1、Motivation,Must consume less energy to reduce dependence on foreign sourcesCould start by decreasing amount of energy in industry (33%) chemical industry (24%) petroleum refining industry (10%)Separations is a large part of the energy expense of these industries (60%),Why Distillation?,95% of separa
2、tions energy used for distillationMore than 6% of total U.S. energy consumption used for distillationTotal consumption by U.S. 94.27 quadrillion Btu Consumption by distillation 6.03 quadrillion Btu If process improved 0.1%, we could save 6.03 x 1012 Btu Over 1 million barrels of crude oil $70 millio
3、n/year,http:/news.bbc.co.uk/1/hi/sci/tech/4669260.stm,Distillation,Common method of separation in chemical and petroleum refining industriesUses concept of relative volatility tendency to vaporize more volatile = higher vapor pressure at operating temperatureVery energy intensive 40,000 distillation
4、 columns 200 different processesOptimizing process will increase efficiency & minimize energy waste,http:/www.energyinst.org.uk/education/coryton/page7.htm,How to Improve the Process of Distillation,Steady state process behavior is well-known; less is known about performance of dynamic systems Study
5、 the dynamic process to see how uncertainty affects performance cost energy required Show effects of uncertainty with integrated design and control Considering control is necessary to perform a realistic uncertainty analysisMore energy efficient columns in real life situations by considering the eff
6、ects of dynamics and uncertainty in the design stage,Distillation Column,Rectifying Section,Stripping Section,Purify light component,Purify heavy component,(prevent light component loss to bottoms product),V,L,Total amount in LN-1xN-1 + VN+1yN+1,Material Balance,= Total amount out = LNxN + VNyN,Tray
7、 Balance,LN-1xN-1,LNxN,VN+1yN+1,VNyN,Case Study Dynamic Column Model,Components hexanep-xyleneInputs Temperature - 70F Pressure 1 atm (1.01325 bar) Feed rate basis 5 kmol/hr Feed compositions zh = 0.4 zx = 0.6Aim: Using Matlab, study how different sources of uncertainty affect the operation and cost
8、 of a dynamic column,Controlled Column,Feed,B,Reflux,D,Boilup,Sensitivity Studies of Design and Uncertainty Effects on Cost,Changing design affects mainly capital cost More trays, higher capital costUncertain process parameters affect operating cost Feed composition Lower zF, higher operating cost R
9、elative volatility Lower , higher operating costUncertainty in both zF and leads to significantly higher costs Avg. operating cost variation - $3,700 40,000 columns Over $135 million totalThis cost could be diminished if these sources of uncertainty were considered while designing columns,Conclusion
10、s/Future Directions,Improve operating cost model better correlation of cost to energy requirements Develop systematic design methodology predict column performance, cost, & energy requirements when many variables are uncertain Study other parameter variations heat quality tray efficiency,http:/www.e
11、ia.doe.gov/kids/energyfacts/,More energy efficient columns can be obtained by considering the effects of dynamics and uncertainty in the design stage Design & uncertainty greatly affect costs More trays - higher capital cost Feed less concentrated in light component - higher operating cost Lower rel
12、ative volatility higher operating cost Many types of uncertainty should be studied simultaneously With both lower zF and , millions of dollars are lost to uncertainty,References,Annual Energy Outlook 2003. Energy Information Association, DOE, 2003. http:/tonto.eia.doe.gov/FTPROOT/forecasting/0383(20
13、03).pdf Bansal, Vikrant, John D. Perkins, and Efstratios N. Pistikopoulos, A Case Study in Simultaneous Design and Control Using Rigorous, Mixed-Integer Dynamic Optimization Models, Ind. Eng. Chem. Res. 2002, 41, 760-778. Bequette, B. Wayne, Process Dynamics: Modeling, Analysis, and Simulation, Pren
14、tice Hall PTR, New Jersey, 1998. Doherty, M.F. and M.F. Malone. Conceptual Design of Distillation Systems. McGraw-Hill, 2001. Douglas, James M. Conceptual Design of Chemical Processes. McGraw Hill, 1988. Eldridge, R. Bruce and A. Frank Seibert. Hybrid Separations/Distillation Technology: Research Op
15、portunities for Energy and Emissions Reduction, 2005. Energy and Environmental Profile of the U.S. Petroleum Refining Industry. U.S. DOE/OIT, December 1998. http:/www.eia.doe.gov/emeu/mecs/iab98/petroleum/sector.html Felder, Richard M. and Ronald W. Rousseau. Elementary Principles of Chemical Proces
16、ses, 3rd ed. John Wiley & Sons, New York, 2000. Malcolm, A. and A. A. Linninger, Integrating systems design and control using dynamic flexibility analysis, submitted to I&ECR, 2006. Manufacturing Energy Consumption Survey. Energy Information Administration, DOE, 2001. http:/www.eia.doe.gov/emeu/mecs
17、/iab98/petroleum/energy_use.html NIST National Institute of Standards and Technology Chemistry WebBook Database. Accessed Wed, May 31, 2006. Perry, Robert H., Don W. Green. Perrys Chemical Engineers Handbook. The McGraw-Hill Companies, Inc., 1999. Seader, J.D. and Ernest J. Henley. Separation Proces
18、s Principles. John Wiley & Sons, Inc., New York, 1998. World Crude Oil Prices. Energy Information Association, DOE, 2006. http:/tonto.eia.doe.gov/dnav/pet/pet_pri_wco_k_w.htm,Acknowledgements,Supplement from NSF DMI 0328134 “CLEAN CHEMICAL MANUFACTURING UNDER UNCERTAINTY” PI Andreas A. Linninger Professor Andreas LinningerAndrs MalcolmLPPD,http:/www.schoolscience.co.uk/petroleum/index.html,
