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““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
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.