Harcros Narrow Range Ethoxylation Technology

Harcros Narrow Range Ethoxylation Technology

Presented by

Dr. Peter Radford

President, Organics Division

Harcros Chemicals Inc

Patent Approved August 2006, “Method of Preparing Alkoxylation Catalysts and their use in Alkoxylation

Reactions” (US 7,119,236)

Narrow Range Ethoxylation

For Alcohol Substrates, this results in• a broad ethoxymer distribution• higher free, un-reacted alcohol• increased PEG’s• lower overall concentration of surfactant range

ethoxymers

Typical ethoxylation processes rely upon KOH, NaOH, or Methylate Catalysts.

Narrow Range Ethoxylation

Narrow Range Alcohol Ethoxylates (NRE’s) have• a compressed ethoxymer curve similar to the distribution

of alkylphenol ethoxylates

• lower free alcohol = lower VOC’s

• increased concentration of surfactant range adducts

• lower PEG levels

• In some cases, an improved aquatic toxicity profile

Narrow range processes utilize unique catalyst systems to produce a tighter ethoxymer distribution.

Ethoxymer Distribution Comparison

0 2 4 6 8 10 12 14 16

Moles EO

Mo

le %

NP-8

NRE6 mole

BRE6 mole

Unreacted Alcohol

Surfactant Range

Ethoxylates

Free Alcohol Comparisons

0

5

10

15

20

25

30

35

C1216

-2.5

C1216

-6

C1216

-9.5

TDA-2.5

TDA-6

TDA-9.5

% F

ree

Alc

oh

ol

BRE

NRE

None Detected for NRE

Linear Alc. Ethoxylate Branched Alc. Ethoxylate

Branched substrates contain higher levels of un-reacted alcohol due to the steric bulk of the hydrophobe.

BRE

NRE

Wetting Time Comparison

0

5

10

15

20

25

30

35

40

45

C1216-6 C1216-9.5 Isodecyl-6

Wet

tin

g T

ime

(sec

)

BR

E

NP-9.5, 8 sec.

NR

E

5.8 mole NRE

8.6 mole NRE

5.8 mole NRE

Wetting Time Comparison (Skein Test) 25 C

42ºC 37ºC 37ºC

87ºC 86ºC

72ºC

43ºC 36ºC 36ºC

NRE’s display a higher cloud point versus the BRE of the same EO level. When comparing certain properties, it is necessary to match cloud points, not moles of EO.

NRE’s show better wetting times if cloud point is matched.

Ethoxylate NRE BREC1216-6 42 37C1216-5.8 37C1216-9.5 87 86C1216-8.6 72Isodecyl-6 43 36Isodecyl-5.8 36NP-9.5 58

Cloud Point ( C )

Foam Height Comparison

0

2

4

6

8

10

12

14

C1216

-6

C1216

-9.5

C1216

-8.6

C1216

-6

C1216

-9.5

Fo

am H

eig

ht

(cm

)

NRE BRE

1min

5 min

1min

5 min

Less stable foam for NRE’s

Less high mole adducts and lower free alcohol lead to decreased foam stability for NRE’s.

Interfacial Surface TensionInterfacial Surface Tension

00.5

11.5

22.5

3

C1216

-6

C1216

-9.5

TDA-9.5

C1012

-6

C1012

-9.5

(d

ynes

/cm

)

NRE BRE

NP-9.5

8.6 Mole NRE

NRE’s display higher surface tensions than BRE’s due to increased hydrophilicity. If the EO level is adjusted to match surface tension of the BRE (8.6 mole NRE), a much lower IFT is achieved. Even with higher surface tensions, NRE’s show better wetting times than BRE’s.

NRE/BRECMC

(ppm)Sur. Ten

(dynes/cm)Wet. (sec)

C1216-9.5 32.5/35 35/33.5 41/40C1216-8.6 32.5 33.5 23

Narrow Range Technology

Acid Catalyst Systems • Limited to low-mole adducts

• Produce high levels of 1,4 dioxane which must be scrubbed

Metal Cyanide• Used predominately for polyol production

Calcium Based Systems• Milder catalyst yields neutral pH ethoxylate, no neutralization step required

• Higher catalytic activity, lower levels required (100 ppm Ca+ vs 350 ppm K+)

• Catalyst residue is water soluble

• Ethoxylation of alternative substrates possible – Soybean Oil, Methyl Esters, etc.

• Commercial products – Harcros NR series,

General Summary of NRE Benefits

• Tailored wetting performance

• Lower CMC’s and IFT’s

• Less un-reacted alcohol = lower VOC’s and Ether Sulfates with lower irritation indices (less alcohol sulfate)

• Greater concentration of surfactant range ethoxymers

• Decreased foam stability

• Reduced PEG’s

Formulators seeking to replace Alkyl Phenol Ethoxylates can turn to Narrow Range Ethoxylates as performance alternatives.

Narrow Range Ethoxylation technology utilizes a milder, higher active catalyst to produce robust ethoxylates of alcohol, ester, and other hydrophobes yielding

Products used in Energy Recovery- NRE Benefits

• Fatty alcohol ethoxylates – Lower interfacial surface tensions for lower

mole adducts• Mutual Solvents (short chain ethoxylates)

– Perform considerably more efficiently at higher temperature, in the presence of electrolytes.

Products Used in Energy Recovery- NRE Benefits (Continued)

• Foamer Products (short chain ether sulfates)– Retain form density better than their NRE

counterparts– Perform very well in higher brine systems.

• Soap Sticks (highly ethoxylated NPE’s): – High mole NPE’s are considerably more

crystalline, and have higher melt points when prepared with the NRE catalyst.

Mutual Solvents – Improved efficiency under real world conditions

BRE in Brine 50C

98.8

38.330

39.1 40

49.2

0

10

20

30

40

50

60

70

80

90

100

110

2.8 3.1 3.5 4.5 5.5 6

EO Level

mL

Etho

xyla

te

BRE Brine, 50C

NRE in Brine 50C

78.2

60

30.9

19 21.625

0

10

20

30

40

50

60

70

80

90

2.57 2.95 3.5 4.5 5.5 6

EO Levelm

L Et

hoxy

late

NRE Brine, 50C

Graphs show milliliters of ethoxylate required to reach one single phase at the indicated temperature –note the improvement with the NRE version

Foamers - Foam Heights for Linear Ether Sulfates (NRE vs. BRE)

470

480

490

500

510

520

530

540

550

560

NRE Linear Ether Sulfate BRE Linear Ether Sulfate

DeionizedWater(mL)

10%NACEbrine (mL)

•NRE Based Foamers have Improved Brine Foam Height

Height, mm

Foamers- Foam Stability and Branched Ether Sulfates

(NRE vs. BRE )

0:00

0:28

0:57

1:26

1:55

2:24

2:52

3:21

3:50

4:19

NRE BranchedEther Sulfate

BRE BranchedEther Sulfate

Deionized Water

5% CaCl2

10% CaCl2

Hal

f L

ife

(min

utes

)

Foamers – Foam Density on Standing

(NRE vs. BRE)

0

0.05

0.1

0.15

0.2

Foam Density (g/cc)

Broad Range Narow Range

Ethoxylate Type

Foam 'Wetness" for NRE and BRE ether sulfates

30 secs

240 secs

High mole adducts- higher melt points,

greater crystallinity. Alcohol Ethoxylate NRE BRE

A1012GB-30EO 44 - 45 43 - 44

A1216CO-30EO 41 - 42 41- 42

Isodecyl-30EO 42 - 44 40 - 44

Tridecyl-30EO 42 - 43 40 - 43

Nonyl Phenol-30EO 45 - 46 42 - 44