““AIR POLLUTION”AIR POLLUTION”

NC STATEUNIVERSITY

Process Integration for Environmental Control Process Integration for Environmental Control in Engineering Curriculain Engineering Curricula

I. Q. Francisco Gómez RiveraI. Q. Francisco Gómez Rivera

Dr. Pedro Medellín MilánDr. Pedro Medellín MilánUniversidad Autónoma de San Luis PotosíUniversidad Autónoma de San Luis Potosí

Dr. John Heitmann Jr.Dr. John Heitmann Jr.North Carolina State UniversityNorth Carolina State University

January-May 2005January-May 2005

U.A.S.L.P.U.A.S.L.P.

Universidad Autónoma de San Luis PotosíUniversidad Autónoma de San Luis Potosí

POLLUTIONPOLLUTION

WHY AIR POLLUTION?WHY AIR POLLUTION?

CO2: Increasing 5% per year

1 CFC 10,000 O3 HCl

1 KWh Coal-burning industrial boiler

1 Kg Particles

2 Kg Sulfur dioxide

1 Kg Nitrogen oxides

NATURAL RESOURCES

INDUSTRIAL PLANTS

TRANSPORTATION

Richard P. TurcoEARTH UNDER SIEGE Pg: 111

David T. Allen; David R. Shonnard GREEN ENGINEERING. Environmentally Conscious Design of Chemical Processes Pg: 11-12

destroys

precipitates

6.45 BILLION 9.22 BILLION 2005 2050

U.S. Census Bureau, International Data BaseData updated 4-26-2005http://www.census.gov/ipc/www/worldpop.html

COMMON POLLUTANTSCOMMON POLLUTANTS Sulfur oxides

Nitrogen oxide

Carbon monoxide

Chlorine and fluorine compounds

Hydrocarbons

Organic compounds

MAIN SOURCES OF AIR POLLUTIONMAIN SOURCES OF AIR POLLUTION

ENERGY PRODUCTION

CHEMICAL PROCESSES

TRANSPORTATION

Particulate Material

QUIZQUIZ

Percentage that CO2 increases each year:

Time Trial

Main sources of air pollution:(10s)ClickTo

Start5 seconds left

R= Energy ProductionR= Energy Production Chemical ProcessesChemical Processes TransportationTransportation

Mention 3 common pollutants of the atmosphere: (10s)ClickTo

Start

R= Sulfur oxidesR= Sulfur oxides Nitrogen oxidesNitrogen oxides Carbon monoxideCarbon monoxide HydrocarbonsHydrocarbons Organic compoundsOrganic compounds Particle materialParticle material Chlorine and fluorine compoundsChlorine and fluorine compounds

a) 5%a) 5% b) 10%b) 10% c) 15%c) 15% d) 20%d) 20%

5 seconds left

ENERGY PRODUCTION ENERGY PRODUCTION SITUATIONSITUATION

Sulfur oxides

Nitrogen oxides

Carbon dioxide

Mercury

Production of fossil fuels

Generation of electricity based on fossil fuels

Generation of electricity based on geothermal energy

EMISSIONSEMISSIONS

WHERE DO THEY COME FROM?WHERE DO THEY COME FROM?

Estudio Temático 3: La Electricidad en América del NorteJohn Paul Moscarella y Edward Hoyt (EIC). Ralph Cavanagh (Consejo para la Defensa de losRecursos Naturales). Dermot Foley (Asociación para el Avance de la Energía Sustentable). Rogelio Ramírez (O, de Ecanal, S.A. de C.V)http://www.cec.org/programs_projects/law_policy/index.cfm?varlan=espanol

PERCENTAGE OF POLLUTANTS RELEASED BY PERCENTAGE OF POLLUTANTS RELEASED BY THE PRODUCTION OF ENERGY (1995)THE PRODUCTION OF ENERGY (1995)

NONOxxMexico: 15%

United States: 33% = 6.4 millions tons

Canada: 10% = 186,000 tons

SOSO22Mexico: 48%

United States: 70% = 10,519 tons

Canada: 22% = 524,000 tons

COCO22Mexico: 25% = 73 millions tons

United States: 33% = 17 billions tons

Canada: 16.6% = 103 million tons

North America = 33%

Comisión para la Cooperación Ambiental (1997), Continental Pollutant Pathways: An Agenda for Cooperation to Address Long-Range Transport of Air Pollutionin North America (Montreal: CEC).

Coal

Hydroelectric

Natural Gas

Nuclear

Petroleum

Renewable

PRODUCTION OF ELECTRICITY IN NORTH AMERICAPRODUCTION OF ELECTRICITY IN NORTH AMERICA

Mexico: 4%

United States: 83%

Canada: 13%

Fossil Fuels: 66%

Hydroelectric Energy: 18%

Nuclear Energy: 13%

Renewable Energy: less than 2%

CanadaCanada

554.2 Terawatt-hour (1994)

CEA, EIA y CFE.

CEA. 1997

59%

19%16%

3%

2% 1%

Coal

Hydroelectric

Natural Gas

Nuclear

Petroleum

Renewable

United StatesUnited States

3,473.6 Terawatt-hour (1994)

MexicoMexico

147.9 Terawatt-hour (1994)

53%

21%

14%

8%

3% 1%

EIA, 1998.

CFE, 1995.

Coal

Hydroelectric

Natural Gas

Nuclear

Petroleum

Renewable

59%

14%

12%

9%

4%

2%

GROWTHGROWTHThe consumption of electricity is growing. Between 1997 and 2005 the growth in North America has been:

Mexico:Mexico: 4.5% per year

United States:United States: 1.7% per year

Canada:Canada: 1.6% per year

OTHER TECHNOLOGIES?OTHER TECHNOLOGIES?

In order to supply the new necessities of electricity technologies based in natural gas and hydroelectric energy are the main sources

Coal

Hydroelectric

Natural Gas

Geothemirc

Diesel

Wind energy

Mexico:Mexico:

TECHNOLOGIES EMPLOYED FOR THE TECHNOLOGIES EMPLOYED FOR THE NEW DEMAND (1997-2006) NEW DEMAND (1997-2006)

New capacity 10,000 MW

82 %

10% 5%

2% 1% <1%

CFE, Documento de prospectiva, 1997.

Hydroelectric

Natural Gas

Others

Coal

Hydroelectric

Natural Gas

Nuclear

Petroleum

Renewable

United United States:States:

Canada:Canada:

8,212 MW in 2010

69%

15% 11%

3% 1%

1%

75% 22%

3%

Departamento de Energía de Estados Unidos, EIA.

CEA, Electric Power in Canada, 1995.

REGULATIONSREGULATIONS

Mexico:Mexico:

NOM-ECOL-085-1994

NOM-ECOL-086-1994

Permissible emissions for NOx and SOx in

point and mobile sources

Pollutant MZMC (ppm) CZ (ppm) RC (ppm)

SO2 1.13 2.26 4.53

NOx 0.16 0.16 0.55

PM 0.04 0.19 0.27

MZMC: Metropolitan Zone, Mexico City

CZ: Critic Zone. Monterrey, Guadalajara, Ciudad Juarez

RC: Rest of the country

Sources of more than 110,000 MJ/hour

NOM-ECOL-085-1994

United States:United States:

Pollutant Primary Stds. Averaging Times Secondary Stds.

Carbon Monoxide 9 ppm (10 mg/m3) 8-hour None

35 ppm (40 mg/m3)

1-hour None

Lead 1.5 µg/m3 Quarterly Average Same as Primary

Nitrogen Dioxide 0.053 ppm (100 µg/m3)

Annual (Arithmetic Mean) Same as Primary

Particulate Matter (PM10) 50 µg/m3 Annual (Arith. Mean) Same as Primary

150 ug/m3 24-hour  

Particulate Matter (PM2.5) 15.0 µg/m3 Annual (Arith. Mean) Same as Primary

65 ug/m3 24-hour  

Ozone 0.08 ppm 8-hour Same as Primary

0.12 ppm 1-hour Same as Primary

Sulfur Oxides 0.03 ppm Annual (Arith. Mean) -------

0.14 ppm 24-hour -------

------- 3-hour 0.5 ppm (1300 ug/m3)

The Clean Air Act requires EPA to set National Ambient Air Quality Standards for pollutants considered harmful to public health and the environment.

National Ambient Air Quality Standards

QUIZQUIZ

Principal emissions related to energy production :(10s)

Time Trial

ClickTo

Start

R= Carbon dioxideR= Carbon dioxide Sulfur oxidesSulfur oxides Nitrogen Nitrogen oxidesoxides MercuryMercury

5 seconds left

Percentage of CO2 generated by energy production in N.A.:

Percentage of fossil fuel in the energy production:

Name one of the 2 technologies used to meet the new demand:(10s)ClickTo

Start5 seconds left

R= Hydroelectric R= Hydroelectric energyenergy Natural GasNatural Gas

a) a) 20%20%

b) 10%b) 10% c) 40%c) 40% d) 30%d) 30%

a) a) 60%60%

b) 62%b) 62% c) 64%c) 64% d) 66%d) 66%

GLOBAL ISSUE?GLOBAL ISSUE? Air pollutants are not stationary

Some of them can last several years in the atmosphere

No borders, cross countries

WHO IS INVOLVED?WHO IS INVOLVED?

SCIENTISTS

SOCIETY

GOVERMENTS

INDUSTRY

““What to do?” EVOLUTIONWhat to do?” EVOLUTION

End-of-the-pipe (70´s)

Recycle/reuse (80´s)

Plant design (90´s)

Progress = Pollution (past)

Process Integration ??? Atom Production ???

Progress = PollutionProgress = Pollution

Pollution Inevitable result of a chemical process

Wastes were released without treatment

Bad effects on human health and environment Strict Laws

RECYCLE/ REUSE. Plant designRECYCLE/ REUSE. Plant design

Raw materials

High efficiency Atom production

Good results

Treat, reduce or eliminate a pollutant

Avoid the creation of pollution

CONTROL vs PREVENTIONCONTROL vs PREVENTION

END-OF-PIPEEND-OF-PIPE Reduce/Eliminate Concentration/Toxicity

Transfer pollutant from one medium to other

≠ Good results Application

Pollution decreasing

Pollution increasing

HIERARCHYHIERARCHY

SOURCE SOURCE REDUCTIONREDUCTION

REDUCE / RECYCLEREDUCE / RECYCLE

WASTE TREATMENTWASTE TREATMENT

SAFE DISPOSALSAFE DISPOSAL

IN-PROCESS RECYCLEIN-PROCESS RECYCLE

ON-SITE RECYCLEON-SITE RECYCLE

OFF-SITE RECYCLEOFF-SITE RECYCLE

QUIZQUIZ

Name the “what to do?” evolution:(10s)

Time Trial

ClickTo

Start

R= Progress = PollutionR= Progress = Pollution End-of-pipe (70’s)End-of-pipe (70’s) Recycle/Reuse (80’s) Process Recycle/Reuse (80’s) Process integration???integration??? Plant design (90’s)Plant design (90’s)

5 seconds left

What is pollution control?:(10s)ClickTo

Start5 seconds left

R= Treat, reduce or eliminate a R= Treat, reduce or eliminate a pollutantpollutant

What is pollution prevention?: (10s)ClickTo

Start5 seconds left

R= Avoid the creation of R= Avoid the creation of pollutionpollution

Name the hierarchy pyramid: (10s)ClickTo

Start5 seconds left

R= Source reductionR= Source reduction Reduce/recycle: in-process, on-site, Reduce/recycle: in-process, on-site, off-site off-site Waste treatmentWaste treatment Safe disposalSafe disposal

PROCESS INTEGRATIONPROCESS INTEGRATION

ENERGY INTEGRATION

MASS INTEGRATION

It was developed in the 1970’sThermodynamic approach

(1980’s)

employed for heat exchanger networks

Reduction of wastes in a process

reduction of the utility demand and a reduction of utility waste

Smith and

Petelea

LinnhoffGundersen and Naess

Delaby and Smith

Source-Sink Mapping

Optimization Strategies

Mass Exchange Network

determinates which waste streams can be used as feedstocks to other processes or equipments

when the process involves too many sources and sinks it is necessary to employ both mathematical optimization and simulation packages

reaches mass integration by a direct exchange between streams

MASS EXCHANGE NETWORKMASS EXCHANGE NETWORK

MASS EXCHANGE NETWORK

Waste

(Rich)

Streams

In

MSA’s (Lean Streams) In

MSA’s (Rich Streams) Out

(to Final Dischargeor Recycle to

Process Sinks)

Employs either MSA or lean phase

The MSA must be immiscible

Equilibrium controls the mass transfer: yi = mjxj* + bj

yi : solute in the rich phase

xj : solute in the lean phase

Gradient concentration = Driving force: xj* = (yi – bj)/mj

MSA= Mass Separation Agent

Waste

(Lean)

Streams

Out

REGULATIONSREGULATIONS

COMISSION FOR ENVIRONMENTAL COOPERATIONCOMISSION FOR ENVIRONMENTAL COOPERATION

CANADA:ENVIRONMENT CANADA

UNITED STATES:ENVIRONMENTAL PROTECTION AGENCY

MEXICO:SECRETARIA DEL MEDIO AMBIENTE Y

RECURSOS NATURALES

http://www.epa.com

http://www.ec.gc.ca

http://www.semarnat.gob.mx

http://www.cec.org/programs_projects/law_policy/index.cfm?varlan=english

MONTREAL PROTOCOL

PROTOCOLSPROTOCOLS

OTHERSOTHERS

REGULATIONSREGULATIONS

Protect the Stratospheric Ozone Layer

Originally signed in 1987. and substantially amended in 1990 and 1992

Chlorofluorocarbons (CFCs), Halons, Carbon Tetrachloride, and Methyl Chloroform

RIO DECLARATION

Enforcing Adoption of Sustainable

Development

June 1992. Reaffirming the Declaration of the United Nations Conference on the Human Environment (Stockholm 1972)

ISO 14000Managerial procedures for the continuous

minimization of pollutants. Enforce the concept of sustainable development

http://www.ciesin.org/TG/PI/POLICY/montpro.html

http://www.unep.org/Documents/?DocumentID=78&ArticleID=1163

http://www.iso14000.com/

QUIZQUIZ

Governmental Offices in charge of environmental quality on each country :(10s)

Time Trial

ClickTo

Start

R= Canada: Environment CanadaR= Canada: Environment Canada United States: EPAUnited States: EPA Mexico: SemarnatMexico: Semarnat5 seconds left

Protocols that protect the environment:(10s)ClickTo

Start5 seconds left

R= Montreal ProtocolR= Montreal Protocol Rio de Janeiro Rio de Janeiro ConventionConvention

Branches of Process Integration: (10s)ClickTo

Start5 seconds left

R= Energy IntegrationR= Energy Integration Mass IntegrationMass Integration

Principal driving force on mass exchange: (10s)ClickTo

Start 5 seconds left

R= Gradient of concentrationR= Gradient of concentration

RECOVERY OF BENZENE FROM GASEOUS EMISSION RECOVERY OF BENZENE FROM GASEOUS EMISSION OF A POLYMER PRODUCTION FACILITYOF A POLYMER PRODUCTION FACILITY

Copolymer(to Coagulation and

Finishing)

Monomers Monomers Mixing Tank

First Stage Reactor

Second Stage Reactor

Separation

Recycled Solvent (Benzene)

Unreacted Monomers

SolventMakeup

Gaseous Waste R1

Additives Mixing Column

CatalyticSolution

(S2)

S1

Inhibitors+

Special Additives

ExtendingAgent

(Benzene as primary pollutant)

Pollution Prevention Trhough Process IntegrationMahmound M. El-HalwagiPg: 53-62

Copolymer(to Coagulation and

Finishing)

Monomers Monomers Mixing Tank

Separation

Recycled Solvent (Benzene)

Unreacted Monomers

SolventMakeup

Gaseous Waste R1

(Benzene as primary pollutant)

First Stage Reactor

Second Stage Reactor

Additives Mixing Column

CatalyticSolution

(S2)

S1

Inhibitors+

Special Additives

ExtendingAgent

Monomers Mixing Tank

First Stage Reactor

Second Stage Reactor

Separation

Recycled Solvent (Benzene)

Unreacted Monomers

SolventMakeup

Gaseous Waste

R1

Monomers

Benzene Recovery MEN

Reg

eneratio

n

To

Atmosphere

Benzene

OilMakeup

Oil

S3 S2 S1

Catalytic Solution

Additives(Extending Agent, Inhibitors,

And Special Additives)

Copolymer(to Coagulation and Finishing)

COMPARISONCOMPARISON

““Problem”Problem”

““Possible solution”Possible solution”

POSSIBLE SOLUTIONPOSSIBLE SOLUTIONTWO PROCESS MSA´s: S1 and S2

Copolymer(to Coagulation and

Finishing)Monomers

Mixing Tank

First Stage Reactor

Second Stage Reactor

Separation

Recycled Solvent

Unreacted Monomers

SolventMakeup

Gaseous Waste

R1

Monomers

Benzene Recovery MEN

Re

ge

ne

ratio

n

To

Atmosphere

Benzene

OilMakeup

Oil

S3 S2 S1

Catalytic Solution

Additives(Extending Agent, Inhibitors,

And Special Additives)

ONE EXTERNAL MSA´s: ORGANIC OIL (S3)

0.0

1.0

2.0

3.0

4.0

5.0

6.0

0.0000 0.0005 0.0010 0.0015 0.0020 0.0025

y

Mas

s E

xch

ang

ed,

10-4

Kg

mo

l

Ben

zen

e/s

3.8

0..0001

Rich Composite Stream

Stream

DescriptionFlowrate

Gi, Kgmol/s

Supply composition

(mole fraction)yi

s

Target composition

(mole fraction)yi

t

R1

Off-gas from product

separation0.2 0.0020 0.0001

RICH COMPOSITE STREAMRICH COMPOSITE STREAM

Mass Exchanged = (Gi)*(y)

MRi = Gi*(yis – yi

t)

Mass Exchanged = (Gi)*(y) MRi = Gi*(yis – yi

t)

Separation

Waste Stream

R1

x1

x2

y

3.4

2.4

S1

S2

Stream Description

Upper bound on flowrate

Ljc Kgmol/s

Supply composition of benzene

(mole fraction)xj

s

Target composition Of benzene

(mole fraction)yj

t

S1 Additives 0.08 0.003 0.006

S2 Catalytic solution 0.05 0.002 0.004

LEAN COMPOSITE STREAMLEAN COMPOSITE STREAM

First Stage Reactor

Second Stage Reactor

Additives Mixing Column

CatalyticSolution

(S2)

S1

Inhibitors+

Special Additives

ExtendingAgent

MSj = Ljc(xj

t – xjs)

MSi = Ljc(xj

t – xjs)

yi = Ljc (xj + ξj) + bj

ξj = 0.001

yi = Ljc(xj + ξj) + bj

ξj = 0.001

3.4

2.4

y

x1

x2

S2

S1

Lean Composite

Stream

LEAN COMPOSITE STREAMLEAN COMPOSITE STREAM

x1x2

y

3.4

2.4

S1

S2

Superposition of the Streams

PINCH POINTPINCH POINT

3.4

2.4

y

x1

x2

S2

S1

Lean Composite

Stream

0.0

1.0

2.0

3.0

4.0

5.0

6.0

0.0000 0.0005 0.0010 0.0015 0.0020 0.0025

y

Mas

s Ex

chan

ged,

10

-4 K

gmol

Be

nzen

e/s 3.8

0..0001

Rich Composite Stream

+

Lean Composite StreamLean Composite Stream

5.2

Excess Capacity of Excess Capacity of Process MSA´sProcess MSA´s

4.2

3.8

Pinch Point

Integrated Mass Integrated Mass ExchangeExchange

1.8

Load to be Removed by Load to be Removed by External MSA´sExternal MSA´s

y

x1

x2

0.0001

Load to be Removed by External MSA´s

PINCH POINTPINCH POINT

1.4 x 10-4 (y,x1,x2) = (0.0010,0.0030,0.0010)

Excess Capacity = 1.4 x 10-4 kgmol B/s

Process MSA´s = 2.0 x 10-4 kgmol B/s

External MSA’s = 1.8 x 10-4 kgmol B/s

Integrated Mass Integrated Mass ExchangeExchange

Load to be Load to be Removed by Removed by

External MSA´sExternal MSA´s

Pinch Pinch PointPoint

Rich Rich Composite Composite StreamStream

y

x1

4.2

3.8

1.8

S1

SOLUTIONSOLUTION

S1 = L1 (x1out – x1

s)

L1 = S1 / (x1out – x1

s)

x1out = 0.0055

Gaseous Waste, R1G1=0.2 kgmol/sy1

s=0.0020x1

out=0.0055

ypinch=0.0010

y1t=0.0001

Regeneration

x3out=0.0085

Additives Mixture, S1

L1=0.08 Kgmol/sx1

s=0.0030

Regenerated Solvent, S3

L3=0.0234 Kgmol/sx3

s=0.0008

Makeup

SOLUTIONSOLUTION

Pinch PointPinch Point

External Process External Process MSA (SMSA (S33))

Internal Process Internal Process MSA (SMSA (S11))

Flash Flash SeparationSeparation

MINIMUM ALLOWABLE COMPOSITIONMINIMUM ALLOWABLE COMPOSITIONDIFFERENCE (DIFFERENCE (ξξJJ))

y

xj

Practical Feasibility Region

Practical Feasibility Line

ξj

ξj

Equilibrium Line

x*j= (y-bj)/mj

yi = mjx*j + bj

x*j = xj + ξj

yi = mj * (xj + ξj) + b

5.7

4.7

3.8

2.3

0.0030

0.00125

Lean Composite Lean Composite StreamStreamExcess Capacity of Excess Capacity of

Process MSAsProcess MSAs

Integrated Integrated Mass ExchangeMass Exchange

Rich Rich Composite Composite StreamStream Pinch Pinch

PointPoint

Load to be Removed Load to be Removed by External MSAsby External MSAs

0.0001 y

x1

x2

MINIMUN ALLOWABLE COMPOSITIONMINIMUN ALLOWABLE COMPOSITIONDIFFERENCE (DIFFERENCE (ξξJJ))

yi = Ljc(xj + ξj) + bj

ξj = 0.002

(y,x1,x2) = (0.00125,0.0030,0.0015)

Excess Capacity = 1.9 x 10-4 kgmol Ben/s

Process MSA´s = 1.5 x 10-4 kgmol Ben/s

External MSA’s = 2.3 x 10-4 kgmol Ben/s

SUMMARYSUMMARYAir pollution is a serious problem which will continue to become more critical in the future due to increasing

PopulationEnergy needsTransportation needsIndustrial and chemical manufacturing

Efforts to reduce and control air pollution have evolved over time, but require further development to meet the increasing need.

Currently the best approach may be process integration to optimize plant design to minimize pollutants. “Atom production”, manufacturing with zero waste and byproducts, is a future goal not generally achieve now.

Process integration for plant design centers around pinch analysis of mass exchange network (MEN) to minimize waste streams, recycle them in the process, or recover them external to the process.