Engineering topics
Publications and source records attributed to Yu, Liang.
A novel 4,8-c scu -type aluminum-based metal–organic framework shows a robust structure, reversible SO 2 adsorption with high capacity, and high SO 2 /N 2 , SO 2 /CO 2 , and SO 2 /CH 4 selectivities.
Efficient separation of physicochemically similar alkanes is of vital importance. Adsorptive separation utilizing porous materials such as metal–organic frameworks with tunable pore structure and surface functionality represents an energy-efficient technology. In this study, we demonstrate successful separation of alkanes with varying degree of branching using a microporous nickel isonicotinate framework, Ni(4-PyC) 2 . Its 2-fold interpenetrated diamondoid structure with well-suited pore size enables selective adsorption of linear and monobranched hexane isomers, while excluding dibranched isomer. Breakthrough experiments validated its capability to completely discriminate all three hexane isomers. Ab initio calculations combined with in situ infrared spectroscopic analysis unveiled the nature of host–guest interactions and differences in the binding energies and diffusion barriers among the isomers. Furthermore, having well-balanced adsorption uptakes (146 and 79 mg g –1 of nHEX and 3MP), high nHEX/DMB uptake ratio (12.2) and fast kinetics, Ni(4-PyC) 2 stands out as a promising adsorbent for complete separation of hexane isomers under ambient conditions.
Recovering ammonia from anaerobic digestion (AD) effluent offers the opportunity to produce a renewablefertilizer and reduce environmental impact. A novel process developed for such an application was evaluatedduring this study. The feature of the process is integrating biogas stripping and gypsum (CaSO 4 •2H 2 O) absorption. The result revealed that the lower CO 2 content and the absorption temperature contributed the higherefficiency of ammonia recovery. The gypsum solution recovered around 95% of the stripped ammonia when thestripping gas contained 10% CO 2 and it rose to 100% when the gas contained more than 30% CO 2 . Furthermore,a statistical model and genetic algorithm were applied to estimate the total ammonia recovery and optimize theoperating parameters. The experimental and modeling results indicated that integrating biogas stripping withgypsum absorption can effectively harvest ammonia nitrogen and reduce CO 2 emissions while producing(NH 4 ) 2 SO 4 fertilizer from AD effluent.
Simultaneous removal of C 2 H 6 and C 2 H 2 from C 2 H 4 streams is of great importance in the petrochemical industry but remains a challenging task. To address this challenge, we have selected three isoreticular MOFs with high stability, low cost, and desirable scale-up ability, namely, MOF-303, MIL-160, and CAU-23 and assessed their potential in simultaneous removal of acetylene and ethane for ethylene purification. Each MOF exhibits desirable C 2 H 2 and C 2 H 6 uptake capacity (>5.5 mmol g –1 and >4 mmol g –1 , respectively), as well as good C 2 H 2 /C 2 H 4 selectivity (>2) and C 2 H 6 /C 2 H 4 selectivity (>1.5). Notably, MOF-303 takes up 4.96 mmol g –1 C 2 H 6 at 298 K and 1 bar, the highest value among the three MOFs, with C 2 H 6 /C 2 H 4 selectivity in the range of 1.55–2.47. MIL-160 possesses a very high C 2 H 2 uptake (9.1 mmol g –1 ) and C 2 H 2 /C 2 H 4 selectivity, 10.6 (1 : 1, v/v), at 298 K, much higher than those of all other MOFs tested to date for simultaneous removal of C 2 H 6 and C 2 H 2 from C 2 H 4 . The results from breakthrough experiments confirm that all three MOFs demonstrate excellent performance for C 2 H 4 purification in a ternary mixture of C 2 H 6 /C 2 H 4 /C 2 H 2 (1 : 1 : 1, v/v/v). Here, for MOF-303, MIL-160, and CAU-23, polymer-grade C 2 H 4 up to 0.164, 0.21, and 0.181 mmol g –1 can be obtained from the equimolar ternary mixture in a single separation step from the breakthrough experiment. Additionally, DFT calculations have been performed to further investigate the mechanism of adsorption/separation for C 2 H 6 , C 2 H 4 , and C 2 H 2 .
Abstract The purification of p‐xylene (pX) from its xylene isomers represents a challenging but important industrial process. Herein, we report the efficient separation of pX from its ortho‐ and meta‐ isomers by a microporous calcium‐based metal–organic framework material (HIAM‐203) with a flexible skeleton. At 30 °C, all three isomers are accommodated but the adsorption kinetics of o‐xylene (oX) and m‐xylene (mX) are substantially slower than that of pX, and at an elevated temperature of 120 °C, oX and mX are fully excluded while pX can be adsorbed. Multicomponent column breakthrough measurements and vapor‐phase/liquid‐phase adsorption experiments have demonstrated the capability of HIAM‐203 for efficient separation of xylene isomers. Ab initio calculations have provided useful information for understanding the adsorption mechanism.
Here, the purification of p-xylene (pX) from its xylene isomers represents a challenging but important industrial process. Herein, we report the efficient separation of pX from its ortho- and meta- isomers by a microporous calcium-based metal–organic framework material (HIAM-203) with a flexible skeleton. At 30 °C, all three isomers are accommodated but the adsorption kinetics of o-xylene (oX) and m-xylene (mX) are substantially slower than that of pX, and at an elevated temperature of 120 °C, oX and mX are fully excluded while pX can be adsorbed. Multicomponent column breakthrough measurements and vapor-phase/liquid-phase adsorption experiments have demonstrated the capability of HIAM-203 for efficient separation of xylene isomers. Ab initio calculations have provided useful information for understanding the adsorption mechanism.
Context Postherpetic neuralgia (PHN) is a refractory neuropathic pain condition in which new treatment options are being developed. Repetitive transcranial magnetic stimulation (rTMS) may have the potential to reduce pain sensations in patients with postherpetic neuralgia. Objectives This study investigated the efficacy on postherpetic neuralgia by stimulating two potential targets, the motor cortex (M1) and the dorsolateral prefrontal cortex (DLPFC). Methods This is a double-blind, randomised, sham-controlled study. Potential participants were recruited from Hangzhou First People’s Hospital. Patients were randomly assigned to either the M1, DLPFC or Sham group. Patients received ten daily sessions of 10-Hz rTMS in 2 consecutive weeks. The primary outcome measure was visual analogue scale (VAS) assessed at baseline, first week of treatment (week 1), post-treatment (week 2), 1-week (week 4), 1-month (week 6) and 3-month (week 14) follow-up. Results Of sixty patients enrolled, 51 received treatment and completed all outcome assessments. M1 stimulation resulted in a larger analgesia during and after treatment compared to the Sham (week 2 – week 14, p < 0.005), as well as to the DLPFC stimulation (week 1 – week 14, p < 0.05). In addition to pain, sleep disturbance was significantly improved and relieved by targeting either the M1 or the DLPFC (M1: week 4 – week 14, p < 0.01; DLPFC: week 4 – week 14, p < 0.01). Moreover, pain sensations following M1 stimulation uniquely predicted improvement in sleep quality. Conclusion M1 rTMS is superior to DLPFC stimulation in treating PHN with excellent pain response and long-term analgesia. Meanwhile, M1 and DLPFC stimulation were equally effective in improving sleep quality in PHN. Clinical trial registration https://www.chictr.org.cn/ , identifier ChiCTR2100051963.
High-efficiency separation of hexane isomers through selective molecular exclusion represents an important yet challenging task in the petrochemical industry. It has stringent requirements on the adsorbents' pore shape and dimensions. Here we report the complete exclusion of branched hexanes from their linear isomer by an aluminum metal-organic framework, CAU-21-ODB (ODB = 4,4'-oxydibenzoate) with high stability. The unique gourd-shaped channels with suitable pore aperture lead to substantial uptake of nHEX (141 mg/g at 30 °C) but negligible adsorption of its branched isomers under identical conditions. Furthermore, the capability of CAU-21-ODB for the separation of hexane isomers has been verified by multicomponent breakthrough experiments. DFT calculations further confirm the size-exclusion based separation mechanism.
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Abstract The separation of alkane isomers is an important yet challenging process in the petrochemical industry. Being a crucial step to produce premium gasoline components as well as optimum ethylene feed, the current industrial separation by distillation is extremely energy intensive. Adsorptive separation based on zeolite is limited by insufficient adsorption capacity. Metal‐organic frameworks (MOFs) hold enormous promise as alternative adsorbents due to their diverse structural tunability and exceptional porosity. Precise control of their pore geometry/dimensions has led to superior performance. In this minireview, we highlight the recent progresses in developing MOFs for the separation of C6 alkane isomers. Representative MOFs are reviewed based on their separation mechanisms. Emphasis is put on the material design rationale for achieving optimal separation capability. Finally, we briefly discuss the existing challenges, possible solutions, and future directions of this important field.
To overcome major limiting factors of microbial processes in anaerobic digestion (AD), metal and metal ions have been extensively studied. However, there is confusion about the effects of metals and metal ions on biomethane productivity in previous research. In this study, Zn and Zn 2+ were selected as representatives of metals and metal ions, respectively, to investigate the effects on biomethane productivity. After the metals and metal ions at different concentrations were added to the batch AD experiments under the same mesophilic conditions, a Zn dose of 1 g/L and a Zn 2+ dose of 4 mg/L were found to cause the highest biomethane production, respectively. The results indicate that metal (Zn) and metal ion (Zn 2+ ) have different mechanisms to improve AD performance. There may be two possible explanations. To act as conductive materials in interspecies electron transfer (IET), relatively high doses of metals (e.g., 1 g/L of Zn, 10 g/L of Fe) are needed to bridge the electron transfer from syntrophic bacteria to methanogenic archaea in the AD process. As essential mineral nutrients, the AD system requires relatively low doses of metal ions (e.g., 4 mg/L of Zn 2+ , 5 mg/L of Fe 2+ ) to supplement the component of various enzymes that catalyze anaerobic reactions and transformations. This research will provide clear insight for selecting appropriate amounts of metals or metal ions to enhance biomethane productivity for industrial AD processes.
The separation of alkane isomers is an important yet challenging process in the petrochemical industry. Being a crucial step to produce premium gasoline components as well as optimum ethylene feed, the current industrial separation by distillation is extremely energy intensive. Adsorptive separation based on zeolite is limited by insufficient adsorption capacity. Metal-organic frameworks (MOFs) hold enormous promise as alternative adsorbents due to their diverse structural tunability and exceptional porosity. Precise control of their pore geometry/dimensions has led to superior performance. In this minireview, we highlight the recent progresses in developing MOFs for the separation of C6 alkane isomers. Representative MOFs are reviewed based on their separation mechanisms. Emphasis is put on the material design rationale for achieving optimal separation capability. Lastly, we briefly discuss the existing challenges, possible solutions, and future directions of this important field.
Given that Campaign 16 of the K2 mission is one of just two K2 campaigns observed so far in "forward-facing" mode, which enables immediate follow-up observations from the ground, we present a catalog of interesting targets identified through photometry alone. Our catalog includes 30 high-quality planet candidates (showing no signs of being non-planetary in nature), 48 more ambiguous events that may be either planets or false positives, 164 eclipsing binaries, and 231 other regularly periodic variable sources. We have released light curves for all targets in C16 and have also released system parameters and transit vetting plots for all interesting candidates identified in this paper. Of particular interest is a candidate planet orbiting the bright F dwarf HD 73344 (V = 6.9, K = 5.6) with an orbital period of 15 days. If confirmed, this object would correspond to a 2.56 +/- 0.18 R⊕ planet and would likely be a favorable target for radial velocity characterization. This paper is intended as a rapid release of planet candidates, eclipsing binaries, and other interesting periodic variables to maximize the scientific yield of this campaign, and as a test run for the upcoming TESS mission, whose frequent data releases call for similarly rapid candidate identification and efficient follow up.