Sodium carbonate (aka soda ash) is a key industrial chemical, but its production emits copious amounts of carbon dioxide — 800 kg per tonne. The conventional method (Solvay process) involves burning limestone with coke to produce carbon dioxide, which reacts in the subsequent steps with brine, ammonia and lime to produce soda ash. It also produces calcium chloride and wastewater, which need to be disposed of.
The Fraunhofer Institute for Ceramic Technologies and Systems, Germany, has developed an alternative means to produce soda ash. At the heart of the electrochemical route to produce ‘green soda’ is bipolar electrodialysis, a process that uses ultra-thin membranes. The pores in these membranes are so tiny that only individual ions can pass through them. The membranes function as an exchange medium by allowing only the negatively charged anions or positively charged cations to pass through.
This means that a mixture of salt and water — brine — is split into sodium hydroxide and hydrochloric acid. Hydroxides are salt-like compounds that form sodium hydroxide on contact with water. Then, when carbon dioxide is added to the sodium hydroxide, the final product is soda.
“This lets us produce sodium carbonate without spewing greenhouse gases into the atmosphere and without harmful industrial wastewater increasing the salinity of rivers or other bodies of water,” says Hans-Jürgen Friedrich, group manager for technical electrolysis.
Sustainable chemical generation of amides
Amides are essential in chemistry, serving as key components in a wide range of organic compounds, including proteins, pharmaceuticals, and synthetic materials. Traditional amide synthesis often requires high temperatures and harsh conditions, leading to significant environmental impact and inefficiency. These conventional approaches typically involve transition metal catalysts and generate substantial waste, prompting the need for more sustainable alternatives.
Scientists at the SN Bose National Centre for Basic Sciences have found a green and efficient chemical process for preparing amides that can revolutionise industrial manufacturing of pharmaceuticals and synthetic materials.
The scientists have developed a novel method for synthesising amides from alcohols using a covalent organic framework (COF) as a photocatalyst under red light irradiation.
This catalytic method can be helpful in chemical processes across industries — including pharmaceutical manufacturing, materials science, and green chemistry — offering a more sustainable, efficient, and recyclable approach to creating vital chemical structures, says a press release.
The advantages of this method include mild reaction conditions, high efficiency, excellent recyclability, and the practicality of red-light activation, which is less harmful and penetrates more effectively, making it suitable for large-scale applications.
The implications of this research are significant. In the pharmaceutical industry, this method could streamline drug production, reduce costs, and eliminate metal contamination. In materials science, it could enable the development of new polymers and materials with amide linkages, expanding the range of materials for various applications.
“Further research may optimise the COF structure for even better performance and stability, and scaling up the process for industrial applications will be crucial to realising its full potential,” the release says.
