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CHAPTER 7 ENVIRONMENTAL PERFORMANCE EVALUATION
CHAPTER 7
ENVIRONMENTAL PERFORMANCE EVALUATION
Ideas for the ChapterVariety of methodologies that may be employed
at different design stages will be discussed in this chapter :
Section A : Tier 1 Environmental Performance Tools
Section B : Tier 2 Environmental Performance Tools
Introduction to Tier 3 Environmental Performance Tools.
Environmental Performance Evaluation(EPE) – Goals
An internal management process that provides informationto facilitate management decisions regarding an
organization’s environmental performance
Supported by ISO 14001 – Environmental management systems –Specifications with guidance for use, 1996, 2003.
By means of the tool ISO/TC 207/SC 4 - develops international guidanceon EPE, and,
ISO 14031 – Environmental management – Environmental performance evaluation – Guidelines, 1999
ISO/TR 14032 – Environmental management - Examples of EPE, 1999
The EPE in context of the ISO 14000 Series: Environmental Management
NEW ITEM: ENVIRONMENTAL COMMUNICATION( TR 14063)
ENVIRONMENTAL MANAGEMENT SYSTEMS
ISO 14001/ 4 ENVIRONMENTAL PERFORMANCE
EVALUATION 14030 SERIES
LIFE CYCLE ASSESSMENT 14040
SÉRIES
ENVIRONMENTAL AUDITING 14010 SERIES
(19011)DESIGN FOR
ENVIRONMENT TR 14062
ENVIROMENTAL LABELLING 14020
SERIES
FOCUS: Organizations FOCUS: Product
Objectives and Benefits of an EPE Program
• Better understanding of an organization’s impacts on the environment,
• Providing a basis for benchmarking management, operational and environmental performance,
• Identifying opportunities for improving efficiency ofenergy and resource usage,
• Determining whether environmental objectives and targetsare being met,
• Demonstrating compliance with regulations,• Determining proper allocation of resources,• Increasing the awareness of employees, and,• Improving community and customer relations
EPE Indicators
Environmentalperformance indicators
(EPIs)- Managementperformance indicators(MPIs): policy, people, planning activities, practice, procedures, decisions and actions in theorganization
- Operational performanceindicators (OPIs): inputs, thesupply of inputs, the design, installation, operation and maintenanceof the physical facilities andequipment, outputs and their delivery
Environmental conditionindicators (ECIs)
Provide information about thelocal, regional, national or global condition of the environment
INTEREST: Help an organizationto better understand the actual impact or potential impact of itsenvironmental aspects and assist in the planning and implementation ofthe EPE
Plan-Do-Check-Act Model: ISO 14031
Plan-Do-Check-Act Model: ISO 14031....
PlanObjective: Selection of
indicators based on- significant environmental
aspects- Environmental
performance criteria(internal and regulatory)
- Views of interested parties(business plan)
Indicators: ECI, EPI, MPI and OPI (see table forexamples)
Do – assessing performance- Collecting data -regulations,
operating permits, EMS procedures and records, reports government agencies (production, process, monitoring), environmentalbudgets, chemical inventories, storage tanks and spillrecords.
- Converting data toinformation
- Evaluating the information- Communicating the results
Examples of performance indicators and metrics1
Employee blood lead levels(µg/100 mL)
Management levels with specificenviron responsabilities (#)
Air emissions were exceeded(days/yr)
Fish deaths in a specificwatercourse (#/yr)
Number of suppliers contactedabout environ. mngment. (#/yr)
Wastewater discharged per unitof product (1000 L/unit)
Population of an specific specieswithin a defined area (#/m2)
Number of complaints frompublic or employees (#/yr)
Emissions of specific pollutantsto air (Ton CO2/yr)
Concentration of a contaminantin the tissue of a specific local specie (µg/Kg)
Time spent responding toenvironmental incidents (person-hr/yr)
Hazardous waste generated perunit of product (Kg/unit)
Contaminant concentration in surface soil (mg/Kg)
Time spent to correct auditfindings (person-hr)
Average fuel consumption ofvehicle fleet (L/100 Km)
Change in groundwater level (m)Number of audit findings (#)Number of emergency events orunplanned shutdowns (#/yr)
Contaminant concentration in ground- or surface water (mg/L)
Number employees trained (% # trained/to be trained)
Energy conserved (MJ)
Frequency of photochemicalsmog events (#/yr)
Percentage of environmentaltargets achieved (%)
Energy used annually per unit ofproduct (MJ/1000 L product)
Contaminant concentration in ambient air (µg/m3)
Environmental costs or budget($/yr)
Raw material used per unit ofproduct (Kg/unit)
ECIMPIOPI
Plan-Do-Check-Act Model: ISO 14031....
Check and Act –reviewing and improving performance
Objective: To identifyopportunities forimproving environmentalperformance including
- Program cost and benefit- Progress towards meeting
environmental performancetargets
- How appropriate are theenvironmental performancecriteria and indicators
- Data quality and collectionmethods
Case study1
Implementation of EPE at MotherDairy Fruit and Vegetable Ltd., NewDelhi, India, 2001Problem: the dairy was monitoringliquid fuel and electric powerconsumption together with the volumeof wastewater processed in the effluenttreatment systemEPE strategy: all parameters werenormalized using the volume of milkprocessedResults: the dairy increased the amountof milk processed per unit of electricalpower (23%) an diesel fuel consumed(38%) and reductions of wastewatergenerated (20%)
Case Study: Mother Dairy Company - EPIs
OPIOPI
# PlantingsQuantity of compostproduced (Kg)
On and off-site gardeningBiosludge composting by vermiculture
Green horticulture
MPI# Employees trainedEnvironmental awarenesstraining
Employee training and awareness
OPI
OPI
Effluent processed (L)
Energy consumed (MJ/L effluent)
Microbiological analysisof sludgeUse of improvedmicroculture
Wastewatertreatment efficiency
OPIWell water used per volumeof milk processed (L water/L milk)
Water auditWater use reduction
ECIECI
Static well water levelWell water analysis
Rain water harvestingWell waterconservation
IndicatorType
Performance IndicatorsProgramObjective
Example of EPE’s application: Measuring Environmental Performance of Industry (MEPI)
Project in Europe
MEPI’s Objective: the improvement of internal and external transparency about the effects on the environment and responses to mitigate them
MEPI’s Tools: Environmental Performance Indicators – physical, business and environmental impact
MEPI’s Focus: materials and energy use and waste emissions at the level of plant and firm
Tools (indicators) in the MEPI Project
Emissions ofozone depletingsubstances to air
Certifications ISO 14001 and/orEMAS (yes / no)Disclosure ofenvironmentalinvestments (yes / no)Number of non-compliance eventsreported
Energy and waterinputsWaste generationCO2, SO2, Noxand VOC’s emissions to airCOD/BOD, N, P, heavy metalsemissions to water
Value added(Sales – Cost of materials)SalesOperating profitNumber ofemployees
Impactindicators
Businessmanagement
indicators
Physicalindicators
Businessactivity
MEPI’s indicators include: generic (Table) and sector - specific
Most significant variables influencing environmentalperformance in the Paper, Fertiliser and Electricity
Industry in European Countries
Total fuel (16; total oil (78); Renewables (20); Total energy (10)
No variables selecteddue to missing values
CO2 (118)NOx (134)SO2 (135)
Total solidwaste (75)
ElectricityN=184
Total energy input(26)
Total waterconsumption(26)
COD (9); N (20); P (12); Heavy metals (17)
SO2 (13)NOx (15)
Total solidwaste (10)
FertiliserN=91
Total energy input(39)
Total waterconsumption(120)
COD (107)N (91)P (54)
CO2 (63)SO2 (44)
Total solidwaste(53)Recycledwaste(71)
PaperN=270
Energyconsumption
Waterconsumption
Water emissionsAiremissions
Wasteemissiones
Sector
Numbers in parenthesis indicate available cases of the total (n)
Environmental Performance Tools
Section ATier 1
Environmental Performance Main Tools
• Economic Criteria• Environmental Criteria (Persistence and
Bioaccumulation)• Toxicity Criteria and Weighting• Evaluating Alternative Synthetic Pathways
• Input and Output Structures Known• Chemical Structures are Known• Many Alternative Pathways Exist
Design Synthesis Steps
Economic CriteriaEstimate the cost of raw materials versus the value and/or cost of byproducts and products.The cost of the various options can be estimated by:
This is more of a qualitative analysis because it does not take into account other potential costs associated with the production of the given substance (i.e. higher temperatures require more energy, etc).
[ ]∑= ii tcoefficientricStoichiomeCostCost *
Environmental Criteria
• It only takes into account the substances’Persistent, Toxic and Bioaccumulatingproperties.
• Persistence and Bioaccumulation are easily estimated and a table shows rating index values on the following slide.
Rating Index (RI)
RI = 13.5 > log Kow or 250 > BCFLow Potential
RI = 24.3 > log Kow > 3.5 or 1000 > BCF > 250Moderate Potential
RI = 38.0 > log Kow > 4.3 or BCF > 1000High Potential
Bioaccumulation
RI = 3<30% degradation over more than 28 daysVery slow
RI = 2<30% degradation over 28 daysSlow
RI = 1>30% degradation over 28 daysModerate
RI = 0>60% degradation over 1 weekRapid
Persistence
Source : Green Engineering text, Allen and Shonnard, pp. 204
Toxicity EvaluationsThreshold Limit Values (TLVs) : – Definition : Airborne concentration limit for individual exposures
in a workplace environment.– Established by : ACGIH -http://www.acgih.org
Permissible Exposure Limits (PELs) : – Definition : similar to TLV ; represents the legal implications in
defining workplace conditions.– Established by : OSHA -http://www.osha.gov/
Recommended Exposure Limits (RELs) :– Definition : more current then PELs ; solely based on toxicity research.– Established by : NIOSH -http://www.cdc.gov/niosh/homepage.html
One Toxicity Index can be calculated using :
)(1
TLVIndextalEnvironmen =
Toxicity Index
Source : Green Engineering, Allen and Shonnard, pp 205.
Toxicity Weighting
Taking into account ingestion pathways :- Inhalation Reference Concentration- Oral Ingestion Slope Factor- Unit Risk - IRIS database is one source of data :
http://www.epa.gov/ngispgm3/iris/subst/index.html
The toxic weighting factor (Ftox) represents the “weight” to be given to each substance to make possible the comparison of the discharges.
The toxic weighting factor is defined as the inverse of the most stringent water quality criterion for each substance (MSCi):
Ftox i = 1/MSCi
MSCi = min (CTACi, CCOAi)
This is a dimensionless number, and represents the toxic potential to be assigned to a given pollutant to evaluate its relative importance in the discharges.
Source: http://www.slv2000.qc.ca/plan_action/phase1/chimiotox_a.pdf
Evaluating Alternative
• A general Composite Index of the overall input-output structure can be established with the substance’s PBT properties and can also rely on the emission rates.
Synthetic Pathways
• Methods of applying Weighting Factors :1) Toxicity as Weighting Factor. 2) US EPA Toxicity Approach. 3) Using PBT Weighting Factors.
Environmental Performance Tools
Section BTier 2
Tier 2 :Environmental Performance Tools
• Environmental Release Assessment• Release Quantification Methods• Modeled Release Estimates• Release Characterization and Documentation• Assessing Environmental Performance
Topics covered in this section:
• Preliminary Process Flowsheets.• Basic Knowledge of Unit Operations.• Rough Estimate of Unit Operation Sizing.
Design Synthesis StepsBasic information needed
Environmental Release Assessment
Environment includes : - Water - Air - Land
Releases may include : Spilling - Leaking - PumpingPouring - Emitting - EmptyingDischarging - Injecting - EscapingLeaching - Dumping into the environmentDisposing into the environment
Necessary Knowledge about Releases
Release Assessment Components
Determine best method for quantifying the
release rate of each WES
Obtain/DiagramA processFlowsheet
Determine data/infoneeded to use the
methods determined
Identify Purposeand Need for
Release Assessment
Identify and ListWaste and Emission
Streams (WESs)
Document release assessment; include characterization of
estimate uncertainties
Quantify chemical’s release rates +
frequencies + the mediain which it is released
Collect data + infoto fill in the gaps
Determine Additional
WESs
Process AnalysisWhen analyzing flowsheets, account for missing releases that include : – Fugitive Emissions (which include leaks).– Venting of Equipment (including breathing and
displacement losses).– Periodic Equipment Cleaning (frequent and infrequent).– Transport Container Residuals (including drums, totes,
tank trucks, rail cars and barges).– Incomplete Separations (including destilation, gravity
phase separation and filtration).
• Determining the manner in which substances are released is crucial in assessing environmental impacts
• Releases can also occur on and off site, including : - Air : include primary and secondary emissions.- Water : transfers into streams or water bodies.- Underground Injection : generally into wells.- Land : within the boundaries of the facility.
Process Analysis... continues
There are different dispersion patterns to high-stack (over 75 meters), medium-stack (25 meters–75 meters) and low-stack sources (less than 25 meters).
High-stack sources are synonymous with modern power plants; medium-stack sources with large industrial plants, district heating plants, and suboptimal power utilities; and low-stack, or low-level, sources with small industrial and commercial users, transport, and the domestic sector.
Air: Primary EmissionsStacks Emissions
Source: http://lnweb18.worldbank.org/SAR/sa.nsf/Attachments/FFCh2/$File/FFCh2.pdf
Air: Secondary EmissionsFugitive Emissions
The sources of fugitive emissions are categorized as (1) industrial processes, operations, activities, or materials that emit particulate or chemical pollutants or (2) activities or operations that create fugitive dust.
Particulates that become airborne by wind and/or human activity are also referred to as fugitive dust.
Source: http://www.seattle.battelle.org/forscom/Hot_Air/Fugitive.htm
Release Quantification Methods
1. Measured release data for the chemical or indirectly measured release data using mass balance or stoichiometric ratios.
2. Release data for a surrogate chemical with similar release-affecting properties and used in the same (or very similar) process. Surrogate data may be measured, indirectly measured, modeled or some combination of these. Some emission factors would be considered to be surrogate data.
3. Modeled release estimates :
a. Mathematically modeled (eg) release estimates for the chemical or by analogy to a surrogate chemical.
b. Rule of thumb release estimates, or those being developed using engineering judgement.
• Usually only applicable for actual processes• For a continuous process :
• Can also be estimated using the chemical’s weight fraction and the mass flowrate of the release stream
Measured Release Data for the Chemical
[ ] streamreleaseavgstreamreleaseavg Qrelease ρ**=
• By using surrogate chemical data, it should be ensured that there exist similarities in some physical/chemical properties of the chemicals, unit ops and their operating conditions and quantities of chemical throughput.
Release Data for a Surrogate Chemical
- Usually only used for Air Emissions.- Many databases exist containing these factors.
Emission Factors
A. Average Marginal CO2 Emissions Factors for Electricity Generation by EPA Region (2000):
Source: http://www.epa.gov/appdstar/pdf/brochure.pdf
B. CO2 Emission Factors by Fuel Type per Unit Volume, Mass, and Energy:
Source: http://www.epa.gov/appdstar/pdf/brochure.pdf
Equation for Rate of Emission :
Where : mvoc is the mass fraction of the VOC in the stream or
process unit,EFav is the average emissions factor ascribed to the stream
or process unit (kg emitted/103kg throughput),M is the mass flow rate through the unit (mass/time).See tables with lists of various factors examples.
Emissions from Process Units and Fugitive Sources
MEFmE avvoc=
Losses of Residuals from Cleaning ofDrums and Tanks
– Nature of the cleaning process should be considered– Capacities.– Shapes.– Materials of construction of the vessels to be cleaned.– Cleaning schedule.– The residual quantity of the chemical in the vessels.– The type and amount of solvent used (aq. Vs. Organic).– Solubility/miscibility of the chemical in the solvent.– If applicable, treatment of wastewater containing the chemical.
• Utility use is extensive in causing environmental impact. • Emission estimation equations :
Where:ED is the energy demand of a process unit(energy demand/unit/yr).EF is the emission factor for the fuel type(kg/volume of fuel combusted).FV is the fuel value (energy/volume fuel combusted).BE is the boiler efficiency (unitless; 0.75-0.9 typical values).
Secondary Emissions from Utility Sources
11 )())()(()//( −−= BEFVEFEDyruntikgE
Where:ED is the electricity demand of a process unit(energy demand/unit/yr).EF is the emission factor for the fuel type (kg/volume of fuel combusted).ME is the efficiency of the device.
1))()(()//( −= MEEFEDyrunitkgE
Modeled Release Estimates
• Process design software account for some releases, but not all. The following slides will introduce information that allows the calculation of the missed releases :- Loading transport containers- Evaporative losses from static liquid pools- Storage tank working and breathing loss.
• Quantity of evaporative losses from a loading container is a function of :- Physical and chemical characteristics of the previous
cargo- Method of unloading the previous cargo- Operations to transport the empty carrier to a loading
terminal- Method of loading the new cargo- Physical and chemical characteristics of the new cargo
Loading Transport Containers
- Evaporation Rate :
Where : G is the generation rate (lb/hr),M is the molecular weight (lb/lb mole),P is the vapor pressure (in Hg),A is the area (ft2),Dab is the diffusion coefficient (ft2/s of a through b is air),Vz is the air velocity (ft/min),T is the temperature (K),Δz is the pool lenght along flow direction (ft).
Evaporative Losses from Static Liquid Pools
5.011 )(32.13 −− Δ= zvDTAPMG zab
- Diffusion Coefficient
Where the units are :
Dab (cm2/s), M (g/gmole),
Pt (atm), T (K).
133.05.0119.15 )29(1009.4 −−−−− +×= tPMMTD
• Two types of losses exist : - Working Losses (originating from the raising
and lowering of the liquid level in the tank as a result of raw material utilization and production of product)
- Standing Losses (originating from daily temperature and ambient pressure fluctuations)
Storage Tank Working and Breathing Loss
Release Characterization and Documentation
The uncertainty depends on how well we know the process, how well we understand the estimation method and its data and parameters, and how well the method and parametersseem to match up with those expected for the actual process.
HIGH EFFICIENCY GENERATIONOF HYDROGEN FUELS USING NUCLEAR POWER
• A thermochemical water-splitting cycle is a set of chemical reactions that sum to the decomposition of water into hydrogen.
“The objective of this work is to define an economically feasible concept for the production of hydrogen, by nuclear
means, using an advanced high temperature nuclear reactor as the energy source.”
• The Sulfur-Iodine cycle, an example of a pure thermochemical water-splitting cycle.
Source: web.gat.com/hydrogen/images/pdf%20files/ brown_si_cycle.pdf
Section 1 – Chemical recycle and acid generation
Section 2 – Sulfuric acid concentration and decomposition
Section 3 – Hydrogen iodide concentration and decomposition
Assessing Environmental Performance
Two types of overall assessments can be used :
1. Evaluates the treatablility or costs of treatment of the waste streams.
2. Evaluates a set of environmental performance indicators :
a. Energy consumed from all sources within the manufacturing or delivery process per unit of manufactured output.
b. Total mass of materials used directly in the product, minus the mass of the product, per unit of manufactured output.
c. Water consumption per unit of manufactured output.
d. Emissions of targetted pollutants per unit of manufactured output.
e. Total pollutantsper unit of manufactured output.
Environmental Performance Tools
IntroductionTier 3
Introduction to Tier 3 Environmental Performance Tools
• Design synthesis steps.- Detailed process flowsheets.- Equipment specifications.- Energy specifications.
• Limited design alternatives to screen.• More is known, therefore all knowledge
should be incorporated into the evaluation.
