Intelligent automation supports advances in plastic recycling 

From water to land to air, and even up in outer space, hardly a realm exists that is untouched by the plastic. The invention of this durable and versatile material has proven to be both a blessing and a curse. The sheer amount in existence has endangered ecosystems, posing a threat to human health and causing an environmental crisis of sorts.

Over the past 10 years, award-winning Plastic Energy has been working on decomposing the plastic problem. The company takes discarded films and flexibles that are mostly unrecyclable with conventional mechanical methods and – using its patented technology – turns them into a valuable substance to serve as feedstock for new plastics.

To monitor and control the complex chemical processes at their two plants in Spain, and to ensure that their systems stay stable when innovations and changes are introduced to their relatively new technology, the chemical recycler turned to intelligent automation systems from Siemens.

Not all plastics are the same. Some are single-layered, others multilayered. Different types and colors are recycled separately. Mechanical recycling, the kind associated most with plastic recycling, handles mostly monolayered plastics. These downcycled to create packaging that – with the exception of PET bottles – are unsuitable for foodstuffs.

The most common plastic packaging, however, are multilayer films and flexibles. The conundrum man faces is how to make the most of valuable plastic discards, 50 percent of which land in incinerators and landfills, or are exported to regions that lack proper waste management infrastructure.

Plastic Energy saw an opportunity to meet the problem in a unique way. “We created a solution to prevent plastic pollution by converting difficult-to-recycle mixed plastic waste into a recycled oil, called TACOIL,” explains Carlos Monreal, CEO of Plastic Energy. TACOIL is a fusion of TAC – thermal anaerobic cycle – and oil.

Multilayer plastics are processed together, with no separation by type or color needed. All are heated in an oxygen-free, or anaerobic, atmosphere to create hydrocarbon gases, which are then condensed. TACOIL is produced and is used in the same way as virgin polymers to manufacture new plastic for food-grade packaging. From plastic to oil and back, it seems that plastic has come full circle.

This novel technology is still undergoing constant change. To introduce new product quality and efficiencies, Plastic Energy has to make adjustments quickly and safely. In Siemens’ Simatic PCS 7 system, they saw the solution for automating, measuring, and regulating their processes. It also monitors and manages all inputs, flows, and variables. Siemens’ automation systems allows Plastic Energy to amend and scale their plants as they see fit.

In chemical environments, preventing setbacks and unexpected events is key. “Plastic Energy’s recycling plants need to be flexible, carefully controlled, and able to meet or exceed all safety and security standards,” says Miguel-Angel Fernandez, head of vertical management Chemical, Glass and Oil & Gas at Siemens. The two plants located in Spain use predictive analysis software from Siemens to preempt issues and guarantee operational stability. Their operators are equipped with smart field devices that make it easy for them to manage and maintain plant assets, ensuring maximum reliability.

The company is also working closely with Siemens to find new solutions for instrumentation, which has proved to be challenging in their unique environment. “We are proud to support the creation of these standards as a technology partner – not just with our product portfolio, but also with services and consulting – and to ensure the proper and safe functioning of these plants,” Miquel-Angel Fernandez concludes.

Chemical recycling, combined with mechanical recycling, can reduce the impact of plastic leakage into the environment. “Through our process, we prevent the depletion of natural resources while simultaneously protecting the environment from plastic pollution by decreasing the volume of end-of-life plastic waste,” comments Carlos Monreal. Plastic Energy’s technology, complete with Siemens automation hardware and software, has been implemented not just within their plants, but in facilities all over the world.

Plastic is unavoidable. If man cannot reduce its dependence on it, what is the best way for it to be sustainable? With the help of Siemens, Plastic Energy will continue to devise new answers to this question and find ways of ensuring that this multifaceted material become part of a truly circular economy.

May 2022