Calcium Sulfate Sequestration for Cementitious Materials

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Solution Overview

Problem

Carbon dioxide emissions contribute to global warming and ocean acidification, necessitating effective methods for carbon dioxide sequestration and mitigation of anthropogenic processes.

Innovation Solution

A method involving the contact of an industrial waste gas stream containing carbon dioxide with an alkaline solution to form carbon dioxide charged water, which is then reacted with calcium sulfate to produce a cementitious composition comprising metastable components like vaterite, amorphous calcium carbonate, or their combination, under specific precipitation conditions, followed by conversion to aragonite for enhanced compressive strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If carbon dioxide is sequestered through conventional methods, then CO2 emissions are reduced, but the process is complex and costly

Engineering Contradiction:

ImproveCO2 emissionsVSAvoidsequestration process complexity

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The invention converts CO2, a harmful greenhouse gas, into a beneficial cementitious material. By reacting CO2 with alkaline solutions and calcium sulfate, the process produces vaterite and amorphous calcium carbonate that serve as binding agents in construction materials, thereby eliminating CO2 rather than merely storing it.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The process utilizes industrial waste streams (CO2 and calcium sulfate) as raw materials for producing construction materials. The waste CO2 from industrial processes becomes the carbon source for forming calcium carbonate minerals, while calcium sulfate from flue gas desulfurization or other sources provides the calcium component, creating a self-sufficient circular economy system.

Inventive Principle:

Principle #25Self-service

2Ease of manufacture

If conventional cementitious materials are used, then construction materials are available, but environmental impact is high due to CO2 emissions

Engineering Contradiction:

Improvebuilding material productionVSAvoidenvironmental impact

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The invention changes the chemical parameters of cementitious materials by incorporating metastable calcium carbonate phases (vaterite and amorphous calcium carbonate) formed through controlled precipitation from CO2-saturated alkaline solutions. These phases provide binding properties while the carbon originates from sequestered CO2 rather than traditional limestone quarrying and high-temperature calcination.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention creates composite construction materials that combine calcium sulfate (from waste sources), sequestered CO2 (converted to calcium carbonate), and other construction aggregates. This composite approach integrates waste stream components into a functional building material with reduced environmental footprint.

Inventive Principle:

Principle #40Composite materials

3Strength

If metastable components like vaterite are formed, then compressive strength is enhanced, but the composition requires precise precipitation conditions

Engineering Contradiction:

Improvecompressive strengthVSAvoidprecipitation conditions control

Core Design Contradiction:

StrengthVSManufacturing precision

Solution Approach 1:

The invention optimizes precipitation parameters including pH (maintained alkaline), temperature, and mixing conditions to selectively form metastable vaterite and amorphous calcium carbonate phases. By controlling these parameters, the process achieves high compressive strength in the resulting cementitious material while managing the complexity of phase formation.

Inventive Principle:

Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The method effectively sequesters carbon dioxide and produces a cementitious composition with high compressive strength, suitable for building materials, while reducing environmental impact by utilizing industrial waste gases and calcium sulfate from various sources.

Implementation Method 1

contacting an industrial waste gas stream comprising carbon dioxide with an alkaline solution to form a carbon dioxide charged water

Methodology Applied

Scientific EffectAbsorption: Absorption (physical)

Implementation Method 2

contacting the carbon dioxide charged water with calcium sulfate to form a composition comprising a metastable component selected from the group consisting of vaterite, amorphous calcium carbonate, and combination thereof

Methodology Applied

Scientific EffectPrecipitation: Precipitation

Implementation Method 3

contacting the composition with water and converting the vaterite to aragonite

Methodology Applied

Scientific EffectPhase transformation: Phase Change

Data Source

PatentUS8691175B2Calcium sulfate and CO<sub>2 </sub>sequestration

Publication Date: 2014.04.08 ARELAC INC

AI summary

Systems, methods, and compositions are provided related to utilizing gypsum for CO2 sequestration to form solid products containing calcium carbonate.