Seeking a Source of Low-Carbon Calcium Hydroxide

Detailed Description and Evaluation Criteria

We would like to source calcium hydroxide from a low-carbon manufacturing process for use in multiple small-scale carbon capture devices.

If all the requirements below are met, we will then score proposals based on the following formula:

(kg calcium hydroxide) / (carbon footprint * price per kg)

We will contact those suppliers that maximize this score to discuss further details.

Requirements

• Calcium hydroxide must be greater than 90% purity
• The impure fraction must not contain any toxic chemicals or heavy metals; if calcium hydroxide is derived from waste alkalinity sources, these co-occurring products must be screened out of the final product
• All proposals should mention an estimate of the carbon footprint of the process used to generate calcium hydroxide, in units of kg CO2 per kg calcium hydroxide.
• All proposals should also mention the price per kg of calcium hydroxide.
• If your company or organization is outside the United States, please also include a description of how you might enable supply within the United States, and include estimates of cost and carbon footprint for doing so.

Discarded solutions

• Calcium hydroxide made from calcium oxide that has been produced by calcination will not meet our criteria because it is not a low-carbon source.
• Calcium hydroxide bought at a hardware store or made from cement bought at a hardware store without proof that these were derived from a low-carbon source

Possible solution areas

• Electrochemical generation of calcium hydroxide from waste cement or other sources of waste alkalinity is one area we are hoping to derive solutions from