US 8,927,766 B2  27  28  TABLE 3-continued  Hydrocarboxylation of Paraformaldehyde in Prop ionic Acid Catalyzed by  AMBERLYST 36D (4.6-4.8 wt%).  Yield of  desired  Pressure Temperature  Feed(wt%)  products  Selectivity  EX  (psig)  ("C.)  F0  A3  Water  Time(h)  (%)  (%)  21  500  100  9.0  88.8  0.0  0.5  9  73  1.0  12  87  1.5  17  85  2.0  21  81  2.5  24  81  3.0  28  81  22  1,500  100  8.6  84.4  4.9  0.5  4  27  1.0  4  28  1.5  5  28  2.0  6  24  2.5  6  24  3.0  7  26  23  500  100  8.5  84.4  4.9  0.5  77  1.0  6  87  1.5  6  80  2.0  6  80  2.5  7  75  3.0  8  76  24  1000  100  8.8  86.6  2.5  0.5  6  77  1.0  10  82  1.5  12  90  2.0  13  87  2.5  19  90  3.0  21  90  25  500  140  9.0  88.8  0.0  0.5  45  81  1.0  63  85  1.5  77  99  2.0  78  104  2.5  78  106  3.0  79  108  26  1,500  140  8.6  84.4  4.9  0.5  38  75  1.0  48  78  1.5  59  83  2.0  65  90  2.5  68  92  3.0  69  92  27  1,000  120  8.6  86.6  2.5  0.5  16  68  1.0  24  70  1.5  32  70  2.0  39  86  2.5  48  87  3.0  52  89  28  500  140  8.6  84.4  4.9  0.5  20  63  1.0  32  65  1.5  40  69  2.0  54  76  2.5  48  79  3.0  52  82  29  1,500  140  9.0  88.8  0.0  0.5  67  97  1.0  82  100  1.5  75  102  2.0  84  107  2.5  84  108  3.0  84  108  30  2,000  140  9.0  88.9  0.0  0.5  78  97  1.0  83  100  1.5  84  102  2.0  85  103  2.5  86  104  3.0  87  104  31  2,000  140  8.6  84.5  4.9  0.5  38  77  1.0  61  84  1.5  71  87  2.0  76  89  2.5  77  90  3.0  79  91 