Figures (10)  Tables (7)
    • Figure 1. 

      Reaction equation for the synthesis of adipic acid by oxidation of cyclohexene with H2O2 catalyzed by Na2WO4.

    • Figure 2. 

      High pressure microchannel reactor.

    • Figure 3. 

      The Tr, Tj, and qr curves of adipic acid synthesis reaction in RC1e experiment.

    • Figure 4. 

      Tcf curves and MTSR of adipic acid synthesis reaction (a) Phase A; (b) Phase B.

    • Figure 5. 

      Effect of reaction temperature and residence time on hydrogen peroxide ecomposition in a stainless steel capillary microreactor. (a) Reaction condition 1; (b) Reaction condition 2.

    • Figure 6. 

      Relationship between k1*Vreactor and H2O2 conversion rate. (a) Reaction condition 1; (b) Reaction condition 2.

    • Figure 7. 

      Relationship between k0*Vreactor and hydrogen peroxide conversion rate. (a) Reaction condition 1; (b) Reaction condition 2.

    • Figure 8. 

      Experimental value and fitting curve of lnk to 1/T in hydrogen peroxide decomposition. (a) Reaction condition 1; (b) Reaction condition 2.

    • Figure 9. 

      Schematic diagram of gas to liquid ratio in pipelines.

    • Figure 10. 

      Green synthesis yield of adipic acid under different pressures and residence times.

    • MaterialMolecular formulaFinenessCAS No.Manufacturer
      H2O2 aqueous solutionH2O230.0%7722-84-1Sinopharm Chemical Reagent Co., Ltd.
      Sodium tungstateNa2WO4≥ 99.5%10213-10-2Shanghai Macklin Biochemical Co., Ltd.
      Concentrated H2SO4H2SO4≥ 98%7664-93-9Sinopharm Chemical Reagent Co., Ltd.
      EDTAC10H16N2O8AR60-00-4TCI (Shanghai) Development Co., Ltd.

      Table 1. 

      Material information used in decomposition experiments.

    • Reaction conditionn (H2O2) : n (Na2WO4)Molar concentration of H2SO4 (mol/L)Mass concentration of EDTA (g/L)
      14.4:0.060.22
      24.4:0.060.2218.3

      Table 2. 

      Information table of different reaction conditions.

    • Phase−ΔHr
      (kJ)
      Cp
      (J·K−1·g−1)
      ΔTad,r
      (°C)
      MTSRr (°C)
      (Adding EDTA)
      MTSRr (°C)
      (No EDTA)
      A103.213.837.23104.76209.77
      B504.774.1168.74268.81345.61

      Table 3. 

      Thermal parameters of adipic acid synthesis reaction in RC1e experiment.

    • Reaction temperature (°C)Reaction condition 2 calculated rate constant average k1 (10−3 s−1)Reaction condition 2 calculated rate constant average k1 (10−3 s−1)
      900.25950.2082
      950.77720.5695
      1001.33040.9690

      Table 4. 

      Average values of reaction rate constants at different temperatures in a stainless steel capillary microreactor calculated based on the first order reaction assumption under different reaction conditions.

    • Reaction temperature (°C)Reaction condition 2 calculated rate constant average k0 (10−3 mol/(L·s)Reaction condition 3 calculated rate constant average k0 (10−3 mol/(L·s)
      902.33801.9032
      956.16594.7752
      1009.47327.38445

      Table 5. 

      Average values of reaction rate constants at different temperatures in a stainless steel capillary microreactor calculated based on the zero order reaction assumption under different reaction conditions.

    • Reaction temperature (°C)k1(10−3 s−1)SD95% confidence interval of k1k0 (10−3 mol/L·s)SD95% confidence interval for k0
      900.25950.10450.2471−0.27192.33800.04932.2806−2.3953
      950.77721.07540.6495−0.90496.16590.02256.1397−6.1920
      1001.33042.90350.9856−1.67529.47320.02719.4417−9.5048

      Table 6. 

      Comparison of the calculated reaction rate constant k, standard deviation (SD), and confidence interval of the calculated reaction rate constant k based on the assumption of first and zero order reactions in a stainless steel capillary microreactor under reaction condition 2.

    • Reaction temperature (°C)k1 (10−3 s−1)SD95% confidence interval of k1k0 (10−3 mol/L·s)SD95% confidence interval for k0
      900.20820.07190.1967−0.21961.90320.00981.8875−1.9188
      950.56950.48710.4920−0.64701.90320.00684.7644−4.7861
      1000.96900.12010.7778−1.16014.77520.02057.3518−7.4171

      Table 7. 

      Comparison of the calculated reaction rate constant k, standard deviation (SD), and confidence interval of the calculated reaction rate constant k based on the assumption of first and zero order reactions in a stainless steel capillary microreactor under reaction condition 3.