Lanlang ® CA005DR is a sort of cation exchange resin which has sulfonic group (-SO3H) in the styrene-DVB copolymer with clear gel structure. Lanlang ® CA005DR used for biodiesel purification.
Ion exchange resin was introduced in the biodiesel industry as a dry-wash media. Now, it is being used for a number of other applications in biodiesel plants, including esterification catalysts, media to improve cold soak filtration test performance and glycerin purification. Ironically, ion exchange resin is increasingly being utilized in water-wash plants to decatonize wash water, and to polish and dry the finished fuel.
The base structure DW-Resin is a copolymer of styrene cross-linked with divinylbenzene. This compound is extremely tough. The next step in the manufacturing process attaches millions of ion exchange sites to the copolymer matrix through a process called sulfonation.
These strongly charged sites will exchange a hydrogen ion for other cations (i.e., Na++, K++ and Ca++). Of course, this exchange can result in soap being split by the removal of sodium or potassium from the molecule. It is important to note, however, that this is the least desirable activity the DW-Resin can perform. Of greater importance is the powerful attraction that the resin exhibits for polar compounds, particularly glycerin. This attraction is due to the demand for hydration by the charged sites within the resin bead. The absorption of glycerin, or other polar compounds like water and methanol, does not exhaust the ion exchange capacity of the resin. Glycerin absorption can be reversed by replacing the glycerin with another polar compound like methanol, in the wash process. Theoretically, the resin could go through the glycerin absorption cycle an infinite number of times. In practice, the exchange of cations from soap, or excess catalyst, reduces the absorptive capacity of the resin. Another factor that will reduce resin life is fouling by organics like unsaponifiable matter.