scholarly journals Effect of using regenerated combined FAU and MOR zeolites as catalysts during the pyrolysis of kraft lignin

BioResources ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 417-440
Author(s):  
Ajoy Kanti Mondal ◽  
Chengrong Qin ◽  
Arthur J. Ragauskas ◽  
Yonghao Ni ◽  
Fang Huang
Keyword(s):  
Gel Permeation Chromatography ◽  
Kraft Lignin ◽  
Acid Sites ◽  
Heavy Oils ◽  
Total Acid ◽  
Zeolite Sample ◽  
Catalytic Activities ◽  
Lower Weight ◽  
Micropore Surface Area ◽  
The Individual

The SiO2/Al2O3 mole ratio, pore size, and acid sites are the key parameters of zeolite’s activity in lignin pyrolysis. In this study, the comparison of individual Y and M zeolites, the combined ‘Y + M’ sample after regeneration, and their effect on lignin pyrolysis were studied in five cycles (regeneration and reuse). The results were explained using Brunauer, Emmet, and Teller (BET), micropore surface area (MSA), and total acid sites (TAS) analyses. In comparison with the individual Y or M zeolite sample, the consistent higher catalytic activities of the combined ‘Y + M’ sample in repeated cycles were observed. Pyrolysis heavy oils were characterized by nuclear magnetic resonance (NMR) spectroscopy and gel permeation chromatography (GPC). The NMR analyses revealed that with increased zeolite regeneration cycles, p-hydroxy phenyl and methoxyl groups increased. Decreases in guaiacyl phenolic hydroxyl were less for the combined ‘Y + M’ sample than the individual Y and M zeolites. Lower weight average (Mw) of heavy oil for the combined ‘Y + M’ sample indicated the enhanced cleavage of lignin structures in pyrolysis. These results support the higher catalytic activity of regenerated zeolites for the combined ‘Y + M’ sample compared with individual Y and M zeolites due to the improved MSA and TAS.

scholarly journals ACTIVITY TEST AND REGENERATION OF NiMo/Z CATALYST FOR HYDROCRACKING OF WASTE PLASTIC FRACTION TO GASOLINE FRACTION

2010 ◽  
Vol 5 (3) ◽  
pp. 261-268 ◽  
Author(s):  
Rodiansono Rodiansono ◽  
Wega Trisunaryanti
Keyword(s):  
Natural Zeolite ◽  
Pore Radius ◽  
Total Pore Volume ◽  
Acid Sites ◽  
Gasoline Fraction ◽  
Total Acid ◽  
Average Pore ◽  
Average Pore Radius ◽  
Activity Test ◽  
Hydrogen Stream

Activity test and regeneration of NiMo/active natural zeolite catalyst for hydrocracking of waste plastic fraction of polyprophylene (PP) type have been carried out. The catalysts was prepared by loading Mo followed by Ni Metals onto the natural zeolite (Z) sample, then calcined at 500oC, oxidized and reduced at 400oC under nitrogen, oxygen and hydrogen stream, respectively. The characterization of catalysts including spesific surface area, average pore radius, and total pore volume were performed by gas sorption analyzer, amount of total acid sites was determined by gas sorption method, and acid site strength was confirmed by IR spectroscopy. The hydrocracking process was carried out in a semi-flow reactor system at 360 oC and catalyst:feed ratio 0.5 under hydrogen stream (150 mL/hour). The feed was vaporized from the pyrolisis reactor into the hydrocracking reactor. A liquid product was collected and analyzed by gas chromatography (GC) and gas chromatography-mass spectroscopy (GC-MS). The characterization results showed that spesific surface area, average pore radius, and total pore volume of the Z sample decreased after loading of the Ni and Mo metals. Amount of total acid sites of the NiMo/Z catalyst was higher than that of the Z sample. The activity of NiMo/Z catalyst decreased after several continously runs. Its regeneration produced the NiMo/Z reg catalyst with similar activity and selectivity to the fresh catalyst (NiMo/Z). The activity of catalysts at the optimum condition followed the order of NiMo/Z reg>NiMo/Z>Z (conversion of hydrocarbon C>12) and NiMo/Z reg>NiMo/Z>Z (total yield of gasoline fraction). The selectivity of catalysts for C7-C8 product followed the order of Z>NiMo/Z>NiMo/Z reg. Keywords: activity, polyprophylene, catalyst, gasoline fraction.

Water-assisted Flow of Heavy Oil in a Vertical Pipe: Pilot-scale Experiments

2012 ◽  
Vol 10 (1) ◽  
Author(s):  
Antonio C. Bannwart ◽  
Oscar M. H. Rodriguez ◽  
Jorge L. Biazussi ◽  
Fabio N. Martins ◽  
Marcelo F. Selli ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Annular Flow ◽  
Water Injection ◽  
Pilot Scale ◽  
Heavy Oils ◽  
Monitoring And Control ◽  
Two Phase ◽  
The Core ◽  
Artificial Lift ◽  
The Individual

The use of the core-annular flow pattern, where a thin fluid surrounds a very viscous one, has been suggested as an attractive artificial-lift method for heavy oils in the current Brazilian ultra-deepwater production scenario. This paper reports the pressure drop measurements and the core-annular flow observed in a 2 7/8-inch and 300 meter deep pilot-scale well conveying a mixture of heavy crude oil (2000 mPa.s and 950 kg/m3 at 35 C) and water at several combinations of the individual flow rates. The two-phase pressure drop data are compared with those of single-phase oil flow to assess the gains due to water injection. Another issue is the handling of the core-annular flow once it has been established. High-frequency pressure-gradient signals were collected and a treatment based on the Gabor transform together with neural networks is proposed as a promising solution for monitoring and control. The preliminary results are encouraging. The pilot-scale tests, including long-term experiments, were conducted in order to investigate the applicability of using water to transport heavy oils in actual wells. It represents an important step towards the full scale application of the proposed artificial-lift technology. The registered improvements in terms of oil production rate and pressure drop reductions are remarkable.

Solvent, LICL, and Temperature Effects on the Morphological Structure and Electronic Properties of Polyaniline

1995 ◽  
Vol 413 ◽  
Author(s):  
Marie Angelopoulos ◽  
Yun-Hsin Liao ◽  
Bruce Furman ◽  
Teresita Graham
Keyword(s):  
Hydrogen Bonding ◽  
Surface Structure ◽  
Morphological Changes ◽  
Base Material ◽  
Morphological Structure ◽  
Gel Permeation Chromatography ◽  
The Individual ◽  
High Degree ◽  
Pani Base ◽  
Different Levels

ABSTRACTExtensive gel permeation chromatography coupled with surface structure measurements clearly indicate that polyaniline (pani) base has a tendency to aggregate as a result of interchain hydrogen-bonding. The aggregation is present in the solid state powder; the extent of aggregation is found to be significantly dependent on the synthetic conditions. Pani base powders having a high degree of aggregation have significantly reduced solubility. The degree of aggregation of pani base in solution is found to be dependent on the solvent, concentration, and temperature. As the solvent becomes a better solvent for the base material, the less aggregated is the structure. Solvents which can strongly interact with the polymer disrupt the aggregation. In addition, salts such as LiCl which complex the polymer via a “pseudo-doping” process, also disrupt the internal pani hydrogen-bonding and deaggregate the polymer. As the polymer is deaggregated to different levels by a solvent or by LiCl, the individual chains can better be solvated and thus a conformational change also occurs. The chains adapt a more expanded coil type of conformation. The degree of expansion depends on the solvation power of the solvent. As the level of deaggregation and subsequent chain expansion increases, a significant red shift is observed in the λmaximum of the exciton absorbance and the surface structure of the polymer becomes smoother. It is found that the LiCl induced morphological changes results in increased conductivity upon doping pani base with a protonic acid.

scholarly journals Monitoring of oligopeptides from blue-veined cheese during ripening

2004 ◽  
Vol 22 (SI - Chem. Reactions in Foods V) ◽  
pp. S314-S316
Author(s):  
J. Zemanová ◽  
E. Vítová ◽  
L. Hadra ◽  
M. Fišera
Keyword(s):  
Capillary Electrophoresis ◽  
Soluble Fraction ◽  
Gel Permeation Chromatography ◽  
Nitrogen Compounds ◽  
Bitter Peptides ◽  
Gel Permeation ◽  
The Individual

The aim of this study is an isolation of oligopeptides from blue-veined cheese during different stages of ripening and sugests a method which allows their determination, especially electrophoresis. Extraction by water was used to isolate nitrogen compounds and the obtained extract was further fractionated and recleaned. First, high-molecular peptides and proteins were precipitated by methanol, second, the methanol-soluble fraction was further fractionated by gel permeation chromatography. The fractions obtained by this procedures were then analysed using capillary electrophoresis. The obtained results indicate that this procedure, may be applicable for isolation of oligopeptides from cheese allowing also determination of the individual peptides. This is necessary in particular for monitoring of formation and origin of bitter peptides in cheese, which cannegativelly influence the final flavour of cheese.

Purification and characterization of kraft lignin

Holzforschung ◽  
2015 ◽  
Vol 69 (8) ◽  
pp. 943-950 ◽  
Author(s):  
Wenwen Fang ◽  
Marina Alekhina ◽  
Olga Ershova ◽  
Sami Heikkinen ◽  
Herbert Sixta
Keyword(s):  
Thermal Properties ◽  
High Performance ◽  
Inorganic Compounds ◽  
Gel Permeation Chromatography ◽  
Kraft Lignin ◽  
Hot Water ◽  
Scanning Calorimetry ◽  
Target Values ◽  
Lower Glass Transition Temperature

Abstract To upgrade the utilization of kraft lignin (KL) for high-performance lignin-based materials (e.g., carbon fiber), the purity, molecular mass distribution (MMD), and thermal properties need to be improved and adjusted to target values. Therefore, different methods, such as ultrasonic extraction (UE), solvent extraction, dialysis, and hot water treatment (HWT), were applied for the purification of KL. The chemical and thermal properties of purified lignin have been characterized by nuclear magnetic resonance, Fourier transform infrared, gel permeation chromatography, elemental analysis, differential scanning calorimetry, and thermogravimetric analysis. The lignin fractions obtained by UE with ethanol/acetone (E/A) mixture (9:1) revealed a very narrow MMD and were nearly free of inorganic compounds and carbohydrates. Further, the E/A-extracted lignin showed a lower glass transition temperature (Tg) and a clearly detectable melting temperature (Tm). Dialysis followed by HWT at 220°C is an efficient method for the removal of inorganics and carbohydrates; however, lignin was partly forming condensed structures during the treatment.

scholarly journals ZmFAR1 and ZmABCG26 Regulated by microRNA Are Essential for Lipid Metabolism in Maize Anther

2021 ◽  
Vol 22 (15) ◽  
pp. 7916
Author(s):  
Yilin Jiang ◽  
Ziwen Li ◽  
Xinze Liu ◽  
Taotao Zhu ◽  
Ke Xie ◽  
...  
Keyword(s):  
Acid Sites ◽  
Male Reproduction ◽  
Transcriptome Data ◽  
Wild Type ◽  
Male Sterile ◽  
Catalytic Activities ◽  
Qrt Pcr ◽  
Metabolic Genes ◽  
Atp Binding Cassette Transporter

The function and regulation of lipid metabolic genes are essential for plant male reproduction. However, expression regulation of lipid metabolic genic male sterility (GMS) genes by noncoding RNAs is largely unclear. Here, we systematically predicted the microRNA regulators of 34 maize white brown complex members in ATP-binding cassette transporter G subfamily (WBC/ABCG) genes using transcriptome analysis. Results indicate that the ZmABCG26 transcript was predicted to be targeted by zma-miR164h-5p, and their expression levels were negatively correlated in maize B73 and Oh43 genetic backgrounds based on both transcriptome data and qRT-PCR experiments. CRISPR/Cas9-induced gene mutagenesis was performed on ZmABCG26 and another lipid metabolic gene, ZmFAR1. DNA sequencing, phenotypic, and cytological observations demonstrated that both ZmABCG26 and ZmFAR1 are GMS genes in maize. Notably, ZmABCG26 proteins are localized in the endoplasmic reticulum (ER), chloroplast/plastid, and plasma membrane. Furthermore, ZmFAR1 shows catalytic activities to three CoA substrates in vitro with the activity order of C12:0-CoA > C16:0-CoA > C18:0-CoA, and its four key amino acid sites were critical to its catalytic activities. Lipidomics analysis revealed decreased cutin amounts and increased wax contents in anthers of both zmabcg26 and zmfar1 GMS mutants. A more detailed analysis exhibited differential changes in 54 monomer contents between wild type and mutants, as well as between zmabcg26 and zmfar1. These findings will promote a deeper understanding of miRNA-regulated lipid metabolic genes and the functional diversity of lipid metabolic genes, contributing to lipid biosynthesis in maize anthers. Additionally, cosegregating molecular markers for ZmABCG26 and ZmFAR1 were developed to facilitate the breeding of male sterile lines.

scholarly journals Optimization of Lignin-Based Biocatalyst Production from Pine Sawdust and Wheat Straw

Molecules ◽  
2018 ◽  
Vol 23 (8) ◽  
pp. 1877
Author(s):  
Froylán Escalante ◽  
Alejandra Carranza-Hernández ◽  
Adelina García-Zamora ◽  
Efrén Aguilar-Garnica
Keyword(s):  
Wheat Straw ◽  
Acid Sites ◽  
Operating Conditions ◽  
Added Value ◽  
Design Engineering ◽  
Total Acid ◽  
Pine Sawdust ◽  
Lignocellulosic Wastes ◽  
Optimization Methodology ◽  
Esterification Reactions

Pine sawdust and wheat straw are abundant lignocellulosic wastes that have been recently converted into bioethanol under a biochemical platform scheme whose main waste is lignin. Lignin can be transformed into a wide variety of high added-value products, including its functionalization as a catalyst. A key step in the synthesis of a lignin-based catalyst is the sulfonation reaction, whose operating conditions, namely, H2SO4 to lignin ratio (mL/g), temperature and time, have been arbitrarily chosen. In this contribution, an optimization methodology (i.e., Box-Behnken) is applied in order to found the operating conditions during the sulfonation reaction that maximizes the total acid sites density of lignin-based catalysts from pine sawdust and wheat straw. The optimization results show that the time in sulfonation reactions can be significantly reduced, compared to those previously reported, without affecting the performance of both catalysts in esterification reactions. These results could be further considered for energy and costs reduction purposes during the conceptual design engineering of the sulfonation reaction.

scholarly journals Purification and Immunogenicity of a Recombinant Bordetella pertussis S1S3FHA Fusion Protein Expressed by Streptococcus gordonii

2002 ◽  
Vol 68 (9) ◽  
pp. 4253-4258 ◽  
Author(s):  
Song F. Lee ◽  
Scott A. Halperin ◽  
Jennifer B. Knight ◽  
Aaron Tait
Keyword(s):  
Amino Acids ◽  
Fusion Protein ◽  
Bordetella Pertussis ◽  
Gel Permeation Chromatography ◽  
Amino Acid Type ◽  
Type I ◽  
Streptococcus Gordonii ◽  
Western Blots ◽  
Acid Type ◽  
The Individual

ABSTRACT Acellular pertussis vaccines typically consist of antigens isolated from Bordetella pertussis, and pertussis toxin (PT) and filamentous hemagglutinin (FHA) are two prominent components. One of the disadvantages of a multiple-component vaccine is the cost associated with the production of the individual components. In this study, we constructed an in-frame fusion protein consisting of PT fragments (179 amino acids of PT subunit S1 and 180 amino acids of PT subunit S3) and a 456-amino-acid type I domain of FHA. The fusion protein was expressed by the commensal oral bacterium Streptococcus gordonii. The fusion protein was secreted into the culture medium as an expected 155-kDa protein, which was recognized by a polyclonal anti-PT antibody, a monoclonal anti-S1 antibody, and a monoclonal anti-FHA antibody. The fusion protein was purified from the culture supernatant by affinity and gel permeation chromatography. The immunogenicity of the purified fusion protein was assessed in BALB/c mice by performing parenteral and mucosal immunization experiments. When given parenterally, the fusion protein elicited a very strong antibody titer against the FHA type I domain, a moderate titer against native FHA, and a weak titer against PT. When given mucosally, it elicited a systemic response and a mucosal response to FHA and PT. In Western blots, the immune sera recognized the S1, S3, and S2 subunits of PT. These data collectively indicate that fragments of the pertussis vaccine components can be expressed in a single fusion protein by S. gordonii and that the fusion protein is immunogenic. This multivalent fusion protein approach may be used in designing a new generation of acellular pertussis vaccines.

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