Waste to Clean Energy in Robeson County
Paul Grylls – GraniteFuel Engineering
Cody Hunt – Hunt Environmental
Harrell “Gene” Walters – Robeson County Landfill
April 5th, 2017
Field Evaluation
Robeson County Landfill – Installation February 2016
Dual Vessel Regeneration
What is Siloxane?
Man-made organic compounds
• Frequently used in a range of personal
hygiene products, food ingredients and
industrial products.
• Added to increase ease of spreading,
absorption, flexibility in plastics and heat
resistance.
• Used as a low-cost oil substitution in
various food ingredients such as salad
dressings and potato chips.
• Anti foaming agent used in fast food,
cheese and beer production.
3
Impacts of Siloxane on WTE Projects
• Loss of Revenue
• More Downtime
• Loss of Power
• Increased Cost
• Increased Maintenance
• Increased Repair
Impacts of Siloxane on WTE Projects
Effects of extensive Siloxane
damage to catalyst
White
Granular
Ash
Plugged
Channels
The catalyst was plugged after
three days of running time.
Design of SRT
• Media lifespan of over 10 years
• No annual downtime or media
changeover
• Minimal maintenance
• Minimal regeneration energy
consumption
Design of SRT
Operation of SRT
Design Criteria
• System automatically regenerates without shutting down or
bypassing.
• Regeneration intervals between 24-72 hours
• System can allow future expansion
• Regeneration air to be vented through flare.
• Greatly improved maintenance schedules
• Piston cleaning mostly eliminated & piston replacement at
manufacturer recommended intervals
• Si level in lube oil no longer decisive factor in lube oil
replacement
Operation of SRT
Operation of SRT
Operation of SRT
Siloxane Adsorption Efficiency Over One Cycle
100%
Siloxane Adsorption Efficiency
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
0
10
20
30
40
Cycle Hour
50
60
70
Effects of SRT
Robeson County Landfill – Oil Analyses
With the installation of the SRT, the Si levels in the lube oil were no longer the
deciding factor in requiring oil replacement.
300
250
245
Si in oil (ppm)
200
186
Aug-Oct - Prior to SRT
154
150
May-Jun - SRT continuous
Aug-Oct - Trendline
100
90
62
50
71
71
82
72
91
May-Jul - Trendline
0
0
200
400
600
800
1000
Hours (oil life)
1200
1400
1600
1800
Effects of SRT
• No downtime caused by SRT
• Longer maintenance
intervals
• Spark plugs look relatively
clean during former change
out period
• Engine parts much cleaner
during de-coating
Summary
•
•
•
•
•
•
Siloxanes cause loss of production and increased
maintenance and repair
Regenerative Siloxane Removal Technology is cost effective
solution over the long term
• Beneficial ROI
Dual vessel system continuously adsorbs siloxanes
• Long media life 10+ years between exchanges
Periodic regenerations keep the system active
Silicon levels in oil dramatically reduced
Engine parts observed to be much cleaner during regular
maintenance
Paul Grylls – GraniteFuel Engineering
Cody Hunt – Hunt Environmental
Harrell “Gene” Walters – Robeson County Landfill