6.24.24
Nik Papageorgiou
EPFL scientists have made a breakthrough by developing membranes that show exceptional CO2 capture performance. ©iStock
Scientists at EPFL have developed advanced atom-thin graphene membranes with pyridinic-nitrogen at pore edges, showing unprecedented performance in CO2 capture. It marks a significant stride toward more efficient carbon capture technologies.
As the world battles climate change, the need for efficient and cost-effective carbon capture technologies is more urgent than ever. In that vein, scientists are exploring a number of innovations to drastically reduce industrial carbon emissions, which is pivotal in mitigating global warming.
One of these is carbon capture, utilization, and storage (CCUS), a critical technology that reduces carbon dioxide (CO2) emissions from hard-to-abate industrial sources such as power plants, cement factories, steel mills, and waste incinerators. But current capture methods rely on energy-intensive processes, which makes them costly and unsustainable.
Research now aims to develop membranes that can selectively capture CO2 with high efficiency, thereby reducing the energy and financial costs associated with CCS. But even state-of-the-art membranes, such as polymer thin films, are limited in terms of CO2 permeance and selectivity, which limits their scalability.
So the challenge is to create membranes that can simultaneously offer high CO2 permeance and selectivity, crucial for effective carbon capture.
A team of scientists led by Kumar Varoon Agrawal at EPFL has now made a breakthrough in this area by developing membranes that show exceptional CO2 capture performance by incorporating pyridinic nitrogen at the edges of graphene pores. The membranes strike a remarkable balance of high CO2 permeance and selectivity, making them highly promising for various industrial applications. The work is published in Nature Energy.
The researchers began by synthesizing single-layer graphene films using chemical vapor deposition on copper foil. They introduced pores into the graphene through controlled oxidation with ozone, which formed oxygen-atom functionalized pores. They then developed a method to incorporate nitrogen atoms at the pore edge in the form of pyridinic N by reacting the oxidized graphene with ammonia at room temperature.
The researchers confirmed the successful incorporation of pyridinic nitrogen and the formation of CO2 complexes at the pore edges by using various techniques, such as X-ray photoelectron spectroscopy and scanning tunneling microscopy. The incorporation of pyridinic N remarkably improved the binding of CO2 on graphene pores.
The resulting membranes showed a high CO2/N2 separation factor, with an average of 53 for a gas stream containing 20% CO2. Remarkably, streams with about 1% CO2, achieved separation factors above 1000 because of the competitive and reversible binding of CO2 at the pore edges, facilitated by the pyridinic nitrogen.
A schematic of porous graphene hosting pyridinic N (shown as purple spheres) at the pore edges. The resulting membrane is highly selective to CO2. EPFL/Kuang-Jung Hsu CC-BY-SA 4.0
The scientists also showed that the membrane preparation process is scalable, producing high-performance membranes on a centimeter scale. This is crucial for practical applications, meaning that the membranes can be deployed in large-scale industrial settings.
The high performance of these graphene membranes in capturing CO2, even from dilute gas streams, can significantly reduce the costs and energy requirements of carbon capture processes. This innovation opens new avenues in the field of membrane science, potentially leading to more sustainable and economical CCUS solutions.
The uniform and scalable chemistry used in creating the membranes means that they can be scaled-up soon. The team is now looking to produce these membranes by a continuous roll-to-roll process. The versatility and efficiency of these membranes could transform how industries manage their emissions and contribute to a cleaner environment.
Other contributors
EPFL Laboratory of Materials for Renewable Energy
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The Swiss Federal Institute of Technology in Lausanne [EPFL-École Polytechnique Fédérale de Lausanne] (CH) is a research institute and university in Lausanne, Switzerland, that specializes in natural sciences and engineering. It is one of the two Swiss Federal Institutes of Technology, and it has three main missions: education, research and technology transfer.
The QS World University Rankings ranks EPFL(CH) very high, whereas Times Higher Education World University Rankings ranks EPFL(CH) as one of the world’s best schools for Engineering and Technology.
EPFL(CH) is located in the French-speaking part of Switzerland; the sister institution in the German-speaking part of Switzerland is The Swiss Federal Institute of Technology ETH Zürich [Eidgenössische Technische Hochschule Zürich] (CH). Associated with several specialized research institutes, the two universities form The Domain of the Swiss Federal Institutes of Technology (ETH Domain) [ETH-Bereich; Domaine des Écoles Polytechniques Fédérales] (CH) which is directly dependent on the Federal Department of Economic Affairs, Education and Research. In connection with research and teaching activities, EPFL(CH) operates a nuclear reactor CROCUS; a Tokamak Fusion reactor; a Blue Gene/Q Supercomputer; and P3 bio-hazard facilities.
ETH Zürich, EPFL (Swiss Federal Institute of Technology in Lausanne) [École Polytechnique Fédérale de Lausanne](CH), and four associated research institutes form The Domain of the Swiss Federal Institutes of Technology (ETH Domain) [ETH-Bereich; Domaine des Écoles polytechniques fédérales] (CH) with the aim of collaborating on scientific projects.
The roots of modern-day EPFL(CH) can be traced back to the foundation of a private school under the name École Spéciale de Lausanne in 1853 at the initiative of Lois Rivier, a graduate of the École Centrale Paris (FR) and John Gay the then professor and rector of the Académie de Lausanne. At its inception it had only 11 students and the offices were located at Rue du Valentin in Lausanne. In 1869, it became the technical department of the public Académie de Lausanne. When the Académie was reorganized and acquired the status of a university in 1890, the technical faculty changed its name to École d’Ingénieurs de l’Université de Lausanne. In 1946, it was renamed the École polytechnique de l’Université de Lausanne (EPUL). In 1969, the EPUL was separated from the rest of the University of Lausanne and became a federal institute under its current name. EPFL(CH), like ETH Zürich (CH), and it is thus directly controlled by the Swiss federal government. In contrast, all other universities in Switzerland are controlled by their respective cantonal governments. EPFL(CH) has started to develop into the field of life sciences. It absorbed the Swiss Institute for Experimental Cancer Research (ISREC) in 2008.
In 1946, there were 360 students. In 1969, EPFL(CH) had 1,400 students and 55 professors. In the past two decades the university has grown rapidly and over 14,000 people study or work on campus, about 10,000 of these being Bachelor, Master or PhD students. The environment at modern day EPFL(CH) is highly international with the school attracting students and researchers from all over the world. More than 125 countries are represented on the campus and the university has two official languages, French and English.
Organization
EPFL is organized into eight schools, themselves formed of institutes that group research units (laboratories or chairs) around common themes:
School of Basic Sciences
Institute of Mathematics
Institute of Chemical Sciences and Engineering
Institute of Physics
European Centre of Atomic and Molecular Computations
Bernoulli Center
Biomedical Imaging Research Center
Interdisciplinary Center for Electron Microscopy
MPG-EPFL Centre for Molecular Nanosciences and Technology
Swiss Plasma Center
Laboratory of Astrophysics
School of Engineering
Institute of Electrical Engineering
Institute of Mechanical Engineering
Institute of Materials
Institute of Microengineering
Institute of Bioengineering
School of Architecture, Civil and Environmental Engineering
Institute of Architecture
Civil Engineering Institute
Institute of Urban and Regional Sciences
Environmental Engineering Institute
School of Computer and Communication Sciences
Algorithms & Theoretical Computer Science
Artificial Intelligence & Machine Learning
Computational Biology
Computer Architecture & Integrated Systems
Data Management & Information Retrieval
Graphics & Vision
Human-Computer Interaction
Information & Communication Theory
Networking
Programming Languages & Formal Methods
Security & Cryptography
Signal & Image Processing
Systems
School of Life Sciences
Bachelor-Master Teaching Section in Life Sciences and Technologies
Brain Mind Institute
Institute of Bioengineering
Swiss Institute for Experimental Cancer Research
Global Health Institute
Ten Technology Platforms & Core Facilities (PTECH)
Center for Phenogenomics
NCCR Synaptic Bases of Mental Diseases
College of Management of Technology
Swiss Finance Institute at EPFL
Section of Management of Technology and Entrepreneurship
Institute of Technology and Public Policy
Institute of Management of Technology and Entrepreneurship
Section of Financial Engineering
College of Humanities
Human and social sciences teaching program
EPFL Middle East
Section of Energy Management and Sustainability
In addition to the eight schools there are seven closely related institutions
Swiss Cancer Centre
Center for Biomedical Imaging (CIBM)
Centre for Advanced Modelling Science (CADMOS)
École Cantonale d’art de Lausanne (ECAL)
Campus Biotech
Wyss Center for Bio- and Neuro-engineering
Swiss National Supercomputing Centre
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