Utilization of Carbon Dioxide Resource for Sustainable Development
Channel: IYBSSD
Date: 2023-07-11

Presented by Zhimin Liu
Institute of Chemistry, Chinese Academy of Sciences
n the modern era, carbon plays a pivotal role, forming the foundation of numerous aspects of our society. However, the paradox lies in the fact that while carbon is essential for our progress, it also poses a significant threat to human survival.
Carbon resources encompass both nonrenewable and renewable forms. Fossil fuels and nonrenewable carbon sources have led to considerable challenges. Carbon dioxide (CO2) is a key player in natural carbon cycling, essential for photosynthesis and biomass production. Nevertheless, the rapid expansion of the chemical industry has resulted in alarming CO2 emissions.
Presently, fossil fuel usage emits a staggering 40 billion tons of CO2 annually, pushing atmospheric CO2 levels beyond 400 ppm. This imbalance disrupts natural carbon cycles and triggers a host of problems. Consequently, the CO2 issue has garnered substantial attention.
CO2, known for its non-toxic nature, accessibility, and renewability, offers diverse applications due to its unique properties at different temperature and pressure levels. Supercritical CO2, existing in a state with gas-like viscosity and liquid-like density, is particularly notable for its versatility.
Supercritical CO2 finds utility in various sectors, especially as a solvent for extraction. This extraction method boasts advantages of distillation and common extraction, enhancing the purity of components. It proves especially valuable for extracting essential oils, perfumes, caffeine, and more. Additionally, it aids catalyst regeneration and offers environmental benefits by leaving no solid residues.
Supercritical CO2 extends its applications to electronics cleaning, yarn dyeing, aerogel drying, and material processing. Chemical reactions within this state possess unique attributes, facilitated by enhanced mass and heat transfer, yielding products like cyclohexanone with high selectivity.
While CO2's physical utilization falls short of addressing emissions, chemical transformation of CO2 gains traction. As a green carbon feedstock, CO2 contributes to the production of urea, salicylic acid, and carbonate. Converting CO2 via thermal catalysis, photocatalysis, and electrocatalysis presents opportunities for sustainable chemistry, but challenges remain in terms of energy and catalyst efficiency.
Electrocatalytic and photocatalytic routes involve renewable electricity and sunlight, respectively. Efforts to mimic natural photosynthesis for CO2 transformation aim for more efficient and cost-effective catalysts. Mineralization of CO2 via metal ions offers an alternative path, repurposing industrial waste resources for large-scale CO2 recovery.
In conclusion, the age of carbon presents both benefits and challenges. Carbon resources are the backbone of modern society, yet excessive CO2 emissions endanger our environment. While innovative applications of CO2, especially in supercritical state, offer diverse solutions, addressing CO2 emissions through chemical transformation is imperative for a sustainable future. The potential of CO2 utilization as a green feedstock and its role in evolving industries underscore its importance in the journey toward a more sustainable world.