Succinic recovery

N). This area of the process has received considerable attention in recent years as companies strive to improve efficiency and reduce waste. Patents have appeared describing addition of SO2 to improve ion-exchange recovery of vanadium (111), improved separation of glutaric and succinic acids by dehydration and distillation of anhydrides (112), formation of imides (113), improved nitric acid removal prior to dibasic acid recovery (114), and other claims (115). 

Succinic acid reacts with urea in aqeous solution to give a 2 1 compound having mp 141°C (116,117), which has low solubiUty in water. A method for the recovery of succinic acid from the wastes from adipic acid manufacture is based on this reaction (118,119). The monoamide succinamic acid [638-32-4] NH2COCH2CH2COOH, is obtained from ammonia and the anhydride or by partial hydrolysis of succinknide. The diamide succinamide [110-14-3], (CH2C0NH2)2, nip 268—270°C, is obtained from succinyl chloride and ammonia or by partial hydrolysis of succinonitrile. Heating succinknide with a primary amine gives A/-alkylsucckiknides (eq. 9). 

Various techniques have been proposed for the recovery of pure succinic acid, including extraction (141—145), selective crystalliza tion (146—151), heating to dehydrate the acid and subsequent recovery of succinic anhydride by distillation (152), esterification foUowed by fractionation of the mixture of the esters (65—69), and separation as urea adduct (118,119). 

Theobromine was determined by GC in various foods (bitter chocolate, milk chocolate, chocolate cake, cocoa powder, chocolate milk), and results are given in graphs and tables.27 Homogenized samples were boiled in alkaline aqueous media, then fat was extracted with n-hexane. The aqueous layer was acidified with diluted HC1 and NaCl was added. Theobromine was extracted from this treated aqueous solution with dichloromethane and the extract was evaporated to dryness. The residue was redissolved in dichloromethane containing an internal standard. GC analysis was performed on a column packed with 1% cyclohexane dimethanol succinate on Gaschrom Q, with FID. Average recoveries were 99 to 101%, coefficient of variation was less than 3% and the limit of detection for theobromine in foods was about 0.005%. 

Ealy [ 75 ] also used conversion to alkyl mercury iodides for the gas chromatographic determination of organomercury compounds in benzene extracts of water. The iodides were then determined by gas chromatograph of the benzene extract on a glass column packed with 5% of cyclohexane-succinate on Anakron ABS (70-80 mesh) and operated at 200 °C with nitrogen (56 ml min-1) as carrier gas and electron capture detection. Good separation of chromatographic peaks was obtained for the mercury compounds as either chlorides, bromides, or iodides. The extraction recoveries were monitored by the use of alkylmer-cury compounds labelled with 203 Hg. 

Figure 12.1 Clearance of small-molecule impurities from process buffers in a formulated protein product. Trace A the NMR spectrum of a control sample containing a mixture of three components (succinate, tetraethylammonium, and tetramethylammonium) in the final formulation buffer (sodium acetate). These three components were used in the recovery process for a biopharmaceutical product. Traces B and D the proton NMR spectra of the formulated protein product. No TEA or TMA were detected, but a small amount of succinate was observed in this sample. Traces C and E the proton NMR spectra of a formulated protein product spiked with 10 jag/ml of succinate, TEA, and TMA. Traces D and E were recorded with CPMG spin-echo method to reduce the protein signals. The reduction of NMR signals from the protein allows for better observation of the small-molecule signals.

Hogle, B.P., Shekhawat, D., Nagarajan, K., Jackson, J.E., and Miller, DJ. Formation and recovery of itaconic acid from aqueous solutions of citraconic acid and succinic acid, Ind. Eng. Chem. Res., 41(9) 2069-2073, 2002. 

A previously reviewed method was applied for OTC, TC, CTC, DXC, and DMC analysis in tissue and egg samples however, further optimization and improvement were necessary. The optimal recoveries from tissue were obtained using succinate buffer and MeOH as a depro-teinization agent. The eluate from the MCAC column was acidified and further purified on an Empore disk equipped with a poly(styrene-divinylbenzene)-RP sulphonated membrane previously activated with MeOH and hydrochloric acid (pH 1.0). The elution of TCs was done with methanolic ammonia solution. The extract was evaporated under vacuum and reconstituted in oxalic acid solution. Even though the stability of TCs is poor under alkaline conditions, no influence on the recovery was observed (59-76% with RSD < 6.5% for kidney samples) (26). 

Notice the intermediate in the reaction of citrate synthase (fig. 13.7). Do you think at some time in the future evolution will produce a variety of citrate synthase that recovers the energy in the thioester, analogous to the production of GTP (ATP) by succinate thiokinase (page 291) Would this energy recovery have any effect on the thermodynamics of the tricarboxylic acid cycle ... 

There is no current commercial biologic process for the production of succinic acid. In past laboratory systems, when succinic acid has been produced by fermentation, lime is added to the fermentation medium to neutralize the acid, yielding calcium succinate (2). The calcium succinate salt then precipitates out of the solution. Subsequently, sulfuric acid is added to the salt to produce the free soluble succinic acid and solid calcium sulfate (gypsum). The acid is then purified with several washings over a sorbent to remove impurities. The disposal of the solid waste is both a directly economic and an environmental concern, as is the cost of the raw materials. Some key process-related problems have been identified as follows (1) the separation of dilute product streams and the related costs of recovery, (2) the elimination of the salt waste from the current purification process, and (3) the reduction of inhibition to the product succinic acid on the fermentation itself. Acetic acid is also a byproduct of the fermentation of glucose by Anaerobiospirillium succiniciproducens almost 1 mol of acetate will be produced for every 2 mol of succinate (3). Under certain cultivation conditions by a mutant Escherichia coli, lesser amounts of acetate can be produced (4,5). This byproduct will also need to be separated. 

It may also be economical to remove the inhibitory product directly from the ongoing fermentation by extraction, membranes, or sorption. The use of sorption with simultaneous fermentation and separation for succinic acid has not been investigated. Separation has been used to enhance other organic acid fermentations through in situ separation or separation from a recycled side stream. Solid sorbents have been added directly to batch fermentations (18,19). Seevarantnam et al. (20) tested a sorbent in the solvent phase to enhance recovery of lactic acid from free cell batch culture. A sorption column was also used to remove lactate from a recycled side stream in a free-cell continuously stirred tank reactor (21). Continuous sorption for in situ separation in a biparticle fermentor was successful in enhancing the production of lactic acid (16,22). Recovery in this system was tested with hot water (16). 

Despite promising initial results of good capacity (0.06 g of succinic acid/ g of sorbent), 70% recovery using hot water, and a recovered concentration of >100 g/L, the hot water regeneration was not stable over 10 cycles in a packed column. Therefore, alternative regeneration schemes using acid and base were examined for the best resins and more sorbents were reexamined at this time. 

Tests were performed with both simulated broth containing succinic acid at various concentrations and actual broth provided by MBI. Seven resins were tested for regenerability and stability with acid XUS 40285, Dowex 1x2, XUS 40283, XUS 440323, XFS-40422, IRA-35, and IRA-93. Previous results had shown a decrease in capacity with repeated hot water regeneration. It is essential for economical operation that the organic acid recovery be >90% and that the sorbents be stable for at least 20 cycles (based on industrial comments). Several resins were tested for stability with a single-step dilute-acid regeneration. The resins were either low capacity after five cycles or had incomplete recovery of the succinic acid (data not shown). Therefore, we modified the procedure to extract the succinic acid first with dilute base, then hot water. 

Recovery (% succinic acid after 10 successive cycles of loading and regeneration)... 

Resin Capacity (cycle 5) (g succinic acid/g resin) (g Capacity (cycle 10) succinic acid/g resin) Glucose capacity (g/g resin) Recovered in first step of base Combined recovery from base and hot water steps... 

Seven of the most promising resins were tested for regenerability and stability using a modified extraction procedure combining acid and hot water washes. Two (XUS 40285 and XFS-40422) showed both good stable capacities for succinic acid over 10 cycles and >95% recovery in a batch operation. 

Quantitative recoveries of tartaric, malic, citric, citramalic and succinic acids are achieved, and are higher than 90% for acetic and... 

However, for economy of production, maximum yields of alkaloids, and ease of recovery of the products, certain culture media containing relatively simple nutrient sources are preferred. For example, the media which are useful in the production of the alkaloids include an assimilable source of carbon such as glucose, sucrose, starch, molasses, dex-trins, corn steep solids, corn syrup liquor, sorbitol, mannitol, lactose, and the like. A preferred source of carbon is mannitol. Additionally, the media employed contain a source of assimilable nitrogen such as oatmeal meat extracts, peptones, amino acids and their mixtures, proteins and their hydrolysates, com steep liquor, soybean meal, peanut meal and ammonium salts of organic acids such as the citrate, acetate, malate, oxalate, succinate, tartrate and like salts. 

Electrodialysis uses stacks of pairs of anion- and cation-exchange membranes in deionizing water and in recovery of formic, acetic, lactic, gluconic, citric, succinic, and glutamic acids from their sodium and potassium salts in fermentation broths.114 This may have an advantage over processes that involve purification through calcium salts. Electrodialytic bipolar membranes have been used to recover concentrated mineral acids from dilute solution.115 They can be used to convert sodium chloride to hydrogen chloride and sodium hydroxide in a process that avoids the use of chlorine.116 Soy protein has been precipitated by... 

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