Process

Our process, contained within a unit such as a cargo container, will be transported to the paper recycling plant or pulp & paper mill and “tacked onto” the waste stream. The advantages of using a self-contained facility are five-fold:

- It eliminates the need to continuously transport heavy, wet paper waste to our facility

- It lowers infrastructure costs because the manufacturing & assembly process can be standardized

- It breaks the infrastructure cost into smaller amounts which are more easily funded

- It allows us to have long term flexibility, since the semi-permanent infrastructure can be relocated

- It allows us to access emerging markets by shipping our facility overseas

The figure below is an overview of the process within our self-contained facility:

In the first stage, cellulose in the waste stream is converted into glucose. We are working on the development of a stream that will achieve this conversion. Until the strain is ready to be used with proper yields and to accelerate the start-up of the company, we will initially be using the enzyme cocktail Cellic CTec 3 from Novozymes. We will use sequential-batch reactors with controlled temperature and pH for large throughput with high yields of glucose. The effluent stream is dewatered to about 25-30% dry weight and disinfected with 600 ppm NaOCl before being fed to the reactors. The first reactor batch reactor is filled with paper waste and the enzyme cocktail. Hydrolysis occurs at 50°C and atmospheric pressure. The rate of hydrolysis of the fine fractions in the stream increases with temperature. The pH is adjusted to slightly acidic conditions, ranging from 4.0-5.0, and a steam-sterilized nutrient solution is added. When hydrolysis reaches a given level, the solution is transferred to the next batch reactor along with fresh enzyme cocktail. The mean residence time for each of the sequential batch reactors is 4 hours. This design allows us to optimize reaction conditions to achieve the highest glucose yield possible while maintaining high throughput.

At Upcycled Aromatics, we believe sustainable practices should be integrated at every level of our process. For this reason, solids which remain after fermentation are removed by centrifugation and composted. After removing the unconverted solids, we are left with a solution containing glucose. We use membrane filtration to concentrate the glucose, thereby avoiding the use of environmentally damaging solvents. The water recovered in this process is recycled by feeding it back into the sequential-batch reactors used for hydrolysis.

In the second stage of our process, glucose is used as a feedstock for the production of aromatics chemicals through fermentation by genetically engineered Pseudomonas putida. This stage also utilized sequential-batch reaction vessels operating at 30°C. We plan to use a nitrogen-limited fermenter maintaining a pH of approximately 7.0. The mean residence time for each reactor is also 4 hours in this stage. Sequential batch reactors allow for the flexibility to produce a new product every batch by changing the reactor conditions.

Lastly, instead of using expensive and environmentally damaging solvents to purify our products, we intend to use a new technology known as “Switchable polarity solvents”. This technology employs the addition or removal of CO2 to alter the polarity of the solvent and thus the solubility of our products. This feature allows us to repurpose the CO2 given off during fermentation, thereby reducing both our operating costs and our environmental footprint.