Technical solutions for hydrotreating
Revamps and turnarounds allow time to upgrade hydroprocessing units to make refineries both profitable and sustainable
Amy Hearn, Diana Brown, Brian Yeung, Patrick Christensen and Tom Yeung Hydrocarbon Publishing Company
H ydrotreating is one of the most energy-intensive processes in a refinery and is usually near the top of the list for throughput capacity. As a result of these two factors, hydrotreating is viewed as a prime area for energy savings in a refinery. The refining industry is facing increasing pressure to reduce its carbon footprint in its internal operations accord - ing to Scope 1 as defined by the Greenhouse Gas Protocol. As part of this effort to address climate scrutiny, global refiners are implementing a range of decarbonisation strat - egies aimed at reducing their GHG emissions and transi - tioning to a low-carbon energy system. There are two key drivers behind the carbon footprint of a refinery, namely energy consumption and GHG emissions from unit operations. In terms of energy consumption, pro - cesses demand different amounts of electricity, steam, and fuel, which are considered major sources of GHG emis - sions. Figure 1 shows how much steam, fuel, and electric - ity are used by various refinery processes, according to the US Environmental Protection Agency (EPA). A study by the US EPA identified combustion – from energy use – as the leading contributor to GHG emissions, with 63.3% of total shares. It is followed by FCC unit coke
burn-off (23.8%), hydrogen plants (5.8%), flaring (2.5%), and sulphur plants (1.8%), with the remaining emissions from others (3.1%). Based on energy intensity and hydro - gen consumption, very high throughput capacity hydro - treating is a key unit for refiners to establish short- and long-term strategies that specifically address emissions from refinery internal operations as profitability and sus - tainability are key goals. Conventional feedstocks Catalytic hydrotreating can take on several different roles in a refinery. Depending on the feed processed and catalyst used, this process is utilised to remove sulphur, nitrogen, metals, and aromatics from different hydrocarbon streams. Because of this wide range, it will be necessary at times to discuss specific hydrotreating applications for process - ing naphtha, middle distillates, and resid, although some generalisation will occur. The unit requires energy to heat the feed stream and to power the flow of materials. It also indirectly uses a significant amount of energy due to the consumption of hydrogen. Hydrotreaters are one of the major energy consum - ers in a refinery, mainly because they lack adequate heat
0.5 0.0
Fluid catalytic cracking Deasphalting Hydrotreating Catalytic reforming Hydrocracking Sulphur recovery Hydrogen production Lubes production Isomerisation Asphalt production Aromatics production Alkylation Thermal cracking Vacuum distillation Crude distillation Desalting
-100.5
Steam, TBtu
Fuel, TBtu
Electricity, TBtu
228.7
2.6
0.0 2.6
90.9
4.4
1.4
39.8
90.1
2.1
0.0 3.6
50.2
0.9 10.3
9.0 13.0
120.8
0.7 15.9
0.3
69.3
354.9
332.7
10.8
93.7
190.7
39.2
72.7
20.6
0.5
105.1
23.2
90.0
16.4
-11.2
119.9
3.0
130.4
369.3
12.7
230.4
0.9 0.2
0.0
330 110 Note: Data was taken from the EPA’s 2015 Energy Star® Guide for Energy and Plant Managers , but the EPA provided electricity gures in GWh so those gures were converted to TBtu assuming that 1 kWh is equal to 3.412 kBtu 660 550 440 0 -110 220
770
Figure 1 Primary energy use by refinery units
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Revamps 2023
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