LIGNOCELLULOSIC ETHANOL

LIGNOCELLULOSIC ETHANOL

YURIA ANAGAALFRED LYANTO

VIVIEN LEE

YURIA ANAGAALFRED LYANTO

VIVIEN LEE

INTRODUCTIONINTRODUCTION

• Target: 77 million gallons of ethanol/year

• Switchgrass Ethanol Gasohol• Plant location: Iowa, United States

OVERVIEWOVERVIEW

• Improvements on Process – Solid storage (Silo)– Elimination of CO2 Emission– Centrifugation– Lignin Burning – CBP Scheduling– Distillation Columns– Water Recycle and Heat

Exchanger• Economic Analysis• Safety Considerations• Ethics

• Silo storage is added before grinding• To handle the hold up time between

the transport of switchgrass and the rate of switchgrass grinding

• The harvest time for switchgrass is 3 years1

1) http://www.global-greenhouse-warming.com/ethics-of-biofuel.html accesed on October 31, 2009

P-1 / GR-101Grinding

P-16 / SL-101Solids Storage

S-101

Switchgrass

IMPROVEMENTS: Solids Storage (Silo)

IMPROVEMENTS: Solids Storage (Silo)

P-5 / V-102CBP Reactor

P-8 / G-101Gas Compression

CO2 LIQUEFACTIONS-112

P-4 / V-103Pressurized Tank

liquid CO2

hydrogen gasS-106

• 98.5% of CO2 and 1.5% of H2 is produced by CBP• Compress the gas mixture to 40atm and cool it down to 12 0C to

liquefy CO2

• The pressurized tank is used to split the vapor H2 and liquid CO2 streams

• Liquid CO2 is sold to other companies e.g. for refrigerant

• The H2 stream is burnt to generate steam inside the plant2,3

• Although H2 is flammable, BUT no O2 source is available to initiate explosion

2) Smith J.M., Van Ness H.C., Abbott M.M.. Introduction in Chemical Engineering Thermodynamics 7th Ed. McGraw Hill. New York (2005)3) CRC Handbook of Chemistry and Physics (2008-2009) < http://www.hbcpnetbase.com/>

IMPROVEMENTS: Elimination of CO2 Emission

IMPROVEMENTS: Elimination of CO2 Emission

P-14 / DC-101

Centrifugation

Now

P-21 / CF-101

Centrifugation

Before

• Centritech pharmaceutical use, separate finer particle (Volume~5000L)

• Decanter continuous; higher capacity than hydrocyclone, disk-stack, basket centrifuge, and bowl centrifuge; achieve higher separation than clarifier; relatively more expensive4

4) www.lenntech.com accessed on October 31, 2009

IMPROVEMENTS: Centrifugation

IMPROVEMENTS: Centrifugation

P-14 / DC-101Centrifugation

lignin slurry

• Lignin will be burnt with 30% efficiency (ideal Carnot cycle = 51%)5 to support internal steam generation.

• 1 kg of lignin produces 1 kg of steam6:

MW 1.60=0.3kW1000

MW 1

kcal/h 1

kW 0.001162

steam kg 1

kcal 487.303935

lignin kg 1

steam kg 1

hour 1

lignin kg8457.28447 =savingsPower

1$257,940.4=0.3year 1

hours 8472

steam kg 1

$0.012

lignin kg 1

steam kg 1

hour 1

lignin kg8457.28447=savings Annual

11.27%=$2,284,925

1$257,940,4 =Cost on UtilizatiSteamon Savings Annual %

IMPROVEMENTS: Lignin Burning

IMPROVEMENTS: Lignin Burning

5) Smith. “Introduction to Chemical Engineering Thermodynamics”. McGraw-Hill.7th Edition6) Biomass program: lignin-derived co-products, U.S. Department of Energy, Energy Efficiency and Renewable Energy (2007)

P-5 / V-102CBP Reactor

• 2 staggered CBP reactors (12,000L each in batch system) are used to get a continuous process

• Seed Fermentor is used to grow the bacteria• Scheduling: one reactor reacts (36 hours

long) while another one performs: transfer out, cleaning, and transfer in IMPROVEMENTS:

CBP SchedulingIMPROVEMENTS:

CBP Scheduling

• Changing the parameters inside the distillation column to give reasonable ethanol compositions at the bottom streams

• Higher ethanol recovery increases Revenue

NewBefore

IMPROVEMENTS: Distillation Columns

IMPROVEMENTS: Distillation Columns

PRE-TREATM EN T

Liq. Waste 1

P-10 / V-105AFEX Reactor

P-12 / C-103Molecular Sieves

P-9 / C-101Preheat Distillation

P-11 / C-102Distillation

PRODUCT RECOVERY

P-7 / V-101Flash

Air

P-17 / MX-105Mixing

P-18 / HX-104Heat Exchanging

P-20 / FSP-101Flow Splitting

Liq. Waste 2

P-3 / MX-101MixingWater

P-6 / MX-103Mixing

99.8% ethanol

S-103 S-104

S-110

S-111

S-113

S-115

S-116

S-117

S-118

S-119

S-120

Recycled Water

Water Recycle• Water from the bottom

product of the distillation columns is recycled to conserve water

• Ethanol impurity from the distillation columns produces impurity to the liquid NH4OH

• The impure NH4OH is sold to cleaning company e.g. Clorox

• Water from the molecular sieve is recycled as well

Heat Exchanger• Hot liquid waste stream from flash and distillation columns

are used to preheat the raw material before AFEX reactor

IMPROVEMENTS: Water Recycle & Heat Exchanger

IMPROVEMENTS: Water Recycle & Heat Exchanger

Capacity: 77 million gallons/ yearMESP: US$ 2.01/galPayback period: 6.80 yearsNPV: US$ 76,799,000.00

Economics Analysis:MESP, Payback, NPV, & Feasibility

Economics Analysis:MESP, Payback, NPV, & Feasibility

%14.10%100*/10*837.6

/10*932.69

8

yearMJ

yearMJ

Raw Materials0.23669

Labor-De-pendent0.01760

Facility-Dependent0.60605

Laboratory QC/QA

0.00264

Consumables0.00034

Waste Treatment0.04198

Utilities0.09470

Annual Operating Cost

Economics Analysis:COST

Economics Analysis:COST

45 55 65 75 85

-$150,000,000

-$50,000,000

$50,000,000

Sensitivity Analysis: NPV vs Annual Production

Capacity

Annual Production Capacity (million gallon)

NP

V

~77

Economics Analysis:Sensitivity Analysis 1Economics Analysis:

Sensitivity Analysis 1

$0.00 $1.00 $2.00 $3.00

-$3,000,000,000

-$2,000,000,000

-$1,000,000,000

$0

$1,000,000,000

Sensitivity Analysis: NPV vs Price of Raw Mate-

rials

Switchgrass

Price of Raw Materials

NP

V

Economics Analysis:Sensitivity Analysis 2Economics Analysis:

Sensitivity Analysis 2

$1.85 $1.90 $1.95 $2.00 $2.05 $2.10 $2.15$0

$40,000,000

$80,000,000

$120,000,000

Sensitivity Analysis: NPV vs MESP

MESP (per gal)

NP

V

NPV= 0, when MESP~ $1.79

Economics Analysis:Sensitivity Analysis 3Economics Analysis:

Sensitivity Analysis 3

• Basic Safety Training for all employees and specific training for corresponding operators

• Regular Maintenance for all unit operations

• Install Basic Safety Equipment e.g. safety shower

• Ground all the equipment to avoid statics• Install flare-stack in the middle of the

plant to vacuum all the pipe residues and burn it

Safety Considerations:Overall

Safety Considerations:Overall

P-1 / GR-101

Grinding

• Safety Considerations:– Fire explosion due to the dust

from switchgrass– Ignition source: static and

overheat of the agitator• Preventions:

– Install baghouse filtrations– Spray small amount of water

(reduce the floating dust)– Install exhaust ventilation

Safety Considerations:Grinder

Safety Considerations:Grinder

P-10 / V-105

AFEX Reactor

7) Lecture slides

Safety Considerations:AFEX Reactor

Safety Considerations:AFEX Reactor

• Safety Considerations:– High pressure (21 atm), high

temperature (900 C)– Ammonia corrosive, ammonia slip-

toxic, and cause explosion in the presence of air

• Preventions:– Install controllers to monitor the

ammonia, pressure, and temperature– Select proper material for AFEX, that

can withstand 2440 F and 23.1 atm6

– Install exhaust ventilation– Highly closed system

Material (alloys)

Strength (MPa) Cost

(USD/lb.)Criteria FulfilledYield Tensi

leSS 316/317 515 205 3.50 1, 2, 3, 4

SS 304 515 205 3.15 1, 2, 3, 4Inconel 600 675’ 310 9.43 1, 2, 3, 4Monel 400 482 193 8.39 1, 2, 3Nickel 200 496 172 15.00 1, 2, 3Hastelloy N 755 385 40.00 1, 2, 3, 4

‘ at -200-300oC, others are at room T, atmospheric P

Considerations:1. Compatible with ammonia and ammonium hydroxide2. Chromium Oxide Layer (to prevent corrosion)3. Stand mild scratching from 2 mm switchgrass4. High strength to overcome very high pressure P= 65 atm, T= 90oC

Safety Considerations:AFEX Reactor’s Material

Safety Considerations:AFEX Reactor’s Material

Thermal Expansion and Strength Data: SS304Thermal Expansion and Strength Data: SS304

8. Rempe, J.L. et al. High Temperature Thermal and Structural Material Properties for Metals used in LWR Vessels. ICAPP 2008

Safety Considerations:AFEX Reactor’s Material

Safety Considerations:AFEX Reactor’s Material

P-5 / V-102

CBP

• Safety Considerations:– High temperature (650 C)– Flammable liquids and vapor inside

CBP e.g. ethanol, acetic acid, lactic acid, H2

– Highly corrosive to metal (NaCl from the nutrient)

• Preventions:– Install controllers to monitor the

temperature and pressure– Select proper material for CBP, that

can withstand the corrosives, 1990 F, and 1.1 atm5

– Highly closed system Safety Considerations:CBP Reactor

Safety Considerations:CBP Reactor

Material (alloys)

Strength (MPa) Cost

(USD/lb.)Criteria FulfilledYield Tensil

eSS 316/317 515 205 3.50 1, 2, 4, 5

SS 304 515 205 3.15 2, 4, 5

Inconel 600 675* 310 9.43 1, 2, 3, 4, 5

Monel 400 482 193 8.39 1, 2, 3, 4Nickel 200 496 172 15.00 1, 2, 3, 4Hastelloy N 755 385 40.00 1, 2, 3, 4, 5

Considerations:1. Compatible with Acetic acid2. Compatible with Lactic acid3. Compatible with NaCl (nutrients)4. Compatible with ethanol 5. High strength to overcome T= 65oC, P= 1 atm

* at -200-300oC, others are at room T, atmospheric P

9The mean linear thermal expansivity is found to be 11.4 × 10−6 K−1

9. http://www.sciencedirect.com accessed on November 4, 2009

Safety Considerations:CBP Reactor’s MaterialSafety Considerations:CBP Reactor’s Material

• Problems:– Competition with food production– Wildlife habitat

• Alternative Solutions:– Rotational farming with crops– Donating part of the company’s profit for research

in agricultural area and wildlife conservation– Switchgrass is a native plantation in Iowa habitat

for wildlife– Volunteering in wildlife conservation

organization

Ethics:Land Competition

Ethics:Land Competition

• Problems:– Air pollution due to CO2 emission

• Alternative Solutions:– 115% CO2 emission saving (comparing with 40%

only for corn ethanol)10

– Selling some CO2 emitted in liquid form

– The CO2 will be consumed by the switchgrass– Building the plant in a location that is far from

residential area– Ethanol fuel is a cleaner fuel, based on grams of C

per MJ energy generated11

10http://climateethics.org/?p=18 accessed on October 31, 200911CRC Handbook 89th Edition. 2008-2009 Accessed on 31st October 2009.

Ethics:Air Pollution

Ethics:Air Pollution

This process design is practicable because:• The NPV is positive• The payback time is 6.80 years• The energy consumed is 10.14% of the energy

produced• The production process is safe• Alternative solutions can be used to minimize

ethical problems

ConclusionConclusion

ReferencesReferences

• MSDS References1. Jtbaker, MSDS – Lactic Acid. 19th May 20082. Airgas,MSDS – CO2.11th April 2005

3. Air Product, MSDS – Hydrogen. June 19944. ATCC, MSDS – T. Saccharolyticum. February 20025. Megazyme, MSDS – C. Thermocellum. 1st September 20096. Becton, Dickinson and Company, MSDS – Nutrients. 30th June 20037. Temple-Inland, MSDS – Hemicellulose. January 20098. ScienceLab.com, MSDS – Cellulose. 6th November 2008

9. Weyerhaeuser. MSDS – Lignin. 15th October 2009. 10. Praxair Technology Inc.. MSDS – Ammonia Anhydrous. (2006)

11. ScienceLab.com, Inc.. MSDS – Ammonium hydroxide. 6th November 2008. 12. Fisher Scientific. MSDS –Ethanol. 27th July 1999. 13. ScienceLab.com, Inc.. MSDS – Acetic Acid. 10th September 2005.

• Material References1. www.azon.com accessed on October 31, 20092. www.quantumalloys.com accessed on October 31, 20093. http://www.aircraftmaterialsuk.com/data/electronic/al200.html accessed on October 31, 20094. www.haynesintl.com accessed on October 31, 20095. www.metalprices.com accessed on October 31, 2009

THANK YOUTHANK YOU

QUESTIONS?QUESTIONS?

• Precaution:– Corrosive– Eyes, skin, and respiratory tract burns– Ammonia slip toxic gas formation e.g. NOx

– Forms explosive mixture with air• Prevention:

– Gas mask for operators– Ammonia concentration sensor– Keep sources of direct heat and ignition source– Install exhaust ventilations

• Accidental Release Solution:– Fire explosion: waterspray, CO2, fog, or dry chemical– Ammonia leak: evacuate all workers, shut down the plant, clean

up the gas leakage

Safety: Primary Chemicals Ammonia AFEX reactor,

Condenser

Safety: Primary Chemicals Ammonia AFEX reactor,

Condenser

For storage (in cylinders):Temperature < 520 CCylinders should be equipped with pressure relief device

• Precaution:– Dust generation fire explosion– Irritation of the respiratory system

• Prevention:– Dust mask for operators– Baghouse filtrations– Keep sources of direct heat and

ignition source– Install exhaust ventilations/fume

hood• Accidental Release Solution:

– Small fire: use dry powder– Big fire: use waterspray, fog, or

foamSafety: Primary Chemicals SwitchgrassSilo storage,

Grinder

Safety: Primary Chemicals SwitchgrassSilo storage,

Grinder

• Precaution:– Flammable liquid and vapor– Respiratory tract irritation, central nervous system

depression, moderate skin and eyes irritation– Vapors may form an explosive mixture with air

• Prevention:– Use explosion-proof ventilation equipment– Eyewash facility and a safety shower– Use general or local exhaust ventilation

• Accidental Release Solution:– Spills/ leaks: absorb spill with inert material, then place in

a suitable container– Small fires: use dry chemical, carbon dioxide, water spray

or alcohol-resistant foam– Large fires: use water spray, fog, or alcohol-resistant foam

Safety: Primary Chemicals Ethanol CBP, all separation

unit ops

Safety: Primary Chemicals Ethanol CBP, all separation

unit ops

• Precaution:– Causes damage to lungs, cardiovascular system, central

nervous system, skin and eyes irritation, and respiratory tract– Contact with rapidly expanding gas, liquid, or solid can cause

frostbite• Prevention:

– CO2 concentration controller

– Wear a full face shield (working with cryogenic liquid)– Use process enclosures or local exhaust ventilation– Avoid dispersal of spilled material and runoff and contact with

soil, waterways, drains, and sewers– Use only with adequate ventilation– Prevent entrapment of liquid in closed systems or piping

without pressure relief devices MATERIAL!• Accidental Release Solution:

– Spills/ leaks: Shut off gas supply if this can be done safely– Isolate area until gas has dispersed

Safety: Primary Chemicals Carbon dioxide CBP, compressor, and condenser

Safety: Primary Chemicals Carbon dioxide CBP, compressor, and condenser

• Precaution:– Corrosive and flammable– Causes burns to any area of contact (harmful if swallowed

or inhaled)• Prevention:

– Vent hood– Isolate hazard area– Use industrial or local exhaust (to prevent

dispersion)ventilation– Isolate from any source of heat or ignition– Prepare a full-face piece positive-pressure, air-supplied

respirator (for emergency)• Accidental Release Solution:

– Spills/ leaks: ventilate area of leak or spill, collect liquid in an appropriate container or absorb with an inert material, and place in a chemical waste container

– Use CO2 or water spray to extinguish the fire

Safety: Primary Chemicals Acetic and Lactic acid CBP, centrifuge, flash

Safety: Primary Chemicals Acetic and Lactic acid CBP, centrifuge, flash

• Precaution:– Flammable (explosive hazard when concentrations exceed

4%)– High concentrations that will cause suffocation/ asphyxiant

• Prevention:– Eliminate any possible sources of ignition, and provide

maximum explosion-proof ventilation– Provide natural or explosion-proof ventilation adequate to

ensure hydrogen does not reach its lower explosive limit of 4%

– Prepare air supplied respirators• Accidental Release Solution:

– Spills/ leaks: ventilate area of leak or spill, collect liquid in an appropriate container or absorb with an inert material, and place in a chemical waste container

– Use CO2, water spray, dry chemical, or fog to extinguish the fire

– Evacuate all personnel from danger area– Stop flow or gas if without risk while continuing cooling

water spray

Safety: Primary Chemicals Hydrogen gas CBP, compressor, and

condenser

Safety: Primary Chemicals Hydrogen gas CBP, compressor, and

condenser

Safety: Primary Chemicals Bacteria CBP

Safety: Primary Chemicals Bacteria CBP

• Precaution:– Eyes and skin irritant, long term exposure to dusts can

cause respiratory irritation and coughing, an allergic reaction is possible with asthmatics

• Prevention:• Respirator for solid and liquid particulates, including dusts

and mists• Accidental Release Solution:

– Spills/ leaks: contain the spill and decontaminate using suitable disinfectants such as chlorine bleach or 70% ethanol

– Before disposing cultures and exposed materials, autoclave at 121oC for 20 minutes

– Use water or foam to extinguish the fire

Safety: Primary Chemicals Nutrients CBP

Safety: Primary Chemicals Nutrients CBP

• Precaution:• Irritating to eyes, respiratory system, and skin

• Prevention:• Keep container tightly closed• Do not breathe dust

• Accidental Release Solution:– Spills/ leaks: use cleansing agent (water)