4460 Lecture 3 2011

4460 Lecture 3 2011 - Dr.MarioRichardEden AuburnUniversity LectureNo. September6,2011 .DanielR.Lewin,Tec

Info iconThis preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
CHEN 4460 – Process Synthesis,  Simulation and Optimization Dr. Mario Richard Eden Department of Chemical Engineering Auburn University Lecture No. 3 – Heuristics for Process Synthesis September 6, 2011 Contains Material Developed by Dr. Daniel R. Lewin, Technion, Israel   Heuristics for Process Synthesis
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Lecture 3 – Introduction Recalling the operations in process synthesis: Chemical reaction (to eliminate differences in molecular type) Mixing and recycle (to distribute the chemicals) Separation (to eliminate differences in composition)  Temperature, pressure and phase change Task integration (to combine tasks into unit operations) This lecture deals with the heuristic rules that expedite the  selection and positioning of processing operations as  flowsheets are assembled. These rules are based on experience and hold in general,  but should be tested (e.g., by simulation) to ensure that  they apply in the specific application. Later, we will see how algorithmic methods are used to  improve on design decisions.
Background image of page 2
Lecture 3 – Objectives Understand  the  importance  of  selecting  reaction  paths  that  do  not  involve  toxic  or  hazardous  chemicals,  and  when  unavoidable,  to  reduce  their  presence  by  shortening  residence  times  in  the  process  units and avoiding their storage in large quantities. Be able to distribute the chemicals in a process flowsheet, to account  for  the  presence  of  inert  species,  to  purge  species  that  would  otherwise build up to unacceptable concentrations, to achieve a high  selectivity to the desired products. Be  able  to  apply  heuristics  in  selecting  separation  processes  to  separate liquids, vapors, and vapor-liquid mixtures.  Be able to distribute the chemicals, by using excess reactants, inert  diluents, and cold shots, to remove the exothermic heats of reaction. Understand  the  advantages  of  pumping  a  liquid  rather  than  compressing a vapor.
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Select raw materials and chemical reactions to  avoid, or reduce, the handling and storage of  hazardous and toxic chemicals.   Heuristic 1: Manufacture of Ethylene Glycol (EG)   Example: C 2 H 4 + O 2 CH 2 - CH 2 1 - 2 O   (R.1) CH 2 - CH 2 + H 2 O CH 2 - CH 2 O OH OH   (R.2) Since both reactions are highly exothermic, they need to be controlled  carefully.    But  a  water  spill  into  an  ethylene-oxide  storage  tank  could  lead  to  an  accident  similar  to  the  Bhopal  incident.    Often    such  processes  are  designed  with  two  reaction  steps,  with  storage  of  the  intermediate, to enable continuous production, even when maintenance  problems shut down the first reaction operation.
Background image of page 4
Image of page 5
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 12/05/2011 for the course CHEM 4460 taught by Professor Eden during the Fall '11 term at Auburn University.

Page1 / 28

4460 Lecture 3 2011 - Dr.MarioRichardEden AuburnUniversity LectureNo. September6,2011 .DanielR.Lewin,Tec

This preview shows document pages 1 - 5. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online