October 28, 2022

We recently received a request to test Quillaja wood chips at our facility in Tampa, FL. The intent was to measure the effectiveness and throughput of the Quillaja chips through our CP/VP series screw presses. The test was quite successful.

Quillaja is an evergreen tree, native to Peru, Chile, and Bolivia. The trees grow up to 20m in height. They are commonly known as the Soap Bark Tree and have a long history of medicinal uses by the local population in central Chile. Nowadays, extracts from the wood of this tree are used in a wide range of products around the world. The extracts are emulsifying and foaming agents commonly used in antiviral, anti-fungal, antibacterial, anti-parasitic pharmacological products. Other popular applications include foaming additives for detergents, shampoos, and food products (example: foam in root beer).

We were sent two different chip sizes that the wood had been ground into, one coarse and one a little less coarse. The chips were soaked in water and the excess water was drained prior to being loaded into a CP-6 screw press. The press cake of the coarsest grinds represented a 22% weight reduction; these chips started at a higher moisture content, so they had more free water available to be pressed out. Pressing the less coarse wood chips gave a 33% weight reduction. We believe that the reduction might have been greater if the chips were soaked longer. The press liquor was measured as having no dissolved solids, zero Brix.

The press liquor was almost entirely foam as it exited the screen. The foam eventually floated above a liquid; however, it took a while for that to happen. The press cake was so dry that no additional liquid could be squeezed out by hand, and no film was on my hand after squeezing it. The CP-6 press exerted a high amount of torque when pressing the coarse grind material against the cone pressure of 75 psi. A cone pressure of 45 psi was used for the finer chips. The consistency of the press cakes from both grinds of wood chips looked almost identical. This was due to the shredding that occurs within the screw press.

The throughput was measured in tons per day of dry solids in the press cake. The results showed that the press performed at the low end of the range expected in our paper mill applications.

Overall, these results were very satisfactory for the client. There is the possibility of lowering the moisture content of the final press cake by adjusting the process. We did not have enough material to do extensive testing. An engineer at Vincent who regularly deals with dewatering wood chips feels that it may be possible to get a better efficiency with adjustments.

Testing at Vincent Corp for clients is always free. We regularly perform tests at our Tampa facility to ensure that the screw presses will be effective for the application desired by the client. We only need for samples to be shipped to us, and we will perform trials.

ISSUE #346