# US 6,778,378 B1 · Flow-through capacitor and method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 6,778,378 B1 - Document ID: US6778378B1 - Status: Granted - Kind: B1 - Application number: 10/048,632 - Filed: 2002-01-30 - Granted: 2004-08-17 - Earliest claimed: 1999-07-30 - Assignees: Biosource, Inc. - Inventors: Marc D. Andelman - Web page: https://patentgrep.com/patent/US6778378B1 ## CPC - C02F 1/46109: {Electrodes} - C02F 1/4691: {Capacitive deionisation} - C02F 2001/46161: {Porous electrodes} - C02F: TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE (separation in general B01D; special arrangements on waterborne vessels of installations for treating water, waste water or sewage, e.g. for producing fresh water, B63J; adding materials to water to prevent corrosion C23F; treating radioactively-contaminated liquids G21F9/04; regeneration of reactants for recirculation into processes, see the relevant places for the processes) ## Abstract A flow-through capacitor and method for the purification of fluids, like soft water. The capacitor includes anode-cathode electrodes (3) composed of a low surface area electrode material having a surface area between 10 to 1000 square meter per gram BET (Brunauer Emmett Teller method) to form one or more cells. ## Claims ### Claim 1 A flow-through capacitor comprising: a) a housing comprising an inlet for the introduction of a fluid and an outlet for the withdrawal of a fluid; and b) a plurality of anode-cathode electrode layers to form a cell within the housing, the electrode layers comprising an electrode material having a capacitance of above about 1 farad per gram capacitance, the layers arranged and constructed to provide for the flow of the fluid between the layers and through the cell; wherein the flow-through capacitor has a series resistance per individual cell of about 0.03 ohms or less. ### Claim 2 (depends on 1) The flow-through capacitor of claim 1, wherein the electrode material has a surface area of between about 10 and 1000 square meters per gram BET (Brunauer Emmett Teller method). ### Claim 3 (depends on 1) The flow-through capacitor of claim 1, wherein the electrode material has a surface area of between about 100 to 1000 square meters per gram BET (Brunauer Emmett Teller method). ### Claim 4 (depends on 1) The flow-through capacitor of claim 1, wherein the electrode material has an electrical resistance of 0.01 ohms-cm or less and a capacitance of above 10 farads per gram. ### Claim 5 (depends on 1) The flow-through capacitor of claim 1, wherein the electrode material is selected from the group consisting of carbon black, aerogel, activated carbon, carbon cloth, or combinations thereof. ### Claim 6 (depends on 1) The flow-through capacitor of claim 1, wherein the electrode material has a surface area of between about 10 and 400 square meters per gram BET (Brunauer Emmett Teller method). ### Claim 7 (depends on 1) The flow-through capacitor of claim 1, wherein the flow-through capacitor is in electrical contact with an electrical power supply, and the resistive voltage drop from the power supply to the capacitor to less than about 4 volts. ### Claim 8 (depends on 1) The flow-through capacitor of claim 1, whereby the anode-cathode electrodes are electrically connected in series. ### Claim 9 (depends on 1) The flow-through capacitor of claim 1, wherein the capacitor comprises a plurality (n) of cells. ### Claim 10 (depends on 9) The flow-through capacitor of claim 9, wherein at least a portion of the plurality (n) of individual cells is connected in series, and the operating voltage of the individual cells is 1/n of the voltage of the entire series. ### Claim 11 (depends on 1) The flow-through capacitor of claim 1, further comprising means for measuring the voltage of an individual cell. ### Claim 12 (depends on 1) The flow-through capacitor of claim 1, wherein the capacitor is characterized by a fluid flow rate of greater than about 1 milliliter per minute per gram (1 ml/minute/gm) of electrode material. ### Claim 13 (depends on 1) The flow-through capacitor of claim 1, wherein the electrode material is selected from the group consisting of ruthenium oxide and a fibrillated fluorocarbon, ruthenium oxide coated on titanium, tantalum and graphite material, and combinations thereof. ### Claim 14 (depends on 1) The flow-through capacitor of claim 1, which comprises a compressed stack of electrode layers. ### Claim 15 (depends on 1) The flow-through capacitor of claim 1, wherein said inlet fluid is a source of contaminated water, and said outlet fluid is substantially purified water. ### Claim 16 (depends on 1) The flow-through capacitor of claim 1, wherein the electrode layers are characterized by a generally central, flow-through fluid hole. ### Claim 17 (depends on 1) The flow-through capacitor of claim 1, wherein the electrode material has a density of 0.1 grams per cubic centimeter or higher. ### Claim 18 A method for the purification of water containing ionic contaminants, which method comprises the steps of: a) providing the flow-through capacitor of claims b) introducing water to be purified into the inlet; and c) withdrawing substantially purified water from the outlet. ### Claim 19 (depends on 18) The method of claim 18, further comprising the steps of removing ionic contaminants from the capacitor.