Formic acids mineralization

Table 5 Proposed kinetic scheme for formic acid mineralization...

Good soivent chloral hydrate, m-cresol, fluorinated alcohols, formic acid, mineral adds, phenols, trichloroethanol ... 

Dozzi MV, Livraghi S, Giamello E, Selli E (2011) Photocatalytic activity of S-and E-doped Xi02 in formic acid mineralization. Photochem Photobiol Sci 10(3) 343-349... 

Formic acid forms esters with primary, secondary, and tertiary alcohols. The high acidity of formic acid makes use of the usual mineral acid catalysts unnecessary in simple esterifications (17). Formic acid reacts with most amines to form formylamino compounds. With certain diamines imida2ole formation occurs, a reaction that has synthetic utiHty (18) ... 

The reaction of formate salts with mineral acids such as sulfuric acid is the oldest iadustrial process for the production of formic acid, and it stiU has importance ia the 1990s. Sodium formate [141-53-7] and calcium formate [544-17-2] are available iadustriaHy from the production of pentaerythritol and other polyhydric alcohols and of disodium dithionite (23). The acidolysis is technically straightforward, but the unavoidable production of sodium sulfate is a clear disadvantage of this route. 

Although less common, azeotropic mixtures are known which have higher boiling points than their components. These include water with most of the mineral acids (hydrofluoric, hydrochloric, hydrobromic, perchloric, nitric and sulfuric) and formic acid. Other examples are acetic acid-pyridine, acetone-chloroform, aniline-phenol, and chloroform-methyl acetate. 

Acids that are solids can be purified in this way, except that distillation is replaced by repeated crystallisation (preferable from at least two different solvents such as water, alcohol or aqueous alcohol, toluene, toluene/petroleum ether or acetic acid.) Water-insoluble acids can be partially purified by dissolution in N sodium hydroxide solution and precipitation with dilute mineral acid. If the acid is required to be free from sodium ions, then it is better to dissolve the acid in hot N ammonia, heat to ca 80°, adding slightly more than an equal volume of N formic acid and allowing to cool slowly for crystallisation. Any ammonia, formic acid or ammonium formate that adhere to the acid are removed when the acid is dried in a vacuum — they are volatile. The separation and purification of naturally occurring fatty acids, based on distillation, salt solubility and low temperature crystallisation, are described by K.S.Markley (Ed.), Fatty Acids, 2nd Edn, part 3, Chap. 20, Interscience, New York, 1964. 

There are several schemes for the synthesis of cellulose formates (slow) reaction of the polymer with formic acid faster reaction in the presence of a mineral acid catalyst, e.g., sulfuric or phosphoric acid. The latter route is usually associated with extensive degradation of the polymer chain. Reaction of SOCI2 with DMF produces the Vilsmeier-Haack adduct (HC(Cl) = N (CH3)2C1 ) [145]. In the presence of base, cellulose reacts with this adduct to form the unstable intermediate (Cell - O - CH = N" (CH3)2C1 ) from which cellulose formate is obtained by hydrolysis. The DS ranges from 1.2 to 2.5 and the order of reactivity is 5 > C2 > C3 [140-143,146]. 

Although formic acid is oxidised to CO2 by Pb(IV), kinetic data exist only for the oxidations with Hg(II), Hg(I) and Tl(III) in aqueous mineral acids and with Pd(II) in acetic acid . Rate equations are of the form... 

Mixed acid systems are blends of mineral acids and organic acids. Combinations that have been used in carbonate acidizing include acetic acid/HCl and formic acid/HCl. While these are less corrosive than hydrochloric acid alone, the organic acid may not react completely with the rock. Blends of formic acid and hydrofluoric acid have been used in high temperature sandstone acidizing and are less corrosive than HC1/HF blends. 

It is consequently no argument against the carbimine structure of hydrocyanic acid that it likewise does not yield carbon monoxide but formic acid (in addition to ammonia) on decomposition by mineral acids. 

Traditional industrial oxidation routes of alcohols use stoichiometric amounts of heavy metals or mineral acids [51]. Glycerol is also easily converted into formaldehyde, formic acid and carbon dioxide [52]. 

According to Tscherniak methylnitrolic acid decomposes in water to give formic acid and N2O, while Wieland found that when methylnitrolic acid 02NCH=NOH is boiled in aqueous solution, with or without the addition of a mineral acid it yields formic acid, nitrous oxide and fuhninic acid, which is precipitated as the silver or mercuric salt if silver or mercuric nitrate is added to the above mixture (equation 9). The yield of fulminate is increased by the presence of mineral acid and by boiling, but it is also formed at ambient temperatures. 

The acid-catalyzed hydrocarboxylation of olefins (the Koch reaction) can be performed in a number of ways.565 In one method, the olefin is treated with carbon monoxide and water at 100 to 350°C and 500 to 1000 atm pressure with a mineral-acid catalyst. However, the reaction can also be performed under milder conditions. If the olefin is first treated with CO and catalyst and then water added, the reaction can be accomplished at 0 to 50°C and 1 to 100 atm. If formic acid is used as the source of both the CO and the water, the reaction can be carried out at room temperature and atmospheric pressure.566 The formic acid procedure is called the Koch-Haaf reaction (the Koch-Haaf reaction can also be applied to alcohols, see 0-103). Nearly all olefins can be hydrocarboxylated by one or more of these procedures. However, conjugated dienes are polymerized instead. 

Although 3-amino-l,2,4-thiadiazoles (e.g. the 5-phenyl homolog) fail to yield nitrosamines under the usual conditions,126 5-nitrosamines are well known.81, 5,190,191 Thus, 3-alkoxy-,8 3-alkylthio-,85 3-dialkyl-amino-,87 and 3-alkylsulfonyl-5-amino-86 (243) as well as 3-aryl-5-arylamino-l,2,4-thiadiazoles,74 on treatment with the calculated quantity of sodium nitrite in dilute mineral acid, or concentrated formic acid, yield crystalline nitrosamines (244). Their unusual stability has permitted a close study of their formation and properties. 170 Their positive Liebermann reaction85,87,170 and the results of their methylation (outlined in the reaction scheme) show that nitro-sation occurs in the side-chain and not in the nucleus.170... 

The thiocyanates, except those of the heavy metals, are decomposed in the cold by dilute mineral acids, and on heating, the free thiocyanic acid distils over. With moderately concentrated acid, carbonyl sulphide is produced (see p. 270), whilst concentrated sulphuric acid causes rapid decomposition, with evolution of pungent vapours containing carbonyl sulphide, formic acid, carbon dioxide and sulphur dioxide. 

Esters of formic acid (Expt 5.143) are most simply prepared from the alcohol and an excess of formic acid, which, being a comparatively strong acid, does not require the use of added mineral acid to catalyse the esterification reaction. Sulphuric acid in any case should not be added since it causes the decomposition of formic acid to carbon monoxide. 

There are few studies of respiration of organic acids other than amino acids. Percentage respiration of malonic and acetic acids seems similar (ca. 20%) to that of the other compounds mentioned so far, according to experiments in a Swedish lake (Bertilsson and Tranvik, 1998). In contrast, nearly all of the formic acid (98%) taken up by bacteria is mineralized to C02 (Bertilsson and Tranvik, 1998). 

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