Formic acid liquors

The pH of 1.2 liters of filtrate containing 3.B mg/ml of cytidine diphosphate choline, obtained by removing solid matters from the culturing liquor, was adjusted to a pH of B.5 with a 0.5N KOH solution. The filtrate was passed through a column of strongly basic anion exchange resin, Dowex 1 x 2 (formic acid type). After washing the resin with water, a formic acid... 

After treatment of XXXVI with aqueous barium hydroxide, the liquor contained formic, methoxyacetic, and ethoxyacetic acids, methoxyacetone, and ethoxyacetone, produced by the two modes of cleavage XXXVIa and XXXVIb. Formic acid was converted with red mercuric oxide to carbon dioxide this was recovered as barium carbonate, the radioactivity of which was a measure of the C14 incorporated into Cl of kojic acid in the biosynthetic process. The alkoxyacetones were removed from the liquor by steam distillation, and converted to iodoform and a mixture of methoxy- and ethoxy-acetic acids. The iodoform was recovered by filtration its radioactivity indicated the proportion of C14 incorporated into C4. The alkoxy-... 

Methyl esters were identified by comparison with authentic compounds on both the Carbowax 20M column and a XE-60 (a General Electric cyanosilicone gum) column. Some of the earlier identifications were made with a Carbowax 20M + H3P04 column and confirmed on l,2,3-tris(2-cyanoethoxy) propane. Also, some of the analyses of free acids were run on a Carbowax 20M-TPA(terephthalic acid terminated) column rather than the FFAP. Quantitative analysis of free acids and methyl esters was carried out using internal standards. Acetophenone was used with the acids, and veratrole was used with the methyl esters. Formic acid in the nitrobenzene and nitric acid liquors was analyzed quantitatively by direct calibration. 

In the afterchroming method with chrome-developing dyes, the dyeing liquor is prepared with formic acid (pH 3.5-3.8), sodium sulfate, and an amphoteric leveling agent as a wool protectant. The process is started at 40 °C, and dissolved dye is added. The system is heated, and dyeing is performed at 90°C for 30-... 

In the dyeing process, the pH is set at 4.5-5.5 (acetic acid, ammonium sulfate, or ammonium acetate), and the dyeing auxiliaries are added to the liquor. The dyes are added at 30-50°C the system is heated and dyed at boiling temperature. After rinsing, formic acid is used for acidification to improve the feel and wetfastness. 

In aftertreatment, the exhausted bath or fresh liquor is adjusted to pH 4.5 with formic acid, and Synthane is added. Aftertreatment is started at 40°C, and the material is treated at 70-80°C it is then rinsed. 

The mother liquors and washings of fractions I and II are concentrated from a volume of about 1.7 liters to 250 ml, the pH is adjusted to 2.5 with 100% formic acid and the solution is stored overnight in a refrigerator, whereby further substance crystallizes. This is filtered off under suction and washed with a small amount of water. The residue on the suction filter is azeotropically distilled with ethanol. There is obtained solid, almost colorless title substance which is denoted as B. B is purer than A according to thin-layer chromatography. 

In the process (Fig. 2), the main concern in mixing is to avoid loss of temperature control in this exothermic reaction, which can lead to excessive byproduct formation and/or reduced yields of pentaerythritol. The reaction time depends on the reaction temperature and may vary from about 0.5 to 4 hours at final temperatures of about 65 and 35°C, respectively. The reactor product, neutralized with acetic or formic acid, is then stripped of excess formaldehyde and water to produce a highly concentrated solution of pentaerythritol reaction products. This is then cooled under carefully controlled crystallization conditions so that the crystals can be readily separated from the liquors by subsequent filtration. 

In the lowest tank of the cascade, which has no electrodes, the remaining hypochlorite is removed from the liquor, because otherwise the hypochlorite may corrode the steel parts of the next equipment. Tor this purpose the electrolyte in the lowest tank is heated to 80 to 95 °C, to convert hypochlorite into chlorate. The remaining traces of hypochlorite are reduced by formic acid. Finally, the electrolyte is neutralized by sodium hydroxide, to precipitate iron which passed into the solution from the cathodes. 

Hardwood cooking liquors as well as the resulting evaporation condensates from acid liquors contain appreciable quantities of acetic acid. Because the solutions are very dilute, an economic recovery of the acetic acid is difficult but highly desirable to avoid pollution from discharges. Acetic acid can be recovered from neutral sulfite cooking liquors by extraction of the acidified liquor with organic solvents followed by distillation. Formic acid present in small quantities must be removed by azeotropic distillation if a pure product is required. 

The production of wood pulp from lignocellulosic materials by treatment with various chemical liquors, particularly the neutral sulfite semichemical process and the kraft or sulfate process, gives residual black liquors. These contain salts that carry acetic acid and formic acid equivalent to 5% or more of the dry weight of the wood. 

Liquors from Neutral Semichemical Pulping and from Kraft Pulping. In making neutral sulfite semichemical pulp, the black liquors may have about 10 parts of water to 1 part of total solids, of which about one-third is sodium acetate and sodium formate. After evaporation to about 1 part solids to 1 part water, sulfuric acid is added to the concentrate to free the acetic and formic acids. When the concentrate is extracted with acetone, the mixed acids are obtained, the acetone is separated for recycle, and the acids are concentrated and refined. The raffinate is stripped and is passed to the usual furnace to be burned for recovery of the inorganic salt values. This process gives a smelt of sodium sulfate, which may be used in the kraft process as chemical makeup. The loss of the fuel value of the acetic and formic acids is practically negligible. 

Liquors of the kraft process itself contain a large amount of free alkali, which must be neutralized by sulfuric acid before the acetic and formic acids are freed. The corresponding amount of sodium sulfate produced from the free alkali and from the acetate and formate decomposition may be more than can be reused in the recycle liquor system. On the other hand, since the makeup of liquors for a kraft process requires the addition of fresh sodium sulfate as well as the sulfate radical from... 

Hence, a part of the black liquors (10-50%) of a kraft plant may be processed to free, and subsequently to recover, the acetic acid as described by the addition of sulfuric acid and the formation of sodium sulfate. This new sodium sulfate from the sulfuric acid is present in the raffinate from the extractor it is thus the makeup for the balance of the liquors (50-90% ) that can be processed conventionally without recovery of the acetic and formic acids. The liquors from the raffinate are added to the other liquors before they go to the drier and the furnace. This part of the liquors (10-50%) recovers that much of the volatile acids that would otherwise be lost in the burner as salts. 

The exact order of the production steps may vary widely in addition, some parts of the process may also vary. Metal formate removal may occur immediately after the reaction (62) following formaldehyde and water removal, or by separation from the mother liquor of the first-stage crystallization (63). The metal formate may be recovered to hydroxide and/or formic acid by ion exchange or used as is for deicing or other commercial applications. Similarly, crystallization may include sophisticated techniques such as multistage fractional crystallization, which allows a wider choice of composition of the final product(s) (64,65). 

Qeaning Up At the end of this reaction there should be no formaldehyde remaining in the reaction mixture. Should it be necessary to destroy formaldehyde it should be diluted with water and 7 mL of household bleach added to oxidize 100 mg of paraformaldehyde. After 20 min it can be flushed down the drain. The formic acid solvent from the reaction and aqueous washings should be combined, neutralized with sodium carbonate, and flushed down the drain. Mother liquor from recrystallization is placed in the organic solvents container. 

The pH of the liquor is adjusted to 4 0 to 4-5 by further addition of formic acid or sodium carbonate according to which is necessary. 

Method 2 The dye liquor is made up with 10 to 15 per cent of Glauber s salt crystals and 3 to 5 per cent of acetic acid (30 per cent). The temperature is raised to 40°C (105°F) and the goods are entered and, if possible, run for 10 to 20 minutes to equalize their pH. The dye is then added and the liquor is raised to the boil over a period of 45 minutes. Boiling is continued, and after 40 to 45 minutes exhaustion may be completed by slowly adding a further 1 to 3 per cent of acetic acid (30 per cent), 1 per cent of sulphuric acid 168°Tw(98 per cent), or 1 per cent of formic acid (85 per cent). This method would be used for dyes of the type in Table 15.5 and, if further additions of dyestuffs of this class are necessary to correct the shade, the liquor should be cooled. 

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