Where
Tb = Average boiling point, in Kelvin
M = Average molecular weight
S = Specific gravity at 60 °F (= 15.6°C)
See also Molecular weight from average boiling point and gravity
Eq. (1) and (2) are used to calculate Tb for a number of specific gravities and molecular weights and the results, in °C and °F, are given in the figures below.
Example 1: Average boiling point of naphtha
Calculate the average boiling point of a naphtha with specific gravtity, S = 0.763 and a molecular weight of 125.
Naphtha is in the low molecular weight range, and equation (1) should be applied.
ABP = 3.76587*e(3.7741E-03*125+2.98404*0.763-4.25288E-03*125*0.763)*1250.40167*0.763-1.58262 = 418 K
Converted to °C and °F: 418 K = 145°C = 293 °F
Applying equation (2) gives
ABP = 9.3369*e(1.6514E-04*125+1.4103*0.763-7.5152E-04*125*0.763)*1250.5369*0.763-0.7276 = 423 K = 150°C = 302°F
NB! For low molecular weights (< 300) this ABP is consider to be less accurate than calculated from Eq. (1).
Example 2: Average boiling point of a vacuum gas oil.
Calculate the average boiling point of a vacuum gas oil of gravity of 16.7°API and an average molecular weight of 391.
The vacuum gas oil has a molecular weight > 300, and Eq. (2) must be applied.
But first, we have to convert the API gravity to specific gravity:
S, specific gravity = 141.5/(16.7°API +131.5) = 0.955
ABP = 9.3369*e(1.6514E-04*391+1.4103*0.955-7.5152E-04*391*0.955)*3910.5369*0.955-0.7276 = 737 K = 464°C = 867°F
Boiling points of elements, products and chemical species at varying conditions.
The study of fluids - liquids and gases. Involving velocity, pressure, density and temperature as functions of space and time.
Material properties of gases, fluids and solids - densities, specific heats, viscosities and more.
Molweight, melting and boiling point, density, pKa-values, as well as number of carbon and hydrogen atoms in molecules are given for 150 different alcohols and acids.
API expresses the gravity or density of liquid petroleum products. Online API to Specific Gravity calculator.
Variations in crude oil density are shown as function of temperatur, together with volume correction factors.
An introduction to density, specific weight and specific gravity.
Variations in fuel oils density as function of temperatur, together with volume correction factors.
Formulas and examples of calculation of average molecular weight of hydrocarbon mixtures from gravity and average boiling point, achieved from distillation data.
Molweight, melting and boiling point, density, flash point and autoignition temperature, as well as number of carbon and hydrogen atoms in each molecule for 200 different hydrocarbons.
Calculate melting point of hydrocarbons from molecular weight (molar mass).
Variations in jet fuel density as function of temperatur, together with volume correction factors.
Variations in lubricating oil density as function of temperatur, together with volume correction factors.
Boiling and melting points of amines, diamines, pyrroles, pyridines, piperidines and quinolines shown together with their molecular structures, as well as molweights and density.
Boiling and melting points of thoils, sulfides, disulfides and thiophenes shown together with molecular structures, as well as molweights and density.
Definition, explanation and examples of calculation of various types of average boiling point of petroleum products and other mixtures of hydrocarbons: VABP, MABP, WABP, CABP and MeABP.
Introduction to temperature - including Celsius, Fahrenheit, Kelvin and Rankine definitions - and an online temperature converter.
Add standard and customized parametric components - like flange beams, lumbers, piping, stairs and more - to your Sketchup model with the Engineering ToolBox - SketchUp Extension - enabled for use with the amazing, fun and free SketchUp Make and SketchUp Pro . Add the Engineering ToolBox extension to your SketchUp from the Sketchup Extension Warehouse!
We don't collect information from our users. Only emails and answers are saved in our archive. Cookies are only used in the browser to improve user experience.
Some of our calculators and applications let you save application data to your local computer. These applications will - due to browser restrictions - send data between your browser and our server. We don't save this data.
Google use cookies for serving our ads and handling visitor statistics. Please read Google Privacy & Terms for more information about how you can control adserving and the information collected.
AddThis use cookies for handling links to social media. Please read AddThis Privacy for more information.
If you want to promote your products or services in the Engineering ToolBox - please use Google Adwords. You can target the Engineering ToolBox by using AdWords Managed Placements.