Process To Convert Reduced Sulfur Species And Water Into Hydrogen And Sulfuric Acid

Patent metadata

Field	Value
Publication number	US-2022106691-A1
Application number	US-202117505073-A
Country	US
Kind code	A1
Filing date	Oct 19, 2021
Priority date	May 18, 2018
Publication date	Apr 7, 2022
Grant date	—

Abstract

In an aspect, provided herein are methods for producing sulfuric acid and hydrogen gas, the methods comprising steps of: providing sulfur dioxide formed by thermal conversion of a sulfur-containing species; electrochemically oxidizing said sulfur dioxide to sulfuric acid in the presence of water; and electrochemically forming hydrogen gas via a reduction reaction. In some embodiments, the methods comprise a step of thermally converting said sulfur-containing species to said sulfur dioxide. Systems configured to perform these methods are also disclosed herein. Also provided herein are methods and systems for producing sulfuric acid and hydrogen gas by electrochemically forming the sulfuric acid and the hydrogen gas in a mixture comprising a sulfur material, a supporting acid, and water. Also provided herein are methods and systems for producing a cement material.

First claim

1 - 108 . (canceled)

109 . A method for producing a cement material, said method comprising steps of:
a. reacting sulfur dioxide and water to form a first acid, the first acid comprising at least one sulfur-containing anion; b. reacting the first acid and a first cement precursor to form a second cement precursor; wherein the second cement precursor comprises the at least one sulfur-containing anion; and c. converting the second cement precursor to the cement material.

110 . The method of claim 109 , wherein the sulfur-containing anion is a sulfate (SO 4 ) or a sulfite (SO 3 ).

111 - 112 . (canceled)

113 . The method of claim 109 , wherein the cement material is calcium oxide (CaO) and the first cement precursor comprises calcium carbonate (CaCO 3 ).

114 . (canceled)

115 . The method of claim 109 , wherein:
the sulfur-containing anion is sulfate (SO 4 ); the first acid is sulfuric acid (H 2 SO 4 ); the step (a) comprises (i) electrochemically oxidizing the sulfur dioxide to the sulfuric acid electrochemically and (ii) forming hydrogen gas via a reduction reaction; and the sulfur dioxide and the water are reacted at a ratio of 1:2, respectively, during step (a).

116 . The method of claim 115 , wherein the step (a) is performed according to formula FX1:
SO 2 +2H 2 O→H 2 SO 4 +H 2   (FX1).

117 . (canceled)

118 . The method of claim 115 , wherein the second cement precursor is calcium sulfate (CaSO 4 ) and wherein the step (c) is performed according to formula FX3:
CaSO 4 →CaO+SO 2 +½O 2   (FX3).

119 . (canceled)

120 . The method of claim 115 , wherein the steps of electrochemically oxidizing the sulfur dioxide and electrochemically forming the hydrogen gas are performed in the presence of a catalyst.

121 - 123 . (canceled)

124 . The method of claim 115 , comprising burning at least a fraction of the formed hydrogen gas to provide heat for step (c).

125 - 126 . (canceled)

127 . The method of claim 115 , wherein the first cement precursor comprises calcium carbonate (CaCO 3 ); and wherein step (b) is performed according to formula FX2a:
H 2 SO 4 +CaCO 3 →CaSO 4 +CO 2 +H 2 O  (FX2a).

128 . The method of claim 127 , wherein the method is characterized by a net reaction having the formula FX4a:
CaCO 3 +H 2 O→H 2 +CaO+½O 2 +CO 2   (FX4a).

129 - 132 . (canceled)

133 . The method of claim 115 , wherein the first cement precursor comprises calcium carbonate (CaCO 3 ); and wherein step (b) is performed according to formula FX2b:
H 2 SO 4+2 CaCO 3 →CaSO 4 +Ca 2+ +2HCO 3   (FX2b).

134 . The method of claim 115 , wherein the method is characterized by a net reaction having the formula FX4b:
2CaCO 3 +2H 2 O→H 2 +CaO+½O 2 +Ca 2+ +2HCO 3 −   (FX4b).

135 - 136 . (canceled)

137 . The method of claim 109 , wherein:
the sulfur-containing anion is sulfate (SO 3 ); the first acid is sulfurous acid (H 2 SO 3 ); and the sulfur dioxide and the water are reacted at a ratio of equal to or less than 1:1, respectively, during step (a).

138 . The method of claim 137 , wherein the step (a) is performed according to formula FX5:
SO 2 +H 2 O→H 2 SO 3   (FX5).

139 . The method of claim 137 , wherein the second cement precursor is calcium sulfite (CaSO 3 ).

140 . The method of claim 137 , wherein the step (c) is performed according to formula FX7:
CaSO 3 →CaO+SO 2   (FX7).

141 - 143 . (canceled)

144 . The method of claim 137 , wherein the first cement precursor comprises calcium carbonate (CaCO 3 ); and wherein step (b) is performed according to formula FX6a:
H 2 SO 3 +CaCO 3 →CaSO 3 +CO 2 +H 2 O  (FX6a).

145 . The method of claim 137 , wherein the method is characterized by a net reaction having the formula FX8a:
CaCO 3 →CaO+CO 2   (FX8a).

146 - 148 . (canceled)

149 . The method of claim 137 , wherein the first cement precursor comprises calcium carbonate (CaCO 3 ); and wherein step (b) is performed according to formula FX6b:
H 2 SO 3+2 CaCO 3 →CaSO 3 +Ca 2+ +2HCO 3   (FX6b).

150 . The method of claim 149 , wherein the method is characterized by a net reaction having the formula FX8b:
2CaCO 3 +H 2 O+heat→CaO+Ca 2+ +2HCO 3   (FX8b).

151 . The method of claim 133 , further comprising at least one of storing and recycling liquid comprising calcium ions and bicarbonate ions, wherein the calcium ions and bicarbonate ions are formed during step (b).

152 . The method of claim 109 , wherein sulfur dioxide is produced during step (c), the method further comprising recycling the sulfur dioxide produced during step (c) to provide for the sulfur dioxide reacted during step (a).

153 . The method of claim 109 , wherein step (c) comprises heating the second cement precursor in the presence of an additive to form a composite cement material, the composite cement material comprising the cement material.

154 - 157 . (canceled)

158 . The method of claim 109 , wherein:
step (b) is performed without providing water during the reaction, except for the water produced by the reaction during step (b), such that step (b) is performed as a dry reaction; or step (b) is performed with providing water during the reaction, except for the water produced by the reaction during step (b), such that step (b) is performed in a wet slurry.

159 . (canceled)

160 . A system for producing a cement material, said system being configured to:
a. react sulfur dioxide and water to form a first acid, the first acid comprising at least one sulfur-containing anion; b. react the first acid and a first cement precursor to form a second cement precursor; wherein the second cement precursor comprises the at least one sulfur-containing anion; and c. convert the second cement precursor to the cement material.

161 - 165 . (canceled)

Assignees

• California Inst Of Techn

Inventors

• Finke Cody E

Classifications

• C01B17/78

  characterised by the catalyst used · CPC title

• C01B17/88

  Concentration of sulfuric acid · CPC title

• C01B17/74

  Preparation · CPC title

• C01B17/69

  Sulfur trioxide; Sulfuric acid · CPC title

• C01F11/48

  Sulfites · CPC title