Process Simulation Lecture 2

Yehia 2

What is a crude oil assay?

What is a crude oil assay?

A chemical evaluation of petroleum feedstocks

Does assay data help refineries determine if a petroleum feedstock is suitable for a particular petroleum refinery

True

API Gravity is a measure of

how heavy or light a crude oil is compared to water

Select the correct steps for characterising and modeling a crude oil in HYSYS

Import assay data

Characterise the assay

Associate assay data with a material stream

The default specification in a valve unit in HYSYS is:

50% valve opening

does the Mixer in HYSYS always represents a real unit in a plant

False

You are using a Spreadsheet operation for a simulation created by one of your colleagues. One of the values on the Spreadsheet is shown in black colour. This indicates:

Flowsheet calculated values

Are two crude oil types identical?

False

Ways to characterise an assay in HYSYS

•Distillation curve obtained in a lab-test separator. Most common one is the TBP curve which shows volume% boiled off vs boiling point.

•Average density (API Gravity most common)

•Sulphur content

•Light ends (e.g. methane) composition

After the assay is characterised, is it required to choose a fluid package and set component list?

False

What are the common optional inputs

•Average density (use correct units, e.g. API, kg/m³)

•Sulphur wt%

•Kinematic viscosity

Mixer default spec

•product will be at the pressure of the lowest pressure feed stream (can switch this to equal pressures for all streams)

Why would temperature be different from the inlet of a mixer to the outlet?

•The resultant temperature of the mixed streams may be different than those of the feed streams due to mixing effects.

What are control valves used for?

•Used for pressure reduction

What is the model assumption for valves?

•Isenthalpic flow

What are the specifications required for the valve operations to be solved?

•at least one temperature specification and one pressure specification are required.

What is the BLUE BOLD colour code on spreadsheet?

User-defined values

What is the Black colour code on spreadsheet?

Flowsheet calculated values

What is the BLUE Italics colour code on spreadsheet?

Spreadsheet calculated values

•Typical assay data used to model/characterise an oil assay in HYSYS

•Distillation curves

•Density

•Sulphur content

•Light ends

How to add petroleum assays

In the petroleum assays when next to the add, ensure it is entered manually. When asked about the error, select the 850C one. And then go single stream and input the data

How to set volume % for the light components after characterising oil assay?

When doing volume % for components based on provided data, make sure to do that in the pure component section in the petroleum assay.

What is % molar recovery

Amount of component before separation over the amount of component after separation in a specific stream