Is there scope for significantly reducing fractionation furnace energy consumption for FCC and hydrocracker product recovery sections?Jul-2022
Eric Parvin, Parv LLC, email@example.com
If you want to accomplish your goal with zero capital investment, then follow what the midstream companies do around the nation and play around with your operating pressure vs. the cooling temperatures of your condensers. This is really quite simple and not only reduces your energy footprint of your reboilers, it can significantly increase the capacity of your systems (esp. during colder seasons and night time operation). The problem is refining operations really don't like 'swinging towers', but it's very much worth looking into.
Some of the newer tray technologies can also improve efficiency of the trays and reduce boilup ratio requirements.
I can go on at length for optimized heat recovery using the condensing streams vs. the feeds, and even back-integrating with the hydrotreater effluent stream, but the latter is sometimes not economical until you get into 60,000 bpd or more hydrotreaters.
Bruno De Jonckheere, Qpinch, Bruno.firstname.lastname@example.org
Heat can be recovered from the main fractionation overhead condenser with the Qpinch Heat Transformer (is not a heat pump, but converts 50% of the waste heat energy in steam). This does not reduce your local energy consumption but improves your overall heat balance. It also allows you adjust your FCC setting that are sometimes dictated by the steam production.
Barry Dallum, Alternative Petroleum Technology, email@example.com
Depending upon the type of fuel used for your furnace(s) you can reduce the fuel consumption by up to 30% with EcoMix, a low technology solution. It reduces GHG, NOx and soot emissions. You can view additional details here at Alternative Environmental Technologies.
Nagarathinam S Murthy, McKinsey & Company, Chennai, firstname.lastname@example.org
This is a very good question and perhaps it needs a greater study to answer and start realizing energy gain in GASCON sections of these two major secondary processing units viz. FCC & HCU in most refineries. One can start comparing amount of recycle used per tonne of C3s and C4s recovered. We have several recycle in GASCON sections such as recycle of debutanizer / stabilizer bottom, sponge oil, recycle of heart cut naphtha back to FCC riser, recycle of C4s into riser, etc. which take away maximum energy while post stabilizer fractionation of FCC or HCU naphtha too consume energy. In other words, one needs to take a holistic view on all such recycles in-order to optimize GASCON and Rerun sections. Further, refiners spend their fortune to get rid of Benzene in FCC gasoline to meet final gasoline specification which again consumes significant energy. It is time refiners consider use of 'right molecules' (i.e. select streams like alkylate, C5s or isomerates, etc.) which may be produced in same refinery and use judiciously to minimize recycles and in turn reduce overall energy in these sections. Further, Reliance industries Ltd. with Indian Institute of Petroleum in India have patented and commercialized a solvent extraction process which is far superior in overall OPEX as it does not use hydrogen to saturate Benzene like conventional routes in other refineries.
Gary Martin, Sulzer Chemtech, email@example.com
Refiners that fractionate FCC naphtha into three or more streams can take advantage of DWC technology to reduce the energy consumed by the process. This technology has been successfully applied for this application. Typically, this is where refiners are using a processing configuration to shift from fuels production to petrochemicals or using processing schemes to retain octane during sulphur removal. In doing so, not only does the DWC technology provide for lower energy consumption, but the shift in product slate when producing additional petrochemicals can have benefits in product upgrade value and credits.