Arvind AtreyaDepartment of Mechanical Engineering

University of Michigan, Ann Arbor 48109aatreya@umich.edu , (734) 647 4790

DOE–ITP’s Programs at Michigan

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Presentation Outline• Overview of ITP & other programs at Michigan• Programs available free for industry to increase

energy efficiency, productivity and profitability.• Integrated delivery of Service, Education,

Research & Development from Michigan.• Examples and case studies.

– Simple measures.– More complicated measures (use of DOE tools). – CHP example– Measures with great potential but requiring R&D.

• ConclusionsGACCOM - Detroit || 6/23/09 || 2

Supply104

Quads

Domestic67%

Imports33%

Industrial31.98

Consume100

Quads

Nuclear 8%Renewable 6%

Fossil86%

~ 1640 MMtons of ‘CO2’ emissions/yr~ $320 billion

1 Quad = 1015 BTU = 1.05 Exajoules= 1015 BTU $10/106BTU

= $10 billion

U.S. Energy Flow, 2005 (Quads)Note: Industrial usage > Transportation

GACCOM - Detroit || 6/23/09 || 3

Range of Programs at MichiganPurpose: To increase energy efficiency,

productivity and profitability.

1. Industrial Assessment Center (IAC) – ITP

2. Michigan Industrial Energy Center (MIEC) – ITP

3. Industry-University Research Center for: Thermal Technology – NSF (new)

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• Energy audit and industrial assessment

• No cost to small/medium manufacturerswithin 150 miles of a Center

• Conducted by university-based team of engineering faculty/students

• Confidential report sent to plant within 60 days from site visit

• 26 participating universities across the country

• 240 students in training each year

• 650 Assessment Days of service provided to manufacturers

• Average savings per assessment: $55,000/yr

Industrial Assessment Centers (IACs)

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New Michigan Industrial Energy Center (MIEC)

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State of Michigan Energy OfficeProject Director: Roger Doherty

Primary Participants: University of Michigan (UM)

Shephard Advisors (SA)Renewable Energy Systems (RES)

Website & Outreach

Shephard AdvisorsWeb resources

Training lectures Discussion boards

with Q&A

Local Training Center

Univ. of MichiganShort course on

Industrial Energy + DOE-ITP Training. Obtain DOE-UM

certification.

SEN Energy Assessments

Univ. of Michigan3-day assessments of

larger facilities.Local Training of Energy Managers

New Technology Implementation

RES and UMNew technology demonstration

Long-term help in implementing new

technology

New NSF Industry/University Cooperative Research Center for Thermal Technology

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University Michigan(Deans office)Governed by:

Industrial Advisory Board & NSFCenter Director: Arvind Atreya

R&D Project – 1of industry interest

UM Faculty & Industry

Representative +

Graduate Student

R&D Project – 2of industry interest

UM Faculty & Industry

Representative +

Graduate Student

R&D Project – 3of industry interest

UM Faculty & Industry

Representative +

Graduate Student

… etc.

30K/project from industry, rest NSF + University

Industrial Energy Work at Michigan

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Process Heating 38%

Steam 35%

Other4%

Electro-chemical 2%

ProcessCooling

1%

Motor Systems

12%

Facilities 8%

Combustion of fossil fuels. Either in boilers or furnaces.

Manufacturing Energy Used by Plant Size and System Type (%)

Plant Size: % Total Energy Use

4,014 Large Plants

58%MIEC &

NSF I/UCRC

Small 5%(MIEC training)

112,398Mid-SizePlants 37%

IAC & MIEC

System Type: % Total Energy Use

GACCoM - Detroit || 6/23/09 || 9

• To be completed before assessment visit

• Gather plant data including product type, annual sales levels, production levels, operating hours

• Study processes and plant layout

• Analyze utility billing data

• Identify key energy systems

• Develop assessment day strategy

Pre-Assessment

• Conduct engineering and financial analyses of priority recommendations

• Develop first order estimates of implementation costs

• Document results in “GOLD Standard” format assessment report

• Upload report data into IAC database

• Deliver report to plant within 60 days from plant visit

Analysis & Repor ting

• Conduct follow up discussions with plant, 6-9 months following assessment visit

• Identify implemented energy savings

• Upload implementation data into the IAC database

Follow Up

• Duration: One Day

• Meet with plant management team

• Present details of pre-assessment analysis

• Tour plant

• Collect operating data

• Conduct diagnostic testing

• Discuss preliminary assessment findings with management

• Prioritize potential recommendations for further analysis

Assessment Visit

Components of the IAC Assessment

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• $74,000/yr in recommended energy savings +

• $58,000/yr in recommended non-energy savings

• Implementation rates between 45% and 50%

• 5,900 MMBtu/yr per plant savings, additional replicated and spin-off savings of 1,260MMB/yr

• 4-8% of annual IAC plant energy consumption

Typical IAC Assessment

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• Publicly Available• Contains data:

– Facility – Recommendations– Implementation

• Searchable by:– Size (in energy usage,

employees, etc…)– Industry type (NAICS or SIC)– Location– Recommendation type

• Updated in real time as the assessments are completed

IAC Database

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http://www1.eere.energy.gov/industry/bestpractices/iacdatabase.html

Search Examples– What are the most common

recommendations for Forest Product manufacturers?

– What is the average savings for replacing a boiler?

– What are the top ten most common energy recommendations?

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Recommendations # of times

Ave.Sav / pay back-yr

Reduce illumination to minimum level 53 $5,000 / 0.5Use high efficiency lamps and ballasts 238 $7,000 / 2.5Install occupancy sensors 71 $2,000 / 1Use radiant heater for spot heating 25 $18,000 / 2Reduce building air ventilation by air filtering 21 $8,000 / 0.5Proper A/F ratio for boilers and furnaces ~3% O2 in flue gas 58 $13,000 /

0.5Eliminate compressed air leaks 166 $6,000 / 0.5Optimize Plant Power Factor 33 $11,000 / 1Compressor Air Intakes In Coolest Locations 155 $2,000 / 1

Simple Energy Saving MeasuresExamples: – you really don’t need us for these

More complicated measures (PHAST)

Furnace Heat Input

Heat in Flue Gases

Available Heat = (Furnace Heat Input – Heat in flue gases)

In a typical high temp. furnace Largest heat loss is flue gas enthalpyIf a furnace heats products to 1,500 F Flue gases cannot be cooled below this

temperature without using external equipment.

At 1,500 F Flue gas loss ~ 50%.

At 2,000 F (stoichiometric)

Flue gas loss ~ 55%

At 2,000 F (20% excess air)

Flue gas loss ~ 62%

External waste-heat recovery devices: • Recuperators • Regenerators

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Excess air (improper pressure control) Al melting furnace – use of PHAST

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Savings flue gas control $867,248/Yr + $248,577/YrSavings covering the well 162,797/Yr

Excess air (improper pressure control) Example – 903 Melting Furnace

Preheat to 800F2,963,099

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GACCOM - Detroit || 6/23/09 || 17Thermal Energy

Ele

ctri

cal P

ower

Needed Power

Needed Heat

Prime mover characteristics

Combined Heat & PowerIdentifying the Need

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Combined Heat & Power (many options)

Waste Heat Boiler

Power generation – primary consideration

Process Heat– primary consideration

Raw Material:Particle Board

Laminator

Size Cutting

Routing Boards

Secondary Operations:e.g. Drilling hole patterns

Inspection, PackagingShipping

Scrap BoardSaw DustScrap Part

Boiler

Example: Wood Furniture Manufacturer

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• 8,380,800 kWh/yr – Cost: $311,539/yr

• 2,032 kW demand – Cost: $143,188/yr

• Total Electrical Costs: $456,188/yr

• NO NATURAL GAS COSTS

• Steam is generated by wood waste– Used for heating in winter

– Heat is rejected in summer

Energy Usage by the Plant

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• Install 170 kW unit• Generate power

during the summer• Use steam for heating

in winter

• Install 170 kW unit• Generate power year

round• Use natural gas

booster boilers for heatingCosts:

Installation Cost: Same for both optionsAnnual operating costs: $10,000/yr obtained from steam turbine manufacturers assumed same for both options

CHP Options

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• 12 month Option= $67,654 - $13,750 - $10,000 = $43,904/yr

• 6 month Option= $33,862 - $10,000 = $23,862/yr

• Same implementation and O&M costs.• Better utilization of existing equipment with

the 12 month operation• The two options are equal if natural gas

costs increase to $12.87/MMBtu

CHP Options Comparison

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• Average Cost of Steam Turbine from Equipment Manufacturers and Dealers* = $73,000

• Cost of Installation varied*: $35,000 to $75,000

• Total estimated implementation cost = $148,000

Simple Payback on 12 months option = 3.4 years*Much help is now available to obtain these estimates:• Midwest CHP Center: www.chpcentermw.org• Use boiler program – SSAT• Cogen Pro from San Diego IAC

Implementation

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New Technology Measures New flameless (homogeneous) or low-gradient combustion:

• Flameless Oxidation (FLOX),

• High Temperature Air Combustion (HiTAC), and

• Low temperature gradient (MILD) combustion.

The essential conditions for achieving these are:a) Air & gas mixture temperatures are above the auto ignition

temperature (~ 1200K), and

b) Fuel and oxidant must be sufficiently diluted before they react.

Usually this is accomplished by highly diluting the air by hot flue gases which results in flameless combustion. O2% ↓, thus peak T↓ & ‘T’ becomes more uniform. However, radiation may actually go down.

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Known Facts, Problems and SolutionsWell-Known Facts:

• Air preheat & O2-enrichment increase furnace efficiency.– Also ↑ temperatures, NOx & other pollutants.

• Primary mode of heat transfer in a furnace is radiation.– High level of uniform radiation increases furnace productivity.

• High radiation energy transfer from the reaction zone. – Reduces flame temperature Intense radiation is desirable.

• Radiation is a volumetric phenomenon.– Volumetric or homogeneous or flameless combustion ↑ radiation.

A beneficial combination:– Air + hot flue gases (→ flameless combustion) + O2+ radiation.

How to do it?

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Expected Improvements in Efficiency, Productivity and Emissions

Industries such as Steel, Glass, Aluminum, Petrochemical, etc. use large amounts of energy for process heating.

In high Temp furnaces, the useful portion is typically < 50%

The new technology presented here can provide >50% improvement in energy efficiency and reduce NOx & GHGs.

This is done by reducing the loss of flue gas enthalpy. At 1,500°F flue gas temperature flue gas energy loss ~ 50%.

While combustion air preheat & O2-enrichment are traditionally used to reduce flue gas losses, the proposed method is less expensive & low maintenance.

It also offers additional benefits of fuel flexibility, high productivity, and ultralow emissions by enabling Radiative Homogeneous (or Flameless) Combustion (RHC).

GACCOM - Detroit || 6/23/09 || 26

Benefits of Highly Radiative O2-enriched CombustionCalculations for CO2 and NO – for the same amount of CH4

burning in “air” with different O2% & radiation heat loss

NO

(ppm

) / H

eat l

oss r

atio

GACCOM - Detroit || 6/23/09 || 27

Increasing flame radiation:

• Increases productivity for the same fuel consumption.

• Decreases CO2 production by a factor of 5 and NO by five orders of magnitude for the same fuel use.

• Fuel preheat will increase radiation through soot formation as well as, increase furnace efficiency.

Highly Radiative, O2-enriched, Homogeneous (flameless) Combustion has substantial benefits for furnace operation.

Summary: Benefits of Highly Radiative O2-enriched Homogeneous (flameless) Combustion

GACCOM - Detroit || 6/23/09 || 28

O2 Enrichment + Preheating: Al furnace example

Benefits:• Much cheaper to implement• Low maintenance • Beneficial for NOx reduction• We must consider O2 cost

650oC exhaustto atmosphere

AluminumMelting Furnace

Example

High Temperature Recuperator

22oC dilution airHigh pressure 22oC

ambient air

Exhaust 1100oC ± 1” wc. 900oC

Combustion air @ 400oC & 20”wc. Flow ≈ 277.8 SCF/s = 331.61 gmol/s of air (69.67 gmol/s O2 + 261.94 gmol/s N2)

Hot bleed (X)

Make up oxygen

(Y)

700 oC air at 21% O2

CH4

Oxygen balance2

2

0.21 [ ( / ) ( / )](% ) ; 0.2461

X gmol s of bleed Y gmol s O added O in exhaust X Y or Y X

× += × + = ×Energy balance

( / ) 42.74( / ) (1100 700)33 (700 22) (331.61 ) (700 400)

X gmol s J gmolK Y X Y

⋅ ⋅ − =⋅ ⋅ − + − − ⋅ −

X = 137.305 ; Y = 33.79 ; & air = 160.515 gmol/s.

GACCOM - Detroit || 6/23/09 || 29

Fuel Savings – O2 enrichment + air preheat

0

10

20

30

40

50

60

70

20 30 40 50 60 70 80 90 100

% F

uel s

avin

gs

% Oxygen in combustion air

Calculations using DOE - PHAST program.DOE claims that it is accurate to within 5%

Furnace exhaust temperature 2000oF Combustion air preheat in oF

100

20001800

1600

1400 1200

1000 800

600 400

200

It is important to note that the proposed system provides fuel savings due to both preheat and

O2%.

Maximum

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Experiment Results – NOx

NO Emission

0

3

6

9

12

15

18

1 2 3 4 5 6 7 8 9 10 11 12Case No.

PPM

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Steel Furnace Example

Plate Mill or Hot

Mill Furnaces

Recuperator

70FExhaust: flow rate @ 1900 F, with 2% wet O2

Pressure: ~0.8” WC ~1000F

Combustion air at 750F, 21% O2

25” WCGas flow rate

Make up O2

By ~1/3 EGR + O2, the temp. increases to 1100 F. Savings:

(1) Plate Mill furnaces $2,114,070

(2) Hot Mill furnaces $4,797,764

Does not include O2 cost Low maintenance Much cheaper to implement Beneficial for NOx reduction

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CONCLUSIONSIAC, new MIEC and NSF-I/UCRC can help to:1. Significantly reduce energy costs.2. Reduce greenhouse gas emissions.3. Reduce NOx and other pollutant emissions.4. Increase in productivity.5. Help use low calorific value inexpensive fuels.6. Multi-fuel capability.7. Oxygen-free atmosphere to prevent oxidation.8. Potential for in situ incineration of volatile

organic compounds.

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Thank You!

Questions

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GACCOM - Detroit || 6/23/09 || 35

Technology for TodayBestPractices

Steel Mining Petroleum

Aluminum

Metalcasting

Forest Products

Glass

AgricultureChemicals

Technologyfor theFuture

ITP Strategy for Today & Tomorrow

GACCOM - Detroit || 6/23/09 || 36

Industrial Systems Requiring more Knowhow:

• Process Heating Systems (PHAST)

• NOx and Energy Assessment Tool (NxEAT)

• Steam Systems (SSAT)

• Insulation Systems (3E Plus)

• Compressed Air Systems (AirMaster+)http://www1.eere.energy.gov/industry/bestpractices/software.html

Also: http://www1.eere.energy.gov/industry/about/brochures.html

Software available from ITP

GACCoM - Detroit || 6/23/09 || 37

0.00

0.01

0.02

0.03

0.04

0.05

0.06

0.07

1200 1400 1600 1800 2000 2200 2400 2600 2800

Temperature (K)

CO M

ole f

ract

ion

21% O225% O230% O235% O240% O2

Φ=1.0, Residence Time=0.5 sec

CO – A strong function of temperature

Perfect mixingGRI-Mech. 3.0 calculations

GACCOM - Detroit || 6/23/09 || 38

0.000

0.002

0.004

0.006

0.008

0.010

1200 1400 1600 1800 2000 2200 2400 2600 2800

Temperature (K)

NO

Mol

e fr

actio

n21% O2 25% O2 30% O2

35% O2 40% O2

Φ=1.0, Residence Time=0.5 sec

NO – Even stronger function of temperature

Perfect mixingGRI-Mech. 3.0 calculations

GACCOM - Detroit || 6/23/09 || 39

Some well-known facts: Benefits of Air Preheating

0

5

10

15

20

25

30

35

40

45

50

55

60

65

0 200 400 600 800 1000 1200Combustion air temperature oC

1500oF

2200oF

2550oF

Flue gas temperature oF

~ 50% savings are possible if combustion air could be preheated to 1800oF from flue gases at 2200oF

Currently possible with recuperators & regenerators

% R

educ

tion

in F

uel C

onsu

mpt

ion

by A

ir Pr

ehea

ting

GACCOM - Detroit || 6/23/09 || 40

Well known facts: Furnace efficiency for various O2% without air preheating

0

10

20

30

40

50

60

70

80

90

100

0 200 400 600 800 1000 1200 1400 1600 1800 2000Flue gas temperature oC

Eff

icie

ncy %

21% O2 35% O2 50% O2 100% O2

At 21% O2 & flue gas temperature of 1100 oC the furnace eff. is only 50%, whereas, at 100% O2 eff. is ~ 80% because of lower mass flow.

GACCOM - Detroit || 6/23/09 || 41

Oxygen Enrichment

50%

60%

70%

80%

90%

100%

21% 31% 41% 51% 61% 71% 81% 91% 101%% Oxygen in air

% F

uel C

onsu

mpt

ion

2000 1900 1800 1700 1600 1500 1400 1300 1200

1100 1000 900 800 700 600 500

Benefits of oxygen enrichment increase with the flue gas temperature

Oxygen Enrichment – Economic Analysis

GACCOM - Detroit || 6/23/09 || 42

IFRF - Boston || 6/08/09 || 43

FurnaceHigh temp. Exhaust at

1 ” wcExhaust

Optional high temp. recuperator

High pressure ambient air

Preheated high pressure combustion air

Hot bleed

Make up oxygen

HighTempair @21% O2

Schematic of the arrangement

High Temperature Recuperator

Preheatedair

OPTIONAL RECUPERATION

Red

uce

dex

haus

tto

air

o rre

cup

e rat

o r

Dil u

ti on

c ont

rolle

dby

jetl

e ngt

h&

mom

e ntu

m

To burner

80Froom air

o

Exhaust

High

tem

pera

ture

&hi

ghve

loci

tyflu

ega

sdi

lute

dai

ren

riche

dby

O2

Exhaust from the

furnace at ~ 1” wc

1

2

3

4

5

6

External Implementation –vertical orientation

0.00

100.00

200.00

300.00

400.00

500.00

600.00

700.00

800.00

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

1 1.5 2 2.5 3 3.5 4

Mas

s flo

w R

ate

(kg/

s)

Pressure (bar)

SONIC

SC

FM

GACCOM - Detroit || 6/23/09 || 44R

educ

ed e

xhau

st

flow

rate

Dilu

tion

cont

rolle

d by

jet l

engt

h &

mom

entu

m

.

To burner

�

High pressure oxygen-enriched air

Hig

h te

mp

& h

igh

velo

city

flue

ga

s di

lute

d ai

r

.

1

2

3

4

6

Red

uced

exh

aust

flo

w ra

te

Dil u

tion

cont

rolle

d by

jet l

engt

h &

mom

entu

m.

To burner

�

Pressurized fuel gas or liquid or both

Hea

ted

dilu

ted

and

vapo

rized

fu

el g

ases

.

1

2

3

4

6

Ideal External Implementation

Possible Implementation

Preheated & diluted Fuel

Furnace Walls

Furnace Walls

Slot Injection of Fuel & Air to Create a Large

Volume Highly RadiativeCombustion Zone

GACCOM - Detroit || 6/23/09 || 45