This basic soap titration testing kit is great for testing finished Biodiesel to see if all of the soaps have been removed.
It's also ideal for testing the methanol used in the process of flushing the ion exchange
resin in dry wash resin columns to ensure they've been properly cleaned. The test itself is based
loosely on the AOCS Soap Test Method.
The Soap Testing Method
1- Dissolve 12 mL Biodiesel sample into 100 mL 99% Pure Isopropyl Alcohol -- NOTE: 12 mL is based on 10 grams of Biodiesel
2- Add 10-15 drops of Bromophenol Blue (until the color goes blue)
3- Mix together well
4- Begin adding measured amounts of 0.01 N Hydrochloric Acid (HCL)
5- Watch for the color of the liquid to just slightly change from blue or green to yellow
6- Record the amount of HCL used to change the color
7- Calculate the soap content
8- Times the amount of HCL used by the proper soap content multiplier
9- This will indicate the parts per million content of soap in your sample.
Soap Content Multiplier
Depending on which catalyst the Biodiesel was reacted with, the soap multiplier will be different.
If NaOH (Sodium Hydroxide) was used, the multiplier is 304
If KOH (Potassium Hydroxide) was used, the multiplier is 320
ASTM Limits
While the Biodiesel ASTM standard doesn't specify exact soap limits, chemists have calculated
the estimated allowable soap limits based off the allowable ASTM Sodium & Potassium limits. For Sodium Hydroxide reacted Biodiesel - No more than 41 PPM
For Potassium Hydroxide reacted Biodiesel - No more than 66 PPM
See our tutorial video below for more information on soap testing.
Instructional Video
Watch this instructional video on how to properly perform a soap test using this soap testing kit.
It was put together by Utah Biodiesel Supply at the Springboard Biodiesel factory
(manufacturer of the SpringPro T76 Dry Washing Columns).
Upgrade to our Deluxe Soap Testing Kit and get a portable magnetic stirrer with 2 stir bars too!
We took all the great items from our Basic Soap Testing Kit and added our popular
portable battery operated magnetic stirrer to the package!
With this package you'll be able to do soap testing while on the go! The mini magnetic stirrer
runs off of a single battery and works extremely well when doing soap tests!
Need to have it all? Well, then look no further than our Ultimate Soap Testing Kit!
We've added all the goodies from our Basic Soap Test Kit, added our
portable battery operated magnetic stirrer, plus we've
doubled all the chemicals! You'll be able to do double the soap tests!
If you do a lot of soap testing, this is definitely the kit to have! By getting double the chemicals
plus a portable magnetic stirrer, you save a bundle on shipping plus get a discount on the extra chemicals!