Methanol Economy
Methanol fuel cells offer great potential in powering small electrical devices like computers and camcorders.
Methanol can be produced using renewable biomass sources such as sugarcane bagasse or biomass waste materials. CO2 captured via carbon capture and utilization can also be utilized as the base material.
What is a methanol economy?
As more attention has been brought to climate change and carbon emissions, more people have begun exploring alternative fuel sources, with Ethanol often mentioned as an alternative to gasoline.
But questions still abound regarding its viability; one such question being "What exactly is Ethanol?" Ethanol is a single carbon atom compound produced through various processes and used as a gasoline alternative in various blends; most often E85 (85% ethanol/15% gasoline).
Not only is this type of fuel much cheaper than its gasoline equivalent; it provides better mileage as well as reduced engine wear due to reduced engine wear-on.
Methanol production today can come from various sources including biomass, municipal waste, natural gas and coal using synthesis gas (Syngas). This involves catalytic reforming of fossil fuels to produce carbon dioxide-rich flue gases before using chemical processes to convert these flue gases to methanol via catalysis.
Methanol can not only be found at gas stations, but can be easily stored and transported due to its non-volatility. Furthermore, it serves as an efficient hydrogen carrier by packing more hydrogen into its simple alcohol molecule than can be found in pure hydrogen itself.
At points of use hydrogen can even be converted to methanol on demand in order to avoid costly and energy intensive logistics associated with shipping hydrogen in liquid form.
Methanol is more eco-friendly than other petroleum based fuels as its combustion produces significantly fewer harmful greenhouse gases and soot, and burns much cleaner than gasoline, creating far fewer nitrogen oxide emissions that cause respiratory ailments in urban populations.
Methanol makes an ideal replacement fuel, since it is readily available and utilizes existing pumping infrastructure. Furthermore, through the MTO process it can easily be converted to synthetic hydrocarbons and olefins derived from oil for use as automobile, stationary power unit and marine engine fuel sources.
How can methanol be produced?
Methanol production can come from various sources such as natural gas, coal, biomass and municipal waste, making it an alternative fuel that competes and complements ethanol in an energy marketplace. Methanol can be used in fuel cells or burned as pure substance by automobiles; China already employs this practice. Furthermore, methanol serves as an efficient precursor for producing synthetic hydrocarbons such as poly(ethene) and poly(propene) used to manufacture plastics and other high-value chemicals.
University of Illinois researchers have developed a technology using simple catalysts, low temperatures and inexpensive electricity to break carbon-oxygen bonds in methane to convert it to methanol and water - one route towards creating a methanol economy.
While methanol production currently relies on fossil fuels for production, this process may allow production directly from abundant and renewable methane or carbon dioxide found at fossil fuel deposits or byproducts from oil and gas operations; creating circular production cycles in accordance with circular economy principles.
Methanol as an alternative fuel in vehicles produces significantly reduced levels of nitrogen oxides (NOx), dry particulates and greenhouse gas emissions like carbon dioxide (CO2) and sulphur oxides (SOx), making methanol an attractive replacement fuel choice that uses existing gasoline infrastructure while being safe, clean and non-toxic.
Methanol's great advantage lies in its production from renewable feedstocks such as wood wastes, grasses, agricultural crops and their byproducts, animal waste and municipal waste. Furthermore, it can also be produced using methane extracted through syngas from both traditional natural gas resources as well as unconventional fossil fuel sources like coalbed methane, shale gas or even massive methane hydrate deposits that exist under continental shelves of oceans and Siberian-Arctic tundra regions.
How can methanol be used?
Comparative to gasoline, methanol is more cost-competitive and can be easily integrated into existing car engines without modifications. Furthermore, methanol produces significantly fewer air pollutants such as hydrocarbons, NOx and SO2, as well as being produced carbon neutral using renewable feedstocks like biomass or coal; in some instances even waste products from chemical industry production could help further decrease petroleum dependence.
Methanol can be used as fuel for heat engines such as gas turbines and internal combustion engine (ICE) automobiles, and for producing electricity via fuel cells. Methanol-to-hydrogen production yields greater efficiency than gasoline-based combustion engines, decreasing overall energy usage by up to 50 percent.
Chemically reactive carbon atoms in methanol react readily with oxygen molecules at high temperatures to create four molecules of water (4H2O) and two molecules of carbon dioxide (2CO2).
This process can be powered either through waste heat from electrolysis and methanol synthesis processes or surplus energy generated by fuel cells; when using surplus energy produced from a fuel cell instead, an 85-90% thermal overall efficiency can be reached assuming waste heat is used pre-heating the fuel before entering into a fuel cell.
Methanol production goes beyond fossil fuels; renewable feedstocks like agricultural residues, municipal solid waste (including plastics and styrofoam), wood and varied biomass can all provide sources for its production. Another possible source for its creation would be chemical recycling of carbon dioxide. At first this may come from power plants burning fossil fuels or cement factories' flue gas streams but eventually even low concentration atmospheric CO2 could be captured and recycled into methanol production.
Methanol is an ideal alternative to hydrogen as it can be easily stored as a liquid at room temperature and boasts higher energy density per volume than liquid hydrogen. Furthermore, methanol can be easily converted to produce hydrogen at gas stations or other stationary power units on demand - negating the need for costly and energy-intensive storage and transportation solutions for liquid hydrogen.
How can methanol be converted to synthetic hydrocarbons and olefins that are currently derived from petroleum?
Methanol production today can be used for the creation of various chemicals and products, including gasoline through the MTG process and synthetic hydrocarbon fuels like ethylene and propylene through the MTG-to-olefins process; both of which serve as building blocks in polymeric materials we use daily such as LDPE and HDPE plastics reducing our dependence on fossil fuels.
Methanol can serve as a viable replacement fuel in internal combustion engines, thanks to its lack of carbon-to-carbon bonds and higher oxygen content, which allows for soot-free combustion without producing oxides such as NOx. Furthermore, methanol is less toxic than many alternative fuels and less likely to evaporate as quickly than hydrogen fuel cells.
Renewable methanol differs significantly from its black methanol counterpart in that it can be produced from any biomass source with minimal greenhouse gas emissions, including wastes, agricultural residues and byproducts from crop farming, as well as forest harvest residues. Syngas produced through biomass gasification offers the greatest promise when making renewable methanol commercially viable.
Renewable methanol not only meets environmental goals but is an excellent octane enhancer when blended with conventional gasoline - up to M85 blends can be used. High concentrations may also be utilized by vehicles designed specifically for flexible fuel vehicles (FFVs).
Methanol offers an efficient alternative to gasoline due to its cleaner burning characteristics. It can be used in all engine and transmission systems used for gasoline use except the fuel pump and oxygen sensor. Although methanol's energy density is lower than gasoline's, its higher octane number allows higher compression ratios with improved direct injection resulting in improved engine performance and reduced emissions. To offset its lower volumetric energy content (and hence reduce vaporization losses) larger tanks or optimizing vehicle fuel systems may help compensate.
