1 | 9/11/2013

CO2 Processing Unit for Oxy-Fuel

Fired Rotary Cement Kiln Presenter: Bill Mahoney

Authors: Kenneth Burgers, Stefan Laux, Minish Shah

175 East Park Drive, Tonawanda, NY 14150, USA

3rd Oxyfuel Combustion Conference

9-13 September 2013 – Ponferrada, Spain

Copyright © 2013 Praxair Technology, Inc. All rights reserved.

2 | 9/11/2013

The ecra CCS Study

Carbon Capture and Storage

study by the European Cement

Research Academy (ecra)

Multi-phase research initiative to study the implications for capturing carbon dioxide at

cement plants and develop cost estimates

– Post-combustion capture technology

– Oxy-fuel combustion

Phase III, Work Package A5: “General Layout of a Flue Gas Conditioning Facility for

Oxy-fuel Operation of a Rotary Cement Kiln”

This presentation focuses on the design and performance of the

CO2 Processing Unit (CPU)

3 | 9/11/2013

Oxy-Fuel Combustion for CCS

Oxy-fuel combustion reduces flue gas volume

CO2 rich (>80% dry basis) flue gas minimizes purification costs

Potential for fuel savings

Improved heat transfer increased productivity

Flue gas recirculation used to manage combustion temperatures

Air vs Oxy-Fuel

Fuel: Methane

26%

100%

H2O CO2

N2

O2 H2O CO2

Flue Gas Volume

Air

Fuel Raw meal

Luftzerlegung Nitrogen

Klinker brennprozess Clinker

Flue Gas Recirculation

Air Separation Unit (ASU)

Clinker- Burning Process

Flue gas (CO2 - rich) CO2 Processing

Unit (CPU)

Vent of Non-Condensable Gases (N2, Ar, O2, Traces)

CO2

Water

Oxygen

4 | 9/11/2013

Work Package A5

Compress and purify CO2-rich flue gas from a 3000 t/d oxy-fuel cement kiln for pipeline

transport at supercritical pressure

Process variations studied

– Inlet CO2 concentration to quantify effect of air inleakage

– Outlet CO2 purity to quantify effect of pipeline requirements

Major Deliverables

– Process design and utility requirements

– Conceptual layout

– Budgetary capital costs (+/- 30%)

5 | 9/11/2013

Clinker Air

Rotary Kiln

Cooler

Pre-heater

Pre- calciner

Fuel

Raw Mill

Raw Material

Exhaust cleaning

Fuel Preparation

Vent

Air-Fuel Cement Process

6 | 9/11/2013

Clinker

Oxy-Fuel Cement Process

Air

Rotary Kiln

Cooler

Pre-heater

Pre- calciner

Fuel

Raw Mill

Raw Material

Exhaust cleaning

Fuel Preparation

Air Ingress

Air Ingress

Air Ingress Air Ingress

Cooler

Oxygen

Nitrogen Gas Mixing

Air Separation

Unit

Flue Gas Recirculation

Heat exchanger

Bag filter CO2 rich flue gas

Vent

Transport

CO2 Purification

CO2-Storage

Water

CO2 Compression

Optimum excess oxygen for combustion?

Best O2 purity?

CO2 purity specification?

Level of air ingress

into process?

7 | 9/11/2013

CPU Process Schematic

Technology adapted from industrial CO2 process

Auto-refrigeration with partial condensation or distillation

Inert gases (N2, Ar, O2) are removed and vented

CO is removed using Catox Cold Box Vent

CO2-Rich Oxyfuel

Flue Gas

FG Cooler/ Condenser

H2O Compressor

Vent

Dilute acid

Catox

Condensate

> 95% CO2

Cold Box

SOx/NOx/ Removal

Dryer

H2O Expander

Hg

Carbon bed

Condensate

8 | 9/11/2013

Design Basis

Study Case Air

Intrusion CO2 Purity mol%

Type of CO2 Processing Unit (CPU)

1 2% > 95% Partial Condensation

2 4% > 95% Partial Condensation

3 6% > 95% Partial Condensation

4 6% > 99.5% Distillation

9 | 9/11/2013

Inlet Flue Gas Conditions

Case No. 1 2 3 4

Air Intrusion 2% 4% 6% 6%

CPU Type Partial

Condens. Partial

Condens. Partial

Condens. Distillation

Vol Flow, Nm3/h (dry) 56,887 58,971 61,523 61,523

Mass Flow, kg/h 112,232 114,784 118,013 118,013

Temperature, oC 50 50 50 50

Pressure, mbara 1063 1063 1063 1063

Composition, mol%

CO2 90.43% 86.84% 82.97% 82.97%

N2 4.13% 7.44% 11.09% 11.09%

O2 2.67% 2.98% 3.26% 3.26%

Ar 1.41% 1.37% 1.34% 1.34%

H2O 1.00% 1.00% 1.00% 1.00%

10 | 9/11/2013

Minor Flue Gas Components

Mercury and HCl levels assumed by Praxair

Component Inlet Concentration

Dust < 10 mg/Nm3 stp

CO < 1000 mg/Nm3 stp

NOx < 1200 mg/Nm3 stp

SOx < 400 mg/Nm3 stp

Hg < 0.085 mg/Nm3 stp

HCl < 5 mg/Nm3 stp

11 | 9/11/2013

Key Assumptions/Specifications

CO2 outlet pressure 138 bara

Cooling water inlet temperature 18 C

Cooling water outlet temperature 26 C

Steam pressure 22 bara

Currency Conversion € 1.00 = $1.40 US

Cost of Electricity € 0.071/kWh

Cost of Steam € 21.66/tonne

Cost of Cooling Water € 0.028/tonne

Cost of Process Water € 0.66/tonne

12 | 9/11/2013

CPU Cost and Performance

Case No. 1 2 3 4

Air Intrusion 2% 4% 6% 6%

Type of CPU Partial

Condens. Partial

Condens. Partial

Condens. Distill.

Feed CO2 Purity (dry) mol% 91.5% 87.9% 84.0% 84.0%

Product CO2 Purity, mol% 95.8% 95.2% 95.0% 99.9%

CO2 Capture Eff. 93.5% 92.6% 90.3% 90.0%

CO2 Captured, tonnes/day 2353 2320 2255 2248

Relative CPU Power 100 101.5 103 113

CO2 Compression and Purification Cost , €/tonne of CO2

€ 23.90 € 24.60 € 25.40 € 27.20

13 | 9/11/2013

Atmospheric Emission Reduction

Case No. 1 2 3 4

Air Intrusion 2% 4% 6% 6%

Type of CPU Partial

Condens. Partial

Condens. Partial

Condens. Distill.

Atmospheric Emission Reduction

CO 99.44% 99.33% 99.28% 99.00%

SOx 99.99% 99.99% 99.99% 99.99%

NOx 99.36% 99.26% 99.12% 98.79%

Hg >99.9% >99.9% >99.9% >99.9%

14 | 9/11/2013

Study Conclusions

Between 2250 and 2350 tonnes/day of CO2 at a pipeline pressure of 138 bar(a) can be

captured from a 3000 t/d oxy-fuel cement kiln.

Cost of CO2 compression and purification ranges from about € 24/tonne to about €

27/tonne

CPU is able to maintain CO2 recovery of >90% with air intrusion rates of up to 6%. Cost

increases by about € 1.50/tonne when air intrusion increases from 2% to 6%.

Increasing CO2 from 95% to 99.99% increases cost by € 1.80/tonne

15 | 9/11/2013

Summary

Oxygen combustion is used in many industries, including the cement industry

Air separation and CO2 compression/purification

– Technology is available and impact of oxygen purity can be determined

– Equipment scale is not a challenge

– Tradeoffs exists between investment costs and operating costs (energy)

The integration of oxy-fuel combustion into the cement process is a significant challenge

– Effect on process

– Costs

Sequestration requirements and legal framework need to be defined

16 | 9/11/2013

Questions?

Thank You for Your Attention!