The greatest automotive story this century has been the “Dieselgate” conspiracy. Not only has it brought down the established regime at VW, but it’s shaken the very foundation of diesel powered transportation.
VW has already started rolling out a fix in Europe, which many of us are sceptical about, but are still “negotiating” with legislators in North America. This delay has opened the door for many lesser known technologies to offer a solution; some of them snake oil, some showing real potential.
One such technology is hydrogen injection, also commonly known as HHO.
Forty years of hydrogen injection.
Hydrogen injection has been around since the 1970s and works by injecting hydrogen into a modified, internal combustion engine, which allows the engine to burn cleaner with more power and lower emissions. Hydrogen is injected into the air prior to entering the combustion chamber. Hydrogen burns 10 times as fast as diesel and, when mixed with the diesel in the combustion chamber, accelerates the rate at which the diesel burns.
Don’t confuse hydrogen injection with hydrogen fuel cell technology, they’re vastly different:
• A hydrogen fuel cell electric vehicle is powered by a group of individual fuel cells, known as a fuel cell stack. The electricity generated by the fuel cell stack powers the electric motor that propels the vehicle.
Each fuel cell is an anode, a cathode and a proton exchange membrane sandwiched in between. Hydrogen, from a tank onboard the vehicle, enters into the anode side of the fuel cell. Oxygen, pulled from the air, enters the cathode side. As the hydrogen molecule encounters the membrane, a catalyst forces it to split into electron and proton. The proton moves through the fuel cell stack and the electron follows an external circuit, delivering current to the electric motor and other vehicle components. At the cathode side, the proton and electron join again, and then combine with oxygen to form the vehicle’s only tailpipe emission, water.
• Hydrogen injection systems, such as the aftermarket supplemental hydrogen on-demand system developed by Hydrogen Injection Technologies (HIT), utilize electrolysis to produce hydrogen on-demand. This hydrogen gas is synthesized from the atmosphere and released into the air-intake of any fuel based internal combustion engine. (The system is capable of NRE retrofit to any industrial engine, car, boat, RV, generator etc. up to 20 litres capacity)
Over the past 40 years several tests have been performed to investigate the impact of hydrogen injection on performance and emissions. One such test recently published by the SAE, a Direct Injection (DI) diesel engine was tested for its performance and emissions in dual-fuel (hydrogen-diesel) mode.
Using an Electronic Control Unit (ECU) controlled Electronic Gas Injector, the injection timing and duration were varied on a single cylinder, KIRLOSKAR AV1, DI Diesel. Hydrogen injection timing was fixed at TDC and injection duration was timed for 30°, 60°, and 90° crank angles.
The injection timing of the diesel was fixed at 23° BTDC. By using hydrogen and diesel as a fuel emissions of Hydro Carbon (HC), Carbon monoxide (CO) and Oxides of Nitrogen (NOx) decrease without exhausting more smoke.
The maximum brake thermal efficiency obtained was about 30% at full load for the optimized injection timing of 5° after Gas Exchange Top Dead Center (AGTDC) and for an injection duration of 90°-crank angle. The NOx emission tends to reduce to a lower value of 888 parts per million (ppm) at full-load condition for the optimized injection timing of 5° AGTDC and with an injection duration of 90° compared to neat diesel fuel operation.
Of interest in the VW saga the hydrogen supplemental fuel system developed by Hydrogen Injection Technologies has been field and lab tested (by CEE, Inc. a CARB certified laboratory) as a hardware only solution reducing NOx by over 50%.
Unlike hydrogen fuel cells HHO’s do not require a bulky pressure vessel to store the gas, as it’s a low pressure system that generates hydrogen through electrolysis of water.
As a retrofit it’s legal to run a Hydrogen Cell Generator (also called a Hydrogen Booster cell) to add HHO to the air intake, which can achieve 10% to 30% improvement in fuel consumption (Claimed).
According to Bob Boyce, the original H2O booster cell maker, the efficacy of the system relies on generating quality Hydroxy Gas. This requires a higher spin state of HHO, close to the level of deuterium to achieve consistent fuel consumption gains, and cells that can run 24/7 without heating up. Significant gains are achieved when the HHO bonds to hydro-carbon molecules, thereby completing the burn.
Moving hydrogen generation forward.
In 2014 scientists at Stanford University developed a process using a dry cell 1.5-volt battery to split water into hydrogen and oxygen at room temperature, potentially providing a low-cost method to power fuel cells in zero-emissions vehicles and buildings.
The water splitter is made from the relatively cheap and abundant metals nickel and iron. It works by sending an electric current from a single-cell AAA battery through two electrodes.
According to chemistry professor and lead researcher Hongjie Dai: “This is the first time anyone has used non-precious metal catalysts to split water at a voltage that low.” “It’s quite remarkable, because normally you need expensive metals like platinum or iridium to achieve that voltage.”
Fuel cell vehicles have been widely criticized for their high cost, the lack of infrastructure around their fuel delivery, and their low energy efficiency after accounting for the effort it takes to produce compressed hydrogen (often involving large industrial plants that use an energy-intensive process that combines steam and natural gas).
“It’s been a constant pursuit for decades to make low-cost electrocatalysts with high activity and long durability,” Dai explains. “When we found out that a nickel-based catalyst is as effective as platinum, it came as a complete surprise.”
The nickel-metal/nickel-oxide catalyst, discovered by Stanford graduate student Ming Gong, also requires significantly lower voltages to split water when compared to pure nickel or pure nickel oxide. This new technique is not quite ready for commercial production, though.
“The electrodes are fairly stable, but they do slowly decay over time,” Gong says. “The current device would probably run for days, but weeks or months would be preferable. That goal is achievable based on my most recent results.”
The next step is to improve that decay rate and to test a version that runs on electricity produced by solar energy instead of the AAA battery.
Benefits of HHO
In 2013, after eight years of research, Mark Dansie published an article on www.revolution-green.com where he outlined the following benefits:
1. HHO reduces carbon monoxide up to 90%. Carbon monoxide is a fuel and HHO acts a catalyst to promote its combustion
2. HHO decreases hydrocarbons by about 10% to 90%
3. HHO drops particulate levels, especially organic particulates by 10% to 70%
4. HHO will reduce EGT (Exhaust gas temperature) from 50 to 150 degree F (depending on engine load)
5. HHO also decreases mechanical noise (was noticeable in every lab test by all the technicians but not measured)
6. HHO doesn’t always reduce NOx and in some circumstances increase it (water injection reduces it really well)
7. Only a small, and very specific amount of HHO is required to achieve significant results. If too much is supplied engine efficiency will be reduced if using electrolysis to produce the HHO
8. Horsepower is increased between 3% and 12% depending on the engine and Cetane grade of diesel used.
9. HHO improved and cleaned heavily carbonized engines. Often after weeks of running, fuel efficiency increased through this cleaning process. In one case an improvement of 13% was obtained and when the hydrogen unit was removed it still retained an 11% improvement.
10. HHO works best at elevated engine speeds. There were no benefits at idling speed.
Although empirical results indicate that on-demand hydrogen injection technology does improve efficiency and reduce emissions, hard test data under recognized European and North American automotive standards is hard to find.
I for one would like to see before-and-after tests conducted under harmonized driving standards, to substantiate the gains claimed by Dansie, Hydrogen Injection Technologies, and other interested parties.
The timing is right! With France reducing incentives for purchasing new diesel vehicles, Euro6c and real world testing looming and VW’s predicament in America, Diesel engines need a new approach to cleaning up diesel exhaust gas emissions to survive the onslaught.