Production of sodium hydrosulfite from formates

Claim 2

METHOD OF PREPARING SODIUM HYDROSULFITE (NA2S2O4) FROM FORMATES COMPRISING: A. ABSORBING SULFUR DIOXIDE (SO2) IN METHYL ALCOHOL (CH3OH) AS A FIRST FEED SOLUTION; B. DISSOLVING SODIUM HYDROXIDE (NAOH) AND SODIUM FORMATE (HCOONA) IN WATER (H2O) AND HEATING TO EFFECT COMPLETE SOLUTION OF ALL SOLIDS, AS A SECOND FEED SOLUTION; C. FEEDING A SMALL AMOUNT OF METHYL ALCOHOL (CH3OH) AND METHYL FORMATE (HCOOCH3) TO A REACTOR, AS A THIRD FEED SOLUTION, WHILE HEATING IN THE RANGE 60* TO 90*C. AND STIRRING UNDER SUPERATMOSPHERIC PRESSURE WITHIN SAID REACTOR; D. SEQUENTIALLY FEEDING TOGETHER UNDER PRESSURE SAID FIRST AND SECOND FEED SOLUTIONS AS A REACTION LIQUID INTO SAID REACTOR WHILE STIRRING AND HEATING IN THE RANGE 60* TO 90* C. UNDER A SUPERATMOSPHERIC PRESSURE; E. VENTING CARBON DIOXIDE (CO2) FROM SAID REACTION LIQUID WITHIN SAID REACTOR; F. COOLING SAID REACTOR AND CONTENTS; G. RECOVERING BY FILTERING SODIUM HYDROSULFITE (NAS2O4) SOLIDS FROM SAID REACTION LIQUID; AND H. RECOVERING METHYL FORMATE (HCOOCH3) TOGETHER WITH METHYL ALCOHOL (CH3OH), SEQUENTIALLY OF FILTERING SAID HYDROSULFITE FROM SAID REACTION LIQUID, AND RECYCLING BOTH SAID METHYL FORMATE (HCOOCH3) AND SAID METHYL ALCOHOL (CH3OH) INTO SAID THIRD FEED SOLUTION.

Claim 3

Method of preparing sodium hydrosulfite (Na2S2O4) from formates comprising: A. absorbing sulfur dioxide (SO2) in methyl alcohol (CH3OH) as a first feed solution; B. dissolving sodium hydroxide (NaOH) and sodium formate (HCOONa) in water (H2O) and heating to effect complete solution of all solids, as a second feed solution; C. feeding a small amount of methyl alcohol (CH3OH) and methyl formate (HCOOCH3) to a reactor, as a third feed solution, while heating in the range 60* to 90* C. and stirring under superatmospheric pressure within said reactor; D. sequentially feeding together under pressure said first and second feed solutions as a reaction liquid into said reactor while stirring and heating in the range 60* to 90* C. under a superatmospheric pressure; E. venting carbon dioxide (CO2) from said reaction liquid within said reactor; F. cooling said reactor and contents; G. recovering by filtering sodium hydrosulfite (Na2S2O4) solids from said reaction liquid; and H. recovering methyl formate (HCOOCH3) together with methyl alcohol (CH3OH), sequentially of filtering said hydrosulfite from said reaction liquid, and recycling both said methyl formate (HCOOCH3) and said methyl alcohol (CH3OH) into said third feed solution.

Claim 4

Method of preparing sodium hydrosulfite (Na2S2O4) from formates comprising: A. absorbing sulfur dioxide (SO2) in methyl alcohol (CH3OH) as a first feed solution; B. dissolving sodium hydroxide (NaOH) and sodium formate (HCOONa) in water (H2O) and heating to effect complete solution of all solids, as a second feed solution; C. feeding a small amount of methyl alcohol (CH3OH) and methyl formate (HCOOCH3) to a reactor, as a third feed solution, while heating in the range 60* to 90* C. and stirring under superatmospheric pressure within said reactor; D. sequentially feeding together under pressure said first and second feed solutions as a reaction liquid into said reactor while stirring and heating in the range 60* to 90* C. under a superatmospheric pressure; E. venting carbon dioxide (CO2) from said reaction liquid within said reactor; F. cooling said reactor and contents; G. recovering by filtering sodium hydrosulfite (Na2S2O4) solids from said reaction liquid; and H. recovering methyl formate (HCOOCH3) together with methyl alcohol (CH3OH), sequentially of filtering said hydrosulfite from said reaction liquid, and recycling both said methyl formate (HCOOCH3) and said methyl alcohol (CH3OH) into said third feed solution.

Claim 5

Method of preparing sodium hydrosulfite (Na2S2O4) from formates as in claim 1, including varying amounts of sodium hydroxide (NaOH) and sodium formate (HCOONa) dissolved in said second feed solution proportionately to the amount of methyl formate (HCOOCH3) in said third feed solution.

Claim 6

Method of preparing sodium hydrosulfite (Na2S2O4) from formates as in claim 1, including increasing the amount of sodium hydroxide (NaOH) while decreasing the amount of sodium formate (HCOONa) in said second feed solution proportionately to the amount of methyl formate (HCOOCH3) in said third feed solution.

Claim 7

Method of preparing sodium hydrosulfite (Na2S2O4) from formates as in claim 3, wherein one additional mole of sodium hydroxide (NaOH) is added and one mole of sodium formate (HCOONa) is subtracted for each mole of methyl formate (HCOOCH3) in the third feed solution.

Claim 8

Method of preparing sodium hydrosulfite (Na2S2O4) from formates comprising: A. absorbing 1920 parts of sulfur dioxide (SO2) in 2700 parts of methyl alcohol (CH3OH) as a first feed solution; B. dissolving 650 parts of sodium hydroxide (NaOH) and 1190 parts of sodium formate (HCOONa) in 880 parts of hot water (H2O) as a second feed solution; C. heating said second feed solution to approximately 160* C. so as to effect complete solution of all solids; D. feeding 1100 parts of methyl alcohol (CH3OH) and 150 parts of methyl formate (HCOOCH3) to a reactor as a third feed solution, while heating in the range 60* to 90* C. and stirring under a superatmospheric pressure in the range of 10 to 50 psig within said reactor; E. sequentially feeding together under pressure said first and second solutions as a reaction liquid into said reactor while stirring and heating in the range 60* to 90* C. under a superatmospheric pressure in the range of 10 to 50 psig; F. venting carbon dioxide (CO2) from said reaction liquid within said reactor; G. cooling said reactor and contents; and H. recovering by filtering sodium hydrosulfite (Na2S2O4) solids from said reaction liquid.

Claim 9

Method of preparing sodium hydrosulfite (Na2S2O4) from formates comprising: A. absorbing 1920 parts of sulfur dioxide (SO2) in 2700 parts of methyl alcohol (CH3OH) as a first feed solution; B. dissolving 650 parts of sodium hydroxide (NaOH) and 1190 parts of sodium formate (HCOONa) in 880 parts of hot water (H2O) as a second feed solution; C. heating said second feed solution to approximately 160* C. so as to effect complete solution of all solids; D. feeding 1100 parts of methyl alcohol (CH3OH) and 150 parts of methyl formate (HCOOCH3) to a reactor as a third feed solution, while heating in the range 60* to 90* C. and stirring under a superatmospheric pressure in the range of 10 to 50 psig within said reactor; E. sequentially feeding together under pressure said first and second solutions as a reaction liquid into said reactor while stirring and heating in the range 60* to 90* C. under a superatmospheric pressure in the range of 10 to 50 psig; F. venting carbon dioxide (CO2) from said reaction liquid within said reactor; G. cooling said reactor and contents; and H. recovering by filtering sodium hydrosulfite (Na2S2O4) solids from said reaction liquid.