Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences
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An efficient organic magnesium borate-based electrolyte with non-nucleophilic characteristics for magnesium-sulfur battery
No full textEnzymatic hydrogelation of self-assembling peptide I4K2 and its antibacterial and drug sustained-release activities.
No full text化学工程
No full textBecause of the special structure and hydrocarbon ratio, lignin is expected to be Important renewable raw materials which can produce the aromatic hydrocarbon, paraffin, high-grade biofuels and high value-added chemicals. What’s more, lignin is the only able to provide renewable aromatic compounds of fossil resources in nature. The yield of lignin in the field of papermaking and bioethanol production is about 50 million tons, in which only about 5% was used for commercial purposes in the global each year. The rest are being used as fuel in the low-end and didn't get reasonable use which caused great waste of resources and environmental pollution. Therefore, it is imperative to develop efficient depolymerization of lignin to solve the current energy and environmental problems which has the very vital significance.
Lignin is a three-dimensional, highly branched, polyphenolic substance containing plenty of hydroxy- and methoxysubstituted phenylpropane units through ether bond linkages containing β-O-4, α-O-4, 4-O-5 bond. Elaborately designing and improving the catalyst, choosing the appropriate catalytic system and optimizing the reaction conditions are expected to can selectively activate and break the certain chemical bond in the lignin. Thus, it can access some or some kind of specific target product to achieve to the accurate transformation of lignin.
In recent years, nickel-based catalysts have shown excellent catalytic activity and selectivity for products in depolymerization and hydrogenation reaction of lignin to produce phenolic compounds which have attracted more and more attentions. Most of the nickel-based load on the acid support were studied. It should be noted that this kind of bifunctional catalyst system suffers from remarkable carbon deposition and moderate hydrothermal stability. In contrast, catalysts supported on solid base have long been regarded as robust catalysts and show the resistance to carbon deposition but have moderate HDO catalytic activity. Additionally, solid base substrates are mesoporous materials which are benefit to the transfer and diffusion of depolymerization monomer. The oxygen vacancy on the solid base surface is similar to that on the sulfide type catalyst surface and is advantageous to the removal of oxygen atoms.
In the present work, a series of nickel catalysts supported on ZnO-Al2O3 composites with varying Zn/Al atom ratios (Zn/Al = 2, 3, 5, ∞) have been prepared and tested for the hydroprocessing of lignin model compound (2-phenoxy-1-phenylethanone). We have studied the effect of the Zn/Al atom ratio in the support and reaction temperature on the cleavage of β-O-4 linkage ,and we also analyzed and summarized the possible reaction pathways proposed. On this basis, we further explored the kinetics of the β-O-4 lignin model compound depolymerization.中
Imidazolium-based ionic liquids for cellulose pretreatment: recent progresses and future perspectives
No full textAs the most abundant biomass in nature, cellulose is considered to be an excellent feedstock to produce renewable fuels and fine chemicals. Due to its hydrogen-bonded supramolecular structure, cellulose is hardly soluble in water and most conventional organic solvents, limiting its further applications. The emergence of ionic liquids (ILs) provides an environmentally friendly, biodegradable solvent system to dissolve cellulose. This review summarizes recent advances concerning imidazolium-based ILs for cellulose pretreatment. The structure of cations and anions which has an influence on the solubility is emphasized. Methods to assist cellulose pretreatment with ILs are discussed. The state of art of the recovery, regeneration, and reuse aspects of ILs is also presented in this work. The current challenges and development directions of cellulose dissolution in ILs are put forward. Although further studies are still much required, commercialization of IL-based processes has made great progress in recent years
Rapid hydrothermal and post-calcination synthesis of well-shaped LiNi0.5Mn1.5O4 cathode materials for lithium ion batteries
No full textHigh voltage spinel LiNi0.5Mn1.5O4 (LNMO) cathode materials with well-developed polyhedral-shape structure have been successfully synthesized via a rapid hydrothermal process followed by high-temperature calcination with Li source. The as-synthesized samples were characterized by powder X-ray diffraction, Raman spectroscopy, Scanning electron microscopy and electrochemical test. All samples show polyhedral-shape morphologies as well as cubic spinel structure with Fd3m space group. Electrochemical analysis verifies that the spinel LNMO cathode prepared with sulfate at hydrothermal temperature of 200 degrees C exhibits the better electrochemical properties in terms of discharge capacity, cycling stability and rate performance. This sample delivers an initial discharge capacity of 131.1 mAh g(-1) at 0.5 C rate at 25 degrees C, with the capacity retention of 85.2% after 100 charge-discharge cycles. Additionally, it still shows high rate performance with a discharge capacity of 110.9 mAh g(-1) even at 20 C rate. The excellent electrochemical properties are mainly attributed to its high crystallinity, appropriate particle size and uniform particle size distribution. These results suggest that the rapid hydrothermal and post-calcination method is an effective way for preparing high voltage LNMO cathode materials which can be applied to lithium ion batteries. (C) 2016 Elsevier B.V. All rights reserved
A green catalytic method for selective synthesis of iodophenols via aerobic oxyiodination under organic solvent-free conditions
No full textA highly efficient catalytic method for aerobic oxyiodination of various phenols catalysed by copper(11) nitrate was achieved under mild conditions using 12 as an iodinating reagent, molecular oxygen as an oxidant, and water as a solvent. The catalyst shows not only high activity for phenols with either electron-donating or electron-withdrawing groups, but also a remarkable selectivity for the formation of para-iodo substituted phenols. This study offers a green method for iodination of aromatic phenols with high atom economy. (C) 2017 Elsevier B.V. All rights reserved
H-pi Conjugated Molecule-Based Self-Assembly of Surfactants for Promoting Methane Hydrate Formation
No full textSelf-assembled structures of the cationic surfactant cetyltrimethylammonium bromide (CTAB) and reactive red-195 dye molecule (RR195) were achieved under the electrostatic interaction between CTAB and RR195 molecules, pi-pi interaction between RR195 molecules, and hydrophobic force between CTAB molecules. The self-assembled structure was named as CTAB@RR195 and used for the first time to promote methane hydrate formation. CTAB@RR195 appeared as cubic structures at 50-100 nm with -SO3-/-SO4- groups on the surface and therefore could provide a large area of solid/liquid interface during methane hydrate formation. As a result, CTAB@RR195 could not only reduce the methane hydrate growth periods from over 40 h when CTAB was used to 2-3 h but could also improve the methane uptake from 0.054 to 0.072 to about 0.108 mol gas/mol water
Comparison of bacterial community characteristics between complete and shortcut denitrification systems for quinoline degradation
No full textFor quinoline-denitrifying degradation, very few researches focused on shortcut denitrification process and its bacterial community characteristics. In this study, complete and shortcut denitrification systems were constructed simultaneously for quinoline degradation. By calculation, specific quinoline removal rates were 0.905 and 1.123 g/(gVSS d), respectively, in the complete and shortcut systems, and the latter was 1.24 times of the former. Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE), high-throughput sequencing, and quantitative PCR (qPCR) techniques based on 16S rRNA were jointly applied to compare microbial community structures of two systems. Many denitrifying bacteria phyla, classes, and genera were detected in the two systems. Phylum Proteobacteria, Class Gammaproteobacteria, and Genus Alicycliphilus denitrificans were the dominant contributors for quinoline-denitrifying degradation. In the shortcut denitrification system, main and specific strains playing crucial roles were more; the species richness and the total abundance of functional genes (narG, nirS, nirK, and nosZ) were higher compared with the complete denitrification system. It could be supposed that inorganic-nitrogen reductase activity of bacterial community was stronger in the shortcut denitrification system, which was the intrinsic reason to result in higher denitrification rate
Robust mussel-inspired coatings for controlled zinc ion release
No full textAlthough mussel-inspired coatings have been extensively studied, most of them suffer from high-cost preparation, poor mechanical strength and low abrasion resistance, which impede them from practical applications. In this study, we report the synthesis of low-cost but robust mussel-inspired coatings based on polyvinyl alcohol (PVA), which could continuously release zinc ions at a high release rate when immersed into artificial seawater (ASW). The coating exhibits high mechanical strength, strong adhesion to stainless steel (SS), and excellent anti-abrasion properties. Moreover, a complicated fabrication process is not required for the coating, which makes it a potential candidate for marine antifouling coating
Comparison of growth, hydrocarbon accumulation and metabolites of Botryococcus braunii between attached cultivation and aqueous-suspension cultivation
No full textBotryococcus braunii is a colonial green microalga which can produce extracellular hydrocarbons at a high rate, it is considered as one of the most promising feedstocks for sustainable biofuel production. However, B. braunii is generally recognized difficulties for cultivating and has limited amount of substantive scale-up and productivity assessments with conventional aqua-suspended cultivation systems (open pond and varieties of closed photobioreactors). This paper introduces a novel cultivation system based on biofilm technology, which is called "attached cultivation". To investigate the potential of attached cultivation method, attached cultivation of B. braunii SAG 807-1 was compared with aqueous-suspension cultivation (flat plate reactors). The growth, hydrocarbon accumulation and metabolites were studied under identical conditions (e.g. temperature, light intensity, CO2 concentration). The main research results obtained are as follows: compared with conventional aqueous-suspension cultivation, the biomass productivity of B. braunii under biofilm attached cultivation was 4.78 g/(m(2).d), which was higher than of 4.43 g/(m(2).d) by aqueous-suspension, and hydrocarbon productivity of the two cultivation methods were 2.52 g/(m(2).d) and 2.37 g/(m(2).d), respectively. The contents of carbohydrate and protein were also similar. This attached cultivation method showed a new model of commercialization for the microalgae-derived biofuels