Apex Engineering (Pvt) Ltd.

The Project History

Mid 2004: Apex Engineering started research for a source of technology to convert Diesel engines to Dedicated CNG fuel.
End 2004: Technical assistance deal finalized.
Mid 2005: Technical assistance and conversion of fleet to dedicated CNG fuel deal finalized with M/s Khan Brothers Pvt Ltd Multan.
June 2005: Engine parts dispatched to the Technology Provider for analysis ,modifications and preparation of prototype.
Aug 2005: Modified parts along with all conversion equipment received in Pakistan.
Sep 2005: First Hino 6 cylinder engine,7961cc, successfully converted and all static tests completed.
Oct 2005: Bus handed over to the owner after 300 Km road tests.
Nov 2005: Bus completes 45 days trial period without any single fault or break down.

CONVERSION OF DIESEL BUSES TO DEDICATED CNG FUEL

Project for Hino Buses By
Apex Engineering (Pvt) Ltd.

Economics of Conversion(CNG)

Operational Cost
This bus has traveled more than 5800 Km in about 2650 Kg of CNG. The result is 2.19 Km per Kg or Rs 12.78 per Km in the City. This performance can be improved to 2.75 + Km per KG of CNG by restricting the max RPM and Max speed limits.
Maintenance Cost
There has been zero engine maintenance in the last 60 days since the engine has been converted to CNG .

Diesel Engine Economics

Operational Cost
The average performance of a similar diesel engine is 2 Km within city and 2.5 Km on the longer routes.
Wastage/pilferage of diesel within Depots is a major problem for the fleet owners.

Maintenance Cost
Fuel Injection pump and Fuel Injection nozzles need regular calibration and maintenance.

Monitoring Emission Quality

Replacing diesel with CNG vehicles, or converting existing diesels to CNG has substantial health/pollution benefits

PM reductions reasonably certain
NOx reductions depend on CNG technology / implementation
Emission monitoring and followup are needed to ensure that anticipated air quality benefits are actually achieved

Emissions certification data do not adequately predict in-use emissions for heavy-duty vehicles. Emissions should be measured in-use, under normal driving conditions

Heavy-duty chassis dynamometer
On-board emission measurement systems
- More readily available
- Lower measurement cost
- Measure emissions under real (thus, realistic) driving conditions

SUMMARY

In this study, particle number emission was measured on-line for several fuel/engine technologies at three different temperatures.
The study demonstrated that there are huge differences in emission performance between different fuel/engine technologies
Diesel vehicles produced highest NOx and PM emissions

the difference in both PM mass and particle numbers is at least a factor of 10 compared to the other technologies

Ambient temperature had a substantial impact on CO and THC emissions when running on gasoline and E85
Particle mass and number emission was not affected much by temperature
CNG gives superior overall emission performance. including low-temperature operation

in this study, the low-temperature performance of the bi-fuel LPG vehicle was not good due to the gasoline system used for start-up

VTT Technical Research Centre Finland

Conclusion

Diesel is a mature and reliable technology but suffers from severe environmental emission problems.
CNG vehicles are the only commercial alternative to diesel buses.
CNG emission performance is far superior to all current diesel technologies.
Due to reduced prices, CNG is generally cheaper than diesel to operate.
CNG buses have some range and payload restrictions but can be overcome by allocating specific vehicles to specific routes.
CNG bus engines are still developing but the latest fuel-injection technologies offer great promise of emissions, fuel economy, maintenance and reliability