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Capitol-SkyMine project

Brief description:


Country: USA

Project type: Capture

Scale: Small

Status: Identified

Capital cost: $125 million

Year of operation 2014
Industry: Cement

Capture technology: Other
New or retrofit: Retrofit
Transport of CO2 by: none

Type of storage: Not decided


Capitol Aggregates and Skyonic are progressing with plans to install CO2 capture technology at Capitol’s cement mill in San Antonio, Texas.

Skyonic has worked with Zachry Corporation, owner of Capitol Aggregates and engineers Ford, Bacon & Davis to complete Phase 1 project design work, which received a grant of $3 million from the US Department of Energy and the National Energy Technology Laboratory.

The Capitol-SkyMine plant, expected to be operative by 2014, is designed to capture around 75,000 tonnes of CO2 from flue gas emitted by the plant and recycle the emissions into hydrochloric acid, sodium bicarbonate and other byproducts.

In 2010, Skyonic received a $25 million grant from the  DoE to develop its proprietary carbonate mineralization technology, SkyMine®, which will be deployed at the cement mill. It has been successfully testing pilot SkyMine technology at the plant since then.


Skyonic broke ground in October 2013 and it is expected that the plant will be starting up in 2014.


The total cost of the capture facility is estimated at $125 million. The project has to date received $3 million in Phase 1 funding from the DoE and NETL. Skyonic has received $25 million from the DoE to develop its SkyMine® capture technology.

In mid-2012 the project attracted new funding partners Northwater Capital Management, ConocoPhillips, BP, and PVS Chemicals, who will now support construction costs and other R&D and operations.

More information and press releases

Carbon-capture plant breaks ground at San Antonio cement plant, October 3, 2013

First CO2 capture set for cement mill, 24 August 2012

Skyonic gets ConocoPhillips, BP backing for capture plant, June 2012

Skyonic awarded DoE funding, February 2010

SkyMine® process details