Carbon Dioxide → Maleic acid, calcium salt

Participants

Reaction Conditions

Reaction Steps

Maleic anhydride (109.21 g, 1.114 mole) was added to 200 ml of water in a three liter 4-neck flask that was equipped with a mechanical stirrer, thermometer, air sweep inlet and condenser with receiver. The mixture was heated to 85° C. and then 115.57 g, (0.77 mole) of tartaric acid was added along with 25 ml more water. Calcium carbonate (135.54 g, 1.355 mole) was slurried with 112 ml water and added slowly to the reactor. Alternating portions of disodium tartrate solution and calcium hydroxide were added to the reactor while maintaining the heat at 85° C. The total charge of calcium hydroxide was 51.87 g (0.700 mole). The disodium tartrate solution added contained disodium tartrate (277.42 g, 1.43 moles) and disodium maleate (141.81 g, 0.8863 mole). After the reaction to drive off the carbon dioxide and form calcium maleate was complete, the air sweep was begun while holding the reaction temperature at about ~91° C. A total of 730 ml water was collected in the receiver. Then sodium hydroxide, 93.91 g (1.1674 mole) was added and the reaction held at about ~91° C. for eighty minutes more. An additional 270 ml water was removed from the system over the course of the synthesis reaction. The reaction was then quenched and cooled with 230 ml of water (Sample A).

Provenance & Evidence