6.15 Other Fueling

Category 939

6.15.1 Introduction

Category 939 covers organic emissions (TOG and ROG) occurring during the refueling of various equipment using propane fuels. Emissions from this category occur during the refueling of propane fuels used in recreational vehicles, small tanks for barbecues, stoves for mobile homes, camping, balloon flights, and space heaters in rural areas, other internal combustion engines, and other industrial machines sources.

6.15.2 Methodology

Category 939 is considered an area source category since it covers facilities / emission sources that are not directly permitted by the District, and hence not systematically cataloged. Emissions for area source categories are determined using the formula:

Current Year Emissions = Base Year Emission X Growth Profile, and,

Base Year Emission = Throughput X Control Factor X Emission Factor

where,

  • throughput or activity data for applicable base year(s) is determined using a top-down approach (e.g. state-, national-level data);
  • emission factor is derived from general literature, specific literature and reports, and/or source testing results provided by Air District staff;
  • control factor (if applicable) is determined by District and state rules and regulations in effect;
  • and, historical backcasting and forecasting of emissions is based on growth profiles as outlined in the Trends section of this chapter

More details on throughput, county distribution, emission factors and controls is provided in the following subsections.

(a) Activity Data / Throughput

A propane gas annual throughput (87,199 thousand gallons) for Category 939 for base year 2015 was derived from Propane Education & Research Council (PERC), “2016 Propane Market Outlook” report211.

CARB estimated 18% of California state propane usage came from the Bay Area. This estimate was based on Determination of Usage Patterns and Emissions for Propane/LPG in California" report212.

(b) County Distribution / Fractions

Emissions were distributed into the nine counties based on population of each county.

(c) Emission Factors

The emission factor was based on fuel tests by the Western Propane Gas Association which showed an average of about 0.263 grams of total hydrocarbon per liter of fuel (or 2.193 lbs per thousand gallons of fuel).

(d) Control Factors

There are no specific District regulations to control Other Fueling category emissions.

(e) Speciation

The total organic gas (TOG) emissions from the Other Fueling category are considered all reactive organic gas (ROG).

6.15.3 Changes in Methodology

No major changes in methodology were made in this version of the base year emissions inventory. Estimates of fuel consumption (annual throughput) for Other Fueling category were obtained from PERC’s “2016 Propane Market Outlook” report.

6.15.4 Emissions

A summary of emissions by category, county, and year are available via the associated data dashboard for this inventory publication.

6.15.6 Uncertainties

The gasoline consumption estimates for Solano and Sonoma counties could contribute to an increased uncertainty of the Other fueling category for the base year emission inventory.

6.15.7 Contact

Author: Michael Nguyen

Reviewer: Ariana Husain

Last Update: November 06, 2023

6.15.8 References & Footnotes

  1. PERC. 2016. Propane Education & Research Council (PERC), “2016 Propane Market Outlook” report, https://afdc.energy.gov/files/u/publication/2016_propane_market_outlook.pdf↩︎

  2. CARB. 1992. Determination of Usage Patterns and Emissions for Propane/LPG in California, https://ww2.arb.ca.gov/sites/default/files/classic/research/apr/past/a032-092.pdf↩︎

  3. ABAG. 2019. Plan Bay Area 2040. Association of Bay Area Government (ABAG), http://2040.planbayarea.org/reports↩︎