CHAPTER 7 ENVIRONMENTAL PERFORMANCE EVALUATION

CHAPTER 7

ENVIRONMENTAL

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

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

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

Objective: 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 metrics

1

Employee blood lead levels (µg/100 mL)

Management levels with specific environ responsabilities (#) Air emissions were exceeded

(days/yr)

Fish deaths in a specific watercourse (#/yr) Number of suppliers contacted

about environ. mngment. (#/yr) Wastewater discharged per unit

of product (1000 L/unit)

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

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

to air (Ton CO₂/yr)

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

Time spent responding to

environmental incidents (person-hr/yr)

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

Contaminant concentration in surface soil (mg/Kg)

Time spent to correct audit findings (person-hr)

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

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

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

Contaminant concentration in ground- or surface water (mg/L) Number employees trained (% #

trained/to be trained) Energy conserved (MJ)

Frequency of photochemical smog events (#/yr)

Percentage of environmental targets achieved (%)

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

Contaminant concentration in ambient air (µg/m3₎

Environmental costs or budget ($/yr)

Raw material used per unit of product (Kg/unit)

ECI

MPI

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 study

1

Implementation of EPE at Mother Dairy Fruit and Vegetable Ltd., New Delhi, India, 2001

Problem: the dairy was monitoring liquid fuel and electric power

consumption together with the volume of wastewater processed in the effluent treatment system

EPE strategy: all parameters were normalized using the volume of milk processed

Results: 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

OPI OPI # Plantings Quantity of compost produced (Kg)

On and off-site gardening Biosludge composting by vermiculture Green horticulture MPI # Employees trained Environmental awareness training Employee training and awareness OPI OPI Effluent processed (L) Energy consumed (MJ/L effluent) Microbiological analysis of sludge Use of improved microculture Wastewater treatment efficiency OPI Well water used per volume

of milk processed (L water/L milk)

Water audit Water use reduction

ECI ECI Static well water level

Well water analysis Rain water harvesting

Well water conservation Indicator Type Performance Indicators Program Objective

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 of ozone depleting substances to air Certifications ISO 14001 and/or EMAS (yes / no) Disclosure of environmental investments (yes / no) Number of non-compliance events reported

Energy and water inputs

Waste generation CO2, SO2, Nox and VOC’s emissions to air COD/BOD, N, P, heavy metals emissions to water Value added (Sales – Cost of materials) Sales Operating profit Number of employees Impact indicators Business management indicators Physical indicators Business activity

Most significant variables influencing environmental

performance in the Paper, Fertiliser and Electricity

Industry in European Countries

Total fuel (16; total oil (78);

Renewables (20); Total energy (10) No variables selected

due to missing values CO2 (118) NOx (134) SO2 (135) Total solid waste (75) Electricity N=184

Total energy input (26) Total water consumption (26) COD (9); N (20); P (12); Heavy metals (17) SO2 (13) NOx (15) Total solid waste (10) Fertiliser N=91

Total energy input (39) Total water consumption (120) COD (107) N (91) P (54) CO2 (63) SO2 (44) Total solid waste(53) Recycled waste(71) Paper N=270 Energy consumption Water consumptio n Water emissions Air emissions Waste emissiones Sector

Environmental Performance

Tools

Section A

Environmental Performance

Main Tools

• Economic Criteria

• Environmental Criteria (Persistence and

Bioaccumulation)

• Toxicity Criteria and Weighting

• Input and Output Structures Known

• Chemical Structures are Known

• Many Alternative Pathways Exist

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).

[

]

∑

=

Cost

_i

Stoichiome

tric

coefficien

t

_i

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)

RI = 1 3.5 > log K_ow or 250 > BCF Low Potential RI = 2 4.3 > log K_ow > 3.5 or 1000 > BCF > 250 Moderate Potential RI = 3 8.0 > log K_ow > 4.3 or BCF > 1000 High Potential

Bioaccumulation

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

Very slow

RI = 2 <30% degradation over 28 days

Slow

RI = 1 >30% degradation over 28 days

Moderate

RI = 0 >60% degradation over 1 week

Rapid

Persistence

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

TLV

Index

tal

Environmen

=

Toxicity Index

Toxicity Weighting

Taking into account ingestion pathways :

- Inhalation Reference Concentration

- Oral Ingestion Slope Factor

- Unit Risk

- IRIS database is one source of data :

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.

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.

•

Methods of applying Weighting Factors :

1) Toxicity as Weighting Factor.

2) US EPA Toxicity Approach.

3) Using PBT Weighting Factors.

Environmental Performance

Tools

Section B

Tier 2 :Environmental Performance Tools

• Environmental Release Assessment

• Release Quantification Methods

• Modeled Release Estimates

• Release Characterization and Documentation

• Assessing Environmental Performance

• 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

Release Assessment Components

Determine best method for quantifying the

release rate of each WES

Obtain/Diagram

A process

Flowsheet

Determine data/info

needed to use the methods determined Identify Purpose

and Need for Release Assessment

Identify and List

Waste 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

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 Emissions

Stacks Emissions

Air: Secondary Emissions

Fugitive 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.

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

[ ]

_avg

Q

_{releasestreamavg releasestream}

release

=

*

*

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.

- Usually only used for Air Emissions.

- Many databases exist containing these factors.

A. Average Marginal CO₂ Emissions Factors for Electricity Generation by EPA Region (2000):

B. CO₂ Emission Factors by Fuel Type per Unit Volume, Mass, and Energy:

Equation for Rate of Emission :

Where :

m

_voc

is the mass fraction of the VOC in the stream or

process unit,

EF

_av

is the average emissions factor ascribed to the stream

or process unit (kg emitted/10

3

kg 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

M

EF

m

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.

• 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

1 1

)

(

)

)(

)(

(

)

/

/

(

kg

unti

yr

=

ED

EF

FV

−

BE

−

E

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

)

)(

)(

(

)

/

/

(

kg

unit

yr

=

ED

EF

ME

−

E

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

- 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),

D_ab is the diffusion coefficient (ft2_{/s of a through b is air),}

V_z 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 . 0 1 1

)

(

32

.

13

−

Δ

−

=

M

P

A

T

D

v

z

G

_{ab z}

- Diffusion Coefficient

Where the units are :

D_ab (cm2/s), M (g/gmole), P_t (atm), T (K). 1 33 . 0 5 . 0 1 1 9 . 1 5

)

29

(

10

09

.

4

×

− −

+

− − −

=

T

M

M

P

_t

D

• 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)

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 parameters

seem to match up with those expected for the actual process.

HIGH EFFICIENCY GENERATION

OF 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.

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.

Environmental Performance

Tools

Introduction

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.