energy optimization in process designtexasiof.ceer.utexas.edu/pdf/presentations/apr2016/j turner -...

©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


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


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


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.


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


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)


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


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


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”


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


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


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


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


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



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



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


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


Contact Information

For more information, contact:

James Turner, Fluor Enterprises, Inc. Executive Director, Process Technology & Engineering [email protected] 832-654-4239

BUILDING SUSTAINABLE SOLUTIONS

mailto:[email protected]