HCNG: The ‘New’ Gas
HCNG is a mixture of compressed natural gas (CNG) and hydrogen (H). Scientists discovered that adding hydrogen to natural gas makes natural gas burn more cleanly, reducing its emission of pollutants. Although natural gas is a substantially cleaner fuel than gasoline, diesel, fuel oil or coal, the burning of natural gas produces carbon monoxide (CO), carbon dioxide (CO2) and nitrogen oxides (NOx) such as nitric oxide (NO) and nitrogen dioxide (NO2).
Research conducted in India has shown that HCNG reduces CO emissions by 40 to 50 percent, non-methane hydrocarbons (NMHC) emissions by 45 percent and NOx emissions by 20 to 30 percent over CNG. Moreover, there is evidence that there is a power improvement of 11 percent and fuel consumption reduction of 8 percent in an HCNG engine compared to a CNG engine.
Hydrogen is a fuel in its own right. Many people believe that hydrogen is the fuel of the future because when hydrogen is burned, it combines with oxygen creating water vapor emission. However, hydrogen contains much less energy than gasoline, diesel or natural gas, making it difficult to store enough hydrogen onboard a vehicle to go as far as other vehicles between fill-ups. Also hydrogen causes metal to become brittle, which is problematic for most engines and storage tanks.
Hydrogen is generally extracted from water (H2O) through electrolysis where electricity is run through water separating the oxygen and hydrogen atoms. The cost of producing hydrogen is very expensive and the problems of using hydrogen fuel in cars arise from the fact that hydrogen is difficult to store in either a high pressure tank or a cryogenic tank.
Enriching natural gas with hydrogen could be a potential alternative to common hydrocarbon fuels. It is a fuel for multiple purposes, including use in generators, residential appliances as well as trucks and automobiles. All the experiments show that the blends of hydrogen and natural gas reduce the exhaust emissions of both regulated pollutants and CO2 and increase the efficiency of a spark ignition engine. HCNG might also be developed for use in gas-fired power stations, as well as providing a lower-emission alternative to coal-fired power stations for baseload and peak power generation.
All gas stations in the US, including CNG and hydrogen stations, are regulated by Section 52 of the National Fire Protection Association (NFPA 52.) HCNG blended fuel with less than 20 percent hydrogen by volume is treated identically to CNG by NFPA 52. Moreover, hydrogen and CNG blends (HCNG) may be considered as an automotive fuel without any major modification to the existing CNG engine or the CNG fuel dispensing infrastructure.
Blending CNG and hydrogen complement each fuel, making each safer and more effective. For example, HCNG is safer to handle than pure hydrogen. HCNG extends the lean misfire limit of CNG. The phenomenon of hydrogen embrittlement does not occur with respect to the engine components and the excellent anti-knock characteristics of CNG are not undermined.
When using HCNG, no major change is anticipated in the fuel system and engine components, although minor modifications are required in the engine due to the moderate concentration of hydrogen in the fuel mixture. To increase the flame speed of HCNG engines, the ignition timing needs to be retarded; this results in reduction of NOx emissions.
In short, the addition of hydrogen to natural gas can decrease an engine蘑菇视频 unburned hydrocarbons and NOx emissions (by lean burn) and speed up the combustion process which in turn improves engine efficiency and lowers fuel consumption.
A number of research works are currently in progress to make HCNG as alternate for diesel engines with proper modifications.
Proponents of hydrogen fuel see HCNG as the gateway for hydrogen fueled vehicles. But the benefits of HCNG cannot be ignored.
David Pearl is vice president of Infinity Resource Group, Inc., a professional mineral rights consulting firm, specializing in the leasing and sale of mineral rights in Pennsylvania, West Virginia and Ohio. He is also managing director of a natural gas fuel dispensing patent holding company and director of a natural gas fuel island development company. Your questions are welcomed by calling 412-535-9200 or by emailing IRGOilGas@gmail.com.