### Partner Reported Opportunities (PROs) 

## PRO Fact Sheet No. 904 for Reducing Methane Emissions



# Install Flares

Technology/Practice Overview

Description Remote, unmanned production sites andcompressor stations may vent lowpressure natural gas and vapors from storage tanks and other onsite equipment to the atmosphere. These gases, which contai n methane and often volatile organic compounds (VOC), hydrogen sulfide, and hazardous air pollutants (HAP), can pose an environmental, health, and safety hazard. In order to reduce these emissions, Partners have reported installing flares to combust these gases instead of venting them to the atmosphere.
Partners have applied flaring technology typically consisting of a small flare stack with one or two pilots. Emissions sources, such as tank vents, compressor blowdown lines, low- pressure separator vents, overpressure relief valves, and other vent streams are piped directly to the flare.

Operating Requirements If the heat content of the stream is below 300 Btu per scf, auxiliary fuel is needed. The average pilot gas consumption is 70 scf per hour per pilot burner.

Applicability Flares can be applied to all point source vented emissions of combustible gas with minimal sulfur content.



### Methane Emissions

The methane emissions reduction is uniquely dependent on the types and sizes of sources and the methane content of the flared gas. Wellhead gas may range from 70 to 90 percent methane while crude oil production tank vapors Compressors/Engines
Dehydrators
Directed Inspection & Maintenance
Pipelines

Pneumatics/Controls

Tanks

Valves

Wells

Other



### Applicable Sector(s)

Production
Processing

Transmission

Distribution

Other Related PROs:

Install Electronic Flare Ignition Devices, PRO No. 903

Estimated Gas Price Annual Methane Savings Value of Annual Gas Savings* Estimated Implementation Cost Incremental Operating Cost Payback (months)

$7.00/Mcf 2,000 Mcf N/A $21,000 $4,200 None

$5.00/Mcf 2,000 Mcf N/A $21,000 $3,000 None

$3.00/Mcf 2,000 Mcf N/A $21,000 $1,800 None 

### Economic and Environmental Benefits

Economic Evaluation

Additional Benefits
 Safer operations Estimated annual methane emission reductions 2,000 Mcf per flare (with a single pilot) 

### Methane Savings

* Because the natural gas is flared, there are no economic gas savings associated with this activity.PRO Fact Sheet No. 904 Continued 

# Install Flares (Cont’d)

may be as low as 50 percent methane. Partners have reported production site applic ation for tank vents, relief valves, and compressor blow-down at 2,000 Mcf per year, low-pressure separators at 4,000 Mcf per year, and condensate tanks at 36,000 Mcf per year.



### Economic Analysis

Basis for Costs and Emissions Savings Methane emissions reductions of 2,000 Mcf per year apply to a single flare with a single pilot. Costs for a flare are estimated to be $3,000 based on partner experiences (which vary significantly and are often between $1,000 and $5,000). In addition, and there is a fuel cost of $1,800 per year for each pilot (at $3 per Mcf of gas).

Discussion Flares are commonly installed on higher-pressure blowdown or emergency pressure relief valves for safety reasons. Low-pressure ga s installations have been justified by environmental emissions control. There are no revenues from the gas as it is destroyed through combustion. The average methane content of na tural gas varies by natural gas industry sector. The Natural Gas STAR Program assumes the following methane content of natural gas when estimating methane savings for Partner Reported Opportunities.

Production 79 %

Processing 87 %

Transmission and Distribution 94 % 

### Methane Content of Natural Gas

EPA provides the suggested methane emi ssions estimating methods contained in this document as a tool to develop basic methane emissions estimates only. As regulatory reporting demands a higher-level of accuracy, the methane emis

sion estimating methods and terminology contained in this document may not conform to the Greenhouse Gas Reporting Rule, 40 CFR Part 98, Subpart W methods or those in other EPA regulations.



### 2

2011