ARB Research Seminar

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Maximus (Trademark) SFI - Measurement & Reduction of LP Gas Outage Gauge Emissions (Averting Unnecessary Propane Emissions Into the Atmosphere)

Alex Spataru, President, The ADEPT Group, Inc.

March 19, 2009
Cal EPA Headquarters, 1001 "I" Street, Sacramento, CA

Research Project


As LP Gas cylinders are filled, a fixed maximum liquid level gauge (FMLLG), also known as an “outage gauge” or “spitter valve” is used to determine when liquid has reached the maximum fill level.  This gauge is a valve which is left open during filling to vent gas phase LP Gas until the maximum liquid level is reached.  At that point liquid LP Gas then escapes through the outage gauge opening.  The presence of this escaping liquid is the current industry standard to indicate when filling should be stopped.

It is estimated that approximately 1.8 trillion BTUs are wasted each year nationwide due to current outage gauge venting practices.  This is equivalent to ~500 tons of LP Gas per day.  There has been no cost-effective technology to replace or minimize the use of outage gauges or eliminate such emissions.

Under the ARB ICAT and US DOE I&I programs, The ADEPT Group, Inc. conducted a project to determine the mass flow rates of LP Gas emissions and to develop and commercialize a technology known as the Maximus™ Stop-Fill Instrument (SFI) to prevent such emissions.

The Maximus™ SFI grew out of work conducted at Los Alamos National Laboratory (LANL).  It relies on proprietary acoustic methods to non-invasively detect the presence of either liquid or gas at a specific point on a tank.  When liquid reaches a predetermined maximum fill level, the acoustic signal received by the sensor changes, and the re-fueling is stopped. This eliminates the need to open the outage gauge while filling stationary LP Gas tanks thus reducing the amount of LP Gas vented by ~98%.  Such reductions yield significant energy saving, environmental, health, safety, and economic benefits.  The SFI may similarly impact emissions and waste in the distribution of anhydrous ammonia.

Tests were conducted during both pump-assisted and gravity-based filling of LP Gas forklift cylinders to measure liquid phase and gas phase LP Gas mass flow rates through outage gauges. Gas phase emissions were measured while the cylinder was being filled using a mass flow meter calibrated for propane.  Liquid phase emissions were determined by measuring the drop in mass over a period of time while liquid LP Gas was released through the outage gauge.  The results of the liquid and gas phase emissions tests during pump-assisted fills were 2.96 g/s and 10.0 g/s respectively.  Gas phase emissions for gravity fills averaged 2.53 g/s.  Engineers from SCAQMD witnessed these tests and conducted independent emissions tests during the same session using alternative methods and have reported comparable results.

Speaker Biography

Alex Spataru, started The ADEPT Group, Inc. (ADEPT) in 1983, an engineering consulting firm that provides services at the interface of energy, economics and the environment. ADEPT has a history of being at the forefront of developments in alternative fuels and in providing cost-effective solutions to energy use related environmental problems. Over the years, ADEPT has built close relationships with regional, state and national level air quality regulators while working to bring emissions-reducing technologies to market in the United States and in California in particular.  In 2000 Mr. Spataru started Adept Science & Technologies LLC. (ASCENT).  ASCENT conducts contract R&D work and manufactures acoustics based instruments and devices that are used to detect liquid level in pressurized vessels.

Mr. Spataru has consulted to large and small manufacturers, state and federal regulatory entities, oil and gas companies, as well as to utilities, laboratories (research, certification, testing), and trade associations. He has extensive experience with alternative fuels and engines. He helped commercialize several technologies including: liquefied petroleum gas (LPG) dedicated engines, compressed natural gas (CNG) fueling stations, biodiesel, fuel additives, emulsified fuels, diesel engine enhancement systems, low NOx ceramic burners, co-generation systems, gas detection systems, and high efficiency gas boilers.

Mr. Spataru occasionally speaks at energy or environment related conferences. He is a member of the American Society of Gas Engineers, the American Society for Testing and Materials, the International Standards Organization, the International Society for Measurement and Control, the National Propane Gas Association, and the Society of Automotive Engineers. He is a Certified Gas Engineer.  He served as Director of the Gas Detection Industry Association, the British American Business Council, and of the Harvard Water Polo Foundation.  Mr. Alex Spataru has worked in the aerospace, oil and gas, and management consulting industries in the U.S., Canada, and Europe. After serving on active duty as an U.S. Army Officer from 1969 to 1973, he completed his undergraduate and graduate degrees in engineering and business at UC Los Angeles.

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