Question
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Considering the enormous amounts of thermal energy and stripping steam required for crude distillation unit (CDU) throughputs, are there any new crude oil processing schemes for reducing CDU operating costs?
Dec-2022
Answers
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Marcello Ferrara, ITW Technologies, mferrara@itwtechnologies.com
The CDU is the most energy-intensive process in a refinery (also one of the largest in the whole process industry), with its performance affecting refinery-wide efficiency. Average CDU energy consumption is estimated to be over 192 TWh/y for US refineries (DOE, 2006). Among the CDU asset, the preheat train (PHT) is the most sensitive. If working improperly, it will predicate a series of chain effects: extra CO2 emissions, reduced flow, extra furnace fuel consumption, drop in furnace inlet temperature (FIT), production loss, and reduced throughput to the point that the refiner will shut down the fouled unit for equipment cleaning due to unsustainable fouling conditions.
Formerly, Van Nostrand et al. (1981) estimated that process side fouling cost US refineries around $1.36 billion per year and $861 million due solely to PHT fouling. Currently, these numbers, corrected for inflation and current energy costs, are superior by at least one order of magnitude. The fouling problem is so important that its mitigation in CDU operations could lead to over 15% fuel savings. As fuel consumption for the atmospheric column’s furnace represents around 4% of total refinery throughput, 15% fuel savings in a 500,000 bpd facility equates to more than $347 million in savings per year.
Savings are even higher when considering that the carbon tax can reach $80 per ton or more (depending on refinery location). ITW has developed and patented its Online Cleaning technology, which can clean an entire production unit on a 24-hour feed-out/feed-in basis. The technology will allow refineries to recover losses in one day while reducing emissions and eliminating waste. Online Cleaning technology helps target sustainability development goals (SDGs) while also serving as a tool to improve Operational Excellence, rather than an alternative to mechanical cleaning.
Dec-2022
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