Removing carbon dioxide from waste streams through co-generation of carbonate and/or bicarbonate minerals

• US 20060185985A1
• Filed: 09/22/2005
• Published: 08/24/2006
• Est. Priority Date: 09/23/2004
• Status: Active Grant

• Current Assignee: Carbonfree Chemicals Holdings, LLC
• Original Assignee: Skyonic Corp.
• Inventors: Jones, Joe David
• Granted Patent: US 7,727,374 B2
• Time in Patent Office: Days
• US Class Current: 205/508
• CPC Class Codes: B01D 2251/304 of sodium
• CPC Class Codes: B01D 2251/604 Hydroxides
• CPC Class Codes: B01D 2258/0283 Flue gases
• CPC Class Codes: B01D 53/1418 Recovery of products
• CPC Class Codes: B01D 53/1475 Removing carbon dioxide
• CPC Class Codes: B01D 53/62 Carbon oxides
• CPC Class Codes: B01D 53/73 After-treatment of removed components
• CPC Class Codes: B01D 53/965 including an electrochemical process step
• CPC Class Codes: C01B 32/60 Preparation of carbonates or bicarbonates in general of percarbonates C01B15/10; of specific carbonates or bicarbonates according to the cation C01B-C01G
• CPC Class Codes: C01D 7/07 Preparation from the hydroxides
• CPC Class Codes: C01D 7/14 Preparation of sesquicarbonates
• CPC Class Codes: C01F 1/00 Methods of preparing compounds of the metals beryllium, magnesium, aluminium, calcium, strontium, barium, radium, thorium, or the rare earths, in general
• CPC Class Codes: Y02C 20/40 of CO2
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02P 20/129 Energy recovery, e.g. by cogeneration, H2recovery or pressure recovery turbines
• CPC Class Codes: Y02P 20/133 Renewable energy sources, e.g. sunlight
• CPC Class Codes: Y02P 20/151 Reduction of greenhouse gas [GHG] emissions, e.g. CO2

Abstract

Apparatuses and methods for removing carbon dioxide and other pollutants from a gas stream are provided. The methods include obtaining hydroxide in an aqueous mixture, and mixing the hydroxide with the gas stream to produce carbonate and/or bicarbonate. Some of the apparatuses of the present invention comprise an electrolysis chamber for providing hydroxide and mixing equipment for mixing the hydroxide with a gas stream including carbon dioxide to form an admixture including carbonate and/or bicarbonate.

Claims

1-109. -109. (canceled)

110. A method of removing carbon dioxide from a gas stream comprising:

obtaining a hydroxide in an aqueous mixture;

admixing the hydroxide with the gas stream to produce carbonate products, bicarbonate products, or a mixture of carbonate and bicarbonate products in an admixture; and

separating said carbonate and/or bicarbonate products from the admixture, thereby removing carbon dioxide from the gas stream.

111. The method of claim 110, further comprising process-controlling the method to produce substantially only carbonate products, substantially only bicarbonate products, or a mixture of carbonate and bicarbonate products.

112. The method of claim 110, wherein the admixing occurs in two separate chambers, with one chamber being used to produce carbonate products and the other chamber being used to produce bicarbonate products.

113. The method of claim 110, wherein the admixing occurs in a bubble column or series of bubble columns.

114. The method of claim 110, wherein separation of carbonate and/or bicarbonate products from the admixture involves a heated-precipitation separation process.

115. The method of claim 114, wherein the heat for the separation process is derived from heat exchange with incoming flue-gases.

116. The method of claim 110, further comprising:

transporting the carbonate products to a remote sequestration site;

combining the carbonate products with acid in a neutralization reaction to generate pure carbon dioxide; and

injecting the carbon dioxide into a carbon bank.

117. The method of claim 110, wherein other components of the gas stream are neutralized and/or entrained/captured in the carbonate-formation process.

118. The method of claim 110, wherein obtaining the hydroxide comprises:

obtaining a salt;

admixing the salt with water, steam, or both to produce a solution; and

electrolyzing the solution to produce a hydroxide.

119. The method of claim 118, wherein acid, preferably hydrochloric acid, is added to the solution before it is electrolyzed.

120. The method of claim 119, wherein the amount of acid added to the solution is based on a determination of the optimum protonation rate that achieves the lowest energy to produce reactants and the highest energy to recover from products.

121. The method of claim 118, wherein

the electrolyzing step occurs in an electrochemical cell having a catholyte side and an anolyte side;

and

the carbonate and/or bicarbonate products are recycled to the catholyte side of the electrochemical cell.

122. The method of claim 118, wherein the energy required by the method is supplemented with waste-heat recovered from the gas stream.

123. The method of claim 118, wherein the salt is sodium chloride, the solution produced is brine, and electrolyzing the brine produces sodium hydroxide and chlorine gas.

124. The method of claim 123, wherein hydrogen gas is produced.

125. The method of claim 124, wherein the hydrogen gas and the chlorine gas are combusted to form hydrochloric acid, which is added to the brine before it is electrolyzed.

126. The method of claim 124, wherein the hydrogen gas is combusted with atmospheric oxygen or oxygen from stock chemicals to produce water.

127. The method of claim 124, further comprising using the hydrogen gas to produce energy.

128. The method of claim 127, wherein separation of carbonate and/or bicarbonate products from the admixture involves a heated-precipitation separation process in which the heat for the separation process is derived from the energy produced by the hydrogen gas.

129. The method of claim 127, wherein the hydrogen gas is co-burned with coal to improve coal-fired emissions.

130. The method of claim 127, wherein the hydrogen gas is used in a combustion process for fuel-cell recovery of DC electricity.

131. The method of claim 110, wherein the gas stream is an exhaust stream from a plant.

132. The method of claim 131, wherein the plant is a power plant that employs a carbon-based fuel source.

133. An apparatus comprising:

a electrolysis chamber comprising at least one cathode and at least one anode, the chamber adapted to produce hydroxide during use;

mixing equipment operably connected to the electrolysis chamber and to a conduit adapted to contain a gas stream during use, the mixing equipment adapted to admix hydroxide from the electrolysis chamber with the gas stream during use to create an admixture in which carbon, sulfur, and/or nitrogen compounds in the gas stream can react with the hydroxide; and

a separation chamber operably connected to the mixing equipment and adapted to separate the admixture into a separate gas phase and solid and/or liquid phase.

134. The apparatus of claim 133, wherein the electrolysis chamber comprises a membrane cell, a diaphragm, and/or mercury.

135. The apparatus of claim 133, wherein the mixing equipment is a batch reactor or series of batch reactors, a gas/liquid absorption/reaction device or a series of gas/liquid absorption/reaction devices, a crystallization tower or series of crystallization towers, or a bubble column or series of bubble columns.

136. The apparatus of claim 133, further comprising a drying chamber operably connected to the separation chamber and adapted to remove liquid from the solid and/or liquid phase during use.

137. The apparatus of claim 136, wherein the drying chamber is adapted to heat the solid and/or liquid phase during use.

138. The apparatus of claim 133, further defined as operably connected to a power plant.

139. The apparatus of claim 133, wherein the electrolysis chamber is adapted to produce chlorine gas and sodium hydroxide from sodium chloride and water during use.

140. The apparatus of claim 133, wherein the mixing equipment is adapted to admix hydroxide from the electrolysis chamber with carbon dioxide from the gas stream during use to produce carbonate and/or bicarbonate products.