A Simple, Affordable Material For Carbon Capture, Perhaps From Tailpipes

Using an inexpensive polymer called melamine– the main component of Formica– chemists have created an affordable, accessible, and energy-efficient form to capture CO₂ (Carbon dioxide) from smokestacks, a key aim for the USA and other countries as they seek to reduce greenhouse gas emissions.

The process for synthesizing the melamine material, posted this week in the journal Science Advances, could potentially be scaled down to catch emissions from vehicle exhaust or other movable sources of carbon dioxide. CO₂ from fossil fuel burning makes up about 75% of all greenhouse gases produced in the united state.

The new material is simple to make, needing primarily off-the-shelf melamine powder– which today costs about $40 per ton– along with formaldehyde and cyanuric acid, a chemical that, among other usages, is included with chlorine in swimming pools.

“We wanted to think about a carbon capture product that was derived from sources that were really cheap and easy to get. Thus, we decided to begin with melamine,” stated Jeffrey Reimer, Professor of the Graduate School in the Department of Chemical also Biomolecular Engineering at the College of California, Berkeley, also one of the corresponding writers of the paper.

The so-called melamine porous network catches carbon dioxide with an efficiency comparable to early results for another relatively current material for carbon capture, metal-organic frameworks, or MOFs. UC Berkeley chemists produced the 1st such carbon-capture MOF in 2015, and subsequent versions have proved even more efficient at removing CO₂ from flue gases, such as those from a coal-fired power plant.

However, Haiyan Mao, a UC Berkeley postdoctoral fellow who is the 1st author of the paper, stated that melamine-based materials utilize much cheaper ingredients, are easier to make, and are more power efficient than most MOFs. The affordable of porous melamine means that the product could be deployed widely.

“In this research study, we focused on cheaper product design for capture and storage and elucidating the interaction mechanism between carbon dioxide and the material,” Mao stated. “This work produces a general industrialization method towards sustainable carbon dioxide capture utilizing porous networks. We wish we could design a future attachment for capturing car exhaust gas or perhaps an attachment to a building or coating on the furniture surface.”

The work is a partnership among a group at UC Berkeley led by Reimer; a team at Stanford College led by Yi Cui, who is director of the Precourt Institute for Power, the Somorjai Visiting Miller Teacher at UC Berkeley, also one former UC Berkeley postdoctoral fellow; UC Berkeley Professor of the Graduate Institution Alexander Pines; also a team at Texas A&M College led by Hong-Cai Zhou. Jing Tang, one postdoctoral fellow at Stanford and also the Stanford Linear Accelerator Center and a visiting scholar at UC Berkeley, is the co-1st writer with Mao.

Carbon neutrality by 2050

While deleting fossil fuel burning is essential to halting climate change, a major interim strategy is to capture emissions of carbon dioxide– the main greenhouse gas– and store the gas underground or transform CO₂ into functional products. The United State Department of Power has just announced projects totaling $3.18 billion to boost advanced and also commercially scalable technologies for carbon capture, use, and sequestration (CCUS) to reach an ambitious flue gas CO₂ capture performance target of 90%. The ultimate united state goal is net zero carbon emissions by 2050.

Nevertheless, carbon capture is far from commercially viable. Today’s best strategy involves piping flue gases through liquid amines, which bind CO₂. Nevertheless, this requires large amounts of energy to release the carbon dioxide once it is bound to the amines so that it can be concentrated and also stored underground. The amine mixture must be warmed to between 120 also 150 degrees Celsius (250-300 degrees Fahrenheit) to regenerate the carbon dioxide.

In contrast, the melamine porous network with DETA aslo cyanuric acid modification captures carbon dioxide at about 40 degrees Celsius, slightly above space temperature, and releases it at eighty degrees Celsius, below the boiling point of water. The power savings come from not having to heat the substance to huge temperatures.

In its study research, the Berkeley/Stanford/Texas team focused on the standard polymer melamine, which is utilized not only in Formica but also inexpensive dinnerware and utensils, industrial coatings, and other plastics. Treating melamine powder with formaldehyde– which the researchers did in kilogram quantities– creates nanoscale pores in the melamine that the scientists believed would absorb CO₂.

Mao stated that tests confirmed that formaldehyde-treated melamine adsorbed carbon dioxide somewhat. However, adsorption could be much improved by including another amine-containing chemical, DETA (diethylenetriamine), to bind carbon dioxide. She and her colleagues subsequently found that including cyanuric acid during the polymerization reaction increased the pore size dramatically and substantially improved CO₂ capture efficiency: Nearly all the carbon dioxide in a substitute flue gas mix was absorbed within about 3 minutes.

The addition of cyanuric acid also allowed the product to be utilized repeatedly.

Mao and also her colleagues conducted solid-state nuclear magnetic resonance (NMR) studies to understand how cyanuric acid and DETA interacted to make carbon catch so efficient. The studies showed that cyanuric acid forms solid hydrogen bonds with the melamine network that helps stabilize DETA, preventing it from leaching out of the melamine pores during repeated cycles of carbon catch and regeneration.

“What Haiyan and her colleagues were able to reveal with these elegant methods is exactly how these teams intermingle, exactly how CO₂ reacts with them, and that in the presence of this pore-opening cyanuric acid, she can cycle CO₂ on and off many times with capacity that’s really quite good,” Reimer stated. “And the rate at which carbon dioxide adsorbs is actually quite rapid, relative to some other products. So, all the practical aspects at the lab scale of this material for CO₂ capture have been satisfied, and it is just incredibly cheap and easy to make.”

“Using solid-state nuclear magnetic resonance methods, we systematically elucidated in unprecedented, atomic-level detail the mechanism of the reaction of the amorphous networks with carbon dioxide,” Mao said. “For the power and environmental community, this work creates a high-performance, solid-state network family together with a thorough understanding of the mechanisms; however also encourages the evolution of porous materials research from trial-and-error methods to rational, step-by-step, atomic-level modulation.”

The Reimer and Cui teams are continuing to tweak the pore size and amine teams to get better the carbon catch efficiency of melamine porous networks while maintaining the power efficiency. This involves utilizing a technique called dynamic combinatorial chemistry to differ the proportions of ingredients to achieve effective, scalable, recyclable, and high-capacity carbon dioxide catch.

Reimer and Mao also closely collaborated with the Cui team at Stanford to synthesize other materials, including hierarchical nanoporous membranes– a class of nanocomposites combined with a carbon sphere and graphene oxide– and hierarchical nanoporous carbons made from pine wood, to adsorb CO₂. Reimer developed solid-state NMR precisely to characterize the mechanism by which solid products interact with CO₂ in order to design better products for carbon catch from the environment and power storage. Cui created a robust and sustainable solid-state platform and fabrication techniques for creating new materials to address climate change and energy storage.

More information:

Haiyan Mao et al, A scalable solid-state nanoporous network with atomic-level interaction design for carbon dioxide capture, Science Advances (2022). DOI: 10.1126/sciadv.abo6849

Read the original article on ENN.