1. Supervisor: Prof. H.S. Ghaziaskar
An Evaluation of Evaporative Emissions of Gasoline from Storage Sites and Service Stations
By: J.S. Razavizadeh
Supervisor: Prof. H.S. Ghaziaskar
Tuesday , am

2. 5-Legislation regarding evaporative emissions
Displacement emissions
1- Introduction
Breathing and withdrawal emissions
2- Evaporative emissions
Filling emissions
Emission from vehicle refueling
Emissions prevention and minimization
3- Factors affecting evaporation
Collection of vapor
absorption
4-control of emissions
Vapor recovery
Pressure swing and purge regeneration
Condensation
Diffusion technologies
Treatment of vapor
5-Legislation regarding evaporative emissions

3. The hydrocarbons emitted during petrol storage and distribution
can be broadly classified as volatile organic compounds (VOCs)
1-Pure hydrocarbons
VOCs
2-Partially oxidized hydrocarbons
3-Organics containing chlorine , sulphur and nitrogen
1-Industrial and domestic solvents(40%)
1-Industrial and domestic solvents(40%)
2-exhaust gases from motor vehicles(25%)
2-exhaust gases from motor vehicles(25%)
3-Evaporation and loses from motor vehicle(10%)
VOCs emissions originate from
4-Petrol distribution(3%)
5-Vehicle refueling(2%)
6-Oil refining (3%)
7- from other source(17%)

4. Oxygen Molecule (O2) + NOx + VOC +
                
Sunlight
Ozone Molecule (O3)

5. Typical petrol distribution

7. Typical petrol vapor composition (only VOC)
VOLUME
COMPUND
Traces
Ethane
1.5%
Propane 8%
Isobutane
10%
n-Butane
14%
Pentane
5000ppm
Benzene 6%
Hexane and others
40%
TOTAL
(voc only, remainder in air)

8. EVAPORATIVE EMISSIONS
the average emission from a typical European petrol storage and distribution system, is O.56% volume of the petrol distributed
displacement
refueling
breathing and withdrawal
filling
0.3
0.03
0.05
0.18

9. Displacement emissions Breathing and withdrawal emissions
Displacement emissions occur from fixed roof storage facilities (bulk storage tanks), as well as underground service station tanks due to vapor displacement by incoming petrol.
Displacement emissions from fixed roof storage facilities account for 0,14 %
from service station storage tanks for 0,16 %
Breathing and withdrawal emissions
Breathing emissions are caused by variations in tank contents, temperature and by changes in barometric pressures that cause expansion and contraction of the liquid and vapor in a tank.
Withdrawal emissions occur when petrol is pumped out of a storage tank resulting in the intake of air through pressure/vacuum relief valves or vents
Breathing and withdrawal emissions from bulk storage tanks account for 0,02% and from service station storage tanks for 0,01% of total emission losses.

10. Filling emissions
Filling emissions occur when petrol is transferred from storage tanks to road tankers.
two types of vapor making up filling emissions, namely preloading vapor (PLV) and evolution vapor (Ve).
PLV is residual vapor originating from a tank's previous contents, being displaced by loading of the new product, and is defined as a fraction or percentage of full saturation, Cp,.
Cp less than 1 % (Cp < 0,Ol) when the previous contents of a road tanker were a non-volatile product.
Cp between 10% and 20% (0,l < Cp < 0,2) when the previous contents of a tanker were discharged completely at one point.
Cp between 30% and 50% (0,3 < Cp < 0,5) when the previous contents were discharged at several occasions.
Cp between 90% and 100% (0,9 < Cp < 1,O) when the contents of a tanker were discharged at a service station tank that allows for vapor return.

11. Evolution vapour (ve) evaporates from the product itself when it is being loaded. Petrol can be loaded into a road tanker via top splash loading, submerged top loading or bottom loading.
In order to estimate Ve a parameter VB is used to represent the amount of splashing in a tanker during filling.
VB is equal to the fraction of the original tank atmosphere that is assumed to be completely saturated during loading.
VB = 0,4 for top splash loading.
VB = 0,15 for submerged top loading.
VB = 0,13 for bottom loading.
Concentration of petrol vapor
under equilibrium conditions
Parameter representing
the amount of splashing
filling emission
liquid to vapor
volume equivalence
factor
Average preloading
vapor concentration

12. Emissions from vehicle refueling
These emissions contribute to 0,18 volume % of the total emissions from petrol storage and distribution systems
1- product (liquid petrol) properties.
FACTORS
AFFECTING
EVAPORATION
2- Liquid/vapor interface areas.
3- turbulence in the relevant liquid and vapor.

13. Control of emission Safe operation Ease of operation
Reliable operation
Low maintenance
Low operation costs
Low investment costs
Highest possible emission reduction.
Emissions prevention and minimization
Collection of vapor
absorption
4-control of emissions
Vapor recovery
Pressure swing and purge regeneration
Condensation
Diffusion technologies
Treatment of vapor

15. Emission prevention and minimisatim
decreasing the volatility of petrol
vapor balancing
minimizing the liquid/vapour interface area
reducing turbulence.

16. Typical construction of a modern day tanker

18. Tanker at Terminal (No Vapor Recovery)

19. Tanker at Service Station (No Vapor Recovery)

20. Bottom Loading at Terminal (With Vapor Recovery)

21. Fuel Drop at Service Station (With Vapor Recovery)

22. API to Drop Hose Connection (At Service Station)

23. Vapour recovery Step 1 collection of VOCs/air mixture
Step 2 separation of VOCs from air
Step 3 the recovery of the separated VOCs into liquid state.

27. Condensation: by compression or cooling
Once the vapor has been collected, various processes or combinations of processes can be used to separate and recover the vapor. These include condensation, absorption, diffusion and adsorption.
Condensation: by compression or cooling
Condensation is most efficient for VOC recovery at relatively high VOC
concentration (above 5000 ppm)
Air
Step2 and 3
Separation and
Recovery via
condensation
Step1
collection
VOC/air
mixture
Condensed
VOCs
Flow diagram for condensation as vapor recovery process.

28. Disadvantage Advantage
Advantage and disadvantage of condensation
Disadvantage
Advantage
Energy requirements of Mechanical refrigeration are high
Moderate efficiencies, 50-90%
Nitrogen source needed for cryogenic condensation
Simple, flexible, safe process
May result in the generation of a wastewater stream
Can handle wide range of products

29. Absorption : absorbed in to liquid due to molecular force.
depends of vapor pressure and the temperature of the absorbent.
Low boiling point hydrocarbon liquid( like crude oil or kerosene) are often used for VOC separation from air via absorption.
air
Step2
Separation from
Air via absorption
(with kerosene)
Step1
collection
Absorbent
(kerosene)/
VOC mixture
VOC /air
mixture
Recycling of
Absorbent (kerosene)
Separation from
Absorbent via
distillation
Step3
Recovery via
Absorption
(with petrol)
Absorbent
(petrol)/VOC
mixture
VOC

30. Wide range of vapor flow rates and VOC concentration
Absorption can be used for high vapor flows and VOC concentration ranging between 500 ppm to 5000 ppm.
Advantage and disadvantage of absorption
Disadvantage
Advantage
Liquid absorbent may be transferred to the exit gas
Good for high humidity streams
(relative humidity < 50%)
High efficiencies, 95_98%
Wide range of vapor flow rates and VOC concentration

31. Diffusion technologies: such as membrane is relatively new
Two types of membrane namely diffusion membrane and solubility membrane.
air
Step2
Separation via
diffusion
VOC /air
mixture
Step1
collection
Step3
Recovery via
absorption
Step3
Recovery via
condensation
VOC /absorbent
mixture
Condensed
VOCs

32. Disadvantage Advantage
Advantage and disadvantage of diffusion technology
Disadvantage
Advantage
Constant vapor flow rate are Necessary, but buffer tanks are a major safety concern
Recovery of between 95 and 99%
High power consumption
Safe process and operational flexibility
Post treatment system needed in The case of very high emission standards.
Very wide range of products handling, for example ,hydrogen, Sulphide , acetone , MTBA, ethyl acetate

33. Adsorption: most effective methods and most economical.
the adsorption medium most generally used is activated carbon and hydrophobic zeolites.
two regeneration technologies are currently in use, namely: thermal regeneration and pressure swing and purge regeneration.
air
Step2
Separation via
adsorption
Step1
collection
VOC /air
mixture
Step3
Recovery via
absorption
Step3
Recovery via
condensation
Condensed
VOCs
VOC /absorbent
mixture

34. disadvantages advantages
Advantages and disadvantages of adsorption
disadvantages
advantages
Hydrogen sulphide from crude oil vapor poison the carbon.
Wide range of vapor and vapor concentration can be handled .
organic compounds like ketones, aldehydes and organic acids can causes localised hot spots or bedfires in carbon beds.
Efficient, relatively simple process
Light hydrocarbon fraction such as methane are very poorly adsorbed
Flexible and inexpensive to operate
Carbon performance decreases with high humidity vapor streams (ralative humidity <50%)

36. References:
MEMBRANES FOR VAPOR/GAS SEPARATION Richard W. Baker Membrane Technology and Research, Inc Willow Road, Suite 103, Menlo Park, CA 94025
NEW TECHNOLOGY FOR EMISSION REDUCTION AT PETROL STATIONS OHLROGGE K., WIND J. GKSS-Forschungszentrum Geesthacht GmbH, Institut für Chemie, Max-Planck-Strasse, D Geesthacht, Germany
Safety design of a petrol pump attendant robot Francesco Becchi, Rezia M. Molfino and Roberto P. Razzoli University of Genova, Genova, Italy
The Problem of Volatile Organic Compound (VOC) Emissionsfrom Petrol in Lithuania and Methodological Aspects of Emission Reduction Viktoras Doroševas, Vitalijus Volkovas, Ramūnas Gulbinas Technological Systems Diagostics Institute, Kaunas University of Technology
Membrane Based Vapor Recovery at Petrol Stations Klaus Ohlrogge and Jan Wind
A policy instrument for the reduction of greenhouse gas emissions An Interim Report to the Tyndall Centre for Climate Change Research 7th |January 2004 Dr Kevin Anderson, Tyndall North, UMIST Tel Dr Richard Starkey, Tyndall North, UMIST

37. Questions?