Nitrogen oxides abatement

Feature

p r o b l e m is solved, t h e n liquid membranes would present a v a l u a b l e a l t e r n a t i v e t e c h n o l o g y for u s e in i n d u s t r i a l s e p a r a t i o n s . However, s h o u l d p r o g r e s s in developing liquid m e m b r a n e s c o n t i n u e to be h a m p e r e d by stability p r o b l e m s , t h e n r e s e a r c h e r s s h o u l d n o t be too afraid to leave the original idea of

Patents This is a list of r e c e n t l y p u b l i s h e d p a t e n t s covering d e s i g n s a n d i n v e n t i o n s of r e l e v a n c e to s y n t h e t i c m e m b r a n e technology. W h e r e the s a m e device h a s b e e n p a t e n t e d in several c o u n t r i e s , we n o r m a l l y give the B r i t i s h p a t e n t n u m b e r . If t h e r e is n o UK p a t e n t , we give the n u m b e r of a n E n g l i s h l a n g u a g e p a t e n t , if oneexists. The p a t e n t s list is compiled from i n t e r n a t i o n a l s o u r c e s by BHR G r o u p ' s i n l o r m a t i o n service. The facility c a n also be u s e d to carry out retrospective patent s e a r c h e s - - to test the validity, novelty or i n f r i n g e m e n t of existing p a t e n t s or n e w ideas. BHR G r o u p , Cranfield, Bedford MK43OAJ, UK, will provide free e s t i m a t e s o n request. C o u n t r i e s c a n be identified b y the code i n front of the n u m b e r a s follows: AT Austria AU Australia BE Belgium BR Brazil CH Switzerland DD East Germany DE West Germany DK Denmark EP European Patents ES Spain FI Finland FR France GB Britain HU Hungary IL Israel IR Eire IT Italy JP Japan KP North Korea LI Liechtenstein LU Luxembourg NL Netherlands NO Norway RO Romania RU Russia US United States SE Sweden WO World Patent SU Soviet Union (Patent Treaty Cooperation publication) BHR G r o u p does n o t o p e r a t e a d o c u m e n t delivery service for p a t e n t s , b u t full copies of the original p a t e n t d o c u m e n t s c a n be o b t a i n e d from t h e following addresses: The British Library P a t e n t Express 25 S o u t h a m p t o n B u i l d i n g s L o n d o n WC2A lAW, UK

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liquid m e m b r a n e s a n d e m b r a c e other n e w concepts.

Acknowledgement A n t o i n e K e m p e r m a n of the U n i v e r s i t y of T w e n t e is k i n d l y a c k n o w l e d g e d for u s e f u l d i s c u s s i o n s , a n d the u s e of s o m e of his figures.

Fax: 0171 323 7230 {The British Library will also s u p p l y a list of UK libraries i n c l u d e d in the P a t e n t I n f o r m a t i o n Network.) US P a t e n t Office Scientific Library 15th a n d E a s t Streets, NW W a s h i n g t o n , DC 20231, USA The J a p a n e s e P a t e n t Office 4-3 Kaksumigaseki 3-chome C h i y o d a - k u , Tokyo 100, J a p a n

Computer disk drive aid C l e a n l i n e s s a n d a generally n o n - d a m a g i n g e n v i r o n m e n t are e s s e n t i a l to the m a n u f a c t u r e a n d l o n g - t e r m reliable o p e r a t i o n of b u l k - s t o r a g e m a g n e t i c devices s u c h as fixed-disk or h a r d disk drives, a n d also some of the highcapacity removable storage devices. M a i n t a i n i n g the e n v i r o n m e n t i n s i d e the c a s i n g once the disk drive h a s b e e n m a n u f a c t u r e d is d o n e in several ways; filters cover v e n t i l a t i o n holes to exclude particulates, and some enclosures c o n t a i n cartridges to a b s o r b / adsorb gaseous or vapour impurities. They m a y be t u b e s of e x p a n d e d p o l y c a r b o n a t e or polyacrylonitrile or p o r o u s p o l y t e t r a f l u o r o e t h y l e n e , filled with a h i g h - s u r f a c e - a r e a or reactive material. T h e s e are relatively b u l k y i n the r e s t r i c t e d c o n f i n e s of a disk drive interior, a n d often m u s t be p u t into a c o r n e r a w a y from the s u r f a c e s they are m e a n t to protect. T h e s e c a n be m o u n t e d o u t s i d e the e n c l o s u r e , c o m m u n i c a t i n g with

For further information contact: Dr Tony Franken, Membrane Application Centre Twente, Postbus 545, 7500 AM, Enschede, The Netherlands. Tel: +31 53 483 63 30; Fax: +31 53 433 74 15.

the interior by m e a n s of a b r e a t h e r hole, b u t t h e s e c a n easily be d a m a g e d to allow u n t r e a t e d air to enter, a n d also c o m p r o m i s e the e l e c t r o m a g n e t i c s h i e l d i n g of the disk media. A n o t h e r a d a p t a t i o n is to c o n s t r u c t a t h i n m u l t i l a y e r s a n d w i c h c o n t a i n i n g the a d s o r b e n t , fixed to the i n t e r i o r of the disk drive c a s i n g with adhesive. This suffers from h i g h r e s i s t a n c e to gas flow a c r o s s t h e c o n s t r u c t i o n . The p r e s e n t i n v e n t i o n c o n s i s t s of t h r e e layers; a n a d h e s i v e material, a fiat a b s o r b e n t layer, a n d a fiat t h i n layer of e x p a n d e d PTFE m e m b r a n e . The a d h e s i v e layer c a n o p t i o n a l l y c o n t a i n a m e t a l l i s e d e l e m e n t s u c h as a l u m i n i s e d polyester w h i c h gives e l e c t r o m a g n e t i c protection. In e x a m p l e s the a b s o r b e n t m a t e r i a l w a s activated c a r b o n .

Patent number: US 5 5 9 3 4 8 2 Date: 14th N o v e m b e r 1996 Inventors: E.G. D a u b e r , C.E. Bailey, R.L. S a s s a

Applicant: W.L. Gore a n d Associates, Inc.

Nitrogen oxides abatement C o m b u s t i o n gases c o n t a i n n i t r o g e n oxides as p a r t of t h e p r o d u c t s of c o m b u s t i o n . T h e y c a n b e purified b y a d d i n g extra oxygen to the g a s e s so t h a t the n i t r o g e n oxides are d e c o m p o s e d ; t h i s h a s b e e n p r o p o s e d as a t e c h n i c a l s o l u t i o n to r e d u c i n g n i t r o g e n oxides e m i s s i o n s from m o t o r vehicles. Bosch h a s s o m e existing p a t e n t i n g activity in this area, a n d this p a t e n t refines the b a s i c idea b y p u t t i n g

M e m b r a n e T e c h n o l o g y No. 8 5

Patents

l { n s v a r d ill{: i(h:a {}I {';lrI-yin~ {)tit the {)xy~{'n SCl,ar;tlit}n JI-{}Ill a i r ill Iw{} sla~cs. Tltt:, iwo d e v i c e s [o~{cther cal3 b,:" l n a d e ln()re {'oinpac{ a n d {'lli{'ient t h a n c a n ;l s i m l l e - s i a t ~ e :~as s c p a r a t i o i a t l l l i i . parih'ularly inll)()rtal]l in lhe {'h{}sen at)pli{';~ti{}l~ ;~r(-a o f vehi{'le 1e{'hil{}h}~y. Tim c{as llli>;{IAlC {qllel~iIlg ll-OIll the lirsl t l i l i l ll;tr-; ~i (t{)ulJlcd t ) a r l i a l p r e s s u r e ()1 (}XS~ell. t}{}lyl~lelic ()lz e o l i l e illelnbr~lllCS wilh Kreai{qp e r n i e a l ) i l i l y l{, {}xv~{'n t h a n l l i l r o K e l i { ' a l l t0{' t l s e d ill t i l e lvv'(} s e p a l a l i o n sla~ es. al id I he sec{}nd sia~e separation unil operali{}n b e l i e l i t s w h e n l h e { i n i l is h e a t e d . The otitpnt from lhe second stake iS ttllllt}S| I)ure }x)Ken. a n d evell lhe b y p a s s Kas Ml-('s,lllt h a s a hi,~her {}xyt~{'ll {'{}lllenl lll~iH /llqlle;-/led air

f)atcrll m u n b c r W() 9 6 3 2 1 8 1 Dale: 17ih (){'1{ b{q 1!-}9{; hmcnfors: W. Gi-tu>,vald. K. DielericlL ,%. l:r.uake Ai)pli(arlt: R(}I}{"I I~{}st'h Gmt}tl

Dialysis cleaning system T l w (.{)n|illtlOtlS SlllOtJlh o p c r a l i o n ()1 a blood dialy,
Poleril mmlber: ! S .5589070 Date: 31sl [)e{'enll}cr 15}96

M e r n b r a l l c Tecl nolog~j No. b~5

hn.,enlors: J. A. B. Maltais, A.T. Wood, R.S. H o v l a n d Applicant: COBE Laboratories. in('.

Polymer fractionation New s e p a r a t i o n i n e t h o d s t e r i n e d Elflmnced Partitioning Fraclionation a n d HiKh O s m o t i c P r e s s u r e C h r o m a t o g r a p h y {EPF a n d HOPC} are c l a i m e d in this p a t e n t . HOPC involves p a s s i n g large a m o u n t s of c o n c e n l ral ed p o l y m e r s o l u t i o n s over p a c k e d c o l u m n s c o n t a i n i n ~ m a t e r i a l of specified m o l e c u l a r size d i n m n s i o n s . T h e c()ncentratioll is hiKh u n o u g h to allow lot p o l y m er (:ham overlap a n d to g e n e r a t e hiKh osmotic pressure, which causes increased separation of the polymer s a m p l e b a s e d on m o l e c u l a r size. T h e h i ~ h e r m o l e c u l a r weight c o l n p o l l e u l s ar e c o n c e n t r a t e d ill lh e initial f r a c t i o n s of e l u e n l . Th e m a t e r i a l e m p o l y e d in the p a c k e d c o l u m n c a n be a n l i c r o p o r o t l s p o l y s t y r e n e m a t e r i a l if il can w i l h s t a n d l h e p r e s s u r e s u d e d to i n a k e i nat er i al flow t h r o u g h the c o h l m n . The HOPC p r o c e s s finds pmlicular application m fi'actionating the purilied p o l y c a r b o n a t e s u s e d in c o m p a c t disc p r o d u c l i o n . EPF is not a c h r o m a t o K r a p h i c p r o c e s s bul e m p l o y s solne of l h e s a m e r{nltines, t h o u g h e m p l o y i n ~ a d s o r p l i o n at s u r f a c e s .

Patent munber: US 5 5 8 7 0 7 0 Date: 241h D e c e m b e r 1996 Inventors and Applicants: 1. Teroaka, M. Lu()

Membrane production method A t h e r m o p l a s t i c r e s i n 10am is s u b j e c t e d to p l a s t i c d e f o r m a t i o n to b r e a k the b o u n d a r i e s of s o m e of the cells, w h e r e the ratio of t h e wall t h i c k n e s s to t h e cell s i z e is l e s s t h a n 0 . 5 a n d the void ratio of the initial m a t e r i a l is g r e a t e r t h a n 50%. The r e s u l t i n K m e m b r a n e h a s

w i d e a p p l i c a t i o n , in b a t t e r i e s a n d c a p a c i t o r separat()r m e m b r a n e s , filters, m o i s t u r e p e r m e a b l e w a t e r p r o o f clothe,-;, liquid c r ys t a l lilms a n d m liqui{1 a n d gas s e p a r a t i o n . Th e r { s m m a t e r i a l is s e l e c t e d from p o l y e t h y l e n e or p o l y p r o p y l e n e , bul o l h e r m a t e r i a l s ar e m e n t i o n e d in Ibc p a t e n t , Th e cell wall d e l o r m a t i o n is a c c o m p l i s h e d bv s t r e l c h i n g or calenderinK, loll,~wed I)v orientation.

Patent number: EP 7 5 4 4 8 8 D a t e : 2 2 n d J a n u a l T 1997 I n v e n t o r s : K. Konc, K. T a k i t a A p p l i c a n l : T o n e n { :heroical Corporalio~L

Membrane cleaning by air bubbles This E u r o p e a n l)atent ttrauted It} Mitsui covers the c l e a n i n g of m e m b r a n e s m advei~,c e n v i r o n m e n t s s u c h as s e w a g e lreatmeni plants Th e p r e v e n t i o n {)I tim g r o w t h of gel layers on the m e m b r a n e s in s u c h e n v i r o n m e n t s is a p r i m a r y objective. Th e r e < u l a r d i s m a n t l i n ~ a n d p h y s i c a l cleaninR w h i c h o p e r a t i o n s in su,:'h s i l u a t i o n s e n g e n d e r is cosily }ilia tim,> consuming. A d i f f u s e r at the b o l t o m ol a l a n k c o n l a i n i n < a n alTay ot s h e e t type m e m b r a n e s is ted with c o m p r e s s e d air so thai llne bubbles ar e f o r m ed . T h e s e rise a n d c a r r y the liquid flow p a s t tim m e m b r a n e s u r f a c e st} t h a t t q r b u l e n t flow a i d s t h e c l e a n i n g ol t h e s u r f a c e . Th e flow of liquid[ lifted by the b u b b l e s is suflicienl 50 t h a t o t h e r i n e a n s of circulatiorL for e x a m p l e a liquid p u m p . ar e ::lol n e c e s s a r y . f u r t h e r improvim.~ tim a p p e a l of the s y s t e m .

Patent number: EP ,;3,1758 Date: 2rid O c t o b e r 19{,)6 Inventors: S. Wataya, K, Y a m a m o t o , H. Shira~c. K. lrie. T. H a s h i m o t o Applicant: Mitsui P e l r o c h e m i c a l I n d u s t r i e s Ltd

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