclic aromatic hydrocarbons. The degradations under a nitrogen atmosphere of 300F and RO were investigated by Fourier transform infrared spectrometer. The result shows that 300F and RO consist of two degradation stages and five stages, respectively. CO has significant absorbency in the pyrolysis process of RO, not in 300DF. Modification of formaldehyde and compounds with carboxyl, short-chain fatty, and ester group in 300F generates polymers and fixes these compounds. [ABSTRACT FROM AUTHOR]

In this article, chlorosilane-modified ZSM-5 particles were incorporated into polydimethylsiloxane (PDMS) to form mixed matrix membranes (MMMs) for ethanol/water mixture separation via pervaporation (PV). The membranes were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and mechanical performance testing. The maximum loading and dispersion of ZSM-5 into PDMS were improved by chlorosilane modification. To evaluate the PV performance, the MMMs were used to separate an aqueous ethanol solution. The effect of zeolite loading and operational conditions on PV performance was investigated in detail. The separation factor of the composite membranes filled with modified ZSM-5 increased considerably versus unmodified membrane, while the total flux decreased to some degree. Of all the chlorosilane-modified membranes, dodecyltrichlorosilane modified ZSM-5 filled PDMS showed the best separation factor of 15.8 for ethanol. [ABSTRACT FROM AUTHOR]

The construction of three-dimensional hierarchical porous and hydrophobic-aerophilic interfaces facilitates mass transport and CO 2 enrichment by kinetically accelerating the CO 2 electrochemical reduction reaction (CO 2 RR). Inspired by the process of baking bread, in which pores that connect the interior of the bread to its exterior are created, we propose a template-free metal carbonate-porous metal oxide (MC-PMO) strategy to synthesize porous metal oxides with tunable pore size. Using this strategy, a series of porous metal oxides with different morphologies and different metals was successfully developed. Furthermore, the effect of catalyst mass transport on the CO 2 RR was explored. The porous catalysts with suitable pore size promoted mass transfer, which significantly enhanced the activation and transformation of CO 2. In addition, based on a hydrophobic group-modified metal oxide surface (HG-MO) strategy, a hydrophobic-aerophilic interface microenvironment was constructed to reduce the water dissociation activity and effectively inhibit the hydrogen evolution reaction (HER). HP-ZnO-500 @ 2-NTL was obtained by modifying hierarchical porous zinc oxide (HP-ZnO-500) with the hydrophobic 2-naphthalenethiol (2-NTL). The hydrophobic surface of HP-ZnO-500 @ 2-NTL was easily enriched with CO 2 gas under the influence of the "plastron effect", and the surface hydrophobic film stabilized the M–H bond. Thus, HER was suppressed. At − 1.0 V vs. RHE, HP-ZnO-500 @ 2-NTL achieved a faradaic efficiency of CO (FE CO) as high as 83.0%, and displayed high catalytic activity in a wide potential range. The "MC-PMO" strategy and "HG-MO" strategy reported herein are universal and are expected to guide the further preparation and modification of different metal-based porous metal oxides for sustainable CO 2 RR. [Display omitted] • Three-dimensional porous material synthesis strategy was developed. • Influence of mass transport capability of porous materials on CO 2 RR. • HER was inhibited in the hydrophobic-aerobic interface microenvironment. [ABSTRACT FROM AUTHOR]

Based on the three-link theory of the material balance, namely heat balance, momentum balance, and exergy balance, the reaction-regeneration system was calculated. Results showed that excessive fluidization air and burning dry gas would lead to high velocity, short residence time, low oxygen concentration and high partial pressure of steam in the coke-burning drum. Meanwhile, it would reduce catalyst activity, the burning heat and reutilization of exhaust-heat boiler, which caused the increasing of unit energy consumption. By decreasing the air flow, stopping burning the dry gas, reducing gasoline recycle ratio and increasing the ratio of catalyst to oil, the energy consumption can be reduced. The energy transforms efficiency was improved by reforming the waste heat boiler which could optimize the heat exchange, reduce the heat transfer exergy loss and so on. The energy-saving effect is obvious and the total energy consumption of devices reduced by about 31.04%. [ABSTRACT FROM AUTHOR]

Incorporation of Ni active species with mesoporous carbon and the resulting composite materials have received much attention due to their nature of flexibility derived from a confluence of metallic and carbonic properties and numerous textural advantages inherited from mesoporous carbon substrates, contributing to their versatility in energy transformation. However, the efficient integration of such composite materials with complementary advantages in properties is still highly desired. Herein, confined growth of Ni(OH) 2 nanosheets within three dimensionally ordered mesoporous carbon (3DOMC) by steam-assisted crystallization is propose in this paper. High-crystalline Ni(OH) 2 species are found in two forms of confined extra-small nanosheets within the mesopores of 3DOMC and staggered nanosheets over the particles of 3DOMC, which can be reduced to the highly segregative Ni nanoparticles by sufficient reduction. By using as a catalyst for methane decomposition to produce CO x -free hydrogen, Ni/3DOMC contributes a maximum CH 4 conversion of 66.5% and H 2 output rate of 7.4 mmol. g cat −1·min−1 at 850 °C, more superior to the conventional Ni-incorporated active carbon (Ni/AC) catalyst. Moreover, the Ni/3DOMC catalyst also exhibits not only a higher initial reaction rate but also an improved catalytic stability attributed to the abundant homodispersed Ni active species by the highly hybrid structure. It is expected that the flexible component, well-defined structure, and superior CMD performance could promote a great application potential of Ni/3DOMC nanocomposites in catalysis. [Display omitted] • Efficient loading of Ni(OH) 2 nanosheets by using 3DOM carbon as a confined space provider. • High-crystalline Ni(OH) 2 with dual forms of confined extra-small nanosheets and staggered overgrown nanosheets. • Shorter unactivated period but higher initial reaction rate attributed to rapid mass transfer and well-dispersed Ni species. • NNi/3DOMC contributes a maximum CH 4 conversion of 66.5 % and a maximum H 2 output rate of 7.4 mmol.gcat-1•min-1 at 850 °C. [ABSTRACT FROM AUTHOR]

Background: Excessive tachycardia is associated with impaired hemodynamics and worse outcome in critically ill patients. Previous studies suggested beneficial effect of β-blockers administration in ICU patients, including those with septic shock. However, comparisons in ICU settings are lacking. Our study aims to compare Landiolol and Esmolol regarding heart rate control and hemodynamic variables in general ICU patients. Methods: This retrospective, observational study was conducted in a 56-bed ICU at a university hospital. A propensity score matching (PSM) was employed to balance baseline differences. Generalized estimating equations (GEE) were used to compare heart rate between two drugs. The primary outcome was heart rate control, while secondary outcomes included hemodynamic response, hospital length of stay (HLOS) and ICU length of stay (ICULOS). Results: From June 2016 to December 2022, 438 patients were included after PSM, (292 in the Esmolol group and 146 the in Landiolol group). Baseline heart rate was similar between groups (Landiolol:120.0 [110.2, 131.0] bpm vs. Esmolol:120.0 [111.0, 129.0] bpm, p = 0.925). During 72 h. of β-blocker infusion, Landiolol reduced heart rate by 4.7 (1.3, 8.1) bpm, more than Esmolol (p = 0.007), while preserving a comparable proportion of patients able to stabilize vasopressor doses within the first 24 h. (82.9 vs. 80.8%, respectively, p = 0.596). Norepinephrine doses and lactate levels were similar between groups over 72 h., while the Landiolol group exhibited notably higher minimal ScvO2 levels (72% [63%, 78%] vs 68% [55%, 73%], respectively, p = 0.006) and a lower maximal PCO2 gap compared to the Esmolol group (7.0 [6.0, 9.0] vs. 8.0 [6.0, 10.0] mmHg, respectively, p = 0.040). Patients in the Landiolol group were observed to experience shorter HLOS than patients in the Esmolol group (26.5 [13.0, 42.0] vs 30.0 [17.0, 47.2] days, respectively, p = 0.044) and ICULOS (4.9 [2.8, 10.0] vs.6.7 [3.4, 13.1] days, respectively, p = 0.011). Conclusion: Landiolol provides superior heart rate control in critically ill patients with tachycardia compared to Esmolol, without increasing vasopressor requirements during the first 24 h. Findings from ScvO2 levels and PCO2 gap suggest that Landiolol may exert less impact on cardiac output than Esmolol. Further studies, incorporating comprehensive hemodynamic monitoring, are warranted to clarify the clinical implications of heart rate control with β-blockers in ICU patients with tachycardia. [ABSTRACT FROM AUTHOR]

• CO 2 was hydrogenated to lower olefins and gasoline using EDTA-2Na-modified catalysts. • EDTA-2Na contributed to enhance the sintering resistance of catalysts. • EDTA-2Na modification is favorable for catalyst reduction. • Chemical adsorption of CO 2 is enhanced using EDTA-2Na-modified catalysts. • The catalysts prepared by this strategy are suitable for a low H 2 /CO 2 ratio. Capturing and utilization of carbon dioxide (CO 2) not only leads to effective use of carbon resources, but also alleviates environmental pollution caused by increasing concentration of CO 2 , thus making it a hot research topic in recent years. In this study, a series of highly dispersed iron-cobalt (Fe-Co) catalysts was prepared by ethylenediaminetetraacetic acid disodium salt (EDTA-2Na) modification, which could efficiently convert CO 2 into high value-added chemicals (C 2 -C 4 = and C 5 -C 11). X-ray diffraction (XRD) analysis showed that the addition of a small amount of Co and EDTA-2Na contributed to enhance the sintering resistance of Fe species. During the calcination process, EDTA4− can be decomposed into small organic molecules with reducibility, thus promoting the reduction of iron species. The CO temperature-programmed desorption (CO-TPD) results showed that cobalt enhanced the adsorption and activation of intermediate CO on Na x Fe-Co catalyst, thereby promoting the catalytic conversion of CO 2. The complexation of EDTA promotes the synergistic effect of Fe-Co bimetals, enhances the chemical adsorption of CO 2. Sodium in EDTA-2Na promotes the surface basicity of the catalysts, which is favored for improving the product distribution of hydrocarbons. At lower H 2 /CO 2 (1/1) ratio, the EDTA-2Na modified Fe-Co/Al 2 O 3 catalyst exhibited high conversion of CO 2 (32.8 %) and excellent selectivity toward high value-added chemicals. The selectivity of by-product CO was only 8.1 %; and C 2 -C 4 = (32.5 %) and C 5 -C 11 (46.3 %) accounted for ∼79 % selectivity among the hydrocarbons generated. [ABSTRACT FROM AUTHOR]

To investigate the effect of coordination features of Co(II)-glycine complex on the performance of Co/SiO2 for Fischer–Tropsch (FT) synthesis, Co(II)-glycine complex precursors were prepared by the conventional method, i.e., simply adding glycine to the solution of Co nitrate and novel route, i.e., reaction of glycine with cobalt hydroxide. The SiO2-supported Co catalysts were prepared by using the different Co(II)-glycine complexes. It is found that glycine is an effective chelating agent for improving the dispersion of Co and the mass-specific activity in FT synthesis when the molar ratio of glycine/Co2+ = 3, which is independent to the preparation method in this study. Significantly, the surface Co properties were significantly influenced by the coordination features of the Co2+ and the molar ratio of glycine to Co2+ in the Co(II)-glycine complex. Specifically, the Co(3gly)/SiO2 catalyst prepared by the novel route exhibits smaller and homogenous Co nanoparticles, which result in improved stability compared to Co-3gly/SiO2 prepared by the conventional method. Thus, the newly developed method is more controllable and promising for the synthesis of Co-based catalysts for FT synthesis. [ABSTRACT FROM AUTHOR]