Checking Biodiesel PH

[jdkline]

Before I start using large quantities of my homebrew, I'd like to be absolutely sure that I don't have a highly basic or acidic product. I know to test this I need to check the waste water from the final wash. For that I know I need some litmus paper, but really don't have the faintest idea where the average person would go about buying it. Also I know that titration is/can be important for a good product, so if anyone knows where to get phenol red, I'd appreciate that also. Thanks!

[jwsimons]

You should be able to get both anywhere they sell supplies for swimming pools..... [img]/ubbthreads/images/graemlins/biggrin.gif[/img]

Joe

[jdkline]

Nope, local swimming pool and aquarium stores have more complex kits to test for pH, not sure if it'd even work in this application. Any other ideas?

[OMCUSNR]

I was going to suggest a pond supply place. They have test sets for ph, amonia, nitates, etc. I can't see why they wouldn't work on the wash water. They are pretty reasonable in price, too.

The broad range test kit I use will test to 9.0 - 5.0, & is marketed by tetrapond.

[yaric008]

if you are going to making alot of it you might want to get one of those digital readout deals... the litmus paper might get old..

[jdkline]

OMSCCUR,
What's it called? We do have a place or 2 like that in town. That sounds like it would work. What does it consist of, and is it easy to use? Eric, the digital pH meter would be nice, but I'm not sure where I'd get one. How much do you think something like that would cost?

[OMCUSNR]

[ QUOTE ]
OMSCCUR

[/ QUOTE ] Are you implying I am a cur or maybe I have scurvey?? [img]/ubbthreads/images/graemlins/shocked.gif[/img]

Actually I think its just called broad range ph test. Its pretty easy to use. get a water sample, crush one of the tablets, shake it up to disolve, and wait about 10 mins. Then compare the color with the chart included. About $10 for 20 tests or so.

[shoebear]

You *could* make your own litmus solution from red cabbage. See this and this. Or order pH paper like this online.

[jdkline]

Oops, don't take it personally [img]/ubbthreads/images/graemlins/biggrin.gif[/img], I can't type sometimes. Thanks for the info about teh tetrapond. Should be able to get that or similar at Aquarium Connection. Shoebear, those links were most interesting, and that test paper is even cheap! I have to think they'd charge 4 0r 5 dollars in shipping though [img]/ubbthreads/images/graemlins/phoney.gif[/img] The red cabbage indicator may or may not be accurate enough to tell me what I need to know, but I do wonder if it could be used in titration instead of phenol red???

[ktpauley]

A digital pH meter is very accurate but, you need to keep it calibrated. The probe need to be kept in a buffer solution so it doesn't dry out. They are also fairly expensive. A good replacement probe cost about $200. If you want to use a pH meter check out this site www.hach.com Keith

[jdkline]

Thanks for teh info. Nope, don't think I'll be using that. not only is money tight, I will not be able to take that good of care of it. Just not practical. The tetrapond or pH test strips seems to be the way to go for me. I'm still wondering if the cabbage juice could be used in place of phenol red in the titration process. Whaddya think?

[ktpauley]

I've never heard of that method. The test strips are a good, fast test for this, and they are cheap. Keith

[jdkline]

Well, when I speak of titration, I mean determining how much lye to use above and beyond the accepted norm of 3.5-5 grams for a liter of fresh oil. IE, a titration of 2 means you need 5.5 grams to convert a liter of this particular waste oil to biodiesel AND neutralize all of its FFA content(bad for injectors and pump). BTW, I think you are right with respect to the test papers being best to check pH of the wash water. Thanks.