Molecular Level Description of Crude Oils and Complex Hydrocarbon Streams - PowerPoint PPT Presentation

Loading...

PPT – Molecular Level Description of Crude Oils and Complex Hydrocarbon Streams PowerPoint presentation | free to download - id: 6c263e-MTRjN



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

Molecular Level Description of Crude Oils and Complex Hydrocarbon Streams

Description:

LP models and simulators don t always agree with the refinery ... (Pseudo Component) 51 Pure-components 39 High Fidelity Pseudo-Components 0 10 20 30 40 50 ... – PowerPoint PPT presentation

Number of Views:1
Avg rating:3.0/5.0
Date added: 1 November 2019
Slides: 27
Provided by: DianeK158
Learn more at: http://hydrocarbonchina.com
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Molecular Level Description of Crude Oils and Complex Hydrocarbon Streams


1
Molecular Level Description of Crude Oils and
Complex Hydrocarbon Streams
  • Lanny Carr Invensys Process System

REFINING CHINA 2006 April 24 -26 Beijing, China
2
What if
  • we could remove the uncertainty about using old
    assay data as the basis for how we process
    todays feedstocks?
  • we could reduce inherent assay errors by using
    measurements that we can take at the plant site?
  • we could make those corrections on a daily
    basis?
  • we could produce deeper information about true
    compositional nature of feedstocks and other
    process streams?
  • we could use that detailed knowledge as more
    accurate input to planning and optimization tools
    for daily operational improvements?
  • what if?

3
Assays - What they are
  • Laboratory measurements of distillation yield
    behavior.
  • A convenient way to lump crude oil into a
    manageable number of pseudocomponents.
  • Laboratory measurements of properties of these
    pseudocomponents.
  • Source of data for API correlations.
  • Source of data for Linear and Simulation Programs.

4
Assays - the Problems...
  • High quality assays are costly and time-consuming
    to produce.
  • Library assays go out-of-date as fields mature.
  • Input data used to select assays are often just
    bulk properties that are insensitive to
    distributed properties.
  • Blending during gathering and transportation can
    create compositional characteristics difficult to
    mimic with available assays.
  • Even perfect assays can fail, for fundamental
    reasons, to fully account for compositional
    differences that govern the refining outcome.

5
Issues when Evaluating Quality
  • Crude oil quality is difficult to measure.
  • Analytical measurements contain error.
  • Need to rely on data of unknown quality.
  • Typical assays are commonly used in place of
    measured assays.
  • Bulk property correlations contain deviations and
    are insensitive to important compositional
    variations.
  • LP models and simulators dont always agree with
    the refinery operation.

6
The Z - Based Structural Index Correlation
Z-BaSICtm Method
  • All compounds in crude oil are classified
    according to the general empirical formula
  • CnH2nzNuSvOw
  • z-vectors are the classifying numbers
  • n is the primary correlating variable

7
Crude Oil Composition - Simplified
  • All crudes are made up of a few dozen classes of
    compounds.
  • Each class has a mass distribution with respect
    to molecular weight.
  • Each class and molecular weight set are comprised
    of multiple isomers.
  • In short, crude oil may be described by mass
    distributions with respect to 3 independent
    variables, z, n and i.

8
Refinery Operations - Simplified
  • Refining operations are processes to
  • alter the classes (hydrogenation, reforming, HDS,
    HDN, etc.)
  • alter the molecular weight (FCC, HC, alkylation,
    coking, etc.)
  • alter the isomer structure (isomerization, cat.
    dewaxing, etc.)
  • In Short, refining alters the z, n, and i
    character of crude oil.

9
Correlation of Boiling Point with n and z
10
Correlation of density with n and z
11
Density vs Carbon Number
12
C16-C17 excerpt
13
Jet A Property Variations
14
Jet A Heating Value at Constant Density
15
Jet A Aromatics vs. Paraffins at Constant Density.
16
Speciation with Molecular Modeling
17
NL Planner System (Assay)
ROMeo Non Linear Planner
LPG
LPG
LN
LN
51 Pure-components
Old System Cut-Point Base (Pseudo Component)
HN
HN
KERO
KERO
LGO
LGO
39 High Fidelity Pseudo-Components
HGO
HGO
RC
RC
18
Grouping of Hi Fidelity Pseudocomponents
19
Heavy Naphtha Cut at Constant Density
20
Crude Assay Data Compensation Method
ROMeo Online Model
Z-Basic
Blend Crudes generate pure components high
fidelity pseudo-components
Update individual crude ASSAYS from online
measurements lab data
Data Reconciliation Performance Monitoring
Assay
C4 C12
Component Estimation
Crude Assay Library
21
Data Inputs Outputs
  • NMR provides additional information for the
    Z-BaSIC convergence
  • Total Hydrogen
  • A, O, S Hydrogen
  • Sulfur

22
Interface with Conventional Systems
Conventional Assays Pseudocomponents __________
______ LP Sim Opt
Crude Oil or Monitors Reference file Pure
components Hi Fidelity Pseudocomponents _______
____________ Props, Comp, Sim, Opt
23
Speciated Stream Preparation and Analysis
Reconciled Assay
NL Planner /ROMeo
Pseudo Components Plus Distinct Species
Each Pseudo-Component
Weight Species Properties
Weight HC minus Species Properties
24
What can we do with Speciation?
Yield1 Properties Components
Simulated Unit
Yield2 Properties Components
Yield3 Properties Components
Yield4 Properties Components
Yield5 Properties Components
25
Price Constraint Visibility
Role Activity Technology
Refinery Planner
Refinery NLP or LP Update qualities
Develop Operating Plan
Schedule Refinery
Schedule
Lost Opportunity
Refinery Scheduler
Process Unit Detailed Targets
Daily Crude Mix Daily Liftings
Prices
Set Process Unit Detailed Targets
Daily Targets with Refinery Wide Representation
Approved Targets
Operations Manager
Constraints
Process Unit Targets with Refinery Wide
Representation
Operator
Set Operating Limits
Set points
APC Targets
26
Molecular Modeling - Advantages
  • Overcomes limitations of existing crude oil assay
    technology
  • Enables crude oil analysis on a fundamental
    molecular level
  • Potential benefits in excess of 0.30/bbl
  • Moves technology to a more scientific basis for
    component speciation
About PowerShow.com