Green Engines Development Using Compressed Natural Gas as an Alternative Fuel: A Review

Abstract

Problem statement:The Compressed Natural Gas (CNG) is a gaseous form of natural gas, it have been recognized as one of the promising alternative fuel due to its substantial benefits compared to gasoline and diesel. Natural gas is produced from gas wells or tied in with crude oil production. Approach: Natural gas is promising alternative fuel to meet strict engine emission regulations in many countries. Compressed Natural Gas (CNG) has long been used in stationary engines, but the application of CNG as a transport engines fuel has been considerably advanced over the last decade by the development of lightweight high-pressure storage cylinders. Results: The technology of engine conversion was well established and suitable conversion equipment is readily available. For petrol engines or spark ignition engines there are two options, a bi-fuel conversion and use a dedicated to CNG engine. The diesel engines converted or designed to run on natural gas, there were two main options discussed. There are dual-fuel engines and normal ignition can be initiated. Natural gas engines can be operated at lean burn and stoichiometric conditions with different combustion and emission characteristics. Conclusions: In this study, the low exhaust gas emissions of CNG engines research and development were highlighted. Stoichiometric natural gas engines were briefly reviewed. To keep the output power, torque and emissions of natural gas engines comparable to their gasoline or diesel counterparts. High activity for future green CNG engines research and development to meet future stringent emissions standards was recorded in the study.

Bi-fuel System - Gasoline/LPG in A Used 4-Stroke Motorcycle - Fuel Injection Type

“…Such arrangement provides a back-up fuel where gaseous refuelling facilities are not well developed. Gaseous fuels have low energy density resulting in low engine performance, low engine volumetric efficiency, and need of pressurized storage vessel [14,16]. However large pressure fuel tank could be utilized but weight, space, performance and cost must be compromised.…”

“…The average power output from burning LPG over the speed range of 65-100 km/h was 5.16 hp which was about 3.9% lower than that from using gasoline91 of 5.37 hp. According to Semin et al [14][15][16][17], the performance of the converted bi-fuel engine will generally drop 15-20% in maximum power from the petrol. In general, bi-fuel modified vehicles suffer power loss and encounter drive ability problems as from the design and/or the installation of the retrofit conversion packages.…”

“…Theoretically, it required more LPG about 16.2% for combustion. Like natural gas used as an engine fuel [14][15][16][17], the disadvantages of LPG were low energy density, low engine volumetric volume as a gaseous fuel, and need of pressurized fuel tank. Economically, LPG fuelled vehicles have a significant advantage over petroleum vehicles due to lower cost per energy unit.…”

“…To utilize the original engine arrangement system, the bi-fuel converted vehicle was fitted with fuel-injected engine modified to control the gas flow and revised ignition timing or alternatively, fitted with a standard gaseous control system [14][15][16][17]. Similarly, the motorcycle tested which was a fuel-injection type with water cooling system was fitted with the standard LPG equipment set for vehicle which was modified to control LPG firing properly.…”

Microwave Assisted Bioethanol Production from Sago Starch by Co-Culturing of Ragi Tapai and Saccharomyces Cerevisiae

“…Bio-fuels are liquid or gaseous fuels made from plant matter and residues, such as agricultural crops, municipal wastes and agricultural and forestry by-products. Liquid biofuels can be used as an alternative fuel for transport, besides other alternatives such as Liquid Natural Gas (LNG), Compressed Natural Gas (CNG), Liquefied Petroleum Gas (LPG) and hydrogen (Semin et al, 2009). Bioethanol produced from renewable biomass, such as sugar, starch, or lignocellulosic materials, is one of the alternative energy resources that are both renewable and environmentally friendly (Balat et al, 2008;Baras et al, 2002).…”