Sulfuric acid, selectively accumulated

Partially proton-exchanged Na faujasite X, in turn, is the best catalyst for selective monochlorination with tert-butyl hypochlorite.258 NaX, NaY, and NaKL zeolites used in the chlorination of toluene with sulfuryl chloride undergo rapid deactivation because of the accumulation of polychlorinated toluenes in the pores of the catalysts and dealumination.259, 260 Direct electrophilic fluorination of aromatics can be effected by using Selectfluor in the presence of triflic acid.261 Electrophilic fluorination may also be carried out by R2NF and R3N+FA reagents.262 Elemental fluorine may also act as a powerful electrophile in acidic media (sulfuric acid, trifluoroacetic acid, or formic acid), but monosubstituted aromatics give isomeric mixtures.263-265... 

Sulfur Dioxide and Aldehydes. Sulfur dioxide is commonly added both before and after fermentation in preparing white table wines. It is an effective antioxidant as well as a selective inhibitor of unwanted microorganisms. However, sulfur dioxide, as the bisulfite ion in solution, combines with aldehydes, especially acetaldehyde, during fermentation giving an accumulation of aldehydes in the bound form of aldehyde-sulfurous acid. 

Replacement of sulfuric acid in "mixed acid" aromatic nitrations by inorganic solids, with accumulation or elimination of produced water results in a fundamental different behaviour of the "HN03 - solid" couple. If water accumulates, nitric acid becomes a selective oxidative coupling agent, whereas when water is eliminated efficiently, nitric acid alone behaves as a strong nitrating agent, with increased paraselectivity as compared to the sulfo-nitric system. 

The reactive distillation operation is obviously not limited to zeolite catalysts. It can also be carried out with homogeneous acids such as sulfuric acid or p-toluene-sulfonic acid. Since they lack shape selectivity, these catalysts first convert phenyl-ethanol to the corresponding ether and only then to styrene. Hence, the reaction proceeds in a solution of heavy products that have accumulated over time. Additives have been developed to control the oligomerization reactions and keep the liquid viscosity at a workable level [35]. The heavy liquid medium needs to be bled. Its contamination with strong acid makes its disposal costly, however. 

In this paper, we present data for total organic carbon (TOC), sulfur and iron contents in sediment samples from piston and box cores taken from the shelf and slope off southwestern Taiwan. We also present data of acid soluble iron, sulfidic iron and porewater sulfate in selected samples. The goal of this study is to illuminate the unusual inter-relationships among carbon, sulfur and iron in the rapidly accumulating sediments off southwestern Taiwan, which may serve as a typical example of sedimentation environments around high-standing islands with rapid denudation rates. 

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