Citric acid commercial production

Commercially available products are normally based on saturated monoglycerides with 60-90% monoglycerides, containing approximately 20% (min. 12%) esterified citric acid. The products are sold in powder or flake form. 

Crystallizes from water in large colourless prisms containing 2H2O. It is poisonous, causing paralysis of the nervous system m.p. 101 C (hydrate), 189°C (anhydrous), sublimes 157°C. It occurs as the free acid in beet leaves, and as potassium hydrogen oxalate in wood sorrel and rhubarb. Commercially, oxalic acid is made from sodium methanoate. This is obtained from anhydrous NaOH with CO at 150-200°C and 7-10 atm. At lower pressure sodium oxalate formed from the sodium salt the acid is readily liberated by sulphuric acid. Oxalic acid is also obtained as a by-product in the manufacture of citric acid and by the oxidation of carbohydrates with nitric acid in presence of V2O5. 

Itaconic 2Lcid[97-65-4] (methylenebutanedioic acid, methylenesuccinic acid) is a crystaUine, high, melting acid (mp = 167-168) produced commercially by fermentation of carbohydrates (1 4). Itaconic acid is produced in the broth from citric acid (qv). Isolated from the pyrolysis products of citric acid in 1836, this a-substituted acryUc acid received its name by rearrangement of aconitic, the acid from which it is formed by decarboxylation. 

Physiological Role of Citric Acid. Citric acid occurs ia the terminal oxidative metabolic system of virtually all organisms. This oxidative metabohc system (Fig. 2), variously called the Krebs cycle (for its discoverer, H. A. Krebs), the tricarboxyUc acid cycle, or the citric acid cycle, is a metaboHc cycle involving the conversion of carbohydrates, fats, or proteins to carbon dioxide and water. This cycle releases energy necessary for an organism s growth, movement, luminescence, chemosynthesis, and reproduction. The cycle also provides the carbon-containing materials from which cells synthesize amino acids and fats. Many yeasts, molds, and bacteria conduct the citric acid cycle, and can be selected for thek abiUty to maximize citric acid production in the process. This is the basis for the efficient commercial fermentation processes used today to produce citric acid. 

Fermentation. The microbial production of citric acid on a commercial scale was begun in 1923 utilizing certain strains yispergillus nigerio produce citric acid on the surface of a sucrose and salt solution. This tray fermentation technique is still used today, although it is being replaced by a submerged process known as deep tank fermentation (14—22). 

Citric acid fermentation of cane-molasses is by submerged fermentation in a 21 biostat (B. Braun) stirred fermenter. A strain of Aspergillus niger is the most widely used for commercial production. A. niger is also highly recommended in the present study, which can obtained from the American Type Culture Collection, Rockville, Maryland, USA. Molasses... 

The non-precipitable (that is, lower molecular weight) component of a product from thermolysis (170°C, 80 min.) of anhydrous amorphous sucrose acidified with 1% citric acid contains 19% disaccharides, predominantly di-D-fructose dianhydrides.93 Only two of these were identified, namely a-D-Fru/-1,2 2,1 - 3-D-Fru/ (5) and ct-D-Fru/-l,2 2,1 - 3-D-Frup (1) in the ratio 1 1. This result can be compared with the ratio 2 1 for the commercial caramel.94... 

Recognizing the need for a more economically and environmentally friendly citric acid recovery process, an adsorptive separation process to recover citric acid from fermentation broth was developed by UOP [9-14] using resin adsorbents. No waste gypsum is generated with the adsorption technique. The citric acid product recovered from the Sorbex pilot plant either met or exceeded all specifications, including that for readily carbonizable substances. An analysis of the citric acid product generated from a commercially prepared fermentation broth is shown in Table 6.2, along with typical production specifications. The example sited here is not related to zeolite separation. It is intent to demonstrate the impact of adsorption to other separation processes. 

Some typical commercial biotechnology products are citric acid, semi-synthetic penicillins and cephalosporins, and vitamin B12. World production volumes and bulk prices show a considerable range of values. Prices tend to be inversely proportional to the amount of product sold, that is, the scale of production, and to the concentration at which it can be produced in the bioreactor. The importance of the concentration at which each product is produced in determining the cost of purification and isolation, and thus the... 

As with drugs and purified biomarkers, thermal- and photostability of botanical products are the factors that must be considered. Commercial dried extract and capsules of SJW were evaluated under harmonized test conditions (25). Photostability testing showed all the constituents to be photosensitive in the tested conditions. However, different opacity agents and pigments influenced the stability of the constituents. Amber containers had little effect on the photostability of the investigated constituents. Long-term thermal stability testing showed a shelf life of less than four months for hyperforins and hypericins, even when ascorbic and citric acids were added to the formulation. 

Commercial Synthesis of Citric Acid Citric acid is used as a flavoring agent in soft drinks, fruit juices, and many other foods. Worldwide, the market for citric acid is valued at hundreds of millions of dollars per year. Commercial production uses the mold Aspergillus niger, which metabolizes sucrose under carefully controlled conditions. 

Occurreace. IR-R. R (-Tartaric acid occurs in the juice of the grape and in a few other fruits and plants. It is not as widely distributed as citric acid or St- (-malic acid. The only commercial source is Ihe residues from the wine industry. The racemic acid is nut a primary product of plant processes but is formed readily from the dextrorotatory acid by heating alone or with strong alkali or strong acid. triewi-Tanaric acid is not found in nauire It is obtained from the other isomers hy prolonged boiling with caustic alkali. 

Acids and bases are among the most familiar of all chemical compounds. Acetic acid in vinegar, citric acid in lemons and other citrus fruits, magnesium hydroxide (milk of magnesia) in commercial antacids, and ammonia in household cleaning products are among the acids and bases that we encounter every day. Hydrochloric acid is... 

Wehmet first described citric acid as a product of mold fermentation in 1893. However, it was only in 1919 that commercial fermentation processes based on sucrose were developed.34 Although many organisms have been shown to produce citric acid from carbohydrates, Aspergillus niger has been the best... 

Previously, itaconic acid was isolated from pyrolytic products of citric acid or produced by converting aconitic acid present in sugar cane juice. It is now produced on a commercial basis predominantly by direct fermentation of sugars. The biosynthesis of itaconic acid follows the metabolic sequence shown in Figure 30.15. 

Subsequent to this breakthrough, the subject was extensively investigated and was subsequently reviewed [390]. The acids most effective are BTCA, tricarballylic acid, and citric acid. Owing to the low cost and wide availability of citric acid, it is undergoing widespread commercial development for esterification cross-linking of cotton and paper products, often with minor amounts of BTCA as an activator, together with suitable catalysts. 

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