Preheats Effect on Distributed Reaction Fuel Reforming

2015 ◽  
Author(s):  
Richard Scenna ◽  
Ashwani K. Gupta
Keyword(s):  
Molecular Weight ◽  
Chemical Composition ◽  
Time Scale ◽  
Mixing Time ◽  
Low Molecular Weight ◽  
Fuel Reforming ◽  
Middle Distillate ◽  
Catalytic Reforming ◽  
Reaction Regime ◽  
Low Efficiency

Conventional non-catalytic fuel reforming provides low efficiency, large amounts of char and tar and limited control on chemical composition of the syngas produced. In this paper volume distributed reaction technique is used to enhance reformate quality as compared to conventional reforming that uses non-catalytic reforming. Reforming of middle distillate fuels typically utilize preheats of 300–600°C[1,2]. This work investigates the intermediate regimes between volume distributed reaction regime and conventional flame regime for the reforming of JP8 through the chemical and mixing time scale. The results showed that reformate concentrations of fixed gases and most low molecular weight hydrocarbons changed gradually with air preheats. Reaction regime did not drastically change reformate products except for acetylene. In conventional flame regime acetylene concentration rapidly increased upon on entering the reactor.

Seasonal changes in the chemical composision of the red alga Hypnea musciformis

1973 ◽  
Vol 24 (3) ◽  
pp. 275
Author(s):  
AF Abdel ◽  
NM Abed ◽  
M Edrees
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Chemical Composition ◽  
Seasonal Changes ◽  
Free Amino ◽  
Glucuronic Acid ◽  
Red Alga ◽  
Low Molecular Weight ◽  
Hypnea Musciformis ◽  
Algal Material

Seasonal changes were observed in the chemical composition of the marine red alga Hypnea musciformis. Lipids, cholesterol, and lanosterol were found as constituents of the algal material. No low-molecular weight carbohydrates were found except small amounts of mannitol. The algal hydrolysate was shown to contain galactose, glucose, and xylose in all seasons and was characterized by a high content of glucuronic acid and its lactone in February. Definite seasonal variations were found in the patterns of free amino acids and of amino acid compositions of proteins.

scholarly journals Justification of bioactivated grain triticale use in alcohol production

2019 ◽  
Vol 48 (1) ◽  
pp. 57-65
Author(s):  
Анна Миронцева ◽  
Anna Mirontseva ◽  
Елена Цед ◽  
Elena Tsed ◽  
Светлана Волкова ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Chemical Composition ◽  
Ethyl Alcohol ◽  
Yeast Cells ◽  
Low Molecular Weight ◽  
Technological Parameters ◽  
Alcohol Production ◽  
Enzyme Preparations ◽  
Green Mass ◽  
Low Molecular Weight Compounds

Triticale accounts for the biggest share in gross processing and state procurement of grain in Belarussian production of alcohol. The main difficulty in its processing is the formation of viscous technological fluids due to the presence of non-starch polysaccharides in its chemical composition. All measures taken to solve the problem come down to the selection of the efficient enzyme preparations, hydrolyzing grain polymers into low molecular weight compounds, which have the ability to be disposed by the yeast cells and form the ethyl alcohol. But grain own enzymes are not involved. It is possible to solve the problem by means of biological activation, which will activate grain enzyme systems and partially hydrolyze grain polymers into low molecular weight compounds. The article considers general and special technological parameters of six cultivars of triticale selected in the Republic of Belarus: Antos, Kastus, Dubrava, Run, Prometheus, Impulse. The authors determined that the most promising cultivars for bioactivation and food grade ethyl alcohol production are Antos and Dubrava. The authors explored the possibility of using hot soaking of triticale grain for the biological activation. They also showed the advantages of introduction of amaranth green mass in the amount of 8% during hot soaking for the reduction of grain microbiological contamination. They studied the changes in the technological properties of triticale cultivars Antos and Dubrava after the bioactivation with the green mass of amaranth. The authors determined that grain microbiological characteristics improved, the activity of grain enzymes increased, proportion of low molecular weight compounds in the chemical composition increased. They studied the processes taking place during wort and mash production from the bioactivated triticale grain. The authors showed that the processing of bioactivated triticale grain resulted in the production of wort with higher concentration of dry matter which allowed to increase the ethanol content in the mature mash produced from triticale cultivar Antos by 19.5% and from the triticale cultivar Dubrava by 29.3% and reduce the total quantity of the main impurities in distillates.

Effect of acclimating saccharides on the activated sludge bacterial population: composition abnormality of activated sludge acclimated to glucose

1998 ◽  
Vol 37 (4-5) ◽  
pp. 99-103
Author(s):  
Yuu Ubukata ◽  
Susumu Takii
Keyword(s):  
Molecular Weight ◽  
Chemical Composition ◽  
Activated Sludge ◽  
Bacterial Population ◽  
Municipal Sewage ◽  
Appreciable Amount ◽  
Low Molecular Weight ◽  
Population Composition ◽  
Gram Positive ◽  
Gram Negative

The question of whether the substitution of glucose for starch in municipal sewage as an acclimating saccharide for activated sludge (AS) in the laboratory is valid was investigated using activated sludges acclimated to glucose (G-AS) and dextrin (D-AS), since the bacteria responsible for starch (dextrin) removal in D-AS are verified to take up maltose instead of glucose during dextrin removal. In G-AS, polysaccharides are the major reserve materials, and large amounts of residual organic materials (ROM) are excreted from the AS. In contrast, in D-AS, about half of the reserve materials are low molecular weight saccharides, and no appreciable amount of ROM was detected. It is considered that most bacteria responsible for the removal of dextrin and glucose are Gram-negative and Gram-positive, respectively, based on the results of the chemical composition of AS and the type of reserve saccharide. As a result, in laboratory-scale AS processes, maltose (disaccharide) or dextrin (polysaccharide), instead of glucose (monosaccharide), should be used as a substitute for starch.

Chemical analysis of flavour volatiles in heat-treated milks

1978 ◽  
Vol 45 (3) ◽  
pp. 391-403 ◽  
Author(s):  
Haytham A. Jaddou ◽  
John A. Pavey ◽  
Donald J. Manning
Keyword(s):  
Mass Spectrometry ◽  
Heat Treatment ◽  
Molecular Weight ◽  
Gas Chromatography ◽  
Chemical Composition ◽  
Volatile Compounds ◽  
Raw Milk ◽  
Low Molecular Weight ◽  
Total Volatile ◽  
Heat Treated

SummaryThe effect of heat treatment of milk on low molecular weight, volatile compounds was studied in order to relate changes in the flavour of milks to changes in chemical composition. Milks were heat treated in a UHT plant for 3 or 90 s at 140 °C and stored at ambient temperature for periods up to 112 d. Volatile compounds in raw milk and in heated milks were isolated by a low temperature spray distillation technique and identified using gas chromatography and mass spectrometry. Cabbagey defects in heated milks are correlated with total volatile sulphur and it is concluded that the compounds H2S, COS, CH3SH, CS2 and (CH3)2S could be responsible for this defect.

scholarly journals Canadian permafrost stores large pools of ammonium and optically distinct dissolved organic matter

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
J. Fouché ◽  
C. T. Christiansen ◽  
M. J. Lafrenière ◽  
P. Grogan ◽  
S. F. Lamoureux
Keyword(s):  
Molecular Weight ◽  
Organic Matter ◽  
Optical Properties ◽  
Chemical Composition ◽  
Dissolved Organic Matter ◽  
Active Layer ◽  
Low Molecular Weight ◽  
Permafrost Degradation ◽  
Soil Cores ◽  
Cryogenic Processes

Abstract Permafrost degradation may lead to mobilization of carbon and nutrients and enhance microbial processing rates of previously frozen organic matter. Although the pool size and chemical composition of dissolved organic matter (DOM) are fundamental determinants of the carbon cycle in Arctic watersheds, its source within the seasonally thawing active layer and the underlying permafrost remains largely uncharacterized. Here, we used 25 soil cores that extended down into the permafrost from nine sites across Arctic Canada to quantify dissolved organic carbon (DOC) and nitrogen stocks, and to characterize DOM optical properties. Organic permafrost stores 5–7 times more DOC and ammonium than the active layer and mineral permafrost. Furthermore, the permafrost layers contain substantial low molecular weight DOM with low aromaticity suggesting high biodegradability. We conclude that soil organic matter stoichiometry and cryogenic processes determine permafrost DOM chemistry, and that thawing will mobilize large amounts of labile DOC and ammonium into Arctic watersheds.

Note: Fractionation of Sheep Milk Fat Via Supercritical Carbon Dioxide

2004 ◽  
Vol 10 (6) ◽  
pp. 421-425 ◽  
Author(s):  
V. Spano ◽  
A. Salis ◽  
S. Mele ◽  
P. Madau ◽  
M. Monduzzi
Keyword(s):  
Carbon Dioxide ◽  
Molecular Weight ◽  
Chemical Composition ◽  
Supercritical Carbon Dioxide ◽  
High Molecular Weight ◽  
Milk Fat ◽  
Low Molecular Weight ◽  
Sheep Milk ◽  
Supercritical Carbon

Supercritical carbon dioxide (SC-CO2) was used for anhydrous ovine milk fat (AMF) fractionation. Two different fractions were obtained: a low molecular weight triacylglycerol (TAG), named fraction E, and a high molecular weight TAG, termed fraction R. Fractionation was performed at different pressure and temperature values. The effect of these parameters on the chemical composition of the two fractions were analysed in relation to the original AMF. Among the searched conditions, 250 bar and 40°C gave the best fractionation results.

scholarly journals Identification and Differentiation of Light- and Middle-Distillate Petroleum for NRDA Using Chemical Forensics

1999 ◽  
Vol 1999 (1) ◽  
pp. 203-209 ◽  
Author(s):  
Allen D. Uhler ◽  
Scott A. Stout ◽  
Kevin J. McCarthy ◽  
Julie A. Seavey ◽  
Richard M. Uhler
Keyword(s):  
Molecular Weight ◽  
Chemical Composition ◽  
Detailed Analysis ◽  
Middle Distillate ◽  
Molecular Weight Range ◽  
Data Set ◽  
Chromatographic Profile ◽  
Middle Distillates ◽  
Epa Methods ◽  
Detailed Chemical

ABSTRACT The need for identification, delineation, and differentiation of petroleum-derived contaminants in support of NRDA investigations of chronic or catastrophic release of petroleum is paramount for the equitable settlement of damages related to the incidents. Significant advances have been made over the last decade with regard to these issues for crude oil and heavy residual fuels, but less emphasis has been place on the forensic chemistry of light- and middle-distillates. Historically, identification and differentiation among similar light-distillates by standard EPA methods have been hampered by analytical limitations. In this paper the authors suggest analysis of light-distillate products begin with a chromatographic profile obtained using a modified EPA 8015 GC/FID. Subsequently, the detailed chemical composition of the distillate products is accomplished via a modified version of EPA Method 8260, examining a targeted list of diagnostic petroleum compounds in the C5 to C12 range that represent five important categories of hydrocarbons: Paraffins, Isoparaffins, Aromatics, Naphthenes, and Olefins. Detailed analysis of over 50 2–6 ring PAH and related heteroatomics from a modified EPA 8270 GC/MS analysis can be used to compliment the data set. The analysis of the full suite of hydrocarbons across a broad molecular weight range provides much of the information necessary to identify and distinguish among light- and middle-distillate products.

scholarly journals An integrated chemical and micromorphological investigation of humic substances in three podzolized soils of the Netherlands.

1982 ◽  
Vol 30 (3) ◽  
pp. 205-226
Author(s):  
J. Drozd ◽  
A. Jongerius ◽  
S. Kowalinski
Keyword(s):  
Molecular Weight ◽  
Chemical Composition ◽  
The Netherlands ◽  
Humic Substances ◽  
Humic Acids ◽  
Infrared Spectra ◽  
Fulvic Acids ◽  
Low Molecular Weight ◽  
Ap Horizon ◽  
The Stability

The humic substances in a 'Holt' leptic podzol, a 'Haar' humic podzol and a 'Veld' gleyic podzol from the Netherlands were analysed chemically and micromorphologically. The absorption spectra of Na-humates in visible light and infrared spectra were determined for the humic acids. The translocation and distribution of the principal humus compounds occurred by mechanical illuviation in the 'Holt' podzol, and by translocation in solution in the 'Haar' podzol and the 'Veld' podzol. The micromorphological images were closely correlated with the chemical composition of the humic substances. Illuviation cutans occurring in the B horizons of the 'Haar' podzol and the 'Veld' podzol appeared to consist mainly of fulvic acids. The dark humus micro-aggregates characteristic of the 'Haar' podzol and the Ap horizon of the 'Veld' podzol were composed mainly of bitumens, humins and humic acids of high molecular weight, while the brown micro-aggregates of the 'Holt' podzol and the lower horizons of the 'Veld' podzol consisted mainly of fulvic acids and humic acids of low molecular weight. The stability of micro-aggregates was correlated with their composition. (Abstract retrieved from CAB Abstracts by CABI’s permission)

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