Batch salicylic acid nitration by nitric acid/acetic acid mixture under isothermal, isoperibolic and adiabatic conditions

Andreozzi, Roberto; Canterino, Marisa; Caprio, V.; Somma, Ilaria Di; Sanchirico, Roberto

doi:10.1016/j.jhazmat.2006.05.104

Cited by 12 publications

(12 citation statements)

References 3 publications

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“…The synthesis can be performed in a solution of nitric and acetic acid under intensified conditions in order to avoid waste disposal and hazards associated with traditional mixtures of nitric and sulfuric acids . The nitration of aromatic compounds has the potential for autocatalytic behavior and run-away scenarios due to their high exothermicity. ,, Consequently, a continuous process using a microreactor brings added safety by reducing the working volumes associated with the synthesis as well as increasing the specific heat transfer area.…”

Section: Case Studiesmentioning

confidence: 99%

“…The reaction network producing 5-NSA acid has a reaction half-life of 0.5 s under undiluted conditions at 65 °C . The presence of water, however, has been shown to reduce the activity of the nitric acid by preventing the formation of the nitronium ion (NO 2 + ). , The homogeneous reaction is thus considered a Type A or B at different water concentrations and temperatures.…”

Section: Case Studiesmentioning

confidence: 99%

“…53 The nitration of aromatic compounds has the potential for autocatalytic behavior and run-away scenarios due to their high exothermicity. 8,52,54 Consequently, a continuous process using a microreactor brings added safety by reducing the working volumes associated with the synthesis as well as increasing the specific heat transfer area.…”

Section: Decomposition Hazardsalicylic Acid Nitrationmentioning

confidence: 99%

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From Batch to Continuous Chemical Synthesis—A Toolbox Approach

Plouffe

Macchi

Roberge

2014

Org. Process Res. Dev.

127

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A toolbox approach for the transfer of batch to continuous chemical synthesis is presented. The approach considers reaction kinetics (Type A, B, C), reacting phases (single phase, liquid−liquid, gas−liquid and liquid−solid), and the reaction network (parallel and consecutive reactions) in order to select the most appropriate reactor module (Plate, Coil, or CSTR) for continuous operation. Then, three case studies using these three fundamental reactors are presented but require special considerations. For the reaction of dimethyl-oxalate with ethylmagnesium chloride, a plug-flow multi-injection technology must be used to decrease the local heat generation and improve yield. For the nitration of salicylic acid, a Plate reactor with mixing elements favoring some back-mixing followed by a plug-flow system at elevated temperatures is used instead of a tandem mixed-flow CSTR and plug-flow Coil reactor in order to minimize the risk of thermal decomposition of intermediates with a reduced volume penalty. Finally, a ring-closing metathesis reaction is discussed for which the utilization of a CSTR allows the removal of catalyst-poisoning ethylene formed during the reaction and keeps the substrate concentration low to increase the yield above that of a batch or plug-flow system.

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Section: Case Studiesmentioning

confidence: 99%

Section: Case Studiesmentioning

confidence: 99%

Section: Decomposition Hazardsalicylic Acid Nitrationmentioning

confidence: 99%

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From Batch to Continuous Chemical Synthesis—A Toolbox Approach

Plouffe

Macchi

Roberge

2014

Org. Process Res. Dev.

127

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“…Upon hydrogenation, 5‐NS is converted to 5‐aminosalicylic acid, which is the active ingredient in the treatment of Crohn's disease and ulcerative colitis. Several nitrating systems have been used to produce 5‐NS, including nitric acid/sulfuric acid/water (mixed acid), nitric acid/acetic anhydride/acetic acid, and aqueous nitric acid; however, Andreozzi et al15–17 have recently proposed a nitric acid/acetic acid mixture for the nitration of SA. This system has several potential advantages such as higher selectivity and yield, ease of product separation, improved process safety, and lower waste disposal costs.…”

Section: Salicylic Acid Nitration Case Studymentioning

confidence: 99%

“…Andreozzi et al16 consider the following set of reactions with second‐order kinetics shown in Eq. 18, the kinetic parameters are given in Table 5.…”

Section: Salicylic Acid Nitration Case Studymentioning

confidence: 99%

Selectivity versus conversion and optimal operating policies for plants with recycle

2008

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in Wiley InterScience (www.interscience.wiley.com).A simple and fast procedure is developed for determining optimal steady state operating policies for chemical plants with recycle. This article improves upon the previous findings by Griffin et al. (Ind Eng Chem Res. 2006;45:8056-8062) and now provides a more general classification procedure for process chemistries that have reversible reactions or reactions of unequal overall order or both. Selectivity vs. conversion relationships are indirectly determined herein, requiring only the reaction orders of reaction species. The effect of these relationships allows process chemistries to be classified into two equivalence classes: bounded and nonbounded. This classification has important implications for the optimal operation and plantwide control structure of a flexible plant with spare equipment capacity. For instance, using the classification procedure and decision tree developed in this article, it can be determined quickly whether or not it is economically optimal to operate the reactor at the holdup constraint under all operating conditions (bounded) or away from the constraint with a variable holdup operating policy (nonbounded).

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