×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Crude Oil Blending

Crude Oil Blending

Crude Oil Blending

(OP)
Dear All,

I found below in a test paper. but still searching for the API/ASTM crude reference which puts why API’s cannot be averages into understandable language???

Question 1

Equal volumes of a 30°API, 20°API, and 15°API crude are blended to produce a feed to refinery. Estimate the °API of the resulting blend. Clearly state your assumptions and comment on your result. (Hint: Would °API blend linearly?) 15 pts
Answer:
Blend: Equal volumes of 30°API, 20°API, and 15°API
°API = 141.5/SG60oF - 131.5

°Theoretically APIs cannot be averaged, but SGs can be, assuming that the volume change upon mixing the three crudes is negligible.
Determine SG of each crude, calculate average SG, and use this value to calculate the blend °API.

30= 141.5/SG1–131.5, 20= 141.5/SG2–131.5, 15=141.5/SG3 – 131.5
SG1 = 0.876 SG2 = 0.933 SG3= 0.966

SGavg = AVG (0.876:0.933:0.966)
SGavg = 0.925

°APIblend = 141.5/0.863 – 131.5
°APIblend = 21.4

Note that the blend °API is not a simple a mean of the component °API’s (AVG 30:20:15) = 21.7. Although the difference appears to be small, it is important to use the precise °API in several calculations and correlations that are used to predict the quality and yield of refinery products.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login



News


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close