Comparisons of H2S and Siloxane Removal Technologies

at the PNGC Coffin Butte Resource ProjectJeff Friesen, P.E. and Brad Jeffers, ESI

Steve King, Project Manager, PNGC Power

NW Regional SWANA SymposiumTroutdale, Oregon

April 30, 2015

• Engineering & Design– Gas Collection Systems– Biogas Cleanup – Biogas-to-Energy Facilities– High BTU Facilities

• Construction Management & Oversight• Facility Operations• Controls (SCADA) Integrator• Custom Products

Coffin Butte Resource Project

5.66 MW Landfill Gas-to-Energy Facility

Project Background

• Guttered valves• Detonation shutdowns

• Blower/treatment system corrosion

• Fuel train corrosion

Existing Blower/Pretreatment Systems

Blower/Pretreatment System • 2,100scfm capacity• Condensate knockout and aftercooler system Coalescing filters prior to engines

LFG Characteristics

• Current Flow: ~1,900 SCFM– 53% CH4, 40% CO2, 6-6.5% N2, 0.5% O2

• Sulfur Content: ~320ppmv H2S and other Compounds

• Siloxane Content: – 2014 Sample: ~16.5 mg/m³– 2012 Sample: ~35 mg/m³

Design Target

• 2,100 – 2,700 SCFM• Hydrogen Sulfide: <10ppmv• Siloxane: <10mg/m³

– Per CAT Recommendations

Important Considerations

Capital Cost Considerations– Pressure drop– Required ancillary equipment– Equipment footprint– Total installed cost

Operating Cost Considerations– Media cost/life– Waste stream disposal costs– O&M costs (not evaluated by ESI)

Technology Performance History

H2S Removal TechnologiesBulk Media (Non-Regenerative)

Bulk Media (Semi-Regenenerative)

Liquid Solvents/ Scavengers

Bio-Filtration

Chelated Iron (Iron Redox)

H2S Removal TechnologiesBulk Media (Non-Regenerative)

Bulk Media (Semi-Regenenerative)

Liquid Solvents/ Scavengers

Bio-Filtration

Chelated Iron (Iron Redox)

$$$$$ $$$$$

Surprise! Limited Capital Savings

Iron Sponge Sulfatreat

H2S Removal TechnologiesBulk Media (Non-Regenerative)

Bulk Media (Semi-Regenenerative)

Liquid Solvents/ Scavengers

Bio-Filtration

Chelated Iron (Iron Redox)

1. Extended Media Life

2. Competitive Capital Cost

H2S Removal TechnologiesBulk Media (Non-Regenerative)

Bulk Media (Semi-Regenenerative)

Liquid Solvents/ Scavengers

Bio-Filtration

Chelated Iron (Iron Redox)

H2S Removal TechnologiesBulk Media (Non-Regenerative)

Bulk Media (Semi-Regenenerative)

Liquid Solvents/ Scavengers

Bio-Filtration

Chelated Iron (Iron Redox)

Almont Emissions

1. Unproven on LFG2. Promising Capital Cost3. Implementation Concerns

H2S Removal TechnologiesBulk Media (Non-Regenerative)

Bulk Media (Semi-Regenenerative)

Liquid Solvents/ Scavengers

Bio-Filtration

Chelated Iron (Iron Redox)

H2S Removal TechnologiesBulk Media (Non-Regenerative)

Bulk Media (Semi-Regenenerative)

Liquid Solvents/ Scavengers

Bio-Filtration

Chelated Iron (Iron Redox) LO CAT®, SulFerox® Process

H2S Removal TechnologiesBulk Media (Non-Regenerative)

Bulk Media (Semi-Regenenerative)

Liquid Solvents/ Scavengers

Bio-Filtration

Chelated Iron (Iron Redox)

Complex System

Prohibitive Capital Cost

Results – H2S Removal

MV Tech. Iron Sponge1 (ESC)

AlmontEmission

SulfaTreat 1(ESC)

SulfaTreat 2(US)

ChelatedIron

Biological 1(B)

Biological 2(T)

NRGTek

$

Equipment Cost 7-Year OPEX Installation Cost

Results – H2S Removal

MV Tech. Iron Sponge AlmontEmission

SulfaTreat 1(ESC)

SulfaTreat 2(US)

ChelatedIron

Biological 1(B)

Biological 2(T)

NRGTek

$

Equipment Cost 7-Year OPEX Installation Cost

Siloxane Removal TechnologiesBulk Media (Non-Regenerative)

Regenerative

Liquid Solvents/ Scavengers

Siloxane Removal TechnologiesBulk Media (Non-Regenerative)

Regenerative

Liquid Solvents/ Scavengers

Activated Carbon

1.High Operational Cost 2.High Capital Cost

Silica Gel

Siloxane Removal TechnologiesBulk Media (Non-Regenerative)

Regenerative

Liquid Solvents/ Scavengers

Siloxane Removal TechnologiesBulk Media (Non-Regenerative)

Regenerative

Liquid Solvents/ Scavengers

Important Factors to Consider:1. Dehydration/Refrigeration

System2. Pressure Drop- Booster Blower

Siloxane Removal TechnologiesBulk Media (Non-Regenerative)

Regenerative

Liquid Solvents/ Scavengers

Multiple Providers

Siloxane Removal TechnologiesBulk Media (Non-Regenerative)

Regenerative

Liquid Solvents/ Scavengers

PPTEK System

Willexa System

Siloxane Removal TechnologiesBulk Media (Non-Regenerative)

Regenerative

Liquid Solvents/ Scavengers

NRGTek Process

Siloxane Removal TechnologiesBulk Media (Non-Regenerative)

Regenerative

Liquid Solvents/ Scavengers

NRGTek System

Results – Siloxane Removal

Venture GCE/AB Willexa PpTek Willexa SRS NRGTek Activated Carbon(US)

$

Base Equipment Cost Ancillary Equipment Cost 7-Year OPEX Installation Cost

Results – Siloxane Removal

Venture GCE/AB Willexa PpTek Willexa SRS NRGTek Activated Carbon(US)

$

Base Equipment Cost Ancillary Equipment Cost 7-Year OPEX Installation Cost

Results & Recommendations

H2S Removal Technology 7-Year Net Present ValueMV Technologies $1,410,000

Siloxane Removal TechnologyWillexa PpTek $1,334,000

Study Recommendations to PNGC

Results & Recommendations

H2S Removal Technology 7-Year Net Present ValueMV Technologies $1,410,000

Siloxane Removal TechnologyWillexa PpTek $1,846,000

Willexa SRS $1,672,000

Revised Recommendations to PNGC

Results & Recommendations

H2S Removal Technology 7-Year Net Present Value

Almont Emissions $794,000*Siloxane Removal Technology

NRGTek $1,307,000*Combined H2S/Siloxane Removal

TechnologyNRGTek $1,800,000????

Possible Pilot Projects/Experimental Technologies

*Potential Operational Concerns

Conclusions & Lessons Learned