What does “band-wise” mean in a sentence?

"It means “band-shaped”; in other words, the area that is inactive is in the form of a band

Agree with rainwolf’s explanation. Moreover, this deactivation zone moves along the catalyst bed, until the entire catalytic bed becomes deactivated. It should be similar to the adsorption zone in activated carbon adsorption used in water treatment, and the ion exchange zone in the ion exchange process.

Deactivation caused by basic compound impurities in the benzene feed generally results in band-wise deactivation of the first catalyst bed in the benzene flow path. Catalyst deactivation due to the presence of alkaline impurities in the benzene feed usually leads to the formation of an inactive zone in the first catalyst bed where the benzene flows.

Sometimes when I don’t understand English, looking up relevant English explanations online can also help with understanding. A disadvantage of the prior solid acid catalysts is that the catalyst can become rapidly deactivated due to the formation of polyalkylates (e.g., C12+ products), which inhibit the alkylation reactions – somewhat similar to very soft coke. Once a certain amount of polyalkylates is formed on the catalyst, the alkylation reactions essentially cease. In a fixed-bed reactor, which is often the preferred configuration, this deactivation can be seen as a gradual aging process, with the deactivated zone moving through the reactor over time until most of the reactor volume becomes inactive. This catalyst deactivation necessitates periodic regeneration of the catalyst in order to ensure that the process yields a sufficient amount of the desired product. Last edited by echommm on 2009-2-17 at 16:53