Dry Washing

Dry Washing

The New B100-WH Biodiesel Reactor

The New B100WH Biodiesel Reactor System with Purolite PD 206 resin purification system

The New B100WH Biodiesel Reactor System with Purolite PD 206 resin purification system

While water washing is still the most popular method cleaning biodiesel for the homebased producer there exists yet another, more scientific, way using ion exchange resin beads. While there are a few companies offering biodiesel purification resin we will be focussing on Purolite PD-206 as this is the one we use.

PD206 Purification System (.pdf file) – PD 206 Data Sheet (.pdf file) . PD206 Info Sheet (.pdf file)
We find that it is a natural progression in homebased biodiesel production to always be on the lookout for better methods that enable us to make an ever higher quality product, and this is what we have done by upgrading to using resin purification. The technology has been in use for big commercial biodiesel plants for a couple of years but is just now starting to find it’s way into the homebased producing market.

While the initial cost of setting up for ion exchange resin purification is daunting for some we have found it to be well worth the expense in time saved, and the overall cost of only a cent or two per litre to the final product a reasonable one. “Dry washing” using resin has eliminated all water use in our homebased production of biodiesel, making of it an environmentally responsible choice. The decrease in power usage has also significantly dropped, as has the time needed to final process following the settling phase.

Those are just some of the more obvious benefits to using resin for “dry washing”. Another, less obvious, benefit is the quality of the final product. This type of resin is scientifically designed for use with methyl esters (biodiesel) and removes residual glycerine, impurities and leaves an end product worthy of the highest standards in the industry. Not using water also eliminates the potentila for water in the fuel should it not be dried properly.

Hot on the heels of the use of ion exchange resins has been the discovery of hard wood chips and/or sawdust in place of or in conjunction with resins. It is our opinion that a combination of the two types of purification methods is optimum in achieving top quality biodiesel while increasing the life of the resins themselves. The hard wood chips have shown not only promise but great success in the real world having been thoroughly tested in both homebased and mid sized commercial applications. ( See RolfQuo Biodiesel Interview )

We have therefore incorporated a 200L drum of hard wood chips, thanks to RolfQuo Biodiesel, in line with the resin beds to further insure quality and extend resin life. From the reaction to dedicated settling and followed by demething the biodiesel to wood chips and then a lead/lag configuration of Purolite PD206 resin to finally end up through a canister type fuel filter as a final polish we are producing very high quality biodiesel suitable for any domestic or industrial application.

Far right is the demething tank in both photos. Then into the wood chip drum and afterwards the resin beds and finally through the CAT 2 micron canister filter. In the wood chip drum the biodiesel enters the top and filters down through the chips and then from the bottom back up to the top of resin lead tank followed by the resin lag tank. The long tube on top of the chip drum is a vent used for filling the drum or checking on the quality of the biodiesel.

In order of use, once the reaction is done we immediately transfer the biodiesel mixture to the dedicated settling tank equipped with a StandPipe so that glycerine will drop below the SP’s outlet and we can drain off the biodiesel first and get the glycerine later from the floor drain.

Folowing the dedicated settling tank is the demething tank. This is where the biodiesel, which is free of glyerine, will be gradually heated using a heat spear from Rilla Biofuels until the methanol has been removed. The pump used is a ShurFlo series 2088 . Inside the demething tank we have kept an industrial 120degree full cone spray head from Bete for this purpose. By spraying the biodiesel out into a full cone while hot it further promotes methanol evaporation.

The use of a second tank (“Lag Tank”) for many is redundant, but we feel that it serves an important purpose in polishing the biodiesel before it enters the final filter stage. A 2 micron CAT 1R-0749 filter can is our filter of choice. The Advanced Efficiency CAT filter (here mounted on aPerma Cool 1 1/14 threaded head) IS redundant, but it is there as a safeguard against any particulates that may get through the resin beds, say like a small hair or something. Our aim is crystal clear biodiesel that passes scrutiny from the highest standards.

To see how the resin and wood chip tanks are set up visit our DryWash Tank Descriprion page.