Hydrogen fuel enhancement is the process of using a mixture of hydrogen and conventional hydrocarbon fuel in an internal combustion engine, typically in a car or truck, in an attempt to improve fuel economy, power output, emissions, or a combination thereof. Methods include hydrogen produced through an electrolysis, storing hydrogen on the vehicle as a second fuel, or reforming conventional fuel into hydrogen with a catalyst.
There has been a great deal of research into fuel mixtures, such as gasoline and nitrous oxide injection. Mixtures of hydrogen and hydrocarbons are no exception. [1] [2] [3] [4] [5] [6] [7] [8] These sources say that contamination from exhaust gases has been reduced in all cases, and they suggest that a small efficiency increase is sometimes possible.
Many of these sources also suggest that modifications to the engine's air-fuel ratio, ignition timing, emissions control systems, electronic control systems and possibly other design elements, might be required in order to obtain any significant results. A modified vehicle in this way may not pass mandatory anti-smog controls. [9] Due to the inherent complexity of these subsystems, a necessity of modern engine design and emissions standards, such claims made by proponents of hydrogen fuel enhancement are difficult to substantiate and always disputed. [10]
To date, hydrogen fuel enhancement products have not been specifically addressed by the United States Environmental Protection Agency, as no research devices or commercial products have reports available as per the "Motor Vehicle Aftermarket Retrofit Device Evaluation Program." [11] They do, however, point out that installation of such devices often involves illegally tampering with an automobile's emissions control system, which could result in significant fines. [12]
Environment Canada does have a research paper on the subject. In tests done in their laboratory in 2004 they found no improvement in engine efficiency or fuel economy. [13]
There are also many aftermarket kits available for sale outside of the US. The fitting of these kits outside the US may not contravene laws in those countries where fitted.
Hydrogen fuel enhancement from electrolysis (using automotive alternators) has been promoted for use with gasoline-powered and diesel trucks, [14] [15] [16] although electrolysis-based designs have repeatedly failed efficiency tests and contradict widely accepted laws of thermodynamics (i.e. conservation of energy). Proponents, who sell the units (often called "HHO devices"), claim that the dynamics are often misconstrued, and due to the chemical properties of the resulting mixture, it is possible to gain efficiency increases in a manner that does not violate any scientific laws. Many tests by consumer watch groups have shown negative results. This technique may seem appealing to some at first because it is easy to overlook energy losses in the system as a whole. Those unfamiliar with electrodynamics may not realize that the electrolytic cell drains current from a car's electrical system, causing an increase in mechanical resistance in the alternator that will always result in a net power reduction. [9] [17] [18] [19] Since it requires more energy to separate hydrogen from oxygen than would be gained from burning the hydrogen produced in this method, the concept of such a device is often stated to be in direct violation of the first and second laws of thermodynamics. [20] [21] [22] [23] [24] [25] Monetary prizes have been offered to sellers or promoters of these devices to demonstrate their claims of increased fuel economy are true, with very few sellers taking the challenges and no device passing the challenges[ citation needed ].
Arvin Meritor, a Tier 1 supplier of automotive technology, at one time, was experimenting with a plasma reformer technology which would use hydrogen produced from the fuel to enhance engine combustion efficiency and reduce emissions of NOx. [26] This reference states that a 20% to 30% increase in engine thermal efficiency is possible. However, this requires that the engine should be modified to operate in the ultra-lean region of the plot of compression ratio vs. air/fuel equivalence ratio (lambda), along with other modifications. This technology would not work well as a retrofit to unmodified engine technology. This research was conducted in conjunction with the Sloan Automotive Laboratory at MIT. Eventually, the division conducting this research was sold off to an equity investment firm. [27]
In internal combustion engines, exhaust gas recirculation (EGR) is a nitrogen oxide (NOx) emissions reduction technique used in petrol/gasoline, diesel engines and some hydrogen engines. EGR works by recirculating a portion of an engine's exhaust gas back to the engine cylinders. The exhaust gas displaces atmospheric air and reduces O2 in the combustion chamber. Reducing the amount of oxygen reduces the amount of fuel that can burn in the cylinder thereby reducing peak in-cylinder temperatures. The actual amount of recirculated exhaust gas varies with the engine operating parameters.
A four-strokeengine is an internal combustion (IC) engine in which the piston completes four separate strokes while turning the crankshaft. A stroke refers to the full travel of the piston along the cylinder, in either direction. The four separate strokes are termed:
Fuel efficiency is a form of thermal efficiency, meaning the ratio of effort to result of a process that converts chemical potential energy contained in a carrier (fuel) into kinetic energy or work. Overall fuel efficiency may vary per device, which in turn may vary per application, and this spectrum of variance is often illustrated as a continuous energy profile. Non-transportation applications, such as industry, benefit from increased fuel efficiency, especially fossil fuel power plants or industries dealing with combustion, such as ammonia production during the Haber process.
Alternative fuels, also known as non-conventional and advanced fuels, are fuels derived from sources other than petroleum. Alternative fuels include gaseous fossil fuels like propane, natural gas, methane, and ammonia; biofuels like biodiesel, bioalcohol, and refuse-derived fuel; and other renewable fuels like hydrogen and electricity.
Lean-burn refers to the burning of fuel with an excess of air in an internal combustion engine. In lean-burn engines the air–fuel ratio may be as lean as 65:1. The air / fuel ratio needed to stoichiometrically combust gasoline, by contrast, is 14.64:1. The excess of air in a lean-burn engine emits far less hydrocarbons. High air–fuel ratios can also be used to reduce losses caused by other engine power management systems such as throttling losses.
The methanol economy is a suggested future economy in which methanol and dimethyl ether replace fossil fuels as a means of energy storage, ground transportation fuel, and raw material for synthetic hydrocarbons and their products. It offers an alternative to the proposed hydrogen economy or ethanol economy, although these concepts are not exclusive. Methanol can be produced from a variety of sources including fossil fuels as well as agricultural products and municipal waste, wood and varied biomass. It can also be made from chemical recycling of carbon dioxide.
Homogeneous Charge Compression Ignition (HCCI) is a form of internal combustion in which well-mixed fuel and oxidizer are compressed to the point of auto-ignition. As in other forms of combustion, this exothermic reaction produces heat that can be transformed into work in a heat engine.
In internal combustion engines, water injection, also known as anti-detonant injection (ADI), can spray water into the incoming air or fuel-air mixture, or directly into the combustion chamber to cool certain parts of the induction system where "hot points" could produce premature ignition. In jet engines — particularly early turbojets or engines in which it is not practical or desirable to have an afterburner — water injection may be used to increase engine thrust, particularly at low-altitudes and at takeoff.
Gasoline gallon equivalent (GGE) or gasoline-equivalent gallon (GEG) is the amount of an alternative fuel it takes to equal the energy content of one liquid gallon of gasoline. GGE allows consumers to compare the energy content of competing fuels against a commonly known fuel, namely gasoline.
Oxyhydrogen is a mixture of hydrogen (H2) and oxygen (O2) gases. This gaseous mixture is used for torches to process refractory materials and was the first gaseous mixture used for welding. Theoretically, a ratio of 2:1 hydrogen:oxygen is enough to achieve maximum efficiency; in practice a ratio 4:1 or 5:1 is needed to avoid an oxidizing flame.
Various alcohols are used as fuel for internal combustion engines. The first four aliphatic alcohols are of interest as fuels because they can be synthesized chemically or biologically, and they have characteristics which allow them to be used in internal combustion engines. The general chemical formula for alcohol fuel is CnH2n+1OH.
Fuel-saving devices are sold on the aftermarket with claims they may improve the fuel economy, the exhaust emissions, or optimize ignition, air flow, or fuel flow of automobiles in some way. An early example of such a device sold with difficult-to-justify claims is the 200 mpg‑US (1.2 L/100 km) carburetor designed by Canadian inventor Charles Nelson Pogue.
A bivalent engine is an engine that can use two different types of fuel. Examples are petroleum/CNG and petroleum/LPG engines, which are widely available in the European passenger vehicle aftermarket.
A water-fuelled car is an automobile that hypothetically derives its energy directly from water. Water-fuelled cars have been the subject of numerous international patents, newspaper and popular science magazine articles, local television news coverage, and websites. The claims for these devices have been found to be pseudoscience and some were found to be tied to investment frauds. These vehicles may be claimed to produce fuel from water on board with no other energy input, or may be a hybrid claiming to derive some of its energy from water in addition to a conventional source.
An alternative fuel vehicle is a motor vehicle that runs on alternative fuel rather than traditional petroleum fuels. The term also refers to any technology powering an engine that does not solely involve petroleum. Because of a combination of factors, such as environmental and health concerns including climate change and air pollution, high oil-prices and the potential for peak oil, development of cleaner alternative fuels and advanced power systems for vehicles has become a high priority for many governments and vehicle manufacturers around the world.
A free-piston engine is a linear, 'crankless' internal combustion engine, in which the piston motion is not controlled by a crankshaft but determined by the interaction of forces from the combustion chamber gases, a rebound device and a load device.
The Glossary of fuel cell terms lists the definitions of many terms used within the fuel cell industry. The terms in this fuel cell glossary may be used by fuel cell industry associations, in education material and fuel cell codes and standards to name but a few.
A hydrogen internal combustion engine vehicle (HICEV) is a type of hydrogen vehicle using an internal combustion engine. Hydrogen internal combustion engine vehicles are different from hydrogen fuel cell vehicles. Instead, the hydrogen internal combustion engine is simply a modified version of the traditional gasoline-powered internal combustion engine. The absence of carbon means that no CO2 is produced, which eliminates the main greenhouse gas emission of a conventional petroleum engine.
An internal combustion engine is a heat engine in which the combustion of a fuel occurs with an oxidizer in a combustion chamber that is an integral part of the working fluid flow circuit. In an internal combustion engine, the expansion of the high-temperature and high-pressure gases produced by combustion applies direct force to some component of the engine. The force is typically applied to pistons, turbine blades, a rotor, or a nozzle. This force moves the component over a distance. This process transforms chemical energy into kinetic energy which is used to propel, move or power whatever the engine is attached to.
(...) the definitive verdict of thermodynamics: water is not a fuel. It never has been one, and it never will be one. Water does not burn. Water is already burnt — it is spent fuel. It is exhaust. (...) And then there is poor Stanley Meyer, inventor of the 'water-powered car'. (...) How else can you extract energy by burning water, if not via a mythical substance?