Cornelis F. deHoop, Associate Professor
Louisiana Forest Products Development Center
School of Renewable Natural Resources
LSU Agricultural Center

Sponsors
• SERBEP - Southeastern Regional Biomass
Energy Program
• Louisiana Department of Agriculture and
Forestry

Purpose
To develop a firelog utilizing an agricultural, non-petroleum binder with wood residue that produces lower emissions than firewood or commercial firelogs when combusted.

Firelogs Currently Available
• “Presto logs”
• very dense and difficult to light.
• no binder added.
• use high pressures to form.
• Petroleum-based wax
• helps decrease density.
• promotes ignition and combustion.

1. Firelog development
2. Air emission tests

Firelog Development
Concentrated on different binders that were not petroleum based.
• rice starch
• sugarcane wax
• soybean wax
The soybean wax was selected for further testing.

Modified Log Splitter

Modified Log Splitter

Modified Log Splitter

Fireplace

Instruments
Gas Analyzers
•
•
•
• CO
CO
2
O
2
Total Hydrocarbons,
THC
Mass Spectrometer
•
•
•
• CO
2
NO x
O
2
SO x

Air Emissions Testing
• The testing consisted of three replications.
• Five commercial firelogs, red oak firewood, and 25%, 33%, 50%, and 60% soy-wax firelogs.
• Data on CO
2
, CO, O
2
, THC, and NO x
.
• Other parameters measured were stack flow rate, particulates, temperatures, and weight change during combustion.

Emission Results
• The results for SO x
, and NO negligible for all of the burns.
x were
• The results for O
2 the results for CO
2 were the inverse of
.
• The results for CO, CO
2
, and THC are discussed in the following slides.

Carbon Dioxide Results
• Variations in CO
2 firelog type.
output could not be explained by
• No statistical difference in output between commercial firelogs, oak firewood or the soybean wax firelogs.
• In the soybean wax firelogs, CO
2 output increased with an increase in wax content.
(linear contrast: p > 0.0078)

Carbon Monoxide Results
 The soybean wax firelogs:
– produced 32% less CO than the commercial firelogs tested.
– produced 60% less CO than the oak firewood tested.
– produced less CO as the wax content increased.
 The commercial firelogs:
– produced 42% less CO than the oak firewood tested.

Total Hydrocarbons Results
The soybean wax firelogs:
• produced 66% less THC than the commercial firelogs tested.
• produced 55% less THC than the oak firewood tested.

Conclusions
• The soybean wax firelogs produced fewer CO and THC emissions than the oak firewood tested.
• The commercial firelogs produced fewer
CO emissions than the oak firewood tested.

Conclusions
• The soybean wax firelogs produced fewer CO and THC emissions the commercial firelogs tested.
• Based on the assumption that the oak firewood and commercial firelogs tested are a representative sample of what is being used, the soybean wax firelogs produce less CO and THC emissions than what is available on the market.

Conclusions
• CO
2 emissions did not vary with firewood or firelog type.
• CO
2 emissions for the soybean wax firelogs increased with an increase in wax content.
• CO emissions for the soybean wax firelogs were lower with an increase in wax content.

Trends
• As expected, the CO
2 early in the burn.
emissions were highest
• With CO and THC the peaks were different.
• CO and THC peaks for oak firewood were similar to CO
2
.
• CO and THC peaks for commercial firelogs and the 60% soybean wax firelogs occurred late in the burn.

Example of Oak and Commercial
Firelog CO Peaking
OAK CO
0.06
0.04
0.02
0
0.
05
9
0.
17
7
0.
29
5
0.
41
3
0.
53
1
0.
64
9
0.
76
7
0.
88
5
1.
00
3
Relative Time
Repl. 1
Repl. 2
Repl. 3
DURAFLAME CO
0.015
0.01
0.005
0
Repl. 1
Repl. 2
Repl. 3
Relative Time

Example of Oak and Commercial
Firelog THC Peaking
OAK THC
0.015
0.01
0.005
0
Repl. 1
Repl. 2
Repl. 3
Relative Time
DURAFLAME THC
0.004
0.003
0.002
0.001
0
Repl. 1
Repl. 2
Repl. 3
Relative Time

Recommendations
• Improved firelog production process: multiple firelogs
• Development of a wrapper to promote ignition.
• Testing of a more malleable wax.
• Increase the replications performed.
• Market research to ascertain potential demand.

Questions?
cdehoop@lsu.edu
(225) 578-4242