CHAPTER 7

ENVIRONMENTAL PERFORMANCE EVALUATION

Ideas for the Chapter

Variety 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 information to 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 guidance on 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 of energy and resource usage,

• Determining whether environmental objectives and targets are being met,

• Demonstrating compliance with regulations,• Determining proper allocation of resources,• Increasing the awareness of employees, and,• Improving community and customer relations

EPE Indicators

Environmental performance indicators

(EPIs)- Management performance indicators (MPIs): policy, people, planning activities, practice, procedures, decisions and actions in the organization

- Operational performance indicators (OPIs): inputs, the supply of inputs, the design, installation, operation and maintenance of the physical facilities and equipment, outputs and their delivery

Environmental condition indicators (ECIs)

Provide information about the local, regional, national or global condition of the environment

INTEREST: Help an organization to better understand the actual impact or potential impact of its environmental aspects and assist in the planning and implementation of the 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 for examples)

Do – assessing performance- Collecting data -regulations,

operating permits, EMS procedures and records, reports government agencies (production, process, monitoring), environmental budgets, chemical inventories, storage tanks and spill records.

- Converting data to information

- Evaluating the information- Communicating the results

Examples of performance indicators and metrics1

OPI MPI ECIRaw material used per unit of product (Kg/unit)

Environmental costs or budget ($/yr)

Contaminant concentration in ambient air (µg/m3)

Energy used annually per unit of product (MJ/1000 L product)

Percentage of environmental targets achieved (%)

Frequency of photochemical smog events (#/yr)

Energy conserved (MJ) Number employees trained (% # trained/to be trained)

Contaminant concentration in ground- or surface water (mg/L)

Number of emergency events or unplanned shutdowns (#/yr)

Number of audit findings (#) Change in groundwater level (m)

Average fuel consumption of vehicle fleet (L/100 Km)

Time spent to correct audit findings (person-hr)

Contaminant concentration in surface soil (mg/Kg)

Hazardous waste generated per unit of product (Kg/unit)

Time spent responding to environmental incidents (person-hr/yr)

Concentration of a contaminant in the tissue of a specific local specie (µg/Kg)

Emissions of specific pollutants to air (Ton CO2/yr)

Number of complaints from public or employees (#/yr)

Population of an specific species within a defined area (#/m2)

Wastewater discharged per unit of product (1000 L/unit)

Number of suppliers contacted about environ. mngment. (#/yr)

Fish deaths in a specific watercourse (#/yr)

Air emissions were exceeded (days/yr)

Management levels with specific environ responsabilities (#)

Employee blood lead levels (µg/100 mL)

Plan-Do-Check-Act Model: ISO 14031....

Check and Act – reviewing and improving performance

Objective: To identify opportunities for improving environmental performance including

- Program cost and benefit- Progress towards meeting

environmental performance targets

- How appropriate are the environmental performance criteria and indicators

- Data quality and collection methods

Case study1

Implementation of EPE at Mother Dairy Fruit and Vegetable Ltd., New Delhi, India, 2001Problem: the dairy was monitoring liquid fuel and electric power consumption together with the volume of wastewater processed in the effluent treatment systemEPE strategy: all parameters were normalized using the volume of milk processedResults: the dairy increased the amount of milk processed per unit of electrical power (23%) an diesel fuel consumed (38%) and reductions of wastewater generated (20%)

Case Study: Mother Dairy Company - EPIs

Objective Program Performance Indicators Indicator Type

Well water conservation

Rain water harvesting Static well water level

Well water analysis

ECI

ECI

Water use reduction Water audit Well water used per volume of milk processed (L water/L milk)

OPI

Wastewater treatment efficiency

Microbiological analysis of sludge

Use of improved microculture

Effluent processed (L)

Energy consumed (MJ/L effluent)

OPI

OPI

Employee training and awareness

Environmental awareness training

# Employees trained MPI

Green horticulture On and off-site gardening

Biosludge composting by vermiculture

# Plantings

Quantity of compost produced (Kg)

OPI

OPI

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

Business activity

Physical indicators

Business management

indicators

Impact indicators

Value added (Sales – Cost of materials)

Sales

Operating profit

Number of employees

Energy and water inputs

Waste generation

CO2, SO2, Nox and VOC’s emissions to air

COD/BOD, N, P, heavy metals emissions to water

Certifications ISO 14001 and/or EMAS (yes / no)

Disclosure of environmental investments (yes / no)

Number of non-compliance events reported

Emissions of ozone depleting substances to air

MEPI’s indicators include: generic (Table) and sector - specific

Most significant variables influencing environmental performance in the Paper, Fertiliser and Electricity

Industry in European Countries

Sector Waste emissiones

Air emissions

Water emissions Water consumption

Energy consumption

Paper

N=270

Total solid waste(53)

Recycled waste(71)

CO2 (63)

SO2 (44)

COD (107)

N (91)

P (54)

Total water consumption (120)

Total energy input (39)

Fertiliser

N=91

Total solid waste (10)

SO2 (13)

NOx (15)

COD (9); N (20); P (12); Heavy metals (17)

Total water consumption (26)

Total energy input (26)

Electricity

N=184

Total solid waste (75)

CO2 (118)

NOx (134)

SO2 (135)

No variables selected due to missing values

Total fuel (16; total oil (78); Renewables (20); Total energy (10)

Numbers in parenthesis indicate available cases of the total (n)

Environmental Performance Tools

Section A

Tier 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 Criteria

Estimate 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 Bioaccumulating properties.

• Persistence and Bioaccumulation are easily estimated and a table shows rating index values on the following slide.

Rating Index (RI)

PersistenceRapid >60% degradation over 1 week RI = 0

Moderate >30% degradation over 28 days RI = 1

Slow <30% degradation over 28 days RI = 2

Very slow <30% degradation over more than 28 days RI = 3

BioaccumulationHigh Potential 8.0 > log Kow > 4.3 or BCF > 1000 RI = 3

Moderate Potential 4.3 > log Kow > 3.5 or 1000 > BCF > 250 RI = 2

Low Potential 3.5 > log Kow or 250 > BCF RI = 1

Source : Green Engineering text, Allen and Shonnard, pp. 204

Toxicity Evaluations Threshold 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 Steps

Basic information needed

Environmental Release Assessment

Environment includes : - Water - Air - Land

Releases may include : Spilling - Leaking - Pumping

Pouring - Emitting - Emptying

Discharging - Injecting - Escaping

Leaching - Dumping into the environment

Disposing into the environment

Necessary Knowledge about Releases

Release Assessment Components

Determine best method for quantifying the

release rate of each WES

Obtain/Diagram A 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 media in which it is released

Collect data + info to fill in the gaps

Determine Additional

WESs

Process Analysis When 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 **

• 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 of Drums 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 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.