Heat transfer gaseous nitrogen

An aqueous solution containing ethyl alcohol in water is fermented to produce dilute acetic acid. The feed mixture (the ethanol solution and the bacteria that make the fermentation occur) and a>r are fed at a temperature Tq. The product solution contains ethanol, acetaldehyde (CH CHO), acetic acid, and water. All liquid and gaseous effluents are at temperature T. The variables involved in the process are n (mol feed solution), x (mol eihanol/mol feed solution), n i (mol air fed). (percent excess air),nah, (gram-moles of ethanol, acetaldehyde, acetic acid, and water, respectively, in the product mixture), Hox, n (gram-moles of oxygen and nitrogen, respectively, emerging from the reactor), 7 , 7, and 0(kJ heat transferred . 

The gaseous nitrogen at the top of the pressure column is liquefied in the main condenser (13). This condenser is cooled by evaporating liquid oxygen from the sump of the low-pressure column. Condenser and evaporator are designed as a combined heat transfer unit, see also Section 2.2.5.6. Part of the condensate serves as reflux for the pressure column, the rest is expanded and fed as reflux onto the top of the low-pressure column. 

Sometimes substances to be determined in gaseous samples are adsorbed on solid adsorbents and then transferred to solution. Thus nitrogen oxides present in the atmosphere are chemisorbed on lead dioxide heated to a temperature of 190 °C. The lead nitrate formed is extracted into hot water and the NO3 anion is then determined [29]. 

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