Results from 1977 investigation into the use of hydrogen on demand for use in internal combustion engines.
This investigation concluded there was a significant reduction in emissions and a decrease in the total energy consumption of a multicylinder piston engine running on gasoline (petrol) and a hydrogen-gasoline mixture.
The results was show to extend the efficient lean operating range of gasoline by adding hydrogen. Both botted hydrogen and hydrogen produced by a methanol steam reformer were used and compared to results from all gasoline.
The results were used to explain the advantages of adding hydrogen to gasoline as to a method of extending the lean operating range. The minimum –energy –consumption equivalence ratio was extended to leaner conditions by adding hydrogen while the minimum energy consumption did not change – showing that more usable energy was provided. All emission levels decreased at the leaner conditions and there was a significantly increased flame speed and reduced engine lag over all equivalence ratios (60 cm/sec increase to 120 cm/sec at low RPM to 110 cm/sec increase to 150 cm/sec at high RPM)
- It was shown that pure hydrogen injection produced the same results as for hydrogen produced from the methanol reformer process
- The minimum-energy-consumption equivalence ratio decreased from 0.79 to 0.67….. an 18 % reduction
- Oxides of nitrogen production are appreciably lower for hydrogen / gasoline mixture . Gasoline with reformed hydrogen from methanol have higher NOx emissions as the reformer must produce gas at a high enough temperature to prevent water and methanol condensation and the higher inlet temperature can cause higher peak combustion temperatures and therefore higher NOx emissions
- Whilst there are limitations of using the methanol reformation process , with proper design and catalyst selection to produce the hydrogen it is a possible way to use the energy lost in exhaust gases to produce hydrogen as an interesting supplementary or alternative fuel source..