Really, how they do that? It seem like giant "green-tree" in a factory.
This kind of thing
Chinese scientists develop new catalyst to convert CO2 into liquid fuel
2021-12-16 15:54:29 Ecns.cn Editor : Zhang Dongfang
(ECNS) -- A joint Chinese research team has developed a new catalyst to convert carbon dioxide, the main greenhouse gas, into high-purity formic acid, a valuable liquid fuel.
Turning CO2 into chemicals via electrolysis powered by clean energies like wind, water and solar energy is an emerging technology to reuse CO2, which is expected to effectively cut CO2 emissions. However, besides formic acid, this process will also produce other chemicals like ethanol, carbon monoxide and ethylene. Extracting and purifying certain liquids from a electrolyte solution cost too much.
As a result, the research team has developed a copper-based single-atom catalyst that costs less but is active and realized the single conversion from CO2 to formic acid. Meanwhile, based on solid electrolytes, the team also developed a new electrolysis device that can produce pure formic acid liquid fuel without further separation by using CO2 and water catalyzed by the new catalyst.
This achievement promises to lower the separation cost in CO2 electrolysis and boost the industrialization of CO2 conversion favored by green power, which is of great significance to accomplish carbon neutrality and peak carbon dioxide emissions.
The study was published in the academic journal Nature Nanotechnology.
http://www.ecns.cn/news/cns-wire/2021-12-16/detail-ihattyiu7541103.shtml
Directly converting CO 2 into a gasoline fuel
Jian Wei 1 2,
Qingjie Ge 1,
Ruwei Yao 1 2,
Zhiyong Wen 1 2,
Chuanyan Fang 1,
Lisheng Guo 1 2,
Hengyong Xu 1,
Jian Sun 1
Abstract
The direct production of liquid fuels from CO2 hydrogenation has attracted enormous interest for its significant roles in mitigating CO2 emissions and reducing dependence on petrochemicals. Here we report a highly efficient, stable and multifunctional Na-Fe3O4/HZSM-5 catalyst, which can directly convert CO2 to gasoline-range (C5-C11) hydrocarbons with selectivity up to 78% of all hydrocarbons while only 4% methane at a CO2 conversion of 22% under industrial relevant conditions. It is achieved by a multifunctional catalyst providing three types of active sites (Fe3O4, Fe5C2 and acid sites), which cooperatively catalyse a tandem reaction. More significantly, the appropriate proximity of three types of active sites plays a crucial role in the successive and synergetic catalytic conversion of CO2 to gasoline. The multifunctional catalyst, exhibiting a remarkable stability for 1,000 h on stream, definitely has the potential to be a promising industrial catalyst for CO2 utilization to liquid fuels.
https://pubmed.ncbi.nlm.nih.gov/28462925/
Catalytic Conversion of Carbon Dioxide to Methanol: Current Status and Future Perspective
Xinbao Zhang1,
Guanghui Zhang1*,
Chunshan Song1,2* and
Xinwen Guo1*
- 1State Key Laboratory of Fine Chemicals, PSU-DUT Joint Center for Energy Research, School of Chemical Engineering, Dalian University of Technology, Dalian, China
- 2Department of Chemistry, Faculty of Science, The Chinese University of Hong Kong, Hong Kong, China
With the increasing environmental problems caused by carbon dioxide (CO2) emission and the ultimate carbon resources needed for the development of human society, CO2 hydrogenation to methanol with H2 produced with renewable energy represents a promising path forward. Comprehensive analysis shows that the production of methanol by thermal catalytic CO2 hydrogenation is the most promising technology for large-scale industrialization. This review highlights current developments and future perspectives in the production of methanol from CO2, as well as the main existing problems based on a thorough techno-economic analysis. Moreover, the utilization status and future role of methanol as a platform molecule in the energy system is analyzed. Finally, in this review attention is paid to the development of new catalysts, new routes and new technologies for CO2 conversion aiming to clarify the future direction.
Introduction
While absorbing solar radiation, the earth is also losing energy to the space, so that the energy in and out of the earth system is basically the same (
Figure 1A). However, human activities are breaking the balance, and the situation is becoming more and more serious. In May 2019, CO2 concentration in the atmosphere exceeded 415 ppm, about 48% higher than that before the industrial revolution. The magnitude and rate of this increase, at least in the earth’s nearly 800,000 years of history, is unprecedented (
Figure 1B). The greenhouse effect caused by carbon emission has led to a series of extreme weather and is threatening the future of our living planet (
Iizumi et al., 2018). Researchers speculate that the increase of extremely severe cyclonic storms over the Arabian Sea caused by ocean warming may be the ringleader of this unprecedented locust disaster in 2020 (
Murakami et al., 2017). Moreover, global warming will continue to increase the risk of a deadly flood outbreak due to the collapse of an ice lake in the Himalayas (
Veh et al., 2020). Related researches also pointed out that global warming is making some originally quiet volcanoes restless due to the increase of extremely heavy rainfall (
Zhang et al., 2018;
Farquharson and Amelung, 2020). Presently, slow GDP growth and rising energy prices have not stopped the rise of energy consumption, and carbon emission exceeded ∼34,000 million tons both in 2018 and 2019, higher than the emission in recent years (
Figure 2) (
Dudley, 2019).
FIGURE 1
FIGURE 1.
(A) Schematic diagram of the energy budget of the earth: the yellow arrows are the short wave radiation reflected and absorbed by the earth; the red arrows are the long wave radiation absorbed by greenhouse gases and released from the earth. Figure from:
https://science-u.org/experiments/solar-oven-smores.html.
(B) Changes of atmospheric CO2 concentration in the past 800,000 years. Figure from: Scripps Institute of Oceanography,
https://sioweb.ucsd.edu/programs/keelingcurve/.
FIGURE 2
FIGURE 2. Global CO2 emission from the activities related to the combustion of oil, coal and natural gas (
Dudley, 2019).
CO2 utilization has been defined as the process of using it as a raw material for products or services with a potential market value. The utilization includes direct approach (
International Energy Agency, 2019;
Ra et al., 2020), where CO2 is not chemically altered (non-conversion), and the chemical and biological conversion of CO2 to useful products (
Figure 3). Most existing commercial applications involve direct utilization, including the production of food and beverages, metals fabrication, dry cleaning, healthcare, fire suppression, and the petroleum industry. Although still under development, the chemical and biological utilization has drawn much attention in recent years, including developing CO2-derived fuels (
Satthawong et al., 2013), chemicals and building materials (
Jiang et al., 2015;
Li et al., 2018;
Liu et al., 2018a;
Wang et al., 2020a;
Zhu et al., 2020). Today, around 230 million tons (Mt) of CO2 are used each year (
IEA, 2019a). However, the CO2 utilization is less than 1% of the CO2 released (
Figure 4). The largest consumer is agriculture, where around 130 Mt of CO2 per year is used in urea manufacturing, followed by the oil industry, with a consumption of 70 to 80 Mt of CO2 for enhanced oil recovery (
IEA, 2019b). More than two-thirds of current global demand for CO2 come from North America (33%), China (21%) and Europe (16%), and the demand for existing uses is expected to grow steadily year-on-year (
IEA, 2019a). Until now, the process of CO2 conversion to chemicals is limited by the market scale. Therefore, the development of target product methanol, which can be used as fuels and chemicals (
Sakakura et al., 2007;
Yu et al., 2010;
Cokoja et al., 2011;
Peters et al., 2011), is of great significance for achieving a large-scale application.
FIGURE 3
FIGURE 3. Simple classification of CO2 utilization pathways.
FIGURE 4
FIGURE 4. Growth in global utilization and emission of CO2. Note: Projections for future global CO2 demand are based on an average year-on-year growth rate of 1.7% (
International Energy Agency, 2019). Projections for future global CO2 emission are based on an average year-on-year growth rate of 1.4% (based on the annual average growth rate of 2009–2019) (
Dudley, 2019).
Methanol can be integrated into the current energy system and used as 1) a convenient energy-storage material, 2) a fuel, and 3) a feedstock to synthesize hydrocarbons, and an all-around substitute for petroleum (
Olah, 2005;
He et al., 2013;
Araya et al., 2020). Indian government has been promoting clean transportation and the application of fuel-cell vehicles (
Reddy et al., 2018). Dor Group began pilot testing in 2012 after the government of Israel determined one of the most favorable way to reduce the reliance on conventional fuels which is the use of methanol as the gasoline replacement, or gasoline-blending component, in internal combustion engines (
Dor Group, 2019). China is also speeding up the layout of methanol fuel market. Eight departments including the Ministry of Industry and Information technology of China jointly issued the Guidance on the Application of Methanol Vehicles in Some Regions (2019). Shanxi, Shaanxi, Guizhou, Gansu and other regions are accelerating the application of M100 methanol vehicle and realizing the diversification of vehicle fuel to ensure energy safety, for they have good resource endowment conditions and methanol vehicle operation experience (
Ministry of Industry and Information Technology of the People’s Republic of China, 2019). Compared with the top-down development mode of natural gas, ethanol and other clean energy (policy in front, promotion and application in the back), that of methanol is bottom-up, and after long-term exploration, practice and verification, the above policy documents are in place.
Comprehensive reviews were presented about the recent significant advances in CO2 hydrogenation to methanol, focusing on development of catalysts including metals, metal oxides, and bimetallic catalysts, as well as the structure-activity relationship,
in situ characterizations on identifying key descriptors and understanding reaction mechanisms (
Jiang et al., 2020;
Zhong et al., 2020). Researchers also provided an in-depth assessment of core-shell materials for the catalytic conversion of CO2 into chemicals and fuels (
Das et al., 2020). ZrO2-containing catalysts are also systematically reviewed to offer insights into the modification of surface properties and bulk structure of catalysts driven by the supports and the resulting effects on the performance for CO2 hydrogenation to methanol (
Li and Chen, 2019). Based on the summary of the research status of the catalytic materials in published reviews, this review is organized toward the future development prospects, with an emphasis on the role of methanol in the energy system in the future and technical feasibility. By analyzing the current status of thermocatalytic conversion of CO2 into methanol, the review highlights the development of catalysts regarding precise preparation, large-scale production, high efficiency and low cost.
Analysis of the Whole Process of Thermal Catalysis of CO2 to Methanol
CO2 life cycle assessment is helpful to pick out the main problems existing in the process of CO2 conversion. Researchers have introduced a mathematical formulation to select the promising CO2 capture and utilization (CCU) paths. The results indicate that the optimal solution is greatly influenced by the market demand, scale of CO2 emission source, and H2 availability (
Roh et al., 2019). Therefore, target products that can be used as fuels and chemicals are of great significance for the large-scale emission reduction. Moreover, small-molecule products have irreplaceable advantages compared with large-molecule products, due to the high selectivity, simple process, low energy consumption, etc. As a fuel and an important chemical feedstock, methanol is used on a large scale, and has been used as a feedstock for the synthesis of chemicals and fuels (
Olsbye et al., 2012). The hydrogenation of CO2 to methanol has attracted much attention as a promising way (
Behrens et al., 2012;
Kattel et al., 2017a;
Wang et al., 2017;
Lam et al., 2018;
Dang et al., 2019b;
Wang et al., 2019b;
Li and Chen 2019). Next, we will discuss the role of methanol in the future energy system, technical feasibility and techno-economic analysis for methanol synthesis from CO2. By analyzing the research status and development potential of CO2 hydrogenation to methanol, we aim to find out the existing problems and point out the direction for future research.
The Importance of Methanol in the Field of Energy
In the future we will phase out fossil fuels and switch to sustainable energy, especially hydroelectricity, wind and photovoltaic energy. However, due to the variable nature of the latter sources which depend on time of day, and season of the year, we need to store such energy at peak production times for use in times of low production. Converting such energy into chemical energy and storing it in methanol molecules is regarded as one of the promising methods. Methanol is considered as one of the potential platform molecules because of its available applications in the fields of fuels and chemicals in the future (
Figure 5) (
Su et al., 2013). At present, methanol-based technologies include methanol synthesis, methanol to olefins, chemicals (formaldehyde, acetic acid, methylamines, glycol, etc.), gasoline, biodiesel, direct combustion and so on (
Figure 6). The methanol economy through chemical recycling of CO2 will eventually free human from dependence on fossil fuels (
Tountas et al., 2019). In recent years, China has developed a series of clean coal technologies to transform black-dirty coal into clean fuels and chemicals. Clean coal technologies based on methanol platform will play an important role in Chinese energy system in the future (
Xu et al., 2017). Shenhua, the largest coal company in China is leading the commercialization of modern clean-coal technologies for value-added chemicals and transportation fuels.
https://www.frontiersin.org/articles/10.3389/fenrg.2020.621119/full