aiche 2011 ethanol water

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Ethanol/Water Biomass Feedstock Separation Through Inorganic A-Type Zeolite Membrane on Thin Porous Ni Sheet Support 1 Yuxiang(Tony) Rao , Rong Xing, Wei Liu* Pacific Northwest National Laboratory Richland, WA, USA Presentation at AIChE 2011 Meeting Minneapolis, MN,USA Oct 18th, 2011

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Page 1: Aiche 2011 Ethanol Water

Ethanol/Water Biomass Feedstock Separation Through Inorganic A-Type Zeolite Membrane on Thin Porous Ni

Sheet Support

1

Yuxiang(Tony) Rao, Rong Xing, Wei Liu*

Pacific Northwest National Laboratory

Richland, WA, USA

Presentation at AIChE 2011 Meeting

Minneapolis, MN,USAOct 18th, 2011

Page 2: Aiche 2011 Ethanol Water

Outline

Motivation

New Membrane Product Concept Robust, Large Surface Area Packing Density, Low Cost

Membrane Preparation and Characterization Porous Ni sheet support A-type Zeolite Membrane Layer

Application (Ethanol/water Separation Testing) Model feed (90% ethanol, 10% de-ion water) Real feedstock (1:1 mixture of PEI #4 and PEI #5, Pacific Ethanol Inc’s

plant)

Concluding Remarks

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Page 3: Aiche 2011 Ethanol Water

Motivation

Ethanol production worldwide(Global Renewable Fuels Alliance, GRFA)

Energy consumption for a 40M gal/year dry corn mill ethanol plant:

2/3 of the overall energy (excluding co-products) is consumed in concentration and purification of ethanol from fermentation broth.

Energy consumption is even greater when ethanol level becomes lower from cellulosic biomass.

(Unit in Btu/gal) Steam Natural gas Electricity Total %

Grain Handling 0 0 352 352 2%Starch Conversion 5,544 0 133 5,677 29%

Fermentation 0 0 231 231 1%Ethanol/water separation 13,141 0 33 13,174 68%

Co-Product Drier 0 13,914 1,859 15,773  

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Page 4: Aiche 2011 Ethanol Water

Background and Objective

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Develop thin porous metal sheet-supported zeolite membrane for selective removal of water molecule from process streams with combination of desirable performance attributes High flux and selectivity Good chemical and thermal stability Mechanical strength and flexibility High surface area packing density Low cost

A type Zeolite:

3A-(KA), 4A- (NaA), and 5A-(CaA) type zeolite

materials have been widely used in industrial

drying processes as an adsorbent. Their

selective water adsorption and material stability

has been well demonstrated.

A very attractive class of materials used to

make membranes 4A-type zeolite

Kinetic Diameter

Ethanol: 4.46ÅWater: 2.65Å

Page 5: Aiche 2011 Ethanol Water

Fabrication of porous Ni sheet support

Precursor material•Metallic powder precursor (NiO powder)•Organic pore former•Binder

Green body

Porous support sheet•Pore size, 1-10µm•Porosity,30-60%•Thickness, 25-200µm•Thermal stability up to 600ºC•Chemical stability, pH=2-13•Rupture pressure, >50bar

Tape casting Thermal treatment

•O2/N2

•H2

Thin

Flexible and robust

Uniform structure suitable for membrane deposition5

Page 6: Aiche 2011 Ethanol Water

Seed Coating Secondary membrane growth on porous Ni sheet support

Seed coatingSubstrate Seed coated Ni sheet

03.um/1.4um 4A seeding crystals

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Page 7: Aiche 2011 Ethanol Water

Hydrothermal membrane growth

Hydrothermal growthA-type MembraneSeeded coated Ni sheet

100C, 3.5hrs, 1C/min

Membrane-# Feb-07-2011-No.2-#3

Si:Al:Na:H2O 2:2:2:150

NaA seeding particle 0.3 µm/1.4 µm 4A seeds

Slip coating step First coating w/1.4 µm seed, followed w/ 0.3 µm seed

Membrane growth 100 C, 3.5 hr, 1C/min in 1 L Parr reactor7

Page 8: Aiche 2011 Ethanol Water

CharacterizationXRD

All membranes are NaA zeolite membranes8

Page 9: Aiche 2011 Ethanol Water

Application (model feed)Ethanol/Water Separation (90wt% ethanol+10wt% water)

Separation temperature100ºC

Feed: wt.% of water 10%

Feed: flow rate3sccm

Permeate: sampling

Liquid N2 cold trap

Permeate: vacuum<10 tor

Feed: PH6.6

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Scheme 1 Ethanol/water separation testing unit setup for model feed

Page 10: Aiche 2011 Ethanol Water

Ethanol/Water Separation Results(model feed)

Membranes H2O/EtOH separation factor Permeation flux, kg/(m2.h)

NaA-type membrane

>10,000 7.927

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90wt% ethanol+10wt% water

Page 11: Aiche 2011 Ethanol Water

Application (real feed)Ethanol/Water Separation (EtOH/H2O content=58/42,wt%)

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Element Atomic%C 2.83O 48.57Na 25.51Al 2.79Si 2.87S 13.91Ni 3.01Total 100

NaA membrane lost selectivity due to the corrosion of sulfuric acid, which was deposited on the surface of membrane during separation process (100ºC, pH=4.5)

Feed ID# wt % ethanol pH Note

PEI#4 23.0 3.6 Sampled from bottom of the stripper column

PEI#5 93.6 5.3 Sampled from overhead of the distillation column

PEI #4 & #5 58.3 4.5 1:1 mixture of PEI#4 and #5 to simulate overhead stream of the beer column

Table 1 Feedstock obtained from Ethanol Plant for membrane separation tests

Page 12: Aiche 2011 Ethanol Water

Application (real feed)Ethanol/Water Separation (Titration Experiment)

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Figure 1 Color change of 1:1 mixture of PEI#4 and #5 mixture after addition of base

NaOH NH4OH

Table 2. ICP result for PEI#4 and PEI#5 feed samples

Sample ID# K(ppm) Na(ppm) Ca(ppm) S(ppm)

PEI #4 2.52 5.89 0.89 10.53

PEI #5 0.26 3.05 0.73 5.51

Baker Soda (NaHCO3) Urea

Sulfur and calcium element detected by ICP from real biomass feedstock most likely come from the fermentation and upstream chemical process.

Page 13: Aiche 2011 Ethanol Water

Application (real feed)Ethanol/Water Separation

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Element Atomic%O 50.67Na 0.42Al 0.32Si 0.14S 25.22Ca 22.1Ni 0.82Total 100

NaA Membrane surface was covered with sulfur and calcium compound after three days stability test

ICP result: ppm

Sample ID# Na S

P2064 0.14 0.16

P2069 0.63 0.04

F2064 93.62 15.82

F2069 123.22 19.23

Hydrated Kinetic Diameter

Na+ 7.2 Å

SO42-: 8.6 Å

Page 14: Aiche 2011 Ethanol Water

Application (real feed)Ethanol/Water Separation (EtOH/H2O content=58/42,wt%)

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Scheme 2 Ethanol/water separation testing unit setup for real feed (with guard bed)

Separation temperature100ºC

Feed: wt.% of water 42%

Feed: flow rate3sccm

Permeate: sampling

Liquid N2 cold trap

Permeate: vacuum<10 tor

Feed: PH4.5

Page 15: Aiche 2011 Ethanol Water

Application (real feed)Ethanol/Water Separation

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No. Adsorbent name Supplier

1 Amberlite IRA-458 (strong basic, ion exchange resin)

Polyscience

2 Amberlite IRA-900 (strong basic, ion exchange resin) Polyscience

3 Amberlite IRA-93 (weakly basic, ion exchange resin) Polyscience

4 Amberlite IRA-958 (strong basic, ion exchange resin) Polyscience

5 MgO Aldrich

6 Type D-201 activated alumina 7x12 mesh beads UOP

7 Type A-201 activated alumina 7x12 mesh beads UOP

8 Type AW-300 molecular sieve, 1/16” pellets or beads UOP

9 Type AW-500 molecular sieve, 1/16” pellets or beads UOP

Table 3 Adsorbent materials evaluated for real ethanol/water feedstock

Different adsorbent materials (ion exchange resins, particles, molecular sieves) were tested under harsh separation conditions (100C, pH=4.5) to remove the contaminations (acid, organic compound) from the real feedstock. Only Amberlite IRA-93 shows the best stability and purification performance.

Page 16: Aiche 2011 Ethanol Water

Application (real feed)Ethanol/Water Separation

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0

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Ethanol in Permeate

(a) MgO (b) IRA-93

(c) IRA-958 (d) IRA-458

Figure 1. Stability testing of NaA membrane samples with the actual feed by using different guard bed material.

Page 17: Aiche 2011 Ethanol Water

Application (real feed)Ethanol/Water Separation

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Figure 2. 700-h stability testing of a NaA membrane sample using IRA-93 guard bed material (the model feed was used for first 96 hr, followed by the actual feed

with feed tank refilling at about 96 h and 520h)

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02468101214161820

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Page 18: Aiche 2011 Ethanol Water

Summary

NaA Zeolite membranes have been synthesized on a thin porous metal substrate sheet of 50µm thickness by secondary hydrothermal growth

For model ethanol/water separation (90wt% ethanol+ 10wt%water, pH=6.6) , it has water/ethanol separation factor >10,000 and max water flux close to 8kg/(m2.h), which is much higher than other literature reports.

For real feedstock ethanol/water separation(58wt% ethanol+42wt% water, pH=4.5), the membrane lost its selectivity quickly. However, with Amberlite IRA-93 (ion exchange resin) as guard bed material, it has max water flux close to 12kg/(m2.h) and stable performance during 700hrs stability test.

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Page 19: Aiche 2011 Ethanol Water

Acknowledgment

DOE Industrial Technology Program, contract Number DE- FC36-04GO98014

Environmental Molecular Science Laboratory, PNNL

ADMA products and Pacific Ethanol Inc.

Colleagues

Nathan Canfield

Jarrod Crum

Shenyang Hu

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Page 20: Aiche 2011 Ethanol Water

Thank you!

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