p. 1 

# OAR Box 

# 1147 Prepped by Ollie Stewart



## Document

Number: 

# 222 ) IV-E-9 6 Docket Number: 

# A-87-1 1

Printed 4/22/2008 2:42:59 PM

Sheet 222 of 242P. 2



### MEMORANDU

M 

# A-87-1 1

SUBJECT : Meetin g wit h Blueche r Concernin g aFilte

r Unde r Developmen

t fo r Us e i n Evaporativ e Canisters FROM : DanBarba , Mechanica l Enginee r Standard s Developmen

t an d Suppor t Branc h TO : Cheste

r J . France , Chie

f Standard s Developmen

t an d Suppor t Branc h THRU : Glen

n W . Passavant , Senio

r Project Manage r Standard s Developmen

t an d Suppor t Branc h O n Octobe r 10,199 0 aconsultan

t an d arepresentativ e fo

r Bluecher , aGerma

n filte r company , me t

wit h EP A t o discus s a

n adsorptiv e filte

r unde r development

fo r us e i n evaporativ e syste mcanisters . A s discusse d below , Blueche r claim s tha

t it s filte r ha s severa l advantage s ove

r th e activated charcoa

l currentl y used i n evaporativ e canisters . Suc h afilter , i t wa s suggested , coul d reliev e concern s b y automobil e manufacturer s regardin g canister siz e an d placemen

t fo r the propose d onboar

d refuelin g vapor

recover y systems , which wil l b e require d t o captur e nearl y thre e time s th e amoun t o f vapo r as existin g evaporativ e canisters . Th e Blueche

r filter , show

n on th e attache d page , consist s o f small , sphericall y shape d adsorber s adhere d t o aporou s polyurethane foa mmatrix . Th

e spherica l adsorbers , which ca n b e mad e fromeithe

r activate d charcoa

l or achemically activate d polymer , ar e muc h smalle r tha n the cylindrically shape d charcoa l pellet s normall

y use d i n evaporativ e syste mcanister s and , a s aresult , surfac e are aavailabl e fo r adsorptio n i s increased . Althoug h th e us e o f

smalle r particle s normally lead s t o poore r flow characteristics , the porou s foa

mstructur

e o f th e Blueche

r filte r allow s th e filte

r t o breat h easier , reducin g pressur e dro p substantially . The followin

g summarize s th

e majo r advantage s o

f filte r ove r conventiona

l charcoa l filte r media . Include d i s abrief explanatio n o

f the mechanism s whic

h giv e the filte

r it s improved characteristics .

- Decrease d volume . Increase d adsorptio n abilit y o f smalle r particle s allow s a smalle r volum e t o b e used .

- Decrease d weight . Porou s foa mmatri x an d smalle r volum e reduce s weigh t

- Lowe r pressur e drop . Porou s foa

mstructur e reduce s air

flo w resistance .

- Increase d desig n flexibility . Filte r ma y b e cut an d forme d t o an y desire d shap e withou t appreciabl y affectin g adsorptive efficienc

y o f th e filter .

- Increase d safety . Porou s structur e contain s ai

r pocket s whic

h reduc e potentia

l fo r "ho t spot " formatio

n an d th e abilit y o f aflam e t o propagat e withi n th e filter .P. 3



### Althoug h th e technolog y ha s been use d succesfull y i n severa l industria l applications , Blueche

r ha s not teste d the filte

r t o an y extent i n evaporativ e or

onboar d canisters . Therefore , we hav e aske d Blueche r t o provid e EP

A wit h sample s o

f bot h the charcoa l an d polyme r filter s fo r possibl e in-hous e evaluation .

# Blueche r Filte r

Sampl e Filte r Polyurethan e Foa m Spherica l Adsorber s (Activate d Carcoa l o r Polymer )



## P

# Blueche r Charcoa l Filte r

Sampl e Filte r Polyurethan e Foa m

Spherica l Adsorber s (Activate d Charcoal )

# r P. 6 

# BLOCHE R 

# A SYSTE M FO R TH E CONTRO L O F VEHICL E EVAPORATIN G AN D REFUELIN G EMISSION S Augus t 199 0 Numbe r 1/9 0 BACKGROUN D •M BMa »ai a M i B . MaHBB « B ...._ i The subject

o f evaporativ e volatil e organi c compoun d emission s fromgasoline fuele d vehicle s ha s recently becom e asubjec t o f majo r publi c and politica

l interes t in the US an

d i n Europe . Carbon canister s containin g activated charcoa l t o adsor b evaporativ e emis sion s hav e bee

n used fo r man y year s i n th e USA , Japa

n and Australi aan

d mor e recentl y als o in Europe . Th e functio

n o f thes e canister s ha s onl

y bee n to adsor b th e emission s tha

t occu r whe n th e ca r i s drive n o r whe n the tan k breathe s a s aresul t

o f temperatur

e variations . Th e emission s tha t aris e durin g vehicl e refueling , du e t

o the displace men t o f vapo r fro mth e fue l tan k b y incomin g liqui d fuel , though , ha s no t yet bee n asubject o f unifor mcorrectiv e measures . TW O SYSTE M APPROACHE S AR E CONSIDERED : •••••••••••>—•• — 1 . Sinc e 197

4 som e countie s i

n Cali forni ahav e introduce d the ..Servic e Station Vapo

r Recover y System" . Thi s operate s b y using aseparat e pip e to sen d displace d vapo

r fro mth e vehicl e fue

l tan k back t o the under

groun d tank . Thi s approach require s not onl y th e reequipmen

t o f al l servic e station pump s bu t

als o all vehicle s t

o b e equipped wit

h astandardize d fue

l fillin g orifice . 2 . Equipping th

e vehicle s wit

h a n en larged version o

f the carbo n caniste r describe d above . Wit

h thi s syste

m vapo r emission s tha t

aris e whe

n refuelin g ar e adsorbed b

y the canister . Subsequently , the caniste

r i s desorbe d b y drawing ai

r throug h i t an d int o th e engine . Thi s syste

mi s referre

d t o a s th e „On-Boar

d Refuelin g Contro l System" . COMPARISO N BETWEE N TH E TW O SYSTE M APPROACHES : •«•..• . Th e Servic e Station Vapo

r Recover y Syste mha s the disadvantag e o

f being mor e expensive an

d les s efficien

t tha n th e On-Boar

d Refuelin g Contro l System,se e compariso n below :

... . Efficienc y o f emissio n captur e Cos t pe rretaine d 1,00 0 k g o f gasolin e Servic e Statio n Vapo rRecover

y 5 5 % 13,29 0 DM/ t On-Boar d Refuelin g Contro l 9 8 % 77 0 DM/ t Source : MW

V (The Genm n fctrolcum faduitry Asocialion ) Th e on-boar d syste mapproach primaril

y ha s bee n criticize d for . 1 . Bein g to o ..bulky " - aminimu

msiz e o f 5 1 caniste r fo r a50 1 tan k i s required . 2 . Th e physica l for mo f th e syste mwhic h make s i t difficul t t o adapt an d integrat e int o th e automobile . 3 . A n increased securit

y risk a s aconsequenc e o

f th e inte-gratio n o

f th e enlarged canister s an

d pipe s i n the vehicle . 4 . Th e reduce d immediat

e emissio n retentio n du

e t o the fac t tha t th e syste mca n onl y b e implemented i

n ne w cars .P. 7



## TH E BLUECHE R APPROAC H 

# a fu r ai mha s bee n t o develo p a n activate d charcoa

l filter fo r the On-Boar d Refuelin g Contro l Syste

m that

### c h A : 4>B : 4>C s Require s les s volum e Ha s a n improved , mor e flexible , for m desig n Provide s a safe rsyste m TH E FOLLOWIN G CRITERI A AR E DECISIV E FO R TH E EFFCIENC Y O F TH E ADSORPTIV E MEDIU M I N THI S APPUCATION : 

## 1 . TH E ADSORPTIO N KINETIC S O F TH E CHOSE N ADSORBER

S BB ^ B M i Basicall y thi s i s adynami c proces s wher e smalle r adsorber s shoul

d be use d i n orde r t o increas e th

e oute r surfac e are aan d t o shorte n th e distanc e be twee n the initia l an d fina l adsorption . Sinc e thi s normall

y lead s t o poore r flo w characteristic s large

r particle s have traditionally bee

n chosen . Blueche r designe d it s filte

r wit h smal l spherica l adsorber s ( 0 0.4-0. 7 mm ) adhere d o n afoa mmatrix , thereb

y optimizing adsorptio n and flo w characteristics . Th e efficienc

y o f th e sys te mals o depend s o n the pore structur e o f th e adsorbe r

whic h ha s bee n optimized fo

r thi s applicatio n durin

g manufacture . 2 . TH E ADSORPTIO N CAPACIT Y •MMBHMMH M Th e utilizatio n capacit

y (th e workin

g capacit y including th

e remaining capacit y fo r th e nex t filling ) an

d th e maximu mquantit y o f gasolin e vapo

r t o b e adsorbe d determin e the tota l ad sorbe r capacit y needed . Preliminar

y tes t results hav e show

n tha t fo r ever y 20 1 tan k conten t approximatel

y 1 1 o f ou r filte r mediu mi s needed . 3 . TH E DESORBABIUT Y O F TH E VAPOR S aaa^-aaa—! — Th e gasolin e vapor s ar

e chemicall

y not homogenou s sinc e the

y consis t o f chemical s wit

h differen t molecula r weights and boilin g points . I n orde r t o adsor b substance s wit

h lo w molecula

r weight s lik

e butane , smalle r sized micropore s ar

e needed . These , however , ar

c easil y choke d b y large r molecule s (e.g . octanes ) whic h wil l not easil y desor b an d therefor e reduc e th e efficienc y o f th e filter . Blueche r use s atechniqu e (paten

t pending ) wher

e differen t layer s are use d fo r th e adsorption o

f th e differen t substances . Sinc e the desorptio n flo w i s i n th e reversed directio n o

f th e ad sorptio n flo w th e ris k o f cross-con taminatio n i s eliminated . 4 . OTHE R ADVANTAGE S M ^ Th e Blueche r produc t ca n b e cu t an d forme d int o virtuall y an y shap e t o fi t th e specifi c requirements o f

th e ca r designer . W

e ar e not restricte d to a typica l caniste r for mwhic h i n man y case s i s difficul

t t o locat e o r install . Consequently , alocation fo

r th e filte r ca n b e chose n wit h ahighe r degre e o f safet y an d lowe r cost s fo r th e ca r manufacturer . Th e primar y safet y concer n wit h th e traditiona

l caniste r ha s bee n it s assume d propensit

y t o catc h fire . TH E FOLLOWIN G ADVANTAGE S VS . CONVENTIONA L ACTI VATE D CARBO N CANISTER S CA N B E IDENTIFIED : • A reductio n i n volume . Preliminar y test s hav e show n tha t approximatel y 1 I filtermediu m i s require d fo rever y 2 0 I tan k content . • A reductio n i n weight . • A n infinit e flexibilit y i n desig n an d adap t abilit y o f th e filter whic h wil l enhanc e th e security . • A n improve d safet y o f th e syste m du e t o a reduce d propensit y fo rth e filte rt o becom e overheated . • A substantiall y lowe rpressur e drop . ,

. Th e absenc e o f carbo n dus t whic h ca n aris e whe n traditiona l canister s ar e expose d t o vibrations . The Blueche

r filte r reduce s th e risk

o f the creatio n o

f „ho t spots" , unde

r al l circumstances , b

y the predetermined an d fixe d distance s betwee n th e adsorbers . The hig

h ai r permeabilit

y o f the filter mediu mals o reduce s the ris k o f overheating . Anothe r advantag e ofth e B lueche

r filter i s it s goo d airflow characteristic . The measured pressur

e dro p i s u p t o te n time s les s tha

n fo r conventiona

l caniste r filters. Furthermore , th

e ap plicatio n o

f adsorber s o

n amatri x guarante e ahomogenou s utilizatio n o f the filte r volume . Finally , th e Blueche r filte r i s aver y clea n filter. The absenc e o

f carbo n dust , eve n afte r exposur e t o vibration , should b e d

f considerabl e interes

t t o bot h the filter

an d ca r manufacturers .