Formic Acid Catalyzed Hydrolysis of SO3in the Gas Phase: A Barrierless Mechanism for Sulfuric Acid Production of Potential Atmospheric Importance

2011 ◽  
Vol 133 (43) ◽  
pp. 17444-17453 ◽  
Author(s):  
Montu K. Hazra ◽  
Amitabha Sinha
Keyword(s):  
Sulfuric Acid ◽  
Formic Acid ◽  
Gas Phase ◽  
Acid Production ◽  
Sulfuric Acid Production ◽  
Acid Catalyzed ◽  
Hydrolysis Of

Theoretical Studies on Gas-Phase Reactions of Sulfuric Acid Catalyzed Hydrolysis of Formaldehyde and Formaldehyde with Sulfuric Acid and H2SO4···H2O Complex

2013 ◽  
Vol 117 (24) ◽  
pp. 5106-5116 ◽  
Author(s):  
Bo Long ◽  
Xing-Feng Tan ◽  
Chun-Ran Chang ◽  
Wei-Xiong Zhao ◽  
Zheng-Wen Long ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Gas Phase ◽  
Theoretical Studies ◽  
Gas Phase Reactions ◽  
Acid Catalyzed ◽  
Hydrolysis Of

Acid-catalyzed Solvolysis of Isonitriles. I

1971 ◽  
Vol 49 (14) ◽  
pp. 2455-2459 ◽  
Author(s):  
Y. Y. Lim ◽  
A. R. Stein
Keyword(s):  
Formic Acid ◽  
Acid Catalysis ◽  
Hydrolysis Product ◽  
Rate Dependence ◽  
Linear Rate ◽  
First Order ◽  
Methyl Amine ◽  
Acid Catalyzed ◽  
Pseudo First Order ◽  
Hydrolysis Of

The acid-catalyzed hydrolysis of methyl isonitrile has been examined. The initial hydrolysis product is N-methylformamide which is further hydrolyzed to methyl amine and formic acid at a much slower rate. The hydrolysis to N-methylformamide is pseudo-first order in methyl isonitrile and shows a linear rate dependence on concentration of general (buffer) acid at fixed pH. The significance of general acid-catalysis in terms of the mechanism of the hydrolysis is considered and taken as evidence for carbon protonation rather than nitrogen protonation as the initiating step.

Isocarbostyrils. II. The Conversion of 2-Methyl-4-acyl-5-nitroisocarbostyrils to 2-Substituted Indole-4-carboxylic Acids

1971 ◽  
Vol 49 (17) ◽  
pp. 2797-2802 ◽  
Author(s):  
D. E. Horning ◽  
G. Lacasse ◽  
J. M. Muchowski
Keyword(s):  
Sulfuric Acid ◽  
Carboxylic Acid ◽  
Carboxylic Acids ◽  
Alkaline Hydrolysis ◽  
Mannich Reaction ◽  
Reductive Cyclization ◽  
Acid Catalyzed ◽  
Acid Anhydrides ◽  
Hydrolysis Of ◽  
Derivatives Of

The sulfuric acid catalyzed acylation of 2-methyl-5-nitroisocarbostyril with carboxylic acid anhydrides gave the corresponding 4-acylated derivatives 3, which underwent reductive cyclization to 2-substituted derivatives of 4-methyl-1,3,4,5-tetrahydropyrrolo[4.3.2.de]isoquinolin-5-one (4). Alkaline hydrolysis of the six-membered lactam in 4 was accompanied by a retro-Mannich reaction to produce 2-substituted indole-4-carboxylic acids in about 40 % overall yield from 3.

Pilot-Scale Bioleaching of Metals from Pyritic Ashes

2017 ◽  
Vol 262 ◽  
pp. 147-150
Author(s):  
Elina A. Vuorenmaa ◽  
Jarno Mäkinen ◽  
Tero Korhonen ◽  
Raisa Neitola ◽  
Anna H. Kaksonen
Keyword(s):  
Sulfuric Acid ◽  
Acid Production ◽  
Pilot Scale ◽  
Solution Ph ◽  
Mineral Salts ◽  
Sulfuric Acid Production ◽  
Stirred Tank Reactors ◽  
Working Volume ◽  
Guideline Values ◽  
The Government

Solid waste from sulfuric acid production may contain relatively high levels of metals such as Fe, Zn, Co, Cu and As that are harmful if inappropriately disposed of in the environment, but may be a valuable resource if metals can be recovered. The objective of this research was to investigate the pilot-scale acid bioleaching of metals from pyritic ashes, originating from the roasting of pyrite ores for sulfuric acid production and consisting mainly of hematite. Bioleaching was carried out at 25 °C in pilot-scale continuously stirred tank reactors (CSTR), with 50 L working volume in mineral salts medium supplemented with trace elements, 1 % (w/v) elemental sulfur and with pyritic ash pulp densities 10 % and 20 %. The reactors were inoculated with a mixed culture of iron- and sulfur-oxidising acidophiles containing Acidithiobacillus (At.) ferrooxidans, At. thiooxidans/albertensis, At. caldus, Leptospirillum ferrooxidans, Sulfobacillus (Sb.) thermosulfidooxidans, Sb. thermotolerans and some members of Alicyclobacillus genus. Metal leaching yields from pyritic ashes in the CSTR after 32 days were 54.6-56.7 % Cu, 41.7-43.2 % Zn, 1.7-1.8 % Co, 3.0-5.4 % As and 0.3-0.5 % Fe. Solution pH decreased during the experiment from 2.9 to 1.9-2.2. Elemental analysis using X-ray fluorescence showed that the contents of metals, except for As, in the leach residue were below the higher guideline values given in the Government decree on the assessment of the soil contamination and remediation needs by the Ministry of the Environment, Finland. Bioleaching facilitated the extraction of metals from pyritic ashes and the mitigation of environmental risks related to the residue disposal for other metals except for As.

Gas Phase Hydrolysis of Formaldehyde To Form Methanediol: Impact of Formic Acid Catalysis

2013 ◽  
Vol 117 (46) ◽  
pp. 11704-11710 ◽  
Author(s):  
Montu K. Hazra ◽  
Joseph S. Francisco ◽  
Amitabha Sinha
Keyword(s):  
Formic Acid ◽  
Gas Phase ◽  
Acid Catalysis ◽  
Hydrolysis Of
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