# US 2025/0144565 A1 · Removing heavy metals from off-gas for carbon capture > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2025/0144565 A1 - Document ID: US20250144565A1 - Status: Published application - Kind: A1 - Application number: 18/833,508 - Filed: 2023-03-09 - Published: 2025-05-08 - Earliest claimed: 2022-03-10 - Assignees: HSustainability GmbH - Applicants: HSustainability GmbH - Inventors: Francisco CARRASCO MALDONADO; Maciej ZAJAC; Nicolas PATO - Web page: https://patentgrep.com/patent/US20250144565A1 ## CPC - B01D 53/80: Semi-solid phase processes, i.e. by using slurries - B01D 53/002: {by condensation} - B01D 53/62: Carbon oxides - B01D 53/64: Heavy metals or compounds thereof, e.g. mercury - B01D 53/75: Multi-step processes - C04B 18/167: Recycled materials, i.e. waste materials reused in the production of the same materials - C04B 20/023: {Chemical treatment} - C04B 28/02: containing hydraulic cements other than calcium sulfates - C04B 40/0231: {Carbon dioxide hardening} - B01D 2251/404: of calcium - B01D 2251/602: Oxides - B01D 2257/504: Carbon dioxide - B01D 2257/602: Mercury or mercury compounds - B01D 2258/0233: from cement factories - C04B 2103/0078: {Sorbent materials} - C04B 2111/00017: {Aspects relating to the protection of the environment} - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE ## Abstract Carbon capture method for an industrial plant off-gas involves removing mercury and/or other heavy metals from the off-gas by contacting the off-gas with an at least partially hydrated cement paste as sorbent in a scrubber before a concentration step of the off-gas to concentrate CO2. The at least partially hydrated cement paste is simultaneously carbonated and loaded with the mercury and/or other heavy metals during contacting with the off-gas and is used as supplementary cementitious material in composite cement. The at least partially hydrated cement paste is used as sorbent in a scrubber before a concentration step of the off-gas to concentrate CO2. ## Claims ### Claim 1 A carbon capture method for an off-gas comprising the steps of: removing mercury and/or other heavy metals from the offgas by contacting the off-gas with an at least partially hydrated cement paste as sorbent in a scrubber; and subsequently concentrating the off-gas to concentrate CO2 in a concentration step, wherein the at least partially hydrated cement paste is simultaneously carbonated and loaded with the mercury and/or other heavy metals during contacting with the off-gas and is used as supplementary cementitious material in composite cement. ### Claim 2 (depends on 1) The method according to claim 1, wherein the heavy metal is mercury, lead, chromium, copper, manganese, molybdenum, titanium or any mixture thereof. ### Claim 3 (depends on 1) The method according to claim 1, wherein the at least partially hydrated cement paste is obtained from waste or byproducts, by mixing aged cement with water and/or by retrieving recycled cement paste from a recycling process of cement containing waste. ### Claim 4 (depends on 3) The method according to claim 3, wherein the recycled cement paste is retrieved from suspensions resulting from cleaning concreting equipment, filter cakes thereof, discarded concrete or mortar, fine fractions from concrete demolition waste, and any mixture of two or more of them. ### Claim 5 (depends on 1) The method according to claim 1, wherein the hydration degree of the at least partially hydrated cement paste ranges from 50 to 100% of the hydratable phases in the contained cement paste. ### Claim 6 (depends on 1) The method according to claim 1, wherein the sorbent contains no more than 60 wt.-% substances other than partially hydrated cement paste, calculated as solids with respect to the total solids. ### Claim 7 (depends on 1) The method according to claim 1, wherein the sorbent has a particle size distribution with a d50≤250 μm, and/or a d10 from 1 to 50 μm, and/or a d90 from 60 to 200 μm. ### Claim 8 (depends on 1) The method according to claim 1, wherein a relative humidity of ≥70 Vol.-% is provided during contacting the sorbent with the off-gas by spraying water into a device for contacting and/or by providing the sorbent in the form of a slurry with a solid concentration ranging from 100 to 250 g/l. ### Claim 9 (depends on 1) The method according to claim 1, wherein a temperature during contacting the sorbent with the offgas is set to range from 50 to 100° C. ### Claim 10 (depends on 1) The method according to claim 1, wherein a contact time of contacting the sorbent with the off-gas is set to ≥5 minutes, and/or until at least 20 wt.-% of the heavy metals are removed from the off-gas, and/or until a carbonation degree of the sorbent of 70 to 100% of the carbonatable phases in the sorbent is reached. ### Claim 11 (depends on 1) The method according to claim 1, wherein the CO2 content in the off gas is reduced by not more than 30% with respect to the initial CO2 content and/or the CO2 content in the off-gas after the scrubber is at least 8 Vol.-%. ### Claim 12 (depends on 1) The method according to claim 1, wherein the concentration step comprises chemical or physical absorption of CO2 in a solvent, physical absorption in an absorbent bed comprising silica or zeolites, a pressure or temperature swing absorption process, or extraction using a membrane. ### Claim 13 (depends on 12) The method according to claim 12, wherein the concentrated CO2 is subjected to a series of compression steps and cooling using cryogenic treatment for further CO2 purification. ### Claim at position 14 14-15. (canceled) ### Claim 16 (depends on 2) The method according to claim 2, wherein the heavy metal is mercury, lead, copper, titanium, or any mixture thereof. ### Claim 17 (depends on 16) The method according to claim 16, wherein the heavy metal is mercury. ### Claim 18 (depends on 5) The method according to claim 5, wherein the hydration degree of the at least partially hydrated cement paste ranges from 75 to 100% of the hydratable phases in the contained cement paste. ### Claim 19 (depends on 6) The method according to claim 6, wherein the sorbent contains no more than 30 wt.-% substances other than partially hydrated cement paste. ### Claim 20 (depends on 9) The method according to claim 9, wherein the temperature during contacting the sorbent with the off-gas is set to range from 65 to 80° C. ### Claim 21 (depends on 10) The method according to claim 10, wherein the contact time of contacting the sorbent with the off-gas is set to from ≥15 minutes up to 120 minutes, and/or until at least 40 wt.-% of the heavy metals are removed from the off-gas. ### Claim 22 (depends on 11) The method according to claim 11, wherein the CO2 content in the off-gas is reduced by not more than 20% with respect to the initial CO2 content and/or the CO2 content in the off-gas after the scrubber is at least 12 Vol.-%.