The Principles of Green Chemistry

Our latest blog series is designed to guide chemists towards a greener, more sustainable laboratory. Each blog explores one principle.  If you missed previous ones, they can be found here.  

Sixth Principle: Design for Energy Efficiency  

At the halfway point of our review of the ACS Twelve Principles, the sixth principle, design for energy efficiency, is considered “a key issue of the 21^st century.”¹  “Energy requirements should be recognized for their environmental and economic impacts and should be minimized. Synthetic methods should be conducted at ambient temperature and pressure.”¹ Although energy consumption, if considered within a process, is probably something the chemist feels they have little control over managing.  As Dr. David Constable, Director of the ACS Green Chemistry Institute^® states regarding this principle, “heats of formation, heats of vaporization, enthalpy, exothermic reactions, etc.; these are what we think about.”¹ While that might be the case, he urges chemists to consider, “There is so much more to energy and engaging chemists in thinking about energy than asking them to run reactions at ambient temperature and pressure. Reactions themselves are rarely where a majority of energy is used; most is used in solvent removal to set up for the next reaction, or to remove one solvent and replace it with another, or to isolate the desired product, or to remove impurities.”¹. This brings us back to solvent use, which has been a running theme of this series.  In other words, by reducing solvent use, the chemist is not only reducing the footprint of hazardous materials but also energy use. When using energy to remove solvents, there are essentially three ways to mitigate this consumption: utilize fewer solvents (i.e. eliminate solvent swap or solvent exchanges), employ a different method of synthesis (i.e. chemistry in water), or even an alternative energy source (i.e. from renewable sources or from within the process using the “thermal pinch point analysis” method used by chemical engineers to optimize a process level of energy requirements). While every method has advantages and disadvantages, depending on scale, complexity, and modifications, there are many situations when these considerations do not drive the choice of synthesis, but by habit or conventions. In recent years, there have been many advances that have narrowed the disadvantages between the greener options and traditional methods, while the advantages are more apparent and appealing.^2-7  

While most gains in green chemistry can be made in small molecule work, these can also be applied to gene therapy manufacturing in several ways to make the process more sustainable and environmentally friendly:  

Energy-Efficient Facility Design: Designing manufacturing facilities with energy-efficient infrastructure, incorporating natural lighting, and utilizing renewable energy sources can reduce energy consumption.⁸

Closed-Loop Systems: Implementing closed-loop systems for water and chemicals can minimize resource consumption and waste generation. Recover and reuse materials whenever possible is crucial.

Process Development: Developing and utilizing environmentally friendly processes and chemicals in the manufacturing of gene therapies can significantly reduce the environmental impact.

Single-Use Technologies: While single-use bioreactors and disposable components are widely used in gene therapy manufacturing as well in microbial fermentation and cell culture processes for the manufacturing of biologics, efforts should be made to improve their recyclability and reduce their environmental footprint.

Carbon Offsetting: Companies can invest in carbon offset initiatives to compensate for their emissions, promoting a carbon-neutral manufacturing process.  However, it is always preferred to NOT generate greenhouse gases in the first place.

Bioprocess Intensification: Advancements in bioprocess intensification techniques can increase production efficiency, reducing energy consumption and resource utilization.

Energy Recovery Systems: Implementing energy recovery systems, such as heat exchangers and advanced filtration technologies, can capture and reuse energy within manufacturing facilities.

By implementing these practices and technologies, the field of gene therapy can make significant strides toward a more sustainable and eco-friendly future. Automation opportunities identified early in the Gene therapy scale-up process are also important to minimize the process’s carbon footprint.   

 SK pharmteco collaborates with customers early in the planning process to optimize these guidelines.   

 On a broader scale, SK pharmteco has instituted work to achieve Greenhouse Gas (GHG) Emission – Net Zero Carbon by 2040, aligning with the UN Sustainable Development Goals. Reducing solvent use or reuse benefits a project financially, along with a GHG reduction. Finally, 50% of the electricity used at SK pharmteco is sourced from renewable sources.  