Green Cement Patents

Green cement patents cover electrochemical-cement innovations; alternative-chemistry (carbon-negative) innovations; CO2-mineralization and CO2-curing innovations; and clinker-reduction and supplementary-cementitious-material innovations — with IP held by electrochemical-cement and novel-chemistry startups, CO2-utilization firms, and decarbonizing incumbents (in a field tackling cement's ~8% share of global CO2). MAJOR GREEN-CEMENT PATENT HOLDERS: SUBLIME SYSTEMS: electrochemical cement — making reactive cement (lime/calcium silicates) at AMBIENT temperature in an electrochemical reactor (no high-temperature kiln, no process or fuel CO2, and able to use non-limestone calcium sources), a fundamentally different production route. BRIMSTONE: carbon-negative ordinary Portland cement made from calcium-silicate rock (instead of limestone — eliminating the process CO2 released when limestone is calcined) plus co-producing supplementary materials. FORTERA: ReCarb — capturing kiln CO2 and mineralizing it into a reactive calcium-carbonate cement. CARBONCURE: injecting captured CO2 into fresh concrete during mixing (the CO2 mineralizes, permanently stored, and can reduce cement content) — a widely-deployed retrofit. SOLIDIA (now part of others): CO2-cured low-lime calcium-silicate cement/concrete. OTHERS: Terra CO2 (low-carbon SCM), Furno (modular kiln), Heidelberg Materials and Holcim (kiln CCS, clinker substitution), Ecocem (low-clinker LC3), and Chment/Cemvision. Electrochemical cement, non-limestone chemistry, and CO2 mineralization/curing are the core green-cement patent domains — and the chemistry-changing startups (Sublime, Brimstone) hold the most novel IP.

Electrochemical-production innovations; non-limestone-feedstock innovations; cement-chemistry innovations; and clinker-reduction and SCM innovations represent core green-cement patent domains — and changing HOW cement is made (avoiding the kiln and limestone) is where the most novel IP sits. ELECTROCHEMICAL-CEMENT PATENTS: producing reactive lime/calcium-silicate cement in an electrochemical cell at low/ambient temperature (Sublime) — the electrochemical reactor, the pH-swing/electrolysis chemistry that decomposes calcium sources and precipitates reactive cement, electrode/cell design, and the ability to use non-limestone (and even waste/silicate) calcium sources; this eliminates BOTH the fuel CO2 (no kiln) and the process CO2 (no limestone calcination). ALTERNATIVE-CHEMISTRY PATENTS: making Portland-equivalent cement from calcium-silicate rock instead of limestone (Brimstone — no CO2 released from the feedstock, since silicate rock doesn't carry carbonate), plus belite/CSA (calcium-sulfoaluminate) and other lower-CO2 clinker chemistries that cure at lower temperatures or release less CO2. CLINKER-REDUCTION / SCM PATENTS: supplementary cementitious materials replacing clinker — ground slag, fly ash, calcined clay + limestone (LC3 — a major near-term lever), natural pozzolans, and novel SCMs from waste; blended-cement formulations meeting strength/durability standards with far less clinker. Electrochemical production and non-limestone chemistry are the highest-value green-cement IP because they attack both CO2 sources at the root and are genuinely novel.

CO2-mineralization innovations; CO2-curing innovations; CO2-injection-into-concrete innovations; and kiln carbon-capture and durability innovations represent additional green-cement patent domains — and these utilize or capture CO2 to cut net emissions and permanently store carbon. CO2-MINERALIZATION PATENTS: reacting captured CO2 with calcium/magnesium sources to form carbonate-based reactive cements or aggregates (Fortera ReCarb mineralizing kiln CO2 into calcium carbonate cement), and mineralizing CO2 into supplementary materials or aggregates — permanently storing carbon in the building material. CO2-CURING PATENTS: curing concrete with CO2 instead of (or in addition to) water — low-lime calcium-silicate cements that carbonate-cure (Solidia), gaining strength while sequestering CO2, plus the precast process and product properties. CO2-INJECTION PATENTS: injecting captured CO2 into the ready-mix concrete during batching (CarbonCure) — the CO2 reacts with calcium to form nano-calcium-carbonate, improving strength so LESS cement is needed (a dual benefit), dosing control, and retrofit equipment for existing concrete plants. KILN CARBON-CAPTURE PATENTS: capturing the concentrated CO2 from cement kilns (oxyfuel, amine, calcium-looping — pure CO2 from limestone calcination is relatively capturable) for storage or use. DURABILITY / STANDARDS PATENTS: meeting strength, durability, and ASTM/EN standards with the green product (a gating commercial requirement). CO2 mineralization into reactive cement and CO2-curing/injection are high-value utilization IP; kiln capture is the incumbent retrofit path.

Green cement startup IP strategy must navigate Sublime electrochemical patents, Brimstone non-limestone-chemistry patents, CarbonCure/Solidia/Fortera CO2-utilization patents, decades of cement/SCM and CO2-mineralization prior art, the conservative, standards-bound, low-margin, high-volume nature of the cement/concrete industry (products MUST meet ASTM/EN standards and contractor/code acceptance — a huge non-IP barrier), enormous capital and incumbency, and policy drivers (carbon pricing, EU CBAM, low-carbon procurement); understand that SCM blending and CO2-curing are relatively crowded/incremental, that the most novel, defensible IP is in chemistry-changing production (electrochemical cement, non-limestone chemistry), and that standards compliance and cost-parity matter as much as patents; identify whitespace in electrochemical/low-temperature production, non-limestone chemistry, CO2-to-reactive-cement mineralization, and novel SCMs. GREEN-CEMENT STARTUP IP STRATEGY: CHEMISTRY-CHANGING PRODUCTION IS THE MOST NOVEL IP — SCM/CO2-CURING ARE MORE CROWDED: blended-cement SCM and CO2-curing/injection are incremental and more contested; the strongest, most-defensible IP is in fundamentally different production — electrochemical/ambient cement (Sublime) and non-limestone chemistry (Brimstone) that eliminate process AND fuel CO2; ELECTROCHEMICAL AND NON-LIMESTONE ROUTES ARE HIGHEST-VALUE WHITESPACE: producing reactive cement without a kiln or without limestone attacks both CO2 sources at the root and is genuinely novel, patentable process IP; CO2-TO-REACTIVE-CEMENT MINERALIZATION IS A VALUABLE UTILIZATION PATH: turning captured CO2 into the binding phase (Fortera) permanently stores carbon and is patentable; STANDARDS COMPLIANCE AND COST-PARITY ARE EXISTENTIAL PARALLEL MOATS: cement is a conservative, code-bound, low-margin commodity — meeting ASTM/EN standards and reaching cost parity (with green premiums/CBAM help) gate adoption as much as IP; DROP-IN/PORTLAND-EQUIVALENCE EASES ADOPTION: a product that is chemically equivalent to ordinary Portland cement (Brimstone) avoids the standards/acceptance barrier that novel chemistries face; WHEN TO PATENT: NOVEL PROCESS/MATERIAL WITH MEASURED PERFORMANCE: file once a process/material shows measured results (CO2 intensity kgCO2/t-cement + compressive strength MPa + standard compliance + energy MWh/t + cost $/t) vs. ordinary-Portland-cement baseline — measured CO2 intensity, strength/standard compliance, energy, and cost are the critical green-cement IP metrics; KEY FTO CHECKLIST: Sublime electrochemical ambient-temperature lime/calcium-silicate reactor no-kiln non-limestone-source; Brimstone calcium-silicate-rock carbon-negative Portland-equivalent no-process-CO2; Fortera ReCarb CO2-mineralized calcium-carbonate cement; CarbonCure CO2-injection ready-mix nano-CaCO3 cement-reduction; Solidia CO2-cured low-lime calcium-silicate; Terra CO2/Ecocem LC3 calcined-clay SCM; slag/fly-ash/pozzolan blended-cement; belite/CSA low-CO2 clinker; kiln oxyfuel/amine/calcium-looping capture; ASTM/EN strength-durability standards; CBAM/carbon pricing.