St. Marys Cement Inc. (Canada) - Environmental Compliance Approval (air)

Four comments were received from the local public, the Municipality of Clarington and the Municipality of Durham. All comments received were reviewed and considered by the ministry. The concerns expressed and ministry responses are summarized below:

Concern #1:

The need for the UC3 technology at this time and why was this technology not considered by the company as part of the Alternate Low-Carbon Fuel (ALCF) application to burn 400 tonnes per day of ALCF submitted in March 2020. Concern regarding sufficiency of heat generated by the ALCFs when used at maximum approved rate of 400 tonnes per day.

Response:

The supply of ALCF is dependent on market conditions and the purpose of the electrolysis system such as the UC3 system is to obtain flexibility in the use of blends of approved ALCF at the maximum approved ALCF use of 400 tonnes per day. For the currently approved ALCFs, the kiln system can achieve 400 tonnes/day rate for relatively higher heating value ALCF blends. Adding a unit like UC3 is expected to optimize the combustion environment in the kiln system which will provide more flexibility to also use lower heat value ALCF blends such as blends with higher proportion of woody material.

Concern #2:

Sufficiency of information presented to support no increase of emissions due to the use of UC3 technology.

Response:

The heat input from the UC3 system would be a small fraction of the total kiln heat input and would not change the overall kiln process conditions which dominate air emissions. In addition, the kiln input including the raw material and approved ALCFs would not change and thus the current maximum emission scenario and impacts assessed by the company is not expected to change with the addition of the UC3 electrolysis system.

All existing approval conditions are being maintained in the amended approval, including the requirements for in-stack emission limits, emissions testing, continuous monitoring of emissions and process conditions and the set points for process conditions such as kiln temperature and residual oxygen. Additional conditions have been specified in the amended approval for stack testing with the operation of of the UC3 system and preparation of monthly reports for ministry verification.

Concern #3:

Impacts on carbon dioxide emission intensities and green house gas emissions due to the installation of the UC3 system.

Response:

The carbon dioxide emission intensity report prepared by the proponent as part of the previous March 2020 application for the use of ALCF at 400 tonnes per day demonstrated compliance with the requirements set out in O. Reg 79/15- Alternative Fuel Regulations. The ALCF material tested, including woody material, complied with the minimum heat value requirements set out in O. Reg 79/15.

The facility’s carbon dioxide emission intensity report assumes that all carbon contained in the conventional fuel and the ALCFs is converted to carbon dioxide. Also, information from the company indicates that the addition of oxygen from the UC3 system is a small fraction of the total oxygen in the kiln system and thus would have no significant impact on total carbon dioxide formation in the kiln. Thus, no change is expected in the carbon dioxide emission intensity due to the addition of the UC3 system.

The amended ECA issued maintains the requirement for annual carbon-dioxide emission intensity testing of fuels for the verification of compliance with O. Reg 79/15.

Concern #4:

Flammability hazards and explosion risks associated with UC3 technology.

Response:

Potential flammability and explosion hazards are not included within the jurisdiction of this approval.

The company has indicated that the gases generated in UC3 system would be directly injected into the kiln system and there would be no interim storage of these gases. The UC3 system would include hydrogen and oxygen leak detection systems interlocked for automatic shutdown in case a leak is detected.

Concern #5

Concerns regarding proposal notification, public and indigenous consultation and adequacy of information provided to the public on the proposal.

Response:

The proposal was posted on the Environmental Registry for public commenting in accordance with the requirements. The proposal for the installation of a UC3 system by the proponent is not considered to be an application to which the Alternative Low-Carbon Fuel Regulation (O. Reg 79/15) applies, and thus the public and indigenous consultation requirements under this regulation is not applicable to the UC3 proposal. Information on the proposal was made available to the public when requests were made to the ministry. Public and indigenous consultations were conducted as part of the application to burn 400 tonnes per day of ALCF submitted earlier in March 2020.