Acid temperature calculation

This equation gives all the heat of mixing to H2S04 rather than to (H2S04 + H20). It allows H2 to be used without change in our acid temperature calculations. 

Di-n-amyl ether. Use 50 g. (61 5 ml.) of n-amyl alcohol (b.p. 136-137°) and 7 g. (4 ml.) of concentrated sulphuric acid. The calculated volume of water (5 ml.) is collected when the temperature inside the flask rises to 157° (after 90 minutes). Steam distil the reaction mixture, separate the upper layer of the distillate and dry it with anhydrous potassium carbonate. Distil from a 50 ml. Claisen flask and collect the fractions of boiling point (i) 145-175° (13 g.), (ii) 175-185° (8 g.) and (iii) 185-190° (largely 185-185-5°) (13 g.). Combine fractions (i) and (u), reflux for 1 hour in a small flask with 3 g. of sodium, and distil from the sodium amyloxide and excess of sodium this yields 9 5 g. of fairly pure n-amyl ether (iv). The total yield is therefore 22 - 5 g. A perfectly pure product, b.p. 184 185°, is obtained by further distillation from a Little sodium. 

Quantitative tests are rarely conducted in magazines and for production inspection purposes except for a test devised by Bergmann and Junk [62] in which the quantity of acid products (calculated as NO) evolved by the powder is determined by titration. The quantity of NO evolved on heating for 2 hr at a temperature of 132°C should not exceed 2.5 cm3 NO per 1 g of powder. (For more details see Vol. II p. 26.) Other quantitative tests are usually employed in research. 

The plot in Fig. 3.2 of the acid dissociation constant for acetic acid was calculated using equation 3.2-21 and the values of standard thermodynamic properties tabulated by Edsall and Wyman (1958). When equation 3.2-21 is not satisfactory, empirical functions representing ArC[ as a function of temperature can be used. Clark and Glew (1966) used Taylor series expansions of the enthalpy and the heat capacity to show the form that extensions of equation 3.2-21 should take up to terms in d3ArCp/dT3. 

The role of water in governing the upper thermal limits for life also is based on covalent transformations in which water is a reactant. As emphasized earlier in this chapter, the removal of a molecule of water from reactants is common in diverse biosynthetic reactions, including the polymerization of amino acids into proteins and nucleotide triphosphates into nucleic acids. The breakdown of biomolecules often involves hydrolysis, and increased temperatures generally enhance these hydrolytic reactions. The thermal stabilities of many biomolecules, for instance, certain amino acids and ATP, become limiting at high temperatures. Calculations suggest that ATP hydrolysis becomes a critical limiting factor for life at temperatures between 110°C and 140°C (Leibrock et al., 1995 Jaenicke, 2000). Thus, at temperatures near 110°C, both the covalent and the noncovalent chemistries of water that are so critical for life are altered to the extent that life based on an abundance of liquid water ceases to be possible. 

Fig. 21.1. Heat transfer flowsheet for single contact, sulfur burning sulfuric acid plant. It is simpler than industrial plants, which nearly always have 4 catalyst beds rather than 3. The gaseous product is cool, S03 rich gas, ready for H2S04 making. The heat transfer product is superheated steam. All calculations in this chapter are based on this figure s feed gas composition and catalyst bed input gas temperatures. All bed pressures are 1.2 bar. The catalyst bed output gas temperatures are the intercept temperatures calculated in Sections 12.2, 15.2 and 16.3.

This section shows how Fig. 24.1 s output acid temperature is calculated. It uses (a) Fig. 24.1 s temperatures and acid compositions... 

Fig. 24.1. Fig. 23.1 s single contact H2S04 making tower. Its temperatures and gas compositions are used in Section 24.1 and 24.2 s calculations. The calculations assume that all input S02(g) reacts to form H2S04(f). Note that output gas temperature = input acid temperature. ( Hay et al., 2003). 

Table 24.1. Fig. 24.1 s inputs and outputs. Input and output kg-mole of S03) S02, 02 and N2 are from Fig. 24.1. Input and output H2S04 and H20 masses are calculated in Appendix W. They are all used to calculate Fig. 24.1 s output acid temperature. The H values have been calculated by the equations in Appendix G. (kg-mole H2S04 = kg H2S04/98. kg-mole FI20 = kg H20/18)...

Fig. 24.5. Effect of S03(g)-in-input-gas concentration on H2S04 making output acid temperature. Output acid temperature decreases slightly with increasing S03(g) concentration. The volume% S03 values have been calculated as described in Chapter 16 starting with 8, 9, 10, 11 and 12 volume% S02 in 1st catalyst bed feed gas.

Five hundred grams of potassium nitrate are transformed into nitric acid by heating with sulphuric acid at a low temperature. Calculate —... 

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