The complexity of the client’s recycling technology offered unique challenges to Koch Modular engineers. Proper instrumentation selection, piping design that can handle viscous streams, as well as the incorporation of change orders in the project timeline were among these challenges. Given the large amount of equipment necessary for this complex process, Koch Modular engineers were particularly challenged in packaging everything into a working modular system and allowing for proper operator and maintenance access.
The client’s small-scale pilot plant is designed to process various forms of once-used polypropylene to produce polypropylene with effectively virgin or near virgin properties. This is accomplished in a series of process steps involving supercritical absorption, gravity decantation, extraction, and adsorption to remove the contained impurities. Various equipment such as loss-in-weight feeders, extruders, polymer filters, candle filters, adsorbent columns, high pressure pumps, and heat exchangers are used. The final step of the process is a devolatilizing extruder that feeds the purified polymer melt to a pelletizer that generates ultra-pure recycled polypropylene pellets.
Koch Modular also provided an Emerson Process Management DeltaV based DCS control system complete with Main Control Panel, Remote I/O Panels, and Dell PC based Human Machine Interfaces, in addition to the development programming for all control loops, discrete motor/valve control, alarms, interlock function and general operator interfaces.
The system provided by Koch Modular was critical in demonstrating the validity of the client’s technology that converts waste plastic into ultra-pure recycled polypropylene.
A commercial-scale plant now under construction with Koch Modular. The development of this process at commercial scale will provide a much needed response to the global need for recycled polypropylene to reduce landfilling, export of plastic waste, and other environmentally damaging processes.