Application of the absorption heat pump in an oil refinery

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Journal Title
Journal ISSN
Volume Title
Kemian tekniikan korkeakoulu | Master's thesis
Date
2015-01-27
Department
Major/Subject
Process Systems Enginering
Mcode
KE3004
Degree programme
Master's Programme in Chemical Technology
Language
en
Pages
89 + 10
Series
Abstract
Absorption heat pumps (AHPs) have been popular due to their ability to convert thermal waste into useful energy. This study investigates the applicability of the absorption heat pump to the Porvoo oil refinery and compares the results to the ordinary heat pump (HP). The vacuum distillation unit 2 (TT2) and gas turbine (KTVL-3) units were considered for the case studies. Vacuum condenser is an inseparable part of the vacuum column DA-2201. The pressure at the top of the column DA-2201 is determined by the temperature of the cooling water (CW) of the vacuum condenser. The temperature of the CW of 2013 was collected and analyzed. Rigorous simulation of the vacuum column overhead system was simulated in aspen plus to estimate the pressure at the top of the column DA-2201 at various cooling water temperatures. The absorption heat pump based on lithium bromide water solution and ordinary heat pumps based on propane were simulated to generate the cooling water of 10°C for the TT2 unit. In addition, preheating the inlet air when required was examined for the gas turbine to avoid freezing in the filters by applying the ordinary heat pump based on propane. When the temperature of the CW was 10 °C, the pressure at the top of the column DA-2201 was found to be 5.3 kPa. The decrease in pressure enhanced the separation process with the higher yield of vacuum gas oils. The profit achieved due to the higher yield was also estimated. In case of preheating the atmospheric air for gas turbine, ordinary HP was compared to the existing steam-based heating system. The heat pump based on propane was found to be applicable in comparison to the absorption heat pump for both units i.e. TT2 and KTVL-3 units. Based on the profitability estimation, a detailed study of the HP based on propane for both units is proposed for further studies.
Description
Supervisor
Koskinen, Jukka
Thesis advisor
Tamminen, Esa
Golam, Sarwar
Keywords
absorption heat pump, absorption system, vacuum column, cooling water, pressure at the top of the vacuum column, heat pump
Other note
Citation