BASF seeks to expand C618-grade product supply

Source: CP staff

In partnership with a regional fly ash marketer, BASF Construction Chemicals aims to advance a chemical solution to beneficiate fly ashes exposed to Powder Activated Carbon (PAC), widely accepted to control coal-burning power plants’ mercury emissions.

When installed prior to a particulate control device, PAC injection systems deposit activated carbon onto the fly ash as it travels through the flue gas, subsequently elevating the byproduct’s level of carbon or Loss on Ignition. Measured at up to a thousand times more absorptive than natural carbon, PAC absorbs air-entraining admixtures when used in concrete, rendering the fly ash unusable. BASF will parlay a technology, CarbonBlocker, which applies minute quantities of liquid chemistry to alter the properties of fine powders in a bulk flow environment.

Due to ongoing air pollution regulation, environmental agencies are mandating mercury emissions controls at hundreds of coal-powered generating stations across the U.S. and Canada—already negatively impacting the quality of millions of tons of fly ash. CarbonBlocker is installed at five generating stations throughout the Ohio Valley region and has been deployed to yield more than 2 million tons of ASTM C618-grade fly ash. The technology’s proprietor holds separate patents on the injection system and chemistry, originally developing the process to address the effects of “Natural or Unburned” carbon caused by low-NOx burners or other inefficient burning conditions in the power plant boiler.

BASF Construction Chemicals saw an opportunity to further develop the CarbonBlocker chemistry to address the more aggressive challenge posed by PAC-tainted fly ashes, while expanding the chemistry to treating a wide array of construction materials, including cement and slag.