Yield Of Oxalic Acid Research Articles

Influence of milk whey, nitrogen and phosphorus concentration on oxalic acid production by Aspergillus niger

A factorial design at two levels was used to determine the effect of milk whey concentration and the addition of nitrogen (as NH4NO3) and phosphorus (as KH2PO4) on the oxalic acid production by Aspergillus niger. The results of the experiments indicated that milk whey contains enough nutrients for fungus growth, therefore medium supplementing with N and P is not necessary. The optimum milk whey concentration was 100 kg/m3 reaching a final oxalic acid concentration of 37 kg/m3 and a maximum production rate of 3.4 kg/m3 · d. The yield of oxalic acid was 0.4, a very high value compared to previous works.

Electrooxidation of ethylene glycol on bismuth-modified Pt(111)

The influence of predosed bismuth upon the electrooxidation kinetics and pathways of ethylene glycol on Pt(111) in 0.1 mol dm–3 HClO4 has been examined by means of voltammetry combined with real-time infrared spectroscopy. On both unmodified and bismuth-modified Pt(111), two major oxidation products, oxalic acid and CO2, are formed via distinct reaction pathways. The presence of predosed bismuth adatoms significantly alters the selectivity of the electrocatalyst in that the production of CO2 increases monotonically with the bismuth coverage at the expense of the oxalic acid yield. The formation of CO2 was also observed starting from oxalic acid and other partial oxidation products, yet bismuth exerts little effect on the reaction kinetics in these cases. Adsorbed CO was also seen to be produced at positive potentials prior to, and during, the electrooxidation of ethylene glycol and especially from aldehyde-containing partially oxidized species. While the presence of predosed bismuth efficiently eliminates adsorbed CO formation from ethylene glycol, it has little effect for the aldehyde reactants. Significantly and surprisingly, the results suggest that ensembles of contiguous active sites are required for the partial oxidation of ethylene glycol to form oxalic acid but not for the exhaustive electrooxidation pathway yielding CO2.

Thermochemical conversion of polysaccharides in concentrated alkali to glycolic acid

Degradation of starch and cellulose in alkaline solutions above 8N NaOH favored the production of glycolic acid. In 16N NaOH, starch and cellulose degraded at 240°C to produce, respectively, 46 and 43% yields of glycolic acid. At these same conditions, 24 and 12% yields of oxalic acid were also produced from starch and cellulose. Raising the amount of starch or cellulose above 10 g in 250 mL 16 N NaOH lowered the percent yields of glycolic and oxalic acids, but increased absolute yields sufficiently to consider larger polysaccharide: 16 N NaOH ratios for commercial use. Substituting KOH for NaOH lowered glycolic and oxalic acid yields, and demonstrated the effect of the alkali cation on the conversion reactions.

Utilisation of sugarcane trash and other cellulosic wastes for production of oxalic acid

The nitric acid oxidation process was developed for the production of oxalic acid from sugarcane trash, groundnut shells, corn cobs and rice husks. Good yields of oxalic acid (42·9–51·6% w/w) from the above raw materials were obtained under optimum conditions, with sugarcane trash as the preferable raw material. The absorption of waste nitrogen oxide gases in aqueous NaOH to get a valuable by-product, sodium nitrite, was also successful.

Sonolysis of formic acid-water mixtures

Mixtures of formic acid and water were insonated with 300 kHz ultrasonic waves under an atmosphere of argon. H 2, CO 2, CO and very small amounts of oxalic acid are the products. The oxalic acid yield decreases with increasing HCOOH concentration. However, the yields of the other products pass through a maximum at 15 M. A mechanism is discussed where the decomposition of HCOOH into radicals plays only a minor role, the main reactions being thermal dehydration. The reactions are attributed to the high temperatures which exist in the adiabatic compression phase of cavitating argon bubbles, the temperature becoming lower with increasing HCOOH content of the gas bubbles.

Oxidation of Coals in Liquid Phases. VII. Oxidation of Oxygen-containing Model Compounds of Coal by Oxygen in Concentrated Sodium Hydroxide Solutions

Abstract Oxidation of 26 model compounds of low-ranked coal was performed to study the formation mechanisms of oxalic acid from coal. A mixture of 0.02 mol of the model compound, 4–60 g of NaOH, and 50 g of water was placed in a 300 cm3 autoclave and oxidized at 523 K and PO2=5 MPa for 120 min. Acetic acid was produced from phenols within 15 min and oxidized selectively to oxalic acid. The yield ratio(yield of oxalic acid(%)/yield of CO2 (%)) from most of the model compounds was higher than 1. These phenomena agreed well with those of low-ranked coal under the same oxidation conditions. The overall reaction rates, yields of oxalic acid, and yield ratios increased rapidly with an increasing concentration of NaOH as in the oxidation of coal. This behavior can be explained resonably well by an alkali-catalyzed oxidation mechanism regarding organic substances.

Radiation treatment of molasses

Molasses are a by-product of the sugar industry. Their annual production in México in around 1 million tons and are mainly used as a complement for animal feeding and for the production of alcohols. Their value is relatively low compared with another chemicals. When molasses are irradiated with gamma radiation or accelerated electrons, in presence of nitric acid and oxygen, it is obtained oxalic acid and several polymeric compounds. In both cases, the same products are obtained, but the yield is greater with electrons. It has been studied the effect of dose and dose rate in the yields. As example, when mixtures of molasses-nitric acid, with an initial concentration of 26% of total sugar reductors, are irradiated with 1.0 MeV electrons, in a continuous flow reactor, at 0.11 Gy sec to a total dose of 30 KGy, the oxalic acid yield is around 44% of the total chemical reductors used. The separations of the radiolytic products was made by successive decantations and concentrations, and purified by recristallizations. From the analytical information, the minimal formula were calculated for the acid product and the polymeric compounds.

Effect of different nitrogen sources on the yield of oxalic acid bySclerotium rolfsii

Of the different sources of nitrogen used for the yield of oxalic acid by parent and X-ray mutated strains of Sclerotium rolfsii, organic nitrogen sources gave better results than inorganic nitrogen sources. Cysteine is the best nitrogen source for the parent and one mutant strain while phenylalanine is for the second one.

Oxidation of sodium salts of alduronic and glyculosonic acids by sodium peroxide

Because, in the presence of a large excess of alkaline hydroperoxides, aldoses are oxidized stepwise to formic acid, it was expected that alduronic acids would be degraded to formic acid and carbon dioxide by the mechanism previously proposed. However, in addition to the products expected, substantial yields of oxalic acid were found, indicating a second mechanism, proposed here. With alkali-metal hexuronates, one mechanism yields five moles of formic acid and one mole of carbon dioxide per mole of substrate, whereas the second mechanism yields four moles of formic acid and one mole of oxalic acid. The results show that, under highly alkaline conditions, the two mechanisms are of approximately equal importance. Oxidation of a D- xylo-5-hexulosonate begins with the cleavage of glycolic acid, and this is followed by degradation of the resulting tetruronic acid by the two mechanisms described for the degradation of hexuronic acids. With 2-hexulosonates, also, two reaction-mechanisms appear to be necessary to account for the products formed under highly alkaline conditions; the main reaction (80%) yields one mole each of carbon dioxide and pentonic acid per mole, whereas the other yields one mole of oxalic acid and four moles of formic acid. Under moderately alkaline conditions, both the alduronic acids and the 2-keto acids react almost entirely by the mechanism that yields carbon dioxide; no detectable amount of oxalic acid was found. In all cases, small amounts of unknown products, not further investigated, are formed. The following compounds were studied: sodium D-galacturonate, sodium D-glucuronate, potassium D-mannuronate, sodium D- lyxo-2-hexulosonate, sodium D- arabino-2-hexulosonate, calcium D- xylo-5-hexulosonate, and glyoxylic acid.

The production of oxalic acid from new zealand plant wastes

AbstractRecent work has shown that oxalic acid is capable of replacing sulphuric acid, in whole or part, in the superphosphate process.The most promising method of manufacturing cheap oxalic acid on a large scale is by nitric acid oxidation of plant wastes, provided that most of the nitric acid can be recovered for re‐use. With wood and straw waste, oxalic acid yields of up to 85% are obtained at optimum conditions of temperature, catalyst concentration and reaction time. However, the loss of nitric acid is sufficiently low only when fuming nitric acid is used. In this case the ratio of oxalic acid produced to nitric acid lost is 7:1. The nitric acid lost is converted largely into nitrous oxide and this conversion appears to be connected with the oxidation of the lignin fraction of the sawdust.