Petroleum refineries consume slightly over 5.83 quadrillions Btu of energy per year, about 7.7 % of total energy consumption in the United States in 2019 and about 22% of total industrial energy consumption. Although only a small portion of refinery fuel is crude oil; energy consumption is frequently proportional to the amount of crude oil required; refinery fuel consumption accounts for approximately 12% of crude oil input to refineries.
This study evaluates a crude oil refinery's energy and environmental sustainability metrics of multiple distillation columns. The refinery's feedstock was determined to be 120 000 barrels per day of crude oil. The primary aim is to determine the feasibility of reducing the refinery's thermal energy consumption and CO2 emissions to achieve a more sustainable operation. The considerable energy requirement of crude oil distillation columns is met by expensive utilities such as steam and fuel for fired heaters and heaters, which poses energy savings opportunities via the heat exchanger network (HEN) that minimizes utility costs maximizing heat recovery. We performed pinch analysis using the energy analyzer to address energy intensity metrics to design and optimize the heat exchanger network system for process heat integration. We have applied the pinch technology concept to improve heat recovery and hot and cold utilities for the primary process units without restrictions or constraints. The results indicate that using an energy analyzer and carbon tracking, it is possible to Identify the energy and environmental sustainability metrics associated with an existing design and significant improvements for lowering thermal energy costs and carbon dioxide emissions in a crude oil refinery operation.
Given these high energy values for the utilities equivalent to 1512 GJ/h, an integrated case was developed to reduce the energy consumption from external sources by utilizing some of the process heat. The reduction in this modification's hot and cold utility requirements was 333 GJ/h, equivalent to 22%. Such reductions in energy requirements can provide savings equivalent to 46.89 MM$/year.
Audience take away:
- Learn the importance of applying energy optimization techniques to existing facilities which could help reduce energy and CO2 emissions.
- This presentation will help the audience in their job by the techniques needed to optimize the energy of existing facilities. It provides a practical solution to the current problem of refineries consuming high energy, which could negatively affect the environment.