Carbon Dioxide Generation Research Articles

Structure analysis of counterflow diffusion flames in the forward stagnation region of a porous cylinder

An experimental study was made of the structure of the laminar counterflow diffusion flame established in the forward stagnation region of a porous cylinder. Aerodynamic, temperature, and stable-species-concentration profiles were measured in detail for methane flames at atmospheric pressure. These distributions were analyzed to yield the reaction-rate profiles of stable species and the heat-release-rate profile throughout the flame zone. Results show that, although the maximum concentrations of various intermediate products are observed between the luminous reaction zone and the stagnation point, various chemical reactions, including generation and consumption of such intermediate products, occur in the comparatively narrow region in and around the luminous reaction zone. The maximum rates of consumption of carbon monoxide and generation of carbon dioxide are found on the air side of the flame, and reaction-rate profiles of various stable species are qualitatively similar to those for the two-stage reaction in premixed hydrocarbon-air flames. The comparatively large convection velocity across the flame zone plays an important role, yielding the unique concentration profiles throughout the flame zone. The heat-release-rate profile shows a small valley (negative value) on the fuel side of the major peak, which is attributed to pyrolysis-type reactions. Two kinds of blowoff mechanisms of the present counterflow diffusion flame—namely, thermal quenching of the flame and chemical limitations on the combustion rate—can be clearly explained.

有機微量元素分析法の研究 (第1報)

Evolution of carbon dioxide by the pyrolysis of sodium hydrogen carbonate may advantageously be used for the nitrogen analysis by the micro-Dumas method but the procedure is attended with some defects in that the control of the carbon dioxide stream is difficult and that the life of sodium hydrogen carbonate is very short. The first of such defects was overcome by devising a kind of pressure regulating stopcock which would freely control the carbon dioxide stream, while automatically maintaining the combustion tube at a constant pressure. The second point was somewhat overcome by the devise of a simple carbon dioxide generator. By the use of this generator, about 45g. of sodium hydrogen carbonate is taken and allows continued use for over nine hours.

Modified Carbon Dioxide Generator for Dumas Determination

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTModified Carbon Dioxide Generator for Dumas DeterminationB. A. Parkin, J. B. Fernandez, J. C. Brown, and E. G. RietzCite this: Anal. Chem. 1953, 25, 5, 841Publication Date (Print):May 1, 1953Publication History Published online1 May 2002Published inissue 1 May 1953https://doi.org/10.1021/ac60077a063RIGHTS & PERMISSIONSArticle Views18Altmetric-Citations4LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (193 KB) Get e-Alerts Get e-Alerts

第三級カルボン酸の酸化 (第1報)

Tertiary carboxylic acids possessing benzene nucleus in the α-position are not oxidized by alkaline potassium permanganate but are oxidized by acidic permanganate, generates carbon dioxide and form corresponding tertiary carbinols. Aliphatic tertiary carboxylic acids do not possess such a property. This fact was confirmed by experiments with diphenylpropionic acid (I), ditolylpropionic acid (II) and diphenylethanetricarboxylic acid (III). (III) yields the corresponding tertiary carbinol, diphenylmethylcarbinol-p, p-dicarboxylic acid (IV) which, when heated above its melting point, liberates water to form diphenylethylenedicarboxylic acid (V). Benzilic and benzohydroltricarboxylic (VI) acids are also easily oxidized by acidic potassium permanganate. The compounds (IV), (V) and (VI) are newly synthesized substances.

The origin of high sodium bicarbonate waters in the Atlantic and Gulf Coastal Plains

Some sodium bicarbonate waters at depth in the Atlantic and Gulf Coastal Plains have the same bicarbonate content as the shallower calcium bicarbonate waters in the same formation and appear to be the result of replacement of calcium by sodium through the action of base-exchange minerals. Others, however, contain several hundred parts per million more of bicarbonate than any of the calcium bicarbonate waters and much more bicarbonate than can be attributed to solution of calcium carbonate through the action of carbon dioxide derived from the air and soil. As the waters in the Potomac group (Cretaceous) are all low in sulphate and as the environmental conditions under which the sediments of the Potomac group were deposited do not indicate that large amounts of sulphate are available for solution, it does not seem probable that carbon dioxide generated by chemical or biochemical breakdown of sulphate is responsible for the high sodium bicarbonate waters in this area. Sulphate as a source of oxygen is not necessary for the generation of carbon dioxide by carbonaceous material. Oxygen is an important constituent of carbonaceous material and carbon dioxide is a characteristic decomposition product of such material—as, for example, peat and lignite. Experimental work showed that distilled water, calcium bicarbonate water, and sodium bicarbonate water, after contact with lignite, calcium carbonate, and permutite (a base-exchange material), had all increased greatly in sodium bicarbonate content and had become similar in chemical character and in mineral content to high sodium bicarbonate waters found in the Coastal Plain. The tests indicated that carbonaceous material can act as a source of carbon dioxide, which, when dissolved in water, enables it to take into solution more calcium carbonate. If base-exchange materials are also present to replace calcium with sodium, a still greater amount of bicarbonate can be held in solution. The presence of carbonaceous material, together with calcium carbonate and base-exchange minerals in a formation is, therefore, sufficient to account for the occurrence in it of high sodium bicarbonate waters.