Description
<h2><b>What is Acetylene Gas?</b></h2>
Acetylene gas is an odorless, colorless, and highly volatile gas. Acetylene can be liquefied, compressed, heated, or mixed with air, and in these forms, the gas is highly explosive. Therefore, special precautions must be taken during the production and transportation of acetylene.
Acetylene gas is mostly used as a raw material to produce various organic compounds. For example, it is used to create 1,4-butanediol, a substance widely used in the production of polyurethane and polyester plastics.
In addition, acetylene gas is also used as fuel for oxy-acetylene welding and metal cutting. It is used in the production of dry batteries and acetylenic alcohols, and acetylene also plays a fairly important role in the synthesis of vitamins.
<h3><b>The Process:</b></h3>
There are two different acetylene gas production processes: a reaction at normal temperature and another, a thermal cracking chemical process at extremely high temperatures.
Below are the details of each basic acetylene gas production process.
<h4><b>Chemical Process Details</b></h4>
The chemical reaction between calcium carbide and water produces acetylene and a significant amount of heat. Therefore, heat must be removed to prevent acetylene gas from exploding using a wet process.
This means using water to absorb heat by adding calcium carbide to water or adding water to calcium carbide. Or using a dry process, which uses only a limited amount of water, where the water evaporates and absorbs heat.
Most high-capacity acetylene production machines use a rotating screw conveyor to feed and transport calcium carbide particles with a size of 0.08 x 0.25 inches (2mm x 6mm) into a water-filled reaction chamber. The particle material is fed in according to the desired gas flow to be produced.
<h4><b>Acetylene Gas Preparation</b></h4>
In the reaction chamber, the calcium carbide particle and water solution is continuously stirred by a rotating paddle. This helps prevent acetylene explosions due to particles floating on the surface. The acetylene gas produced rises from the water surface and is extracted under low pressure.
As the gas leaves the reaction chamber, it is cooled with water. This water spray for cooling also simultaneously replenishes water in the reaction chamber. The gas is then passed through a flashback arrestor to limit accidental ignition from other chamber equipment.
<h3><b>Thermal Cracking Process</b></h3>
Acetylene gas can also be created from various other hydrocarbons by increasing the heat to break atomic bonds (thermal cracking process). After these hydrocarbon atoms break, they produce various gases.
This thermal cracking process is used to convert oil or natural gases into many different substances.
The result of the thermal cracking process depends on the input material and the heating method. Electric arcs or combustion chambers can be used to heat the materials, etc.
<h4><b>Acetylene Production in the United States (USA) – How the Common Process of Using a Combustion Chamber to Burn Natural Gas Works:</b></h4>
In the United States, the acetylene gas production process involves heating natural gases such as methane to about 1,200 °F (650°C).
The hot gas is then passed through a narrow venturi tube to mix with oxygen to reduce the speed as desired to avoid creating flames from the gas flowing too quickly or too slowly.
The gas mixture then flows into a burner block through more than 100 narrow channels, and when it enters each channel, it is burned and generates heat. The gas temperature at this time increases to about 2,730°F (1,500°C).
Oxygen will be added to the burner regularly to stabilize the combustion process. The combustion gases flow into a reaction space located just outside the burner, and the combustion process only takes a few hundredths of a second.
One-third of the methane is formed into acetylene where there is high temperature, and the remaining difficult-to-burn methane will be burned.
<h4><b>When the Flames Burn Quickly, They Are Cooled by a Water Spray at the Point Where the Conversion to Acetylene is Greatest</b></h4>
The cooled gases contain CO and H2, which make up the majority, increasing the temperature of the hydrocarbons if the amount of acetylene is low with the thermal cracking process.
The products of the thermal cracking process will produce carbon sludge, carbon dioxide, methane, acetylene, and other gases.
Then, through a second filter with N-methylpyrrolidinone solvent, which absorbs acetylene gas and extracts it at the top of the tower in gaseous form.
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<figure id=”attachment_9574″ class=”wp-caption aligncenter” aria-describedby=”caption-attachment-9574″><img class=”size-full wp-image-9574″ title=”acetylene production process” src=”http://migco.vn/wp-content/uploads/2020/05/quy-trinh-san-xuat-acetylen.jpg” sizes=”(max-width: 850px) 100vw, 850px” srcset=”http://migco.vn/wp-content/uploads/2020/05/quy-trinh-san-xuat-acetylen.jpg 850w, http://migco.vn/wp-content/uploads/2020/05/quy-trinh-san-xuat-acetylen-510×289.jpg 510w, http://migco.vn/wp-content/uploads/2020/05/quy-trinh-san-xuat-acetylen-705×400.jpg 705w, http://migco.vn/wp-content/uploads/2020/05/quy-trinh-san-xuat-acetylen-768×436.jpg 768w, http://migco.vn/wp-content/uploads/2020/05/quy-trinh-san-xuat-acetylen-600×340.jpg 600w” alt=”Acetylene production process” width=”850″ height=”482″ /><figcaption id=”caption-attachment-9574″ class=”wp-caption-text”>Acetylene production process</figcaption></figure>
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<h2><b>What Were the First Applications of Acetylene Gas?</b></h2>
Acetylene gas was discovered to be safely soluble in acetone for storage by Georges Claude and A. Hess in 1897.
Then in 1905, Nils Dalen used this method for signal lights and automatic railway signal beacons. A year later, he invented the acetylene torch used for welding or cutting metal.
<h3><b>Growing Demand and Applications of Acetylene Gas</b></h3>
The demand for acetylene gas is increasing due to its ability to produce many plastics and useful organic chemicals.
The demand for acetylene peaked in the United States from 1965 to 1970 and then decreased sharply because new replacement materials with lower costs emerged. Since the early 1980s, the demand for acetylene gas has grown slowly at a rate of about 2-4%/year.
In 1991, there were 8 acetylene production plants in the United States with an output of 352 million lbs (160 million kg) per year. 66% of acetylene was produced from natural gas and 15% of acetylene gas from petroleum processing, and the remaining 19% of production was from calcium carbide.
