Mapping of Thermal Energy Integration Retrofit Assessment of Industrial Plants

Transcription

1 15 th Conference Process Integration, Modelling and Optimisation for Energy Saving and Pollution Reduction Mapping of Thermal Energy Integration Retrofit Assessment of Industrial Plants Luciana Savulescu, Zoé Périn-Levasseur and Marzouk Benali Prague, Czech Republic, August 25-29, 2012

2 Outline Sustainability through PI A Canadian Perspective Energy Efficiency Strategies Novel Approach for Energy Assessment Steam Mapping Waste Heat Mapping Conclusions 2

3 Our Strategy 3

4 Heat Exchangers creating inefficiencies Composite Curves Minimum energy consumptions and saving potential HEN Retrofit Design Modified Network Pinch Approach 4

5 NRCan s PI Incentive Program Participants Across Canada Actual Fuel Savings 6.6 PJ/year Implementation rate: 55% Enough to heat 100,000 family homes Renewable Electricity 50 MW GHG Reductions Equivalent to < 100,000 cars Economic Activity Water Savings Production Increase Total 53 PI studies funded >16 5

6 Industry Issues INCREASE THROUGHPUT 6

7 Energy Efficiency Strategies Techniques Energy Audit Simulation-based Analysis Process Control, Monitoring and Targeting Process Integration Techniques Characteristics Equipment-based analysis Do not account for the interactions within the energy system Obvious opportunities Complex large amount of info Inefficiencies are not indicated Link to operations, not design Low-hanging fruit measures Global system-based approach Account for the interactions within the energy system Evaluation of savings prior to design 7

8 PI Approach High Pressure Steam Low pressure steam Medium pressure steam T Heat Pump Pinch Cooling Water Refrigeration H 8

9 Challenges for PI Methodology issues Balance: Simplified assumptions vs. Practical elements to capture the complexity of the process Application issues Data gathering and data uncertainties Highly specialized expertise requirement Industry issues Particular plant bottlenecks (operation and economics) Application and interpretation of composite curves. Complementary way? 9

10 Steam Mapping Mill Engineers Mill Simulation Capture the information on steam use from the process perspective, as it illustrates the cold streams energy demand Relate the pressure level and the amount of steam consumed with its corresponding process energy load and temperature levels 10

11 Heat Exchanger Network Composite Curves Name Load Name Hot side Tin Tout Name Cold side Tin Tout Base Case 5000 kw Energy Savings 2200 kw Q H =2800 kw (kw) Hot Stream ( C) ( C) Cold Stream ( C) ( C) Heater Steam - - CSH Heater Steam - - CSH Heater Steam - - CSH Temperature ( C) Effluent/Waste Heat Pinch (50 C) T min =10 C Heater 3 HEX HS CS HEX HS CS Heater 2 Effluent 3000 Effluent Environment - - Heater 1 Q C =800 kw Energy Load (kw) Composite curves provide the energy saving targeting 2200 kw Pinch temperature 50 C to guide the screening of inefficiencies Indirectly information on the location on heaters 11

12 Steam Mapping Temperature ( C) Zone kW 30% Zone kW 34% Zone Economic Penalty (M$/year) kW 36% CSH1-Heater 1 CSH2-Heater 2 CSH3-Heater 3 Steam Users Econ. Zone1 Econ Zone 2 Econ Zone3 0 Preliminary energy target 1800 kw (36%) Steam use inefficiency in Heater 1 and Heater 2 Heater 1 economic penalty is 0.22 M$/y, assuming a 7$/GJ Heater 2 economic penalty is 0.18 M$/y 12

13 Kraft Process Steam Demand Mapping Overall steam distribution Low pressure steam Medium pressure steam 13

14 Waste Heat Mapping Represent the process heat sources as energy loads and temperature levels Facilitate the screening of energy recovery opportunities when combined with the steam mapping diagram 14

15 Waste Heat Mapping Zone 1.8 Temperature ( C) MW 6% Zone 16.4 MW 38% 12.5 MW MW 7 MW 6.3 MW 1.4 Zone MW MW 1.2 MW Economic Benefit (M$/y) MW 56% PM1 effluent PM2 effluent RB flue gases Dryer exhaust Selected Waste Heat Sources Alcalin effluent Screens effluent Saving benefit in zone 1 Saving benefit in zone 2 Saving benefit in zone 3 PM: paper machine, PB: power boiler PB blowdown 0 15

16 Steam and Waste Heat Mapping Assembly Steam users Waste heat MP/LP 4.3 MW MP 25.6 MW MP 9 MW LP 8.8 MW MP 5 MW 7 MW 1.2 MW LP 6 MW 6.3 MW LP MW 12.5 MW 11.1 MW 2.2 MW Temperature ( C) 20 Pulp dryer PM air preheating BL evaporation Water deaerator Bleaching PM1 whitewater RB air preheating PM1 effluent PM2 effluent PB flue gases Dryer exhaust Alcalin effluent Screening effluent PB blowdown 0-20 Heat demands versus Waste heat sources PM: paper machine, Bl: black liquor, RB: recovery boiler, PB: power boiler 16

17 Benefits of the Visualization Thermal mapping provides a novel framework to illustrate: the global distribution of steam use current profile without loosing the specifics through merging rapid screening of steam use inefficiencies as load/economics the potential and economics of waste energy the waste heat recovery opportunities Improve the communication with mill engineers Facilitate the understanding of the PI concepts by industry A way to increase the demand for PI studies A descriptive framework prior to detailed PI case studies 17

18 Optimal Process and Technology Integration UTILITY SYSTEM KRAFT PROCESS Biorefinery NEW BIOREFINERY TECHNOLOGY Data Collection for retrofit Connect with industry Implement project Understand the process Take decisions Get closer to sustainability goals 18

19 PI: A Step Towards Sustainability From Research to Implementation Temperature ( C) Research Zone 2.4 MW 6% Zone 16.4 MW 38% 24 MW 56% 12.5 MW MW PM1 effluent PM2 effluent 7 MW RB flue gases 6.3 MW 1.4 Zone Dryer exhaust Selected Waste Heat Sources Saving benefit in zone 1 Saving benefit in zone 2 Sav PM: paper machine, PB: power boiler A e Integration Software Technologies Retrofit Solutions Incentives Communication Data Collection Training Case Studies Decision-support support Implementation 19

20 Acknowledgments Financial support Program on Energy Research and Development of Natural Resources Canada 20

21 Thank you for your attention Luciana Savulescu, Research Scientist Industrial Systems Optimization Telephone: +1 (450)