TRNG I HC BCH KHOA TP.HCM

KHOA K THUT HA HC

B MN CNG NGH THC PHM

-------o0o-------

BI TP MN HA HC THC PHM

CHT TR LC

Nhm SVTH: - Nguyn Huy Lc (60801164) - V Hoi ng (60800461)GVHD: C Tn N Minh NguytMC LC21.Gii thiu v cht tr lc.

21.1Cht tr lc (Thomas E.Sulpizio, 1999)

21.2Cc cht tr lc thng dng.

21.2.1Diatomite

41.2.2Than hot tnh.

61.2.3Bentonite

71.2.4Perlite

81.2.5Silic oxit v khong garnet

81.2.6Zeolite

81.2.7Tannin

91.2.8Cellulose v cc cht tr lc khc

92ng dng ca cht tr lc trong Cng ngh ha hc v thc phm.

92.1Trong qu trnh sn xut bia ngi ta c th cho thm cc ph gia vo t cc yu cu k thut v tng cht lng ca bia, nng cao bn sinh hc cho bia.

92.2Nghin cu s dng Bentonite Bnh Thun bin tnh lm xc tc cho phn ng ghp i Heck gia Iodotoluene v Styrene.

102.3nh hng ca vic thm Zeolite vo sa ln s bay hi ammoniac v cc hp cht ha hc.

1. Gii thiu v cht tr lc.

1.1 Cht tr lc (Thomas E.Sulpizio, 1999)Cht tr lc l nhng bt v c hay nguyn liu si hu c dng h tr qu trnh lc nng cao hiu qu lc. Nhng cht tr lc thng gp bao gm diatomite, perlite v cellulose, v cc cht ny c s dng trn by mi lm nm nay.Hin nay cht tr lc v lc mng ang c s dng rt rng ri trong cng nghip, bao gm cng nghip ha cht, ch bin thc phm, dc, khai thc qung m, x l nc ung v x l nc thi. World Minerals Inc., cng ty m ca Celite v Harbolite, v nhng t chc khc c nhiu thnh tu to ln trong k thut tr lc. Nhng nghin cu ny thc y vic sn xut v lm sch bng cc sn phm tr lc mi.

Mt trong nhng cht c dng nhiu nht trong k thut lc cht lng hin nay l cc loi bt mn, cht tr lc. Cht tr lc c nhng c im thch hp cho vic lc cht lng nh c th tch cht rn ln, trong cao, d tng hoc gim hm lng, gi thnh r K thut ngy nay cho ra nhiu cht tr lc mi ci tin tinh khit v kh nng lc, v cng m rng phm vi s dng ca cht tr lc.Cht tr lc thng dng kt hp vi nhiu dng c lc khc nhau lm tng s phn ly lng - rn. La chn cht tr lc ph thuc vo ty tng ng dng v dung dch cn lc. V d, trong enzyme v thuc khng sinh, phng php lc quay chn khng c dng lm cch lc chnh loi b ti a cc t bo bi.1.2 Cc cht tr lc thng dng.

1.2.1 Diatomite (V Trung, 2000, 2004)Diatomite t nhin l 1 loi trm tch d dng p v thnh dng bt mu trng hoc trng nht, c cu trc rng, xp. Khi n dng bt s vo s c cm gic try da, bt diatomite rt sng. Thnh phn ch yu ca diatomite l SiO2 86%, Na 5%, Mg 3% v Fe 2%.

Diatomite hnh thnh t ho thch ca to ct, c s dng nh cht tr lc, cht mi mn nh, thuc tr su, cht ht lm trong dung dch N cn l cht chu nhit tt nn c s dng lm cht cch nhit hu hiu.

Tt c cc dng sn phm ca diatomite u c tnh ng dng cao v hu ch. Nm 2002, 68% lng diatomite c s dng hoc bn ra M l dng cho cc qu trnh lc. Do cu trc ca diatomite c cc l xp ln v nhiu khong trng nn vt liu ny c kh nng thm ht cao. Diatomite c tnh tr ha hc. Cng vi nng sut lc cao (tc lc ln); diatomite c kh nng tch cc ht cht rn c kch thc < 0,5 mm. Diatomite rt nh v c th chu nn, trong khi vn gi c 90% cc khong trng; vi u im ny trong sn xut bia ngi ta thng dng diatomite hn l perlite.Diatomite c nhiu ng dng, c th nh:

- Dng lc: nh c c cu ht xp v c tnh tr nn diatomite c dng lm cht tr lc trong sn xut bia, ru, nc ma p, nc qu p hoc lm trong du n.

Lm cht n: diatomite c trong ln ti 90%, chit sut vo khong 1,42 - 1,48, kh tr, chu c la, c kh nng hp th ln nn rt thch hp lm cht n trong sn xut sn, gia cng cht do, cao su, giy, sn xut thuc nh rng v c rng gi.

- Lm vt liu mi bng bc, nh bng v t.

- Lm cht hp th: diatomite c th hp th mt lng cht lng ln gp ba ln khi lng ca n. N c dng lm cht mang cho cc loi thuc tr sinh vt hi, cc cht xc tc, lm cht chng ng vn hay cht hp th mi hi thi ca phn sc vt nui trong nh.

- Cc ng dng khc: lm ph gia trong sn xut xi mng poc- lng, sn xut tm lp, cc cht bc cch, sn xut silic oxyt hot tnh v. v...

Sn xut ru bia l th trng tiu th diatomite ln nht. Mc tiu th cc sn phm ny cc nc cng nghip pht trin s khng tng nhiu do s cnh tranh t cc loi ung c cn khc v mt phn l do c nhng iu lut hn ch tiu th cc sn phm c cn, trong khi cc nc ang pht trin tiu th ru bia li ph thuc vo ng lng thc t. Diatomite mt dn th phn trong lnh vc sn xut bia ru do s cnh tranh ca cc cht tr lc tng hp i t polyme gm hay mng carbon.

Mc d trong ng dng lm cht hp th, nhu cu diatomite c tng nhng n vn phi i mt vi s cnh tranh ca cc khong cht khc nh bentonite. Do c d lun cho rng diatomite gy ung th nn vic x l cc cht thi diatomite ang tr thnh mt vn cn gii quyt. Ngi ta ang nghin cu v pht trin cc cng ngh ti sinh s dng li cc bnh lc (t diatomite) thi qua s dng. Gi diatomite M r hn chu u v dao ng trong khong 370 - 420 USD/tn.

lm cht tr lc, diatomite phi qua ch bin t cc tiu chun v sch m vn gi c vi cu trc thit yu phc v cho mc ch lc. Khi qua ch bin, ngi ta thu c cc sn phm sau: khong diatomite t nhin, khong diatomite nung, khong diatomite nung chy. Khong diatomite t nhin c to ra bng cch nghin v sy qung diatomite. Khi nung khong diatomite t nhin 1.000oC s to ra khong diatomite nung. Trong qu trnh nung, cc ht diatomite c nh nng chy v gn kt li vi nhau, to ra cc ht c kch c to hn, nh vy diatomite c din tch b mt gim i, kch thc cc l xp tng ln lm tc lc tng theo. Trong qu trnh nung ni trn, nu cho thm mt cht tr dung (v d nh sa) th s to ra sn phm khong diatomite nng chy; y nhit nng chy ca diatomite gim xung lm cc ht diatomite kt t li vi mc ln hn m vn gi nguyn c cu trc ca n. Ty theo yu cu v trong ca nc lc hay tc lc m ngi ta to ra nhiu phm cp (cht lng) ring, bng cch trn cc sn phm ni trn vi nhau theo mt t l nht nh.

Hnh 1. Bt diatomite

Hnh 2. Diatomite c ngun gc hi sn1.2.2 Than hot tnh.Than hot tnh (Activated Carbon) l loi than c x l t nhiu ngun vt liu nh tro ca v lc (u phng), go da hoc than . Nhng nguyn liu ny c nung nng t t trong mi trng chn khng, sau c hot tnh ha bng cc kh c tnh xi ha nhit cc cao. Qu trnh ny to nn nhng l nh li ti c tc dng hp th v gi cc tp cht.

Than hot tnh lc nc qua hai qu trnh song song:

Lc c hc, gi li cc ht cn bng nhng l nh.

Hp th cc tp cht ha tan trong nc bng c ch hp th b mt hoc trao i ion.

Than hot tnh l mt cht liu xp, c rt nhiu l ln nh. Di knh hin vi in t, mt ht than trng ging nh mt t kin. V th, din tch tip xc b mt ca n rt rng hp th tp cht. (Ty theo nguyn liu gc, tng din tch b mt ca 1/2kg than hot tnh cn rng hn c mt sn bng )

1. Dng bt cm (Powered - PAC) y l loi c ch to theo cng ngh c, nay thng c s dng trong sn xut pin, ac-quy. C mt s nh sn xut dng loi ny trn vi keo c thnh nhng ng than nhn ging nh dng th 3 di y.

2. Dng ht (Granulated - GAC) l nhng ht than nh, r tin, thch hp cho vic kh mi. Tuy nhin, nc thng c xu hng chy xuyn qua nhng khong trng gia nhng ht than thay v phi chui qua nhng l nh.

3. Dng khi c (Extruded Solid Block SB) l loi hiu qu nht lc cn, khun Coliform, ch, c t, kh mu v kh mi clorine. Loi ny c lm t nguyn mt thi than, c p nh dng di p xut ti 800 tn nn rt chc chn

Hiu sut lc s ty thuc ch yu vo nhng yu t: 1) Tnh cht vt l ca than hot tnh, nh kt cu, kch thc, mt l, din tch tip xc; 2) Tnh cht l ha ca cc loi tp cht cn loi b; v cui cng l 3) Thi gian tip xc ca nc vi than hot tnh cng lu, vic hp th cng tt.

Than hot tnh ch c tc dng vi mt lng nc nht nh. Sau khi lc c mt khi lng nc theo ch nh ca nh sn xut (ch nhng hng uy tn mi ch nh theo tiu ch ny), than s khng cn kh nng hp th mi na.Bng 1. Nhng ha cht c th b than hot tnh hp th

Than hot tnh kt cu khi c c dng kh mi, mu, cn, ha cht v c v hu c, vi khun (ph thuc vo kch thc l lc)

Acetaldehyde

Acetic Acid

Acetone

Alcohols

Alkalinity

Amines

Amyl Acetate

Amyl Alcohol

Antifreeze

Xng

thuc ty

Butyl Alcohol

Butyl Acetate

Calcium Hypochlorite

Chloral

Chloramine

Chloroform

Chlorine

Chlorobenzne

Chlorophenol

Chlorophyll

Citric Acid

Cresol

Defoliants

Bt git/ cht ty ra

Du Diesel

Thuc nhum

Cc loi nh tng

Ethyl Acetate

Ethyl Acrylate

Ethyl Alcohol

Ethyl Amine

Ethyl Chloride

Ethyl Ether

Formaldehyde

xng du

Glycols

Herbicides

Hydrogen Bromide

Hydrogen Iodide

Hydrogen Peroxide

Hydrogen Selenide

Hydrogen Sulfide

Hypochlorous Acid

Insecticides

Iodine

Isopropyl Acetate

Isopropyl Alcohol

Ketones

Lactic

Mercaptans

Methyl Acetate

Methyl Alcohol

Methyl Bromide

Methyl Chloride

Methyl Ethyl Ketone

Du m

Nitric Acid

Nitrobenzene

Nitrotuluene

Cc loi mi

Oil, dissolved

Du ha tan

Acid Hu c

Organic Esters

Mui hu c

Oxalic Acids

Oxygen

Oxone

PCB's

Thuc tr su

Phenol

Ph gia sn xut Plastic

cht thi xi m

Potassium Permanganate

Phn st kt ta

Sulphur kt ta

Propionic Acid

Propionaldehyde

Propyl Acetate

Propyl Alcohol

Propyl Chloride

Phng x

Rubber Hose Taste

Cn th

X phng/ X Bng

Sodium Hypochlorite

cc dung mi cha st

Sulphonated Oils

Suspended Matter

Tannins

Nha ng

Tartaric Acid

V l

V l t cc cht hu c

THM's

Toluene

Toluidine

Trichlorethylene

Turpentine

Nc tiu

Gim n

Xylene

1.2.3 BentoniteTn thng phm ca khong vt monmorilonit, c c ht rt mn, c mu trng, pht xm, pht hng, pht xanh, nh m, kh nng hp ph, trao i ion ln, trng phng mnh, rt do khi trn vi nc. Bentonite c s dng lm dung dch khoan trong cng nghip du m, lm keo chng thm trong cc p nc thu in, thu li, lm nguyn liu hp ph ty ra, lm cht kt dnh trong khun c hay ph gia tng do trong gm s. VN c m Bentonite Di Linh (Lm ng).

T Bentonite ln u c s dng cho t st khi c tm thy vo khong nm 1890 trn nn phn trng gn Fort Benton, Wyoming, thnh phn chnh ca n l khong cht montmorillonite (yu t quyt nh c tnh). Do n c ci tn t trm tch ca vng Montmorillon min Nam nc Php.

Hnh 3. Mt mu bentonite1.2.4 PerlitePerlite l mt loi khong cht gc dung nham ni la trng ging nh thy tinh. Perlite c s dng rng ri c v New Zealand nh l cht dng tr lc thay th cho diatomite. Ngoi cc ng dng i vi ngnh xy dng, perlite xp cn c s dng lm cht tr lc. Ni chung, perlite c v th hn so vi diatomite nn ch c th gi li cc ht tp cht c kch thc > 1mm.

Hnh 4. Cu trc hin vi ca perlite1.2.5 Silic oxit v khong garnet L nhng vt liu lc c s dng trong cc qu trnh x l nc thi cng nghip, nc thi th hay nc b bi. Garnet l mt nhm cc khong cht c cng thc chung l A3B2 (SiO4)3; trong A = Fe2+, Mn2+, Mg hay Ca, cn B = Al3+, Fe3+, Cr3+ hay Ti3+. Do c nhiu u im nh: tr ha hc, chu n mn, c kch thc ng nht nn ct silic oxit c dng cho cc my lc trng lc, c tc lc nhanh. Garnet cng c nhiu c tnh ging nh ct silic oxit.1.2.6 Zeolite Hin ang cnh tranh vi ct silic oxit trn th trng lc M. Clinoptilolit l loi zeolite c s dng nhiu nht cho cc qu trnh lc. Clinoptilolit c kh nng gi cc ht tp cht trong cc l xp hay trn b mt th rp ca n, y l iu m ct silic oxit khng c.

Hnh 5. Tinh th Zeolite

1.2.7 Tannin

L cc hp cht polyoxyphenol, c khi lng phn t t 600-2000. Tannin c trong tr, ru vang , tri cy nh lu, du ty, hng vng, nho Tri chn c hm lng tannin t hn tri xanh.Tannin khng ch c nhng tc dng sinh hc nh chng li qu trnh lo ha m by gi cn c s dng nh l mt cht tr lc.

Hnh 6. Cu trc tannin1.2.8 Cellulose v cc cht tr lc khcBt lc cellulose c sn xut bi qu trnh sulfate v sulfite ha g cng. Cellulose thng dng kt hp vi diatomite. Ging perlite, cellulose c cu trc t xp bng diatomite. Nhiu th nghim c thc hin to cu trc cho cellulose. Cellulose c th hot ng trong mi trng pH ln hn 10.Mt s cht bt hu c bao gm tinh bt trong khoai ty, si cotton, si polymer Nhng nguyn liu ny c th gip phn tn diatomite trong qu trnh lc v mt s ng dng c bit khc. Mt loi khong tr lc t s dng c ngun gc hu c l tro t v tru. Nguyn liu ny c hm lng silic cao v phn cn li l carbon v c ch trong qu trnh x l nc thi.2 ng dng ca cht tr lc trong Cng ngh ha hc v thc phm. 2.1 Trong qu trnh sn xut bia ngi ta c th cho thm cc ph gia vo t cc yu cu k thut v tng cht lng ca bia, nng cao bn sinh hc cho bia.

Nc dng nu bia c cng carbonat cao th chua ca dich bt thp hn rt nhiu so vi chua thch hp cho h enzym thy phn. x l nc ngi ta thng dng: bt tr lc Diatomite, Natriphosphate.i vi nh my bia Heineken thng dng bt tr lc Diatomite l mt loi trm nh, xp, bt Diatomite dng lc bia cn c phn t axit yu hay trung tnh, khng gy nh hng n mi, v, mu sc, pH ca bia v khng lm cho bia c mi l.

2.2 Nghin cu s dng Bentonite Bnh Thun bin tnh lm xc tc cho phn ng ghp i Heck gia Iodotoluene v Styrene.

(Phan Thanh Sn Nam, Vng Quang Tho, 2008)

Tm tt: Xc tc bentonite Bnh Thun bin tnh c iu ch bng phng php trao i cation vi dung dch PdCl2 trong dung mi nc. Hm lng Pd c trong xc tc l 0,14 mmol Pd/g (xc nh bng phng php quang ph hp thu nguyn t), v b mt ring BET ca xc tc l 160,36 m2/g. Xc tc Pd iu ch c c hot tnh tt trong phn ng ghp i Heck gia 4-iodotoluene v styrene. Phn ng c thc hin trong dung mi dimethylformamide (DMF) nhit 120oC, vi s c mt ca Na2CO3 hm lng xc tc nh hn 1 mol % Pd. Phn ng hnh thnh hai sn phm ghp i l trans-4-methylstilben v 1-phenyl-1-tolylethylene, vi t l tng ng khong 7,5:1 (c xc nh bng phng php sc k kh v sc k kh ghp khi ph). Xc tc c tch ra khi hn hp phn ng d dng, c kh nng thu hi v ti s dng. Kt qu nghin cu cn cho thy tc phn ng tng mt cch ng k trong iu kin c s h tr ca vi sng.2.3 nh hng ca vic thm Zeolite vo sa ln s bay hi ammoniac v cc hp cht ha hc.

Zeolite c kh nng lm gim s bay hi ca ammoniac bng cch c lp nguyn t N. Thm vo 6.25% zeolite s lm gim 50% s bay hi ammoniac. Nh vy vic b sung zeolite gip gii hn lng ammoniac s gii phng N trong cy trng. Ti liu tham khoA.M.Lefcourt, J.J.Meisinger, Effect of Adding Alum or Zeolite to Dairy Slurry on Ammonia Volatilization and Chemical Composition, Journal of Dairy Science Vol. 84, No. 8, 2001.

Phan Thanh Sn Nam, Vng Quang Tho, Nghin cu s dng Bentonite Bnh Thun bin tnh lm xc tc cho phn ng ghp i Heck gia Iodotoluene v Styrene, Tp ch pht trin khoa hc v cng ngh, Tp 11, S 8, 2008.

Thomas E. Sulpizio, Advances in Filter Aid and Precoat Filtration technology, Presentation at the American Filtration and Separations Society, Boston Massachusetts, 4/1999.

V Trung, Diatomite - cc ng dng v tnh hnh th trng, Tp ch cng nghip ha cht s 9, 2000.

V Trung, S dng cc khong cht lm cht tr lc, Tp ch cng nghip ha cht s 10, 2004.

http://dictionary.bachkhoatoanthu.gov.vn/default.aspx?param=1506aWQ9Mjg5NjkmZ3JvdXBpZD0yNyZraW5kPSZrZXl3b3JkPQ==&page=1

http://en.wikipedia.org/wiki/Perlitehttp://www.thanhoattinh.com/Than-hoat-tinh/Than-hoat-tinh-va-kha-nang-hap-thu-doc-chat.htmlTh vin online ca trng i hc Melbourne, Australia.0