We are happy to introduce our new InteliBifuel Multiple Point Injection Technology that can significantly reduce the costs and emissions of diesel engines. As its title implies, with multiple point injection (MPI), the alternative fuel is precisely injected into each internal combustion engine cylinder, whether natural gas, hydrogen, or any other future fuel that will enter the market. The MPI technology is offered in several configurations, be it dual-fuel or tri-fuel solution.

“The MPI technology is the most efficient solution in our InteliBifuel portfolio from the performance and emission reduction perspective. Since the substitute fuel is injected into a suction manifold of each cylinder, which means a high level of precision, we can proudly say it´s one of the most effective dual or tri-fuel solutions in the market,“ says Lukas Spilka, Product Manager for Bi-fuel products at ComAp.

Multiple Point Injection technology can be utilized for engine emission reduction in multiple industries, including power generation, mining, oil and gas, industrial transportation and maritime. Depending on the engine speed and preferred substitute fuel, InteliBifuel Multiple Point Injection technology offers several configurations:

• Dual-fuel with Diesel and Natural Gas or Hydrogen 
  The MPI solution is suitable for low, medium and high-speed engines with revolutions ranging from 375 RPM up to 2200 RPM.
  The introduction of hydrogen into a diesel engine provides the most significant emission reduction. This solution might be applied in both stationary power generation and variable speed applications. 
• Tri-fuel with Diesel, Natural Gas, and Hydrogen 
  This application significantly reduces emissions due to hydrogen usage while simultaneously cutting operation costs thanks to natural gas. Tri-fuel applications are suitable for high-speed engines with 1500 RPM and more, both stationary and variable speed. 
• Gas engine with Hydrogen
  This conversion is also suitable for solely gas engines, either in a combination of natural gas and hydrogen (creating dual-fuel) or converting the engine to run solely on hydrogen. The latter offers even better emission reduction and improves the engines response time and injection precision. 

Emission reduction improvement              

The MPI method enables greater emission reductions than before thanks to the precise introduction of substitute fuel. Based on the application, the extent of the decrease in emission may vary.

• Dual-fuel with natural gas decreases CO2, NOx, and particulate matter (PM) and CH4 compared to former Bi-Fuel technologies.
• Dual-fuel with Hydrogen has a positive effect on lowering CO2, CO, and PM. A slight increase in NOx might be easily addressed with appropriate after-treatment.
• Tri-fuel with hydrogen and natural gas leads to a decrease in CO2 and PM when compared to pure diesel operation. Compared to dual-fuel with natural gas only, there is also a reduction in CO and methane slip.

A concrete example of emission reduction in a real-world scenario:

The abovementioned statements about emissions reduction are based on the measurement that has been conducted with following conditions and results.

Engine: 6 in-line cylinder, RPM = 1500 min^-1, max H2/Diesel @ 170 kW = 25%.

Emission results

The effect on emissions is conditioned by several factors such as engine condition, pre-injection, air-to-fuel ratio etc. Some trends can be calculated because of the proportionality to hydrogen substituting diesel.

• CO₂ – the reduction is proportional to the hydrogen amount - less carbon-like fuel, less CO₂:
  15% substitution ~ 15% reduction of CO₂.

• CO – the reduction, explained as better/faster combustion process with higher temperature. allowing to transform CO into CO₂. Generally, the CO amount is very small in diesel engines and the reduction, we observed, slightly surpasses substitution with hydrogen:
  15% substitution ~ 20% reduction of CO.

• PM – the significant effect: 15% substitution ~ 40% reduction of PM.

Hydrogen plays an important role in the reduction of harmful molecules in the exhaust. 

• CH4 emissions 

CH4 emissions reduction by the MPI technology.
Comparison of MPI with Single Point Injection (SPI) and Fumigation technologies with same substitution 40% NG and 60% diesel.