Coal can be converted into gases and liquids for use as fuels or processed into chemicals for use in other products. Synthetic fuels or synfuels are the names given to these gases or liquids. Coal is heated in enormous tanks to produce synthetic fuels. When compared to burning coal directly, these fuels emit fewer toxins in the air.
The Great Plains Synfuels Plant in North Dakota transforms coal into synthetic natural gas (syngas). Coal-derived syngas can also be utilised to generate power and hydrogen. There are currently no commercially active coal-to-liquids facilities in the United States, however coal has been turned to liquids in South Africa for decades.
1Source: Monthly Energy Review, Table 1.3 and Table 6.2, May 2021, preliminary data for 2020, US Energy Information Administration.
2Coal is still used in small volumes in the residential and transportation sectors. In these sectors, the EIA no longer tracks coal consumption.
Is it possible to make gasoline from coal?
The manufacture of liquid transportation fuels, namely gasoline and diesel fuel, has reawakened interest in coal gasification technology due to volatile fuel costs and a desire for energy independence. For the United States, paths to the synthesis of liquid fuels from coal bring significant diversity in fuel supply capabilities, a high capacity for fuels production given the vast amount of domestic coal reserves, and greater energy security.
Although there are a variety of demonstrated process routes for producing gasoline and diesel fuel from coal, not all of which involve coal gasification (e.g. direct coal liquefaction), the most important methods are based on producing synthesis gas (syngas) from coal gasification, which is then converted to liquid hydrocarbons or alcohol for use as fuel or fuel refining feedstock. These are known as indirect liquefaction technologies since the coal is first gasified, then the syngas is converted to liquid products. Because contaminants like sulphur and mercury are eliminated from syngas during fuel synthesis, the outcome is ultra-clean liquid fuels that emit less pollutants than conventional gasoline and diesel. In reality, South Africa’s Sasol has been manufacturing considerable amounts of these clean-burning coal-derived fuels since 1955, with indigenous coal providing 30 percent of the country’s gasoline and diesel needs. Sasol’s coal to liquid fuels include jet fuel, which has been approved for use in commercial jet planes. Environmental concerns, national energy concerns, and global oil markets may all influence the further development of these uses.
Since World War II, Fischer-Tropsch (FT) synthesis has been a very important liquefaction method. The production of hydrocarbons or alcohols from carbon monoxide (CO) and hydrogen (H2) in syngas is aided by FT catalysts. The choice of catalyst, feed composition, and reactor variables such as internal temperature and pressure all influence the process’s end products. Straight-chain, saturated hydrocarbons of the form CnH2n+2 (termed paraffin hydrocarbons), aromatic hydrocarbons, olefins, and other species are produced during the FT synthesis stage. These can be processed into gasoline and diesel. Fuel gases such as methane (SNG) and liquefied petroleum gas (LPG; primarily propane and butane) are typically produced during FT synthesis, but they are typically minimised or recycled to give the most high-value liquid products. Waxes (longer-chain paraffin with 20 to 40 carbon molecules) are also created, although these can be “cracked” into shorter, liquid forms.
Syngas, unlike FT, can be turned to methanol, which can then be converted into gasoline using the ExxonMobil Methanol to Gasoline (MTG) process. A first-of-its-kind facility was established in New Zealand in 1985, and it successfully produced gasoline for ten years. It was developed by Mobil throughout the 1970s and early 1980s. Since then, the process has been developed to the point that it is now a viable alternative to conventional gasoline sources. MTG’s synthetic gasoline is a high-quality, low-sulfur, low-benzene gasoline that is a beneficial blending component for meeting sulphur and benzene-related environmental laws.
The following explanation goes through these major fuel synthesis pathways in detail.
- Clean Gasoline with Coal This article was originally published in September of 2008. Engineering of Hydrocarbons
- World Coal Association, Coal to Liquids
What is the composition of gasoline?
Gasoline is a petroleum-based fuel manufactured from crude oil and other liquids. Gasoline is mostly utilised in vehicles as an engine fuel. Motor gasoline is produced in petroleum refineries and blending facilities for sale at retail gasoline filling stations.
The majority of gasoline produced by petroleum refineries is unfinished gasoline (or gasoline blendstocks). To manufacture finished motor gasoline, gasoline blendstocks must be blended with other liquids to meet the basic standards for fuel acceptable for use in spark ignition engines.
Some finished motor gasoline is produced by petroleum refineries in the United States. Most finished motor gasoline sold in the United States, on the other hand, is made at blending terminals, where gasoline blendstocks, finished gasoline, and fuel ethanol are blended to make finished motor gasoline in various grades and formulas for consumer use. Detergents and other additives are sometimes combined into gasoline before it is delivered to retail outlets by some corporations.
Blending terminals are more numerous and widely distributed than petroleum refineries, and they feature filling stations for tanker trucks that transport finished motor gasoline to retail outlets.
The majority of finished motor gasoline marketed in the United States today contains roughly 10% fuel ethanol by volume. Ethanol is added to gasoline primarily to comply with the Renewable Fuel Standard, which aims to reduce glasshouse gas emissions and the amount of oil imported from other nations by the United States.
What is the use of coal today?
In the United States, coal is largely utilised to create energy. In fact, more than half of the electricity we use is generated by burning it in power plants. Every year, a stove consumes around half a tonne of coal. Each year, a water heater consumes around two tonnes of coal.
How does coal become gas?
Between 2011 and 2019, 121 coal-fired power facilities in the United States were repurposed to burn other types of fuels, with 103 of them being converted to or replaced by natural gas-fired plants, according to data from the US Energy Information Administration (EIA). In 2010, the United States possessed 316.8 GW of coal-fired capacity, but by the end of 2019, 49.2 GW had been retired, 14.3 GW had the boiler changed to use natural gas, and 15.3 GW had been replaced with natural gas combined cycle. Stricter emission rules, low natural gas prices, and more efficient new natural gas turbine technology prompted plants to transition from coal to natural gas.
Coal-fired power facilities are converted to natural gas using two alternative technologies. The first option is to decommission the coal-fired power station and replace it with a new natural gas-fired combined-cycle (NGCC) power plant. The second option is to convert a coal-fired steam plant’s boiler to use other fuels, such as natural gas.
Owners of 17 coal-fired power plants used the first technique between 2011 and 2019, replacing outdated coal-fired power plants with new NGCC plants. The new NGCC plants have a combined producing capacity of 15.3 GW, which is 94 percent greater than the coal-fired power plants they replaced, which had a capacity of 7.9 GW. The upgraded turbine technology utilised in NGCC plants is largely responsible for the rise in capacity.
What is the process of making gasoline?
Gasoline, commonly known as petrol, is a high-energy secondary fuel that can be viewed as a form of cash. It is utilised to power a variety of heat engines and, more critically, it serves as a source of fuel for a huge number of automobiles. Fractional distillation is used to break down crude oil into several petroleum products, including gasoline. Pipelines are used to transport the completed product to gas stations.
Most internal combustion engines require gasoline to operate. Gasoline is one of the most extensively used petroleum products as a result of this. Gasoline accounts for roughly half of all petroleum products consumed. Diesel, on the other hand, made up 20% and kerosene (or jet fuel) accounted for 8%. The cost of operating a vehicle is affected by the price of fuel, which varies dramatically around the world. Furthermore, oil supply and prices have become increasingly interwoven with the global economy, affecting the consumer basket.
Is it possible to convert coal into petroleum?
The process of turning coal into liquid hydrocarbons such as liquid fuels and petrochemicals is known as coal liquefaction. This process is commonly referred to as “Coal to X” or “Carbon to X,” with X referring to a variety of hydrocarbon-based products.
Will there ever be a shortage of gasoline?
As a result, the topic of when fossil fuels will run out remains unanswered. The answer isn’t a precise figure.
Coal, oil, and gas were anticipated to run out in 107, 35, and 37 years, respectively, in a 2008 research published in the peer-reviewed journal Energy Policy. According to this forecast, coal will be the only fossil fuel available after 2042 until 2117.
A 2019 report from Stanford University’s Millennium Alliance for Humanity and the Biosphere depicts a similar scenario. According to the MAHB, the world’s oil reserves will run out in 2052, natural gas reserves will run out in 2060, and coal reserves will run out in 2090.
According to the United States Energy Information Association, the country possesses enough natural gas to last 84 years. However, depending on how much is really generated and variations in predicted amounts of, this could modify “Resources that are technically recoverable. TRR comprises predictions of the amount of natural gas that will be produced as well as the amount that will be ‘technically recoverable’ using current technology “without taking into account the economics or the operational conditions
Meanwhile, during COP26, world leaders agreed to step up efforts to mitigate the effects of climate change. However, there are a slew of elements at work that will all play a role in determining the trajectory of the planet’s climate in the future decades.
Is it possible to make gasoline from natural gas?
A Synfuels gas-to-liquids (GTL) refinery converts natural gas into gasoline in numerous processes, but claims to do so more efficiently overall. First, natural gas is decomposed, or broken down “Under high temperatures, it is fractured into acetylene, a simpler hydrocarbon. A unique catalyst transforms 98 percent of the acetylene into ethylene, a more complex hydrocarbon, in a separate liquid-phase step. This ethylene may then be easily transformed into a variety of fuels, such as high-octane gasoline, diesel, and jet fuel. And the final product is sulfur-free.
“We can make a barrel of gasoline for a lot less money than Fischer-Tropsch can, says Kenneth Hall, the process’s inventor and former chairman of Texas A&M University’s chemical engineering department. According to Hall, a Fischer-Tropsch refinery is lucky if it can generate a barrel of gasoline for $35, but a much smaller Synfuels refinery could do it for $25. According to the business, such a plant might pay for itself in as little as four years at current fuel prices.
What is the most common place where coal is used?
China and India, with 82.3 exajoules and 17.5 exajoules consumed respectively, were the world’s two largest coal consumers in 2020. China contributed for around 54.3 percent of global coal use, while India accounted for 11.6 percent.