ION exchange resins are high tech man made resins that are capable of trapping soap molecules on the surface of a resin bead. Different IX resins work in different ways and use different techniques to clean the biodiesel. All of them generate a new waste stream, the spent beads.
We recommend keeping soap content of the unwashed biodiesel below 500 ppm of soap. That’s how much you usually have after the first or second wash. Commercial biodiesel producers using new oil can meet the 500 ppm level in unwashed biodiesel. The Dry wash biodiesel purification resin removes the soap by replacing the metal ion in the soap with a hydrogen ion forming FFA that is passed through the resin and left in the biodiesel. If there is too much soap, there will be too much FFA in the finished biodiesel to meet TAN (Total Acid Number ASTM D664). Commercial producers have found that if the biodiesel contains more than 1200 ppm going into the drywash towers, it will not meet ASTM D664.
Homebrewers using or standard single stage base method on WVO will have three to five times that much soap in our unwashed biodiesel. That means we would be using it three to five times faster than a commercial biodiesel producer. To make it economical, you would have to wash using some other "wash" technique first to bring your soap levels down.
Lanlang supply dry wash biodiesel purification resin, more information just freely get in touch with us.