Alternative Powered Engines
Internal combustion engines (ICE) have been serving humanity for almost 200 years. However, their wide use turns into a whole range of environmental and resource problems. 26% of all emissions of anthropogenic greenhouse gases are caused by the burning of fossil fuels. At the same time, more than 90% of the fuel used for cars, ships, locomotives and aircraft is derived from oil. When burning petroleum products, extremely harmful carbon monoxide, carbon dioxide, hydrocarbons, nitrogen oxides and other components are released into the atmosphere. Air pollution is the cause of every ninth death in the world and is recognized as one of the biggest challenges regarding health and environment. In a number of developed countries, active measures are being taken to gradually transfer transport from ICE and to expand the use of alternative sources of fuel. For instance, Germany passed a law banning the sale of new cars with ICE from 2030. The country plans to reduce automobile emissions to zero by 2050. Similar initiatives are being discussed in other EU countries, the United States, and India.
More active use of modern alternative powered engines will reduce the amount of harmful emissions into the Earth’s atmosphere, reduce the cost of maintaining vehicles and increase their efficiency. The development of such technologies will enable countries experiencing a deficit of traditional fuel to reduce their energy dependence. In this article we talk about 3 promising technologies for new types of car engines operating on alternative fuels: hydrogen and methanol fuel cells for electric vehicles, as well as internal combustion engines running on dimethyl ether.
HYDROGEN FUEL CELLS FOR ELECTROCARS
The use of hydrogen as a fuel is possible in vehicles with both internal combustion engines and hydrogen fuel elements. However, traditional piston ICEs are difficult to adapt to work on hydrogen. Besides, it is expensive (the cost of operation and maintenance of such a hydrogen power cell is about 100 times higher than that of a conventional internal combustion engine).
Alternative options are fuel cells (FC) that convert the chemical energy of the fuel into heat and a constant electric current feeding the electric motor or the vehicle’s on-board power systems. The fuel cell is a continuously rechargeable battery of two electrolyte-coated electrodes, between which an electrolyte is located. Through one electrode hydrogen is supplied, through the other – pure oxygen or oxygen from the air, to which chemical fuel and oxidizer are constantly added. The connection of hydrogen with oxygen usually occurs inside a porous polymeric membrane.
Hydrogen fuel cells are much more environmentally friendly, efficient (their efficiency is 45%, modern automotive ICE is 35%), reliable, capable of operating at low temperatures, with less overall dimensions. They can be used as power units in hybrid cars, and in electric vehicles – as supercapacitors.
METHANOL FUEL CELLS
Methanol is a high-quality engine fuel for ICE. It is also effective as an energy carrier in fuel cells used in portable electronics, transport applications, and also in electric vehicles. In TE, methanol is broken down by interaction with atmospheric oxygen (air), as a result of this reaction an electric current arises and water is formed as a by-product.
At present methanol production technologies are being developed from natural gas (bypassing synthesis gas) by hydrogenation from industrial carbon dioxide emissions (in the long run we may invent technologies allowing extracting directly from the air). Also, bio-methanol production from biomass (lignocellulose) is being developed, which will trigger the mass distribution of methanol fuel cells.
ENGINES RUNNING ON DIMETHYL ETHER
Dimethyl ether (DME) can become a serious competitor to traditional fossil and synthetic fuels and especially the main alternative to diesel. In comparison with diesel fuel, the ether burns better and is more environmentally friendly (it does not contain sulfur, within 24 hours completely decomposes in the atmosphere into water and carbon dioxide). It is generally cleaner fuel, non-corrosive, non-toxic, does not cause mutations (non-carcinogenic).
Today, DME is produced from recycled coal, natural gas, biomass, domestic and industrial waste. Second-generation synthetic biofuels (BioDME) are also being developed, which can be made from lignocellulosic biomass. It does not cause large expenses to convert a diesel engine into a DME engine, which can stimulate massive implementation of this technology.