Bio-based Polymers: Sustainability and Techno-Economic Feasibility Analyses

SUSTAINABILITY VS. FUNCTIONALITY, DO YOU HAVE TO CHOOSE?

Our design replaces traditional petroleum-based packaging to mitigate environmental concerns and address rising sustainability issues through using bio-based polymers. The bio-based polymer we are creating is polyethylene furanoate (PEF). This polymer is created through the polymerization of two monomers, mono-ethylene glycol (MEG) and 2,5-furandicarboxylic acid (2,5-FDCA) with the biomass source being raw sugar.

PEF is structurally and functionally similar to PET with a similar production process and reduces the need for multi-material functionality in packaging. It has superior barrier, mechanical, and thermal properties thus making it an attractive replacement. PEF has an increased shelf life compared to PET with better performance in humid areas and co-extrusion possibilities with the advantage of being 100% recyclable.

PEF is not classified as a hazardous material with no suggestion for bioaccumulation. Pol-E Green’s production of PEF and subsequent cooling is in place to prevent undesired exposure or reactions from taking place.

PEF SHIFTS THE DEPENDENCY FROM FOSSIL FUELS

Pol-E Green identified a need for sustainably sourced and processed plastic that will not compromise on functional ability and structural integrity. The ability to not compromise on these two factors is what sets us apart. Through our production process a high quality grade of PEF is produced and allows for better bio-degradation/chemical recycling thus lowering overall lifecycle emissions.

The reactors used in our process also differentiate Pol-E Green from other companies through the use of unconventional reactors that increase product grade, conversion, and mass and heat transfer. The two unique reactors we are using are the spinning disc reactor (SDR) and the solid state polymerization reactor (SSP).

The SDR was chosen in order for increased mass transfer and heat transfer coefficients thereby decreasing the residence time needed for reaction thus improving conversion. This reactor allows us to have a continuous process as opposed to the currently used batch process.

The SSP was chosen in order to reach bottle-grade PEF which is a minimum molecular weight of 30kg/mol. The SSP reactor further polymerizes the solid pellets and the longer residence time ensures that more of the by-products of ethylene glycol and water diffuse into the carrier gas and exit the reactor.

ENVIRONMENTALLY CONSCIOUS AND HIGH QUALITY PRODUCTION GO HAND-IN-HAND AT POL-E GREEN

Pol-E Green boasts a design solution that produces high quality PEF while ensuring our production process is renewable and environmentally conscious, ensuring no high risk to ecological wildlife or the surrounding environment. Multiple polymerization reactions in our design increase the molecular weight of PEF, ensuring that the by-products of ethylene glycol and water are removed from the product until over 95% conversion is achieved. These by-products are then recycled back into our process, thus ensuring no waste and sustainability is kept at the forefront of our entire process.

Our selected monomers of MEG and 2,5-FDCA ensure our polymer is derived from renewable sources and our production process exceeds governmental regulations. PEF is not classified as a hazardous material so there is no high risk to ecological wildlife and the surrounding environment during the production process or bio-degradation. There need to be measures in place to avoid accidental release into the environment and water systems, however there is no suggestion of bioaccumulation for this product. PEF is chemically stable so it will be stored in cool, well-ventilated environments and in the case of an unwarranted release the appropriate measures will be observed, such as reporting it to the Alberta Environment Director and informing the community in the surrounding area and plant owner and operator.

Products made of PEF can easily be recycled or converted back to atmospheric CO₂ by incineration. Eventually, that CO₂ will be taken up by grass, weeds and other plants, which can then be used to make more PEF. PEF can be separated from PET by IR sorting and recycled to ‘rPEF’ using the same steps as PET (mechanical or chemical recycling).

DOES THE END JUSTIFY THE MEANS?

While renewable and sustainable plastic alternatives are needed and necessary in the world, the hard reality is that without economic profitability traditional petroleum-based products will not be replaced. Will the Pol-E Green design break through this barrier?

As PEF is an upcoming bio-polymer and our design uses unconventional reactors a pilot plant is necessary to test commercial SDR and SSP reactors. At present, this design is not feasible due to economic and design challenges. However, extensive research shows that in the future it will be viable through technological advancements, increased investments and higher environmental awareness.

Capital and operating cost estimations were done by analyzing PEF at an annual production rate of 50kt/yr, and a discounted cumulative cash flow (DCCF) analysis was performed using Excel. Our minimum selling price is $2.70 USD/kg.

Table 1: Financial Indicators and Values