US 10,619,000 B2  74  73  <Extraction>  The succinic acid aqueous solution was extracted with  10% hydrated MEK in the same method as that in Refer› ential Example 2. In the mixer-settler, 10% hydrated MEK  in an amount of 0.5 weight times the succinic acid aqueous  solution was fed at a rate of 20 g/min and 10 g/min,  respectively. The recovered intermediate phase was sub› jected to pressure filtration, and the raffinate phase was  further subjected to countercurrent multi-stage continuous  extraction with 10% hydrated MEK in an amount of 1.0  weight time the raffinate phase. As a result, 2,882 g of the  extract phase and 1,593 g of the raffinate phase were  recovered. A composition thereof is as follows.  <Distillation>  Distillation was carried out in the same method as that in  Referential Example 2, thereby recovering 438 g of a  succinic acid concentrated liquid. A composition thereof is  shown in the following Table 7. The analysis of each of the  organic acid and the sugar was carried out by means of $_{20 }$ high-performance liquid chromatography under conditions  equal to those in Table 2.  Recovered succinic acid/newly fed succ1mc acid: 113x  0.959/(1,384x0.0865)=91 %  <Highly Purification>  A 30 wt % crude succinic acid aqueous solution was  prepared from the above-obtained crude crystal at 80°  C.,  and a chemically activated, powdered activated carbon Dia- hope 8ED (manufactured by Calgon Mitsubishi Chemical  Corporation) was then added in an amount of 0.3 wt %  relative to the succinic acid. The activated carbon treatment  was carried out at 80°  C. for 2 hours with stirring at 200 rpm  using a three-one motor.  After filtering out the activated carbon at 80° C., the  resulting succinic acid aqueous solution was charged in an  SUS 316-made 500-mL induction stirring autoclave and  subjected to a hydrogen treatment in the presence of 5%  Pd/C (Wako’s catalogue 326-81672, catalyst amount: 0.06  wt % relative to succinic acid) under a condition at a  hydrogen pressure of 0.8 MPa at a reaction temperature of  80°  C. for a reaction time of 3 hours. As a result, fumaric  acid contained in an amount of 1.3% by weight relative to  succinic acid in crude succinic acid was entirely derived into  succinic acid. After completion of the reaction, the catalyst  was filtered out. The hydrogen treatment solution was sub› stantially free from an odor.  This hydrogen-treated succinic acid aqueous solution was  subjected to an ion exchange treatment ( cation exchange  resin (Diaion SKlB-H (manufactured by Mitsubishi Chemi› cal Corporation): H type) at 80° C., thereby removing  cations having been contained in a trace amount.  The ion exchange-treated succinic acid aqueous solution  was cooled to 20°  C. with stirring for about 90 minutes and  further kept at 20°  C. for one hour to deposit a crystal. The  deposited succinic acid was recovered by means of filtration,  and the crystal was washed with cold water and then dried  in vacuo at 70°  C. for 12 hours to obtain white odorless  succinic acid (YI=-1).  In the resulting succinic acid, the concentrations of Na, K,  Mg, Ca and NH$_{4 }$ ions were all not more than 1 ppm; the  sulfur atom content was less than 1 ppm; and the nitrogen  <Crystallization>  Crystallization was carried out in the same method as that  in Referential Example 2, thereby recovering 113 g of  succinic acid and 568 g of a recovered liquid that is a mixed  liquid of a crystallization mother liquid and washings. A  composition of the resulting succinic acid is shown in the  following Table 8, and a composition of the resulting  recovered liquid is shown in the following Table 9. The  analysis of each of the organic acid and the sugar was carried  out by means of high-performance liquid chromatography  under conditions equal to those in Table 2.  TABLE 8-continued  TABLE 7  TABLE 9  TABLE 8  Composition of succinic acid concentrated liquid  Component  Succinic acid  Malic acid  Pyruvic acid  Acetic acid  Fumaric acid  a-Ketoglutaric acid  a-Ketovaline  Alanine  Valine  Glutarnic acid  Trehalose  Protein  MEK  Water  Extract phase  Concentrated liquid  Composition (% by weight)  4.51  29.7  0.19  1.24  0.00  0.00  0.92  6.03  0.12  0.81  0.01  0.05  0.02  0.15  0.00  0.01  0.00  0.01  0.00  0.00  0.00  0.00  0.01  0.08  81.0  03  13.2  Composition of obtained succinic acid  Component  Succinic acid  Malic acid  Pyruvic acid  Acetic acid  Fwnaric acid  a-Ketoglutaric acid  a-Ketovaline  Alanine  Valine  Glutarnic acid  Composition (% by weight)  95.9  0.0  0.0  0.1  3.1  0.0  0.0  0.0  0.0  0.0  Composition of obtained succinic acid  Component  Composition (% by weight)  Trehalose  0.0  Protein  18 ppm  MEK  0.0  Water  0.8  Composition of recovered liquid  Component  Succinic acid  Malic acid  Pyruvic acid  Acetic acid  Fumaric acid  a-Ketoglutaric acid  a-Ketovaline  Alanine  Composition (% by weight)  3.63  0.95  0.00  4.62  0.01  0.04  0.11  0.01  0.01  0.00  0.00  0.06  0.02  Valine  Glutarnic acid  Trehalose  Protein  MEK 