Wednesday, 25 December 2013

Basics of Refinery Inspection properties

Lets discuss on refinery inspection properties there are nearly 100+ RIP properties where petroleum industries are more interested for their different purposes.

Crude Charecterization purposes (Eg: Watson K factor to define paraffinic nature, Aniline point - content of aromatic compounds)
Transportation purposes(Eg: Flash point, Fire point,Pour Point) and
Quality purposes (ON,CN ) etc

There are various equations and limitations provided by API petroleum procedures.
Some of them are listed below:
API Procedure 2B12.1 for Cloud Point(CP).
API Procedure 2B8.1 for Pour Point(PP).
API Procedure 2B14.2 for interaction of CP and PP.
These procedures mostly depends on MABP (mean average boiling point) . Kinematic viscosity and specific gravity.

If we talk in simulation percpective for finding out these RIPs of a mixtures (eg: say crudes) selection of right mixing rule is also important.
Eg: Some mixing rules are Index Method, Factor Method and Summation Method. various organizations may also have there own way of mixing rule with some additional constants.

Any way apart from that 100+ RIPs first come to our minds i.e gasoline related those are RON and MON gasoline knocking characteristics properties.

I don't want to give octane number definition. here i am trying to explain the importance of the RIP.
But hint: it is _______ of _______ n-heptane(0 ON)+i octane (100 ON) which exactly gives_______ knocking characteristics.

These are nothing but acronym of research octane number (RON) and Motor octane number(MON) which are indication parameters of knocking. These are basically a "standard methods" which are calculated by using different engine speeds,air intake and coolant temperature for finding out ON.
So care will be taken by considering these factors (Engine speed, coolant temperature etc ) - Don't bother about these points refineries will take care based on climatic conditions, there will be difference in gasoline parameters that they release to market called summer gasoline or winter gasoline.
Research method is for city driving (means generally at lower say 600 to 650 rpm ) and Motor method is for highway driving(higher rpm say 1000 rpm).

In US gasoline outlets the values will be stipulated by taking average of these numbers from which we can define another parameter called AKI(Anti knocking index).
http://en.wikipedia.org/wiki/File:Gas_Station_Pump_Five_Octane_Ratings.jpg

There are some standards stipulated by ASTM standards on finding out RON and MON.

IS standards you can refer below link:
https://law.resource.org/pub/in/bis/S11/is.1448.26.1960.txt

Some additives will be added to boost up these numbers if that additives contain lead (TEL) the gasoline is called leaded gasoline or leaded petrol.  many countries banned because of damage that causes by lead.
other additives like MTBE used which doesn't have lead it is called "unleaded gasoline"

Why additives because straight run gasoline will have an octane number of 60 to 70 but desired number will be 90 to 100 so additives will fill this gap.

Note: Some Unsaturated HC will have high octane number but not preferred because it is prone to gum formation. don't just confuse. good ON will have good amount of saturates (branched chains) with ON boosters....


Regards,
Mohana krishna Chitikena,
QAE(Thermodynamic Studies)
ChE from AU

4 comments:

  1. well, good to see your interest in refinery business.
    I would like to add few more points to your write up.
    you said "Why additives because straight run gasoline will have an octane number of 60 to 70 but desired number will be 90 to 100 so additives will fill this gap."

    I would like to clarify you that additives like MTBE, ethanol alone may boost your octane number from 70 to 90 but you lack in other properties like Density, RVP, E70, Aromatic content, etc.
    to explain you in brief, Gasoline is a mixture of different streams like Reformates, isomerates, cracked naphtha from units like FCCU, HCU, OHCU etc.
    All these blends are mixed in appropriate ratio to make up the final product gasoline with required E-III or E-IV specifications.
    this can be happened only by using blending technology and cannot be done manually, we use certain softwares like ASPEN PIMS, RPMS, BMA etc to see that we operate the Blending Operation in required manner.

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  2. Manoj so nice to see your comment and thanks for the information. That is correct gasoline is a blended product ... and thanks for specifying the specifications as well.
    Indeed we also use PRO/II simulations for getting that properties and it has a blending options as well. In this blog I have concentrated only on RIP.
    Can you please elaborate of your comment ‘but you lack in other properties like Density, RVP, E70, Aromatic content, etc. ' I am unaware of how these Booster effect properties you mentioned will effected please provide documents if you have any.
    And thanks for commenting....

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  3. Found the relation b/w boosters and RVP and density, but yet to understand optimum % of adding MTBE...Seniors pls comment thanks in advance...

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  4. Ok got some exposure while working in Isomerization unit for OTS. In general the isomerization reactions will occur in Penex reactor along with side reactions. Benzene is readily absorb on a penex catalyst and reduce the active sites of catalyst which effect the overall ON. other undesirables are Olefins,water,C7+ etc all these things will damage catalyst which contain active chloride.

    ReplyDelete

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