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1.
Environ Sci Technol ; 53(23): 14041-14053, 2019 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-31602972

RESUMO

Hydrogen production from renewable resources, such as lignocellulosic biomass, is highly desired, under the most sustainable and mildest reaction conditions. In this study, a new sustainable three-step process for the production of hydrogen has been proposed. In the first step, a crude formic acid (CF) solution, which included typical reaction byproducts, in particular, acetic acid, levulinic acid, saccharides, 5-hydroxymethylfurfural, furfural, and lignin, was obtained through the combined hydrolysis/oxidation of the biomass, in the presence of diluted sulfuric acid/hydrogen peroxide, as homogeneous catalysts. In the second one, the distilled formic acid (DF) solution was obtained by distillation of the CF solution, for example, by isolating liquid byproducts, or the lignin-free CF (LCF) solution was recovered by CF filtration for the elimination of only solid lignin particles. In the final step, hydrogen was produced from the DF or LCF solutions through formic acid dehydrogenation over Pd supported on amine-functionalized mesoporous silica catalysts, in the presence of sodium formate, as an additive. The clean hydrogen, which is produced from biomass passing through formic acid, could be applied as an energy source of fuel cells. This new hydrogen production process is smart, allowing the hydrogen production with mild reaction conditions, eventually starting from different lignocellulosic feedstocks, and it could be integrated within the existing hydrothermal technology for levulinic acid production, which has been already recognized as efficient and sustainable. In addition to the production of hydrogen as an energy source of fuel cells, formic acid derived from biomass could be utilized as a platform chemical for chemical, agricultural, textile, leather, pharmaceutical, and rubber industries.


Assuntos
Formiatos , Lignina , Biomassa , Hidrogênio , Hidrólise , Temperatura
2.
AMB Express ; 8(1): 80, 2018 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-29774473

RESUMO

The yeast strain SJP-SNU was investigated as a probiotic and was characterized with respect to growth temperature, bile salt resistance, hydrogen sulfide reducing activity, intestinal survival ability and chicken embryo pathogenicity. In addition, we determined the complete genomic and mitochondrial sequences of SJP-SNU and conducted comparative genomics analyses. SJP-SNU grew rapidly at 37 °C and formed colonies on MacConkey agar containing bile salt. SJP-SNU reduced hydrogen sulfide produced by Salmonella serotype Enteritidis and, after being fed to 4-week-old chickens, could be isolated from cecal feces. SJP-SNU did not cause mortality in 10-day-old chicken embryos. From 13 initial contigs, 11 were finally assembled and represented 10 chromosomal sequences and 1 mitochondrial DNA sequence. Comparative genomic analyses revealed that SJP-SNU was a strain of Pichia kudriavzevii. Although SJP-SNU possesses pathogenicity-related genes, they showed very low amino acid sequence identities to those of Candida albicans. Furthermore, SJP-SNU possessed useful genes, such as phytases and cellulase. Thus, SJP-SNU is a useful yeast possessing the basic traits of a probiotic, and further studies to demonstrate its efficacy as a probiotic in the future may be warranted.

3.
Nanoscale ; 6(7): 3483-7, 2014 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-24384786

RESUMO

Mesoporous silica and titania supraparticles with controllable pore size, particle size, and macroscopic morphology were readily synthesized by a novel synthetic pathway using meniscus templating on a superhydrophobic surface, which is much simpler than well-known emulsion systems. Moreover, we first report that despite the very large radius of droplet curvature on a millimeter scale, supraparticles kept the round cap morphology due to addition of sucrose as a shape preserver as well as a pore-forming agent. In addition, mesoporous silica and titania supraparticles provided good adsorption performance for Acid Blue 25 and Cr(VI), and were easily separated from the solution by using a scoop net after adsorption tests.


Assuntos
Dióxido de Silício/química , Titânio/química , Adsorção , Antraquinonas/química , Cromo/química , Interações Hidrofóbicas e Hidrofílicas , Nanoestruturas/química , Porosidade , Propriedades de Superfície
4.
Environ Sci Technol ; 47(3): 1704-10, 2013 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-23286316

RESUMO

Coal-fired power plants are facing to two major independent problems, namely, the burden to reduce CO(2) emission to comply with renewable portfolio standard (RPS) and cap-and-trade system, and the need to use low-rank coal due to the instability of high-rank coal supply. To address such unresolved issues, integrated gasification combined cycle (IGCC) with carbon capture and storage (CCS) has been suggested, and low rank coal has been upgraded by high-pressure and high-temperature processes. However, IGCC incurs huge construction costs, and the coal upgrading processes require fossil-fuel-derived additives and harsh operation condition. Here, we first show a hybrid coal that can solve these two problems simultaneously while using existing power plants. Hybrid coal is defined as a two-in-one fuel combining low rank coal with a sugar cane-derived bioliquid, such as molasses and sugar cane juice, by bioliquid diffusion into coal intrapores and precarbonization of the bioliquid. Unlike the simple blend of biomass and coal showing dual combustion behavior, hybrid coal provided a single coal combustion pattern. If hybrid coal (biomass/coal ratio = 28 wt %) is used as a fuel for 500 MW power generation, the net CO(2) emission is 21.2-33.1% and 12.5-25.7% lower than those for low rank coal and designed coal, and the required coal supply can be reduced by 33% compared with low rank coal. Considering high oil prices and time required before a stable renewable energy supply can be established, hybrid coal could be recognized as an innovative low-carbon-emission energy technology that can bridge the gulf between fossil fuels and renewable energy, because various water-soluble biomass could be used as an additive for hybrid coal through proper modification of preparation conditions.


Assuntos
Dióxido de Carbono/análise , Carvão Mineral/análise , Centrais Elétricas , Saccharum/química , Adsorção , Simulação por Computador , Análise Diferencial Térmica , Interações Hidrofóbicas e Hidrofílicas , Melaço , Nitrogênio/química , Porosidade , Temperatura
5.
Korean J Urol ; 51(9): 657-9, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20856653

RESUMO

The synthetic, tension-free midurethral sling procedure using transobturator tape (TOT) was introduced in 2001 and has become the most widely used procedure for the treatment of female urinary incontinence worldwide. However, infectious complications associated with erosions have occasionally been reported because of a foreign body reaction to the polypropylene mesh. We observed a case of a bilateral recurrent thigh abscess manifesting 5 years after a TOT sling procedure. The patient had recurrent thigh abscesses with repeated incisions and drainages in the past 1 year. Five months earlier, she had undergone a procedure to remove the eroded suburethral mesh, but incompletely. The right thigh abscess recurred, and ultimately the residual mesh was completely excised with abscess drainage. Complete mesh removal is very important to prevent abscess recurrence, and it is necessary for any urologist treating women who have undergone the TOT procedure to be aware of the possibility of abscesses occurring for a long time after the operation.

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