Excess milk could reduce power plant emissions
The work is featured on the front cover of the November issue of Advanced Sustainable Systems.
Two major sources of greenhouse gases are CO2 emissions from fossil-based power plants and methane emissions from cattle. The researchers say there is a strong scientific consensus that emissions like these are causing human-induced climate change.
The article, "CO2 Capture: Dry and Wet CO2 Capture from Milk‐Derived Microporous Carbons with Tuned Hydrophobicity," explains it is possible to greatly reduce power plant CO2 emissions by using surplus or waste milk from cows to create activated carbons, which will adsorb or scrub the CO2 from the output.
"Our challenge was to create an inexpensive 'green' activated carbon," said co-author Associate Professor of Chemistry & Biomolecular Science and Kodak CAMP Distinguished Professor Mario Wriedt.
"Powdered milk can be converted into advanced activated carbons with the right porosity and surface chemistry to adsorb the CO2, allowing much better control than with the current materials used for this process, like coconut shells or coal."
This is the first report of performance for an activated carbon derived from a natural compound. The process for making the sorbents is similar to what is done to roast coffee, but with a secondary agent that etches nanoscale holes onto the material.
"Think of extremely dark roast holey coffee beans," says co-author University of Texas at Austin and former Clarkson Professor David Mitlin.
"The nanoscale holes, because of their strict sizes and surface chemistry, are very effective in trapping CO2 while keeping out water vapor. The CO2 is trapped reversibly in the carbon sorbent's micropores, which can be reused once the CO2 is released from its pores."
Wriedt said the dairy product used in the process would not be taken from the food supply.
He said although milk consumption has declined more than 30% since 1980, there has been a 13% increase in annual milk production per-dairy-cow, creating an oversupply meaning farmers now dispose of more than 50m gallons of milk annually.
"This use of waste milk could actually be a boost for the dairy industry," he said.
The article said, on average, cows release 150 to 260 pounds of methane per year and that employing their milk to capture CO2 would also help to offset this emission.
The researchers added these milk-derived carbon sorbents could also be used in other applications, like indoor air purification or water treatment.
The research was enabled by a Clarkson University Craig-Ignite Research Fellowship.
Advanced Sustainable Systems
CO2 Capture: Dry and Wet CO2 Capture from Milk‐Derived Microporous Carbons with Tuned Hydrophobicity
Jesse Pokrzywinski, Darpandeep Aulakh, Wolfgang Verdegaal, Viet Hung Pham, Hubert Bilan, Sam Marble, David Mitlin and Mario Wriedt
