TY - JOUR
AU - Torres, Ednildo
AB - The concern about environmental issues and economic competitiveness has brought discussions on how to make processes more efficient. In Brazil, most oil refineries were introduced between the 1950s and 1980s. Since then, structural changes were carried out which resulted on differences between the quantity of steam demanded for the modified processes and the quantity of steam produced by utility plants. These differences were created by the addition of new processes and modification on the composition of the oil processed over time. This work proposes a methodology to analyze the technical and economic feasibility of the exploitation of the steam wasted in oil refineries. For these analyses, three different technologies are proposed: organic Rankine cycles (ORCs) to generate power, absorption chillers to increase a gas turbine power production, and the pre-heating boiler’s feedwater to reduce fuel consumption. The economic analysis takes into account three different scenarios. The methodology was applied to a refining unit in Brazilian Northeast. Results show that all solutions are feasible technically and economically, except for one solution in the worst-case scenario. The application of ORCs to a 30-t/h stream of steam at 3.5 bar can generate 3364.9 kW of electricity (54.15% of exergy efficiency) with a return of the investment between 4.9 and 7.6 years. For a 10-t/h stream of steam at 1.4 bar, the application of ORCs can generate 878.6 kW of electricity (50.55% of exergy efficiency) with a return of the investment between 13.9 and 22.7 years. This application was not economically feasible in the worst-case scenario. The application of absorption chillers to reduce a gas turbine inlet air temperature, using 3.68 t/h of steam at 1.4 bar, increases in 2650.0 kW (12.5%) the power generated by the turbine (43.7% of exergy efficiency for the extra power). This investment returns in between 2.6 and 4.4 years. The use of a 30-t/h stream of steam at 3.5 bar can elevate boiler’s feedwater temperature from 147.8 to 150.7 °C, which results in a 0.3% reduction in boiler’s fuel consumption (7.7% of the exergy available), which returns the investment in between 3.2 and 5.2 years.
TI - Residual steam recovery in oil refineries: technical and economic analyses
JF - Energy Efficiency
DO - 10.1007/s12053-018-9731-8
DA - 2018-09-12
UR - https://www.deepdyve.com/lp/springer-journals/residual-steam-recovery-in-oil-refineries-technical-and-economic-JajZ0ddTJa
SP - 2039
EP - 2053
VL - 12
IS - 8
DP - DeepDyve
ER -