Questions:
The heat capacity of mash may be assumed to be the same as that of water. The specific gravity of the mash prior to fermentation is 1.1; after fermentation it is 1.05. The heat capacity of grains is 0.25 Btu/Ibm°F. In your solutions to the following problems, cite all sources of data not given in the process description, and clearly state all assumptions.
1. Construct a flowchart of the process but exclude the section of solids recovery arising from the bottoms stream exiting the ethanol concentrator. Fill in the component flow rates (lb,„/h) and temperatures and pressures where relevant of each stream on the flowchart to the extent possible after solving all the problems given.
2. Construct the solids recovery process that results from the bottoms product of the Ethanol Concentrator. Label the flowchart with all information available at the end of the project.
3. Construct one of the fermentation batteries containing two fermenters vessels, a pump, and a heat exchanger set-up for each of the batteries.
4. Calculate the feed rate of corn in Ibm/h. Estimate the acreage required to supply this plant with corn. (Mote: According to the U.S. Department of Agriculture, Crop Production, 11/9/78, p. A-3, 101.2 bushels of corn are harvested from an acre.)
5. Calculate the molar flow rate (lb-moles/h) of ethanol product.
6. How much water (combined fresh water and condensates) must be added to the mixing tank to obtain the desired mash volume?
7. The C02 produced as a by-product from the fermentation reactor may be useful if it is recovered in sufficient quantity. Estimate the production rate of C02 in pound-moles per hour and standard cubic feet per minute.
8. What fraction of the dried grains must be recycled to control the moisture content of the grains entering the dryer? What production rate of dried grains can be expected from this process?
9. What is the minimum pressure at which the cooking vessel must operate? What is the pressure to which the mash must be flashed to provide a resultant liquor temperature of 145°F? At what rate (lbm/h) is water vaporized in this step?
10. Determine the rate (lbm'h) at which 15-psig steam must be supplied to heat the mash from the precooking vessel to 230°F. How much live steam must be injected to raise the tem¬perature of this stream to 320°F? It has been suggested that a portion of these steam requirements could be met by the vapor from the flash occurring at 15 psig. Is this feasible? If so, what fraction of the required 15-psig steam can be supplied by this means?
11. Estimate the quantity of 3A molecular sieves required in one adsorption bed?
Attachment:- project Statement.rar