Chemical recycling: gasification of plastic waste at low temperatures

The specific requirements and high purity of plastic waste from life science research laboratories make recycling it a particular challenge. Re:Lab AB is tackling this problem with a chemical recycling process based on low-temperature conversion, which is a special form of gasification.

In an interview with K-Mag, Dr Flavio Ortigao talks about the special recycling process and how it differs from conventional methods and promises the sustainable reuse of plastics from research laboratories.

Dr Ortigao, could you please give us an insight into the mission and core activities of Re:Lab?

Dr Flavio Ortigao: Re:Lab provides a closed-loop, circular solution, plastics-to-plastics recycling for waste plastics from Life Science research laboratories. Today, there is no recycling for the over 6 million tonnes of research laboratory plastic waste, that is either incinerated or goes to landfill. We have developed a proprietary technology based on Low-Temperature Conversion (LTC). What differentiate our chemical recycling technology form others is that it occurs at a low-temperature (below 450°C) and at normal pressure.

In a comment on a LinkedIn post of us, you mentioned the difference between thermal processes above 4,500°C and those below 450°C. Could you elaborate on this difference? Could you elaborate on this difference? How does it affect the efficiency and feasibility of recycling?

Ortigao: Our technology is a special case of Gasification, which is the partial oxidation of plastics residues to syngas, a gas comprised of hydrogen and carbon monoxide that can be used for chemical synthesis of renewable chemical entities or even new renewable plastics.

Gasification is not new, it has been around for 200 years. Gasification usually occurs at high to extremely high temperature, referred to as plasma gasification, which occurs at temperatures above 4,500°C. Maintaining such a high temperature is not economically feasible, therefore most gasification projects failed. By reducing the temperature, we have changed the game, converting an economically non-feasible project into a totally feasible one.

How do you assess the energy balance in chemical recycling, especially in terms of the sustainability of the process?

Ortigao: Mixed plastics have an energy content of 39Mj/kg, compared to 44Mj/kg of fossil fuel. It is a significant amount of energy, but not enough to sustain plasma temperatures. By reducing the temperature we have made the process auto-thermal, meaning the material provides the energy for its conversion. No external energy sources are necessary for process maintenance.

How do you see the future of chemical recycling, especially in terms of developing new technologies and overcoming global challenges such as the plastics crisis?

Ortigao: Chemical recycling has an important role to play complementing mechanical recycling, which has certain limitations. Chemical recycling is less sensitive to material degradation or degree of contamination. In our case, due to the severity of gasification, where plastics and organic contaminants are converted to syngas, it is the best option for recycling when there is a strict demand on the quality of the resulting recyclate.