Thermal Design Approach of a Shell and Tube Heat Exchanger for Pyrolysis-Vapor Condensations

Abstract

This study aimed to design a condenser for a special application of condensing the vapor of pyrolysis process of hydrocarbon-based material such as plastic and biomass into liquid form or pyrolytic oil. Numerous condensers have been available in the market. However, a condenser cannot be selected and utilized directly for pyrolysis vapor condensation purposes. Before doing selection, the condenser must be designed first to meet the heat transfer requirements. In this work, the condenser was designed based on thermal analysis and validated with numerous published experimental data and the pyrolytic characteristics from related industry. A theoretical model is formulated for describing condensation of the pyrolysis vapor in the condenser to determine heat transfer requirement and the rate of condensation obtained. The effect of operating parameters such as cooling water rate in liters per minute (LPM) and temperature on the condensation rate was examined through an iterative procedure which rely to the heat transfer rate and the allowed pressure drop in the condenser. In this study, it was obtained that the highest cooling load is obtained when the flow rate of cooling water is 1.95 LPM. It was also obtained that the condenser effectiveness decreased of about 29.3 % with the ranges of cooling flow rate from 1.3 to 2.6 LPM