February 26, 1999

SCAQMD Contract No: 98108

  ARB LPG Fuel Blends Evaluation Project

July 1998 Progress Report

 Submitted to:

 LPG Fuel Blends Evaluation Project Task Group (Task Group)

American Automobile Manufacturers Association, ARCO Products Company, California Air Resources Board,Cummins Engine Company, Engine Manufacturers Association, Equilon, Ford Motor Company, GFI, IMPCO,National Propane Gas Association, Natural Resources Canada, Railroad Commission of Texas Alternative FuelsResearch & Education Division, South Coast Air Quality Management District, Tosco Refining Company, WesternStates Petroleum Association


  1. Executive Summary

Medium-duty emissions tests on a Cummins B5.9LPG engine are proceeding at ORTECH.Light-Duty Emissions tests on a Ford F150 Bi-Fuel Truck at ARB Haagen Smit Laboratory(ARB-El Monte) continued. The Tosco Refining Company (Tosco) agreed to fund Test Fuel #5.The LPG fuel blends' major components are listed below in Table 1. The ADEPT Group, Inc.(ADEPT) coordinated with the Technical Assessment Committee (TAC) and the Task Group tofinalize the Performance/Combustion testing protocol. Bids were finalized from qualified labs.Southwest Research Institute (SwRI) was awarded the Performance/Combustion tests.Fundraising continued.

 Table 1: Testing Fuel Blend Content

Fuel Name


PropyleneContent N-ButaneContent
Certification Fuel




Test Fuel #1




Test Fuel #2




Test Fuel #3




Test Fuel #4




Test Fuel #5




 II. Test Program Work Performed
  1. Fuel Properties and Octane Testing

A fuel blend with higher propylene content was added to the program (Test Fuel #5). Toscosponsored it.

ARB-El Monte and ORTECH do not have enough Test Fuel #2 to complete the number of testsagreed to by TAC. Cylinders of Test Fuel #2, Certification Fuel, and the Test Fuel #5 wereordered from Phillips 66.

The Certification Fuels and Test Fuel #2 (supplied by Aeriform and Phillips 66) at ORTECHwill be tested for composition at Dixie. These tests are to assure that the fuel components in thecylinder match the cylinder label. The Phillips 66 supplied Test Fuel #5 will be tested at Dixieonly if significant discrepancies are found in the other blends.

2. Medium-Duty Engine (Cummins B5.9LPG) Emissions Tests at ORTECH.

Emissions testing continued on a Cummins B5.9LPG engine at ORTECH. See Table 2 for asummary of emissions results as of July 24, 1998.

Table 2: Preliminary Medium-Duty Engine Emissions Results (g/bhp-hr)






Base Fuel





Fuel #1





Fuel #2





Fuel #3





Fuel #4





Those candidate fuels (test fuels) that have emissions levels equivalent to or better than the basefuel will be subjected to subsequent phases of Performance/Combustion and Durability tests.Equivalence is based upon the following formula:

XCandidate less than or equal to Xbase (1+2d)

Discussion is ongoing regarding the coefficient of variability (CoV or d) to be used to evaluateemissions results. The Task Group preliminarily approved a set of CoVs at the outset of theproject with the understanding to review these once the emission tests are completed. Theoriginal set was based on previous fuel studies. Statistical analysis of the emissions data fromORTECH and ARB produced a new set of CoVs that is directly related to this project. Thisobserved set of CoVs is significantly different from the original agreed upon CoVs set. The TaskGroup is evaluating which set of CoVs, or if a combination of both, should be used to evaluatethe emissions results. Table 3 illustrates one comparison of possible CoVs from data available asof July 28, 1998.

 Table 3: Medium Duty Emissions Test Variability

Medium Duty





Original Delta1





Observed Delta in Test





Combined Delta2





1 As outlined in the February 9, 1998 LPG test protocol.

2 Combines observed variability only with LPG engine results from original data. This "Combined d " has been proposed by ARB but has not yet been reviewednor approved by the Task Group

(Table provided courtesy of ARB)

The chosen set of CoVs will affect which test fuels will be considered to have "passed". Frompreliminary results, Test Fuels #3 and #4 are not likely to pass (due to high CO results). Fuels #1and #2 are on the borderline. The final evaluation will be made once all of the emissions data iscollected and reviewed.

The Task Group authorized ADEPT to proceed with four contract amendment authorizations(AAs). AA #4 was needed because the two runs on the Certification Fuel and Test Fuel #1 variedby more than the amount allowed by the MOU. AAs #5 and #6 funded additional emissions testson Test Fuel #2, which is close to equivalence. The last AA authorizes ORTECH to test Fuel #5.

  1. AA #4 provides a maximum $18,000 for emission tests on Certification Fuel and Test Fuel #1(one cold start cycle and three hot start cycles on each fuel).
  2. AA #5 provides a maximum $1,000 for emission tests (one cold cycle) on Fuel #2.
  3. AA #6 provides a maximum $1,000 for emission tests (two hot cycles) on Fuel #2.
  4. AA #7 provides a maximum $13,500 for emissions tests on Fuel #5 (one cold and three hotstart cycles).

ADEPT ordered more Test Fuel #2, Certification Fuel, and Test Fuel #5 from Phillips 66. Theseare scheduled for delivery to ORTECH in early of August.

  1. Light-Duty Truck (F150 Bi-Fuel) Emissions Tests at ARB Haagen Smit Laboratory

Testing is underway on the Ford F150 Bi-fuel truck at ARB-El Monte. Table 4 summarizesemissions test results as of July 15, 1998.

Table 4: Preliminary Emissions Results on a Light-Duty Truck at ARB-El Monte

Base Fuel 0.030 0.052 1.89 32.6 0.043
Fuel #1 0.039 0.048 1.83 29.2 0.039
Fuel #2 0.043 0.057 2.08 38.5 0.068
Fuel #3 0.046 0.053 1.49    
1 Suspect data under review.

(Table provided courtesy of ARB)

More variability in the light-duty engine emissions results is expected (and found) because of theFord F150 engine setup. Operating the engine inside a vehicle, rather than on an engine teststand, adds variables that affect the emissions data.

Results to date from ARB-El Monte are too preliminary to formulate conclusions regardingpassing fuels. However, the same discussion of the CoVs applies to the light duty emissions as itdoes to medium duty emissions.

Because the emission results for runs on Fuel #1 were greater than 2.7 times the CoV, more testson Fuel #1 were scheduled. More Fuel #1 and Fuel #5 were ordered from Phillips 66. ARB-ElMonte should receive these in early August.

  1. Performance / Combustion Tests

Proposals were received from three laboratories: SwRI, Cummins, and ORTECH. TAC and thebidding laboratories refined the protocol. Parameters to be measured are:

Engine speed Exhaust temperatures (all cylinders)
Engine torque Engine exhaust backpressure
Air flow Fuel flow
Engine blow-by Intake air temperature
Boost temperature In-cylinder peak pressure
Boost pressure Fuel temperature
Intake air pressure Fuel supply pressure
Barometer reading Test cell ambient humidity
 Parameters to be calculated are:
Engine power Coefficient of variance (CoV)
Equivalence ratio (lambda) Break specific fuel consumption
Mass fraction burned In-cylinder pressure rate of rise
Brake thermal efficiency Combustion duration
Rate of combustion Heat release rate
Tendency to misfire Tendency to knock (knock index)
Ignition evaluation at full load Power and torque map (at max torque, maxpower, and rated speed)
TAC met twice (July 9th and July 15th) to consider the bids and decide on a recommendation tothe Task Group. Table 6 shows the three labs cost estimates.

 Table 5: Cost estimates for Performance/Combustion Tests

Bids Considered Base and One TestFuel Base and TwoTest Fuels
Cummins $98,000 $145,000
SwRI $90,000* $101,000*
ORTECH $83,000* $99,000*
*Bids include a contingency margin added by ADEPT.

At the July 15th meeting, TAC agreed to recommend that the Performance/Combustion tests takeplace at Cummins. Further discussion within TAC, a budget review, and a review of currentemissions data caused TAC and the Task Group to change the prior recommendation at the July28th meeting.

The Task Group awarded the Performance/Combustion work to SwRI. TAC decided that twofuels were to be Performance/Combustion tested. SwRI has significant experience with theB5.9LPG engine.

Cummins promised to donate the engine for Performance/Combustion testing. In late July,Cummins withdrew its donation. ADEPT is searching for a replacement engine and alternativefunding for its purchase.

ADEPT is preparing fuel quotes for the Performance/Combustion tests. The fuel will be orderedafter the emissions results are evaluated.

  1. Durability Tests

ADEPT is preparing Request for Proposals to send to qualified laboratories to perform Durabilitytests. The Durability tests are to be performed on a Cummins B5.9LPG engine tentativelysponsored by the Sacramento Air Quality Management District.

Candidate labs are ORTECH and SwRI. The other candidate labs have declined to bid. Thiswork is scheduled to begin in late September.

  1. Project Management Support and Administrative Work Performed

A. Project Fundraising

A funding proposal for $100,000 was submitted to the Propane Education and Research Council(PERC). This proposal was reduced to $25,000 and resubmitted due to funding available andPERC priorities. ADEPT is coordinating $25,000 in funding from Tosco. SMAQMD funding forthe Durability test engine was postponed until issues regarding the Cummins warranty on theB5.9LPG engine are resolved.

  1. Project Expenditures

Table 6 shows July expenditures and total expenditures to date.

 Table 6: July Expenditures and Total Expenditures to Date

Item FundsExpended InJuly Total FundsExpended
Fuel (Aeriform)



Emissions Tests (ORTECH)



Fuel Properties (Dixie)






Attorney Fees












 Project Account Balance as of July 31, 1998: $40,540.34.

 Table 7: Total Funds Received to Date

Funder Amount












 C. Project Contracts and Other Documents

Except for Cummins, ADEPT received all the signatures to file the MOU. The National PropaneGas Association (NPGA), Propane Gas Association of Canada (PGAC), South Coast Air QualityManagement District (SCAQMD), Shell, and Western Propane Gas Association (WPGA)funding contracts were completed. The Alternative Fuels Research and Education Division(AFRED), ARB, ARCO, Cummins and Ford contracts are in various stages of completion. TheDisclosure of Joint Research Venture Filing awaits an agreement with AFRED and MOUsignature from Cummins.

ADEPT continued weekly project management conference calls with ARB. Other activitiesincluded the preparation of May report, TAC and Task Group conference call/meetings, contractsand amendments, and project bookkeeping.

Travel associated with effort described:

7/28/98 Mr. Spataru traveled to ARB in Sacramento for a Task Group meeting.

IV. Work planned for the next reporting period (August 1 - 31, 1998)

 Project Management-ADEPT

  1. ADEPT will continue general project management.
  2. ADEPT will prepare and complete funding contracts and letters of agreement for co-sponsors.
  3. ADEPT will continue fundraising.
  4. ADEPT will coordinate logistics for Performance/Combustion tests at SwRI.
  5. ADEPT will prepare and distribute a Request for Proposals for Durability tests.
  6. ADEPT will review proposals for Durability tests and recommend a lab.

 Test Program

  1. ORTECH will continue emissions tests.
  2. ARB-El Monte will continue emissions tests.
  3. SwRI will prepare for Performance/Combustion tests.

 V. Attachment:

Project Timeline (GANTT Chart).

 VI. Disclaimer

This report was prepared by The ADEPT Group, Inc. (ADEPT) as a result of work co-sponsoredby the South Coast Air Quality Management District (SCAQMD) and Task Group Members.The opinions, findings, conclusions, and recommendations are those of the author and do notnecessarily represent the views of SCAQMD. SCAQMD, their officers, employees, contractors,and subcontractors make no warranty, expressed or implied, and assumes no legal liability for theinformation in this report. SCAQMD has not approved or disapproved this report, nor have theypassed upon the accuracy or adequacy of the information contained herein.

 VII. Glossary of Acronyms

Delta - Coefficient of Variability

AA - Amendment Authorization

ADEPT - The ADEPT Group, Inc.

AFRED - Alternative Fuels Research and Education Division

ARB - California Air Resources Board

ARB, El Monte - ARB Haagen Smit Laboratory in El Monte, CA

bhp - brake horse power

BSFC - brake specific fuel consumption

CO - carbon monoxide

CoV - Coefficient of Variability

EMA - Engine Manufacturers Association

g/bhp-hr - grams/brake horse power/hour

LPG - liquefied petroleum gases

MOU - memorandum of understanding

NMHC - non-methane hydrocarbons

NMOG - non-methane organic gases

NOx - oxides of nitrogen

NPGA - National Propane Gas Association

NRCan - Natural Resources Canada

PERC - Propane Education and Research Council

PGAC - Propane Gas Association of Canada

SCAQMD - South Coast Air Quality Management District

SMAQMD - Sacramento Air Quality Management District

SwRI - Southwest Research Institute

TAC - Technical Assessment Committee

THC - total hydrocarbons

Tosco - Tosco Refining Company

WPGA - Western Propane Gas Association