Home Cosmetic Science Talk Formulating Advanced Questions Saponification number of motor oil

  • Saponification number of motor oil

    Posted by Ameen on October 22, 2016 at 9:48 pm

    Hi all,

    Moderator, if  this question doesn’t belong here, please do remove or delete it.

    I have been trying  very hard the last 2 weeks to find out the sapo. number of motor oil but did not come to any answer.

    I want to make something useful for  the enviro. by turning motor oil into soap instead of  letting  it become a landfill.

    All my searches gave nothing that I could go after. I thought either the motor oil is unsaponifiable and  therefore no answer or it implies a sofisticated and expensive technical process making it worthless trying.

    Thankfull endlessly in advance to anyone giving any guidance or pointers in the right direction.

    May you all be blessed
    Ameen
    Retired French language teacher

    belassi replied 7 years, 4 months ago 6 Members · 11 Replies
  • 11 Replies
  • microformulation

    Member
    October 22, 2016 at 11:37 pm

    I may be wrong, but in this case oil is not equal to oil. The structure is not such that it could be easily saponified and hence kick out glycerin and a saponified soap.

  • belassi

    Member
    October 23, 2016 at 12:37 am

    Motor oil is a mixture of hydrocarbons and cannot be saponified into soap. Secondly, used oil has all sorts of metal contaminants etc.
    If you’re interested in this kind of thing I suggest you take a look at building a biodiesel reactor; but first, tour the area and discover if the local fast food places will cooperate.

  • bobzchemist

    Member
    October 24, 2016 at 1:54 pm

    Used motor oil is always badly contaminated. There’s no way to purify it enough to make it safe for personal care. In fact, there’s no way to purify it enough to make it safe to burn as a fuel. It’s best to just leave it be.

    If you must use it as a project, how about working on a way to lock it up chemically so that it won’t contaminate the rest of the material in the landfill?

  • Ameen

    Member
    November 3, 2016 at 9:22 am

    @Microformulation, @Belassi, @Bob, thank you all ever so much for eretaking your time answering my question.

    Pity that chemistry/technology did not yet come up with a way to tacle such a big problem, I guess I will simply wait nicely and see what happens.

    I live in a place ruled  by a Maffiocracy where everything is decided in dark rooms  above our heads with no consideration for  the real people that must struggle daily for just existing.

    A place where private initiatives and entrepreneurship are empty words  that  are an abstract threat to the ruling Maffia,  waiting for Godot……….


    Ameen
    Retired French language teacher

  • bobzchemist

    Member
    November 3, 2016 at 1:55 pm

    Used cooking oil, on the other hand, has a variety of uses…

  • chickenskin

    Member
    November 4, 2016 at 4:40 am

    i can try and do an HLB tomorrow for you ;)

  • Ameen

    Member
    November 4, 2016 at 11:06 am

    @Bob…… yes, cooking oil has many uses but unfortunately, cooking oil is not available as such in this maffiocracy here, university and hospital and restaurant kitchens do not discard  oil after  the  first or second  cooking, they simply add new oil  when they see  the oil level diminuish in the frying pans, some have  not changed oils for  periods  of years therefore there is no cooking oil available for recycling……….. there is  no controling authority and  no supervising hierarchy to take care of such control. The only laws that exist here are those that are defined by the ruling maffia and these rules and laws are light years away from what is good and beneficial for us simple citizens.

    @chickenskin U R  by far much greater than a god…..U R Human.

    Thanks Bob, thanks Chickenskin for your  inputs.

    Ameen
    Retired French language teacher

  • johnb

    Member
    November 4, 2016 at 3:04 pm

    chickenskin

    i can try and do an HLB tomorrow for you

    Do not confuse HLB and Sap Value

  • microformulation

    Member
    November 4, 2016 at 3:51 pm

    A predicted required HLB would simply help you to determine the needed emulsifiers to create an emulsion with the oil. It does not address the environmental benefit that was proposed and in fact the emulsified oil would still contain the contaminants.

  • bobzchemist

    Member
    November 4, 2016 at 4:56 pm

    OK, lets look at this for a minute:

    The bulk of a typical motor oil consists of hydrocarbons with between 18 and 34 carbon atoms per molecule. (Wikipedia) It’s not a triglyceride, it won’t have a SAP number, and it won’t turn into soap if you add caustic to it.

    The composition of used motor oil is here: 
    http://www.indianaacademyofscience.org/documents/proceedings/v112/ias_v112_n2_p109-116.aspx

    and here:
    http://www.tandfonline.com/doi/abs/10.1080/15275920802119441

    It is apparently possible to make diesel or home fuel from it:

    http://www.oiltofuel.com/

    http://www.dieselbombers.com/general-diesel-related-tech-articles/10029-converting-waste-motor-oil-diesel-fuel.html

    It may be even also possible to bring it back to a state where it can be used as motor oil again.

    https://www.environment.gov.au/protection/used-oil-recycling/recycling-your-oil/uses-recycled-oil

    https://mobiloil.com/en/article/car-maintenance/used-motor-oil-recycling/used-motor-oil-recycling

    https://en.wikipedia.org/wiki/Automotive_oil_recycling

    http://www.recycleoil.org/

    Using it to make soap, or even surfactants, on the other hand, doesn’t seem possible/feasible. 

  • belassi

    Member
    November 4, 2016 at 7:24 pm

    The used oil contained
    838 .0 mg/kg Zn, 110.0 mg/kg Pb, 9 . 4
    mg/kg Cd and 4100 mg/kg Ba
    The lead and cadmium levels are pretty bad. The idea of spreading it on soil to decompose it is crazy because all the heavy metals will persist for ever poisoning the ground.
    Even if you could make it into soap, the product would be prohibited from sale because of the heavy metals.

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