Mea Heat Exchanger Design
1.0 Introduction
The minor equipment that is designed in this project is lean/rich MEA heat exchanger E-114. This heat exchanger is a counter flow shell and tube heat exchanger and is designed to heat up the rich MEA stream flowing from the CO2 absorber to the stripper. The principle that is applied is heat exchange between cold stream and hot stream which in this case the heat energy is transferred from the lean MEA stream to the rich MEA stream. Apart from this, the chemical engineering design for this heat exchanger includes the determination of its dimensions and heat exchange coefficient as well as pressure drop. The mechanical design covers the design of pressure vessel, head, supports and piping. In addition, the operating design which includes the commissioning, start-up, shutdown and maintenance procedures, process control, and HAZOP study is considered. 2.0 Process Description
Figure 2.1 Schematic of rich/lean MEA heat exchange process flow sheet
The lean/rich MEA heat exchange process is presented in Figure 2.1. The MEA-2 stream containing rich CO2 is flowing from CO2 absorber and enters the heat exchanger to be heated up from 61°C to 80°C by MEA-7 before entering the stripper. The MEA-7 is then cooled down from 105°C to 84°C when pass through the heat exchanger and recycle back to the CO2 absorber. The cold stream in this case is MEA-2 and MEA-3 while the hot stream is MEA-7 and MEA-8.
3.0 Chemical Engineering Design
3.1 Design Methodology
The rich/lean MEA heat exchanger is a counter flow shell and tube heat exchanger. The chemical engineering design methodology for this heat exchanger includes the following steps of Kern’s method according to Sinnott (2005): (a) assume overall heat transfer coefficient , U; (b) select number of shell and tube passes, calculate ΔTlm, correction factor, F and ΔTm; (c) determine heat transfer area; (d) decide tube size, type and arrangements; (e) Calculate number of tubes; (f) Calculate shell diameter;
The minor equipment that is designed in this project is lean/rich MEA heat exchanger E-114. This heat exchanger is a counter flow shell and tube heat exchanger and is designed to heat up the rich MEA stream flowing from the CO2 absorber to the stripper. The principle that is applied is heat exchange between cold stream and hot stream which in this case the heat energy is transferred from the lean MEA stream to the rich MEA stream. Apart from this, the chemical engineering design for this heat exchanger includes the determination of its dimensions and heat exchange coefficient as well as pressure drop. The mechanical design covers the design of pressure vessel, head, supports and piping. In addition, the operating design which includes the commissioning, start-up, shutdown and maintenance procedures, process control, and HAZOP study is considered. 2.0 Process Description
Figure 2.1 Schematic of rich/lean MEA heat exchange process flow sheet
The lean/rich MEA heat exchange process is presented in Figure 2.1. The MEA-2 stream containing rich CO2 is flowing from CO2 absorber and enters the heat exchanger to be heated up from 61°C to 80°C by MEA-7 before entering the stripper. The MEA-7 is then cooled down from 105°C to 84°C when pass through the heat exchanger and recycle back to the CO2 absorber. The cold stream in this case is MEA-2 and MEA-3 while the hot stream is MEA-7 and MEA-8.
3.0 Chemical Engineering Design
3.1 Design Methodology
The rich/lean MEA heat exchanger is a counter flow shell and tube heat exchanger. The chemical engineering design methodology for this heat exchanger includes the following steps of Kern’s method according to Sinnott (2005): (a) assume overall heat transfer coefficient , U; (b) select number of shell and tube passes, calculate ΔTlm, correction factor, F and ΔTm; (c) determine heat transfer area; (d) decide tube size, type and arrangements; (e) Calculate number of tubes; (f) Calculate shell diameter;
References: Riggs, J. B. and M. N. Karim. Chemical and Bio-Process Control. 3rd ed. Pearson. Selmon Company. n.d. Pipe Sizes and Dimensions. http://www.maselmon.com/ (accessed 28 October, 2010). Sinnott,R. K., 2005. Coulson & Richardson’s Chemical Engineering. Vol. 6. Elsevier Butterworth-Heinemann. Society for Amateur Scientists. 2004. Engineering Material Properties Arranged by Material. http://www.sas.org/engineerByMaterial.html (accessed 26 October, 2010). Yula Corporation n.d. Operation and maintenance of industrial heat exchangers. http://www.yulacorp.com/downloads/INDUS_O_M.pdf (assessed November 1, 2010).