Geosynthetics August/September 2019 - 24

A minitube blanket for landfill gas collection and containment

Quantity

Unit

1.5

tons/m3

Trench height

2

meters

Trench width

0.9

meters

Soil extraction for 1 lm

2.7

tons

KG CO2 eq./lm

Excavation Work
Soil density

Soil extraction using machinery
lm of trench per day

70

lm/day

Tons of soil extracted per hour

27

tons

Fuel consumption per hour

40

liters

Fuel consumption for 1 lm

4

liters

Labor costs per hour

30

dollars

Number of workers

2

Dollars for services for 1 lm

6

dollars

1.8

tons/m3

Trench height

2

meters

Trench width

0.9

meters

Tons of gravel extracted for 1 lm

3.2

tons

Distance from quarry to worksite

15

kms one-way

Number of kms for 1 lm

2.43

kms

13.5

tons

Fuel consumption per hour

40

liters

Fuel consumption per lm

9.6

liters

Labor costs per hour

30

dollars

Number of workers

2

Dollars for services for 1 lm

14.4

dollars

Diameter

150

mm

Weight per lm

1413

tons/km

Distance to worksite

50

kms

Transport of products

0.07

tons/km

lm of pipe installed per hour

10

lm

Labor costs per hour

30

dollars

Dollars for services for 1 lm

3

dollars

0.11

TOTAL

79.29

11.77

Soil extraction/application

0.22

Quarry Gravel
Gravel density

32.4

Transport of gravel

2.62

Application of gravel using site machinery
Tons of gravel applied per hour

28.25

Application of gravel

0.53

Collector Pipe
3.37

Transport from manufacturer to worksite

0.02

Product application (labor)

TABLE 2 Kg CO2 eq. emissions per linear meter for a 3-foot × 6.5-foot (0.9-m × 2-m) horizontal trench
24

Geosynthetics | August September 2019

minitube blanket considering a distance
from the manufacturer to the landfill site
of 1,240 miles (2,000 km).
In comparison, the calculation of CO2
emissions per linear meter for a 3-foot
(0.9-m) wide × 6.5-foot (2-m) deep
trench filled with aggregates surrounding
a 6-inch (150-mm) diameter perforated
HDPE pipe is presented in Table 2.
The calculations were carried out
using the carbon footprint method developed by the Agence de l'Environnement
et de la Maîtrise de l'Énergie (ADEME).
The use of the minitube blanket offers
a considerable reduction of CO2e emissions of 77% for the same or better performance. It represents a savings greater
than 18 kg CO2e per linear foot (more
than 60 kg CO2e per linear m) of horizontal LFG collector.

Conclusion
LFG collection has never been of greater
concern than now in the waste management industry. Being able to efficiently
collect landfill gas will help landfill owners-operators and municipalities increase
their revenue by recycling methane and
will reduce the negative impacts to the
environment, like odors and fugitive GHG
emissions. Trenches, gravel, pipes and geotextiles were used for decades to maximize
the LFG collection efficiency. Solutions
now exist to largely improve the management of LFG and convert it to renewable
energy, as a natural and free resource.
One of the better emerging solutions
is the minitube blanket technology, which
offers a more flexible solution with an
enhanced control over LFG collection,
containment and conveyance, as well as
a reliable vacuum radius of influence and
comforting redundancy while drastically
reducing construction costs, odor and
fugitive GHG emissions. Lastly, one of
the greatest advantages of the minitube
blanket over a traditional LFG collector
Geosynthetics August/September 2019

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