Sulfur dioxide complements

Additionally, in a microreactor the intrinsic kinetics and deactivation behavior of SCR catalysts is studied with flows up to 1.5m h . In both test facilities it is possible to vary all process parameters temperature, the ammonia to nitric oxide feed ratio, the nitric oxide and sulfur dioxide concentrations, the space velocity, and the catalyst geometry. These techniques provide information for somewhat small areas and therefore should always be performed to complement bench- or laboratory-scale activity and selectivity measurements. 

The nse of inert gases to protect wines in partly empty containers by preventing oxidation and aerobic microorganism activity may also be considered a physical stabilization process. This techniqne is described elsewhere (Volume 1, Section 9.6.1) as a complement to the use of sulfur dioxide. 

The acids present in a given wine are determined by the grape variety, climate, presence of gray rot [Botrytis cinerea), yeasts, bacteria, and various treatments to which the wine may be subjected (sulfur dioxide, ascorbic acid, acidification, desacidifica-tion). There are at least 50 different acids in wine ranging in concentration from 1 or 2gl (tartaric, malic, succinic acids) to hundreds of mgl (citric, lactic, acetic acids) to tens of mgl (pyruvic, shikimic acids). However, tartaric, malic (depending on the MLF), acetic, and succinic acids constitute 80-90% of total complement of wine acids. 

Products and Methods Complementing the Effect of Sulfur Dioxide... 

Considering the legitimate desire to lower sulfur dioxide concentrations, it is normal to search for adjuvants that complement its action by reinforcing the effectiveness of one of its properties. This chapter covers such chemical products and physical processes that have been or are likely to be authorized by the legislation of different... 

Table 9.2. Sweet-wine sterilization at the end of alcoholic fermentation by the use of octanoic and decanoic acids to complement the action of sulfur dioxide (Larue et al., 1986)...

The addition of ascorbic acid will limit (if not eliminate) must oxidations catalyzed by tyrosinase and laccase. Moreover, it is a substrate of laccase. It does not act by inhibiting the enzymes, as does sulfur dioxide, but rather by monopolizing the oxygen, due to its fast reaction speed. Ascorbic acid is used in this manner in certain countries to complement the protection given by sulfur dioxide against the oxidation of white grape must. Its... 

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