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©2016 Fluor. All rights reserved. 1
©2016 Fluor. All rights reserved.
ENERGY OPTIMIZATION IN PROCESS DESIGN
April 2016
James Turner, Fluor Amit Bhandari, Fluor
Jelle Ernst Oude Lenferink, Fluor
©2016 Fluor. All rights reserved. 2
IN THE PAST……
Historical Approach – Find Economic Optimum Using:
• Predicted cost of fuel • Ability to estimate capital costs • Understanding of Process
INC
REM
ENTA
L
RO
I
CAPITAL COST
©2016 Fluor. All rights reserved. 3
NOW AND FUTURE?
U.S. and other countries introduce greenhouse gas regulation requirements • Treat like toxic pollutants • Introduce “Best Available Technology” criteria • U.S. Permit Applications need to include calculations to document that
next investment hurdle to further reduce greenhouse gas emissions is excessive
• May become an important factor for technology selection
©2016 Fluor. All rights reserved. 4
BACT VS. BAT
BACT (Wikipedia) Best available control technology The U.S. EPA determines what air pollution control technology will be used to control a specific pollutant to a specified limit. When a BACT is determined, factors such as energy consumption, total source emission, regional environmental impact, and economic costs are taken into account. It is the current EPA standard for all polluting sources that fall under the New Source Review guidelines and is determined on a case-by-case basis.
BAT (Wikipedia) Best available technology is a term applied with regulations on limiting pollutant discharges with regard to the abatement strategy. The term constitutes a moving target on practices, since developing societal values and advancing techniques may change what is currently regarded as "reasonably achievable", "best practicable" and "best available".
A literal understanding will connect it with a "spare no expense” doctrine which prescribes the acquisition of the best state of the art technology available, without regard for traditional cost benefit analysis. In practical use, the cost aspect is also taken into account.
©2016 Fluor. All rights reserved. 5
ENERGY EFFICIENCY/GHG/SUSTAINABILITY
Sustainability
Greenhouse Gas Emissions
Energy Efficiency
“Energy Policy” could address any of these three, plus: • Energy Source/Generation • Energy Transmission • Energy Storage • Emissions requirements for any of above • Tax Credits/Fees for any of the above
©2016 Fluor. All rights reserved. 6
RECENT INTERNATIONAL PROJECT
Client desire for “top quartile” for energy efficiency Benchmark targets provided by proposed in country regulations
for some units Use “Best Available Technology” for rest of processes
How do you prove you have complied with these goals? “The Lake Wobegon effect, where all or nearly all of a group claim to
be above average, has been observed in high school students' appraisal of their leadership, drivers' assessments of their driving skill, and cancer patients' expectations of survival” (Wikipedia)
©2016 Fluor. All rights reserved. 7
WHAT TO DO:
“Energy Intensity” The Energy Intensity for a system is the net energy consumed by
the system, divided by the amount of useful product that the system produces, or
EI = Energy Consumed Useful Products Produced
For a physical product, usually expressed in energy/mass For a refining or petrochemical unit, the energy consumed can be
considered the sum of: • Fuel to heaters • Net energy of steam consumed or produced • Electricity consumed
©2016 Fluor. All rights reserved. 8
EXAMPLE EI CALCULATION
Mega Good Project 26-Feb-16
Rev A By: J Turner
Cool Unit Energy Intensity Calculations
P T H Unit Import
(per hour) Qin Export
(per hour) Qout Net
consumption %
Breakdown
bara C GJ/unit (GJ) (GJ) (GJ)
HP Steam 43 376 3.2 t 0.00 0.00 0.00 0.00
MP Steam 19 282 3.0 t 0.00 0.00 0.00 0.00
LP Steam 5 157 2.8 t 19.1 52.74 0.00 52.74 104.63
BFW 24 104 0.44 t 0.00 0.00 0.00 0.00
LP Condensate 3.6 Sat 0.59 t 0.00 19.1 11.25 -11.25 -22.32
Electricity 9.6 MWh 0.93 8.92 0.00 8.92 17.69
Natural Gas (Fuel) 1 GJ 0.00 0.00 0.00 0.00
Q 61.65 11.25 50.40 100.00
Desired product t/h 64.6
Energy Intensity GJ/t 0.78
©2016 Fluor. All rights reserved. 9
ENERGY INTENSITY – BENCHMARKING?
Limitations comparing EI for different facilities: Feed variations (which crude for a C/V unit, feed properties for a
hydrotreater, etc.) Products/product specifications/unit objectives Battery limits conditions Utility constraints Definition of “useful product” Definition of conversions for electricity and steam
Even comparing two designs for same unit in same facility may be
challenging – make sure comparison is “apples to apples”
©2016 Fluor. All rights reserved. 10
BENCHMARKING
Potential sources of benchmark data: Other units designed by the Engineering Contractor or Licensor,
or for the Client Utility data from publicly available data, such as European
Commission BREFs or U.S. DOE Energy “Bandwidth Studies” for different types of facilities
Utility data available from subscription or organization sources Data from consultant companies that specialize in Energy Efficiency
Audits and Benchmarking • Solomon & Associates, KBC, potentially other consultants
For benchmarking EI, it is better to get utility data from reference
and calculate benchmark EI yourself
©2016 Fluor. All rights reserved. 11
SOURCES OF “BAT” INFORMATION
European BREF Documents: • ENE – Energy Efficiency • REF – Refining • LVO – Large Volume Organic Chemicals • OFC – Organic Fine Chemicals • POL – Polymers • ICS – Industrial Cooling Systems • CWW – Waste Water and Waste Gas Treating • ESB – Emissions from Storage
U.S. EPA 2005 funded study report – Energy Efficiency for Petroleum Refineries
U.S. EPA 2010 White Paper – “Available and Emerging Technologies for Reducing GHG Emissions in Refineries”
U.S. Department of Energy “Bandwidth” Studies ECN Dutch Refining – 2030 (funded by Netherlands Government) Published articles and textbooks
©2016 Fluor. All rights reserved. 12
TOP “BEST AVAILABLE TECHNOLOGIES”
Important Design “Best Available Technologies” Top Down/Systems Approach (Nested Layers of Optimization) Optimize Steam/Condensate System Pinch Analysis for heat integration networks Heat Pump for Distillation Systems Optimization of air preheat/control of flue gas temperature in
combustion systems Determination if additional heat can be recovered by using steam
generators Power Recovery Turbine Use Optimization Use of steam drivers and/or variable frequency electrical drivers
instead of fixed speed motors
©2016 Fluor. All rights reserved. 13
PROJECT ENERGY EFFICIENCY PROGRAM
Proposed a Project Energy Efficiency Program: Appointment of a Project Energy Efficiency Leader Develop a Project Energy Efficiency Execution Plan A Top Down (Nested) Approach Calculation of Unit Energy Intensity Use of Best Available Technology (BAT) Procedures and Checklists Benchmarking and Formal Audits Energy Efficiency Project Gate Status Reports
©2016 Fluor. All rights reserved. 14
EXAMPLE : CDU / VDU Optimization (1)
Typical CDU/VDU Design • Energy Intensity ≈ 0.8-1.2 GJ/t • Multiple CDU side draws • Uses steam stripping and fired
heater • VDU integrated with CDU
©2016 Fluor. All rights reserved. 15
EXAMPLE : CDU / VDU Optimization (2)
Simple CDU/VDU Design • Energy Intensity ≈ 1.0 GJ/t • Simple design:
– Typical stripping steam rates – Typical cut points – Single CDU side draw (MD) – Single CDU PA
• Minimum heat integration – To allow independent operation of
CDU and VDU (over sized CDU heater)
– Limited product heat recovery
©2016 Fluor. All rights reserved. 16
EXAMPLE : CDU / VDU Optimization (3)
Optimized CDU/VDU design Energy Intensity ≈ 0.6 GJ/t Pinch Analysis → improved heat
integration Stripping steam optimization:
• Single (MD) side draw product • No sharp cut requirement
Integration between CDU and VDU VDU operating at high vacuum
©2016 Fluor. All rights reserved. 17
SUMMARY
Do “the best you can” to prove your design has the “right” energy efficiency
Use these techniques: • Energy Efficiency Program • “Best Available Technology” • Energy Intensity / Benchmarking • SME Audits
©2016 Fluor. All rights reserved. 18
Contact Information
For more information, contact:
James Turner, Fluor Enterprises, Inc. Executive Director, Process Technology & Engineering [email protected] 832-654-4239
BUILDING SUSTAINABLE SOLUTIONS