Partner Reported Opportunities (PROs) PRO Fact Sheet No. 202 for Reducing Methane Emissions 

Convert Natural Gas-Driven Chemical 

Pumps 

Technology/Practice Overview 

Description 

Circulation pumps in glycol dehydration

units and chemical injection pumps, 

used to inject methanol and other 

chemicals into wells and flow lines, are 

often powered by pressurized natural 

gas at remote locations. As part of 

normal operation, these devices vent 

methane to the atmosphere. Natural Gas 

STAR partner companies have achieved 

significant methane emission reductions

by replacing gas-driven pneumatic

pumps with alternative pumps including 

instrument air, solar-charged direct 

current (DC) electric pumps, and 

standard alternating current (AC)

electric pumps. 

One Natural Gas STAR Partner replaced

natural gas with instrument air to drive 

large-volume glycol circulation pumps. 

The use of instrument air increased 

operational efficiency, decreased 

maintenance costs, and reduced 

emissions of methane, volatile organic

compounds (VOC), and hazardous air 

pollutants (HAP). 

Other partners have replaced gas-driven

chemical pumps with solar-charged DC 

electric pumps. One partner company 

replaced more than 2,000 chemical 

pumps which were used to inhibit 

corrosion and prevent freezing in 

pipelines and wells. The solar-charged 

pumps were installed when older 

natural gas-driven pneumatic pumps 

required replacement. Where electricity 

is already available at the producing 

site, some replacement pumps use onsite

AC electric power. 

Estimated 

Gas Price 

Annual 

Methane 

Savings 

Value of 

Annual

 Gas Savings* 

Estimated 

Implementation 

Cost 

Incremental 

Operating Cost 

Payback 

(months) 

$7.00/Mcf 2,500 Mcf 

183 Mcf 

$18,600 

$1,300 

$1,000—$10,000 

$2,000 

$100—$1,000 

-

 1 - 8 Months 

19 Months 

$5.00/Mcf 2,500 Mcf 

183 Mcf 

$13,300 

$900 

$1,000—$10,000 

$2,000 

$100—$1,000 

-

1 - 11 Months 

27 Months 

$3.00/Mcf 2,500 Mcf 

183 Mcf 

$7,800 

$550 

$1,000—$10,000 

$2,000 

$100-$1,000 

-

2 - 18 Months 

44 Months 

Economic and Environmental Benefits 

Economic Evaluation 

Additional Benefits 

 Operations and maintenance cost savings 

 More precise control of injection volumes and reduced chemical use 

 Less downtime for wells and pipelines 

Estimated annual methane emission reductions Convert Gas-Driven Glycol Pumps to Instrument Air: 

2,500 Mcf per dehydrator unit 

Replace Pneumatic Chemical Injection Pumps with 

Solar Electric Pumps: 182.5 Mcf per pump replaced 

Methane Savings 

* Whole gas savings are calculated using a conversion factor of 94% methane in pipeline quality natural gas. 

Compressors/Engines 

Dehydrators 

Directed Inspection & 

Maintenance 

Pipelines 

Pneumatics/Controls 

Tanks 

Valves 

Wells 

Other 

Applicable Sector(s) 

Production 

Processing 

Transmission 

Distribution 

Other Related Documents: 

Pipe Glycol Dehydrator to Vapor 

Recovery Unit, PRO No. 203 

Replace Glycol Dehydration 

Units with Methanol Injection, 

PRO No. 205 

Solar Charged Chemical Pump 

Source: Chesapeake Energy 
 

 

 

PRO Fact Sheet No. 202 Continued 

Convert Natural Gas-Driven Chemical Pumps 

Operating Requirements 

A facility may take advantage of the excess capacity of its

instrument air system to convert natural gas-driven 

glycol circulation pumps. In a field setting, low volume 

natural gas pneumatic pumps can be replaced with 

electric pumps if the site is electrified, or if sufficient

sunlight is available for solar-charged DC pumps. Other 

operating requirements include installation of solar 

panels and a storage battery for each solar-charged 

pump. No special training is required to operate solar

electric pumps beyond review of the operating manual. 

Applicability 

Converting chemical pumps and circulation pumps to 

instrument air, solar or electric could be applied to gas 

dehydration operations across all gas industry sectors, 

including production operations where low volume 

chemical injection is necessary. For gas production,

typical applications include methanol injection into

pipelines and injection of corrosion inhibitors into 

producing wells and other field equipment. These 

chemical injection pumps are typically sized for 6 to 8 

gallons of methanol injection per day. 

Solar-Charged Glycol Circulation Pump 

Source: BP 

Solar injection pumps can handle a range of throughputs

and injection pressures. Low volume solar-charged DC 

pumps are limited to approximately 5 gallons/day 

discharge at 1,000 psig. Large volume solar pumps are 

available with maximum output of 38 to 100 gallons per 

day at maximum injection pressures of 1,200 to 3,000

psig. Solar panels and storage batteries are nearly

maintenance free, which saves downtime and service 

costs. The solar panels have a life span of up to 15 years

and the electric motors last approximately 5 years in

continuous use. 

Methane Emissions 

Gas savings and methane emission reductions vary

according to the pump size, operating pressure, and the 

size and configuration of the pump installation. For 

glycol circulation pumps, partners report typical methane 

savings of 2,500 Mcf/year for each gas-drive glycol pump 

converted to instrument air. One partner reported total 

annual methane savings of 9,125 MMcf for converting

gas drive glycol pumps plus other pneumatic services.

For chemical injection pumps, one operator reports 

annual methane savings of approximately 365 MMcf 

after replacing 2,000 pneumatic chemical injection 

pumps with solar-charged electric pumps. 

Solar Panels at Remote Production Site 

Source: BP 

Economic Analysis 

Basis for Costs and Emissions Savings 

Typical methane emissions from gas-driven glycol

circulation pumps are estimated based on the following 

relationship: 

Methane Emissions = Pump Gas Use x Glycol Ratio x 

Water Removal Ratio x 

Over Circulation Ratio 

[Methane Emissions, = scf/ MMcf gas processed; Pump Gas Use = scf/ glycol circulated, 

gallons; Glycol Ratio = glycol, gal. / water removed, lb; Water Ratio = water removed, lb./ 

gas processed, MMcf; Over Circulation Ratio (typical default = 2)] 

Methane emissions savings of 2,500 Mcf per year for each

glycol pump conversion to instrument air assume the 

following conditions: 

	 One glycol pump sized for a gas dehydrator that 

processes 10 MMcf per day 

	 Pump gas use = 2 scf per gallon of glycol circulated 

2 
 

 

 

 

 

PRO Fact Sheet No. 202 Continued 

Convert Natural Gas-Driven Chemical Pumps 

	 Glycol ratio = 3 gallons glycol per pound of water 

removed 

	 Water removal ratio = 56 pounds of water per MMcf 

of gas processed 

	 Over circulation ratio = 2 (default) 

The methane emissions savings are equivalent to natural 

gas savings because the emissions savings boost the 

volume of the sales gas stream. At $5.00 per Mcf,

estimated annual revenue is $12,500 for each pump

conversion. The total cost to convert a gas pneumatic

glycol circulation pump to instrument air would include 

installation of piping and an appropriate control system

between the existing instrument air system and the 

glycol pump if the driver is independent of the circulation 

pump. If the driver is separated from the pump by orings, then the pump would have to be replaced as well. If

potential total implementation costs range between 

$1,000 and $10,000, project payback would occur in less

than one year. 

Typical methane emissions savings from converting gas

pneumatic chemical injection pumps to solar-charged

electric pumps are estimated based on Partner 

experiences. One Partner converted 2,000 chemical 

pumps to solar-charged electric pumps thus saving 1,000

Mcfd of methane emissions or approximately 0.5 Mcfd per

pump conversion. This equates to total annual methane 

emissions savings of approximately 182.5 Mcf per pump 

conversion. 

The reporting Partner replaces failed pneumatic pumps, 

on an ongoing basis, with solar-charged electric pumps at 

a cost of approximately $2,000 per pump. Installation of 

the pump is typically included at no additional charge.

No training costs are required. On-going operating and 

maintenance costs have not been quantified, but appear

to be lower for the solar-charged electric pumps compared

to the natural gas-driven pumps. The methane content of 

natural gas in the reporting partner’s operating area is

approximately 90 percent, so annual natural gas savings

are approximately 203 Mcf per pump conversion. At 

$5.00 per Mcf, the value of the natural gas saved equals

$1,015 per year, thus paying back the cost of the pump 

replacement in approximately two years. 

Discussion 

Replacing high volume natural gas-driven glycol

circulation pumps with instrument air may provide a 

relatively quick payback. The installation of piping 

between an existing air compressor and the glycol 

circulation pump accounts for the major capital costs in 

2011 

The average methane content of natural 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 

high volume systems. These capital costs are assumed to 

be incremental to the cost of the existing instrument air 

system. The electric power required to compress the air

is the primary operating cost. 

In field applications discussed above, operators report

that solar-charged electric pumps are more accurate and 

allow more precise control of chemical injection. Electric 

driven pumps are more reliable and require less 

maintenance than pneumatic pumps because they

eliminate the use of wet lease gas and the downtime

associated with freezing and corrosion. The benefits 

associated with reduced chemical use and reduced 

maintenance have not been quantified, but partners

estimate these additional cost savings can be significant

for daily operations. 

EPA provides the suggested methane emissions 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 emission 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. 

Solar Chemical Pump with SCADA Interface 

Source: Encana 

3