Originally, DMSO was made from wood pulp (coming from different types of trees depending on the location of the producer), however that's no longer the case for most DMSO producers currently. With today’s technology, the current process to produce DMSO is more reliable, cleaner, and creates higher purity DMSO than those made as a byproduct of the Kraft (wood pulp) process.
The Kraft process for making DMSO required the byproducts of wood pulp production, but those byproducts were then further reacted in the manufacturing of DMSO.
Nowadays, the manufacturing process no longer depends on the paper/wood pulp making process for obtaining the raw materials needed to make DMSO. Here are the methods to produce DMSO currently:
1. Methylation of Dimethyl Sulfide (DMS): One of the most common methods of producing DMSO is through the methylation of dimethyl sulfide (DMS). In this method, DMS is oxidized using oxygen or other oxidizing agents. The methylation typically involves a reaction where dimethyl sulfide reacts with oxygen under specific conditions to produce DMSO. This process can be conducted using various catalysts or reactants such as:
o Oxidation with oxygen: This method involves passing oxygen over dimethyl sulfide at elevated temperatures, typically with a catalyst (e.g., metal-based catalysts like copper or iron). The reaction produces DMSO as the primary product.
o Reaction with chlorine: DMS can also be chlorinated to form dimethyl sulfonyl chloride, which can then undergo hydrolysis to produce DMSO.
2. Direct Sulfuration of Methane: In this method, methane (CH₄) can be reacted directly with sulfur (S₈) in the presence of a catalyst to form dimethyl sulfone, which can then be reduced to DMSO. This process is a high-temperature reaction, and the direct sulfonation of methane allows for the formation of DMSO.
3. Hydrolysis of Dimethyl Sulfate: Dimethyl sulfate (DMS) can also be hydrolyzed to produce DMSO. This is done by reacting dimethyl sulfate with water under controlled conditions. It is an alternative to using sulfur-based processes.
4. Selective Oxidation of Sulfides: Another approach involves the selective oxidation of sulfide compounds that are available from other sources. Sulfides, such as alkyl sulfides or dialkyl sulfides, can undergo oxidation reactions with oxygen or other oxidizing agents, resulting in the formation of DMSO.
