Does the water in the tetrahydrocarbon feedstock used in MTBE production have any impact on the reaction process?
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I would like to ask: does the water present in the carbon tetrahydrocarbons feedstock used in MTBE production have any impact on the reaction process? Whose quantity needs to be controlled? Water is one of the products of the reaction; does it need to be separated before proceeding to the second and third reaction stages?
There is definitely an impact; not only must the water present in the carbon tetrahydrocarbon raw material be removed continuously, but the water content in the recovered methanol also needs to be controlled (water content < 1%). Water, when combined with isobutylene, forms tert-butanol, which affects the purity of MTBE. As long as the alcohol-to-olefin ratio is properly controlled and too much methanol is not used, not too much water will be produced during the reaction.
It has been observed that water affects the activity of MTBE catalysts; how significant is this effect? If MTBE is used as a gasoline additive, it’s fine if there’s a little bit of tert-butanol, right?
The presence of water causes the sulfonic acid groups of the catalyst to detach, leading to a decrease in the pH value of the methanol recovery system and thereby causing corrosion; this is theoretical. Ultimately, it depends mainly on the amount of water; we have been keeping an eye on the water content, so we’re not sure how great the impact is. In addition, factors that affect catalyst activity include metal cations, sulfides, and alkaline substances present in the raw materials (including C4 and methanol), which can displace H+ from the catalyst, leading to the loss of H+ ； Excessively high reaction temperatures accelerate the loss of sulfonate groups from the catalyst; even at normal reaction temperatures, sulfonate groups can still be lost. Finally, if MTBE is used as a gasoline additive, a small amount of tert-butanol does indeed have no effect; but for uses of MTBE in the chemical industry, the presence of tert-butanol can have an impact.