Call for Papers: Petroleum Technology Quarterly

The excellent technical journal Petroleum Technology Journal (PTQ) has sent a call for papers for several of their upcoming issues. The call for papers is reproduced below.

But first, a quick TIP ,,, take a look at the PTQ 2023 EDITORIAL CALENDAR (https://ptqmagazines.digitalrefining.com/view/463575168/4/).
One, it offers a more complete view of the types of papers they will want to see over the coming year of 2023.
Two, it provides some insight into the email blasts and white papers you keep seeing in your inbox. It can help with your skepticism while simultaneously offering you an opportunity to stay in touch with developments in your field.

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We (PTQ) are accepting proposals for 2,500+ word case study articles that cover the topics listed below for the Catalysis, Q2 and Gas issues of PTQ. Your article should describe practical applications of an established technology together with details of new developments in refining, gas and petrochemical processing.

Send your proposals with a brief synopsis to Rene Gonzalez - editor@petroleumtechnology.com. We provide full editorial support for our authors to ensure that published articles meet the high standards that PTQ’s readers expect.

CATALYSIS 2023 issue
    Molecular Management
    Polymer Chemistry
    Chemical Recycling
    Catalytic Pyrolysis
    Catalysts in Crude-to-Chemical
    Valorisation
    Regenerating and Recycling Catalysts
    FCC Catalyst Developments
    Hydroprocessing Catalyst Developments
    Reactor Design
    Petrochemical Unit Catalysts

Q2 2023 issue
    Hydroprocessing Complexity
    Alkylation & Isomerisation Units
    Refinery/Petrochemical Integration
    Targeting Olefins & Polymers Calue Chains
    Naphtha Upgrading
    Coker Technologies
    Hydrogen Production
    Crude/Vacuum Systems
    Resid Upgrading
    Steam Reforming

    Heat Transfer & Fluid Flow
    Heat Recovery
    Plant utilities optimisation
    Process Heaters
    Heat Exchangers
    Refractory Developments

    Mass Transfer & Separation
    Refinery Distillation Complexity
    Divided Wall Columns
    Superfractionators
    Advanced Distillation Control Systems
    Filtration & Separation

GAS 2023 Issue
    Gas Processing and Conditioning
    Sulphur Recovery & Removal
    Amine Gas Treating
    Methanol Technologies
    Hydrogen Technologies
    LNG/GTL
    Gasification
    Analysers / Measurement
    Control Systems
    Compressors
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Google® Better!
Jean Steinhardt served as Librarian, Aramco Services, Engineering Division, for 13 years. He now heads Jean Steinhardt Consulting LLC, producing the same high quality research that he performed for Aramco.

Follow Jean’s blog at: http://desulf.blogspot.com/ for continuing tips on effective online research
Email Jean at research@jeansteinhardtconsulting.com with questions on research, training, or anything else
Visit Jean’s Web site at http://www.jeansteinhardtconsulting.com/ to see examples of the services we can provide

Thirteen Years of Useful Tips

“Triskaidekaphobia is the fear of the number 13. It is a word of Greek origin made up of the root words tris (“three”), deka (“ten”), and phobia (“fear”)” (https://shmaltzandmenudo.wordpress.com/2016/11/13/famous-sayings-36-lucky-number-13/)

Thirteen years into the Desulfurization Blog, I have developed several series of posts on a number of topics. You may find one or two of them useful. So here is a list, with a link to each series. Enjoy …

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TIPCATALYSIS  http://www.desulf.blogspot.com/search/label/TIPCATALYSIS
Catalysis: The Series
The overarching goal of the Desulfurization Blog (www.desulf.blogspot.com) is to offer tips and tricks on how to save time in your never ending quest to stay on top of developments in your field of interest.
In that time saving vein, the following list provides easy access to each of the posts we produced on Catalysis.  Not every post will interest you.  But when you see one that does, you can just click the link and go right to it.  That way you do not have to go through the tedious process of searching the blog to find it.  Not that you would do that … who has that kind of time?

TIPREFINERYOFTHEFUTURE     http://desulf.blogspot.com/search/label/TIPREFINERYOFTHEFUTURE
FuelsEurope
The EU has the ambitious objective to lead the world in addressing the global climate change challenge.
The EU refining industry is committed to contribute to this objective by continuing to reduce its CO2 emissions and providing the economy and citizens with low-carbon fuels and other products that society needs.
Development of a diversity of energies and energy carriers will give an economy flexibility, resilience and the possibility for the market to select the optimal solution for every sector and use. Liquid fuels, with their unique characteristics will continue to be employed in many transport fields. Therefore, the EU refining industry has an important and enduring role to play in the energy choices of the future, by providing low-carbon liquid fuels to complement low-carbon electrons, gas and hydrogen as energy carriers. Technology and collaboration across industries will facilitate the production of these low-carbon liquid fuels.
The contribution of the EU refining industry can be enhanced by the EU industrial strategy and a policy framework which will enable its transition, while allowing refineries to retain economic viability in the face of a declining domestic market demand and of an increasingly aggressive international competition.
source: https://www.fuelseurope.eu/vision-2050/

TIPVENTURECAPITAL   http://desulf.blogspot.com/search/label/TIPVENTURECAPITAL
The Genius of Venture Capital (Part 1): Connecting Good Ideas with Money
The Genius of Venture Capital: connecting entrepreneurs with good ideas but no money to investors with money but no ideas.
So, how does that work? It is a mysterious process.
In this series of posts, we will penetrate that mystery. We begin with two excellent articles that explain how VC’s do that voodoo that they do so well.
The two articles are rich with insights into the VC world.
Here are three that jumped out at me.

TIPBREAKTHROUGH     https://desulf.blogspot.com/search/label/TIPBREAKTHROUGH
BREAKTHROUGH: How to identify promising breakthrough companies (Part 1)
This is the first post in the BREAKTHROUGH series. The THEME of the series is … How to identify promising breakthrough companies
It is an adjunct to the STARTUP series [ https://desulf.blogspot.com/2020/05/starting-down-startup-path-recap.html ]. While there is some overlap, the focus of the BREAKTHROUGH series is on how to identify companies that may be worth the risk of investing them.
I use the term “investment” in a broad sense. Venture capitalists invest money directly in a chosen company, hoping for a big win.
However, there is another kind of investment … taking a chance on a company with breakthrough but unproven technology to solve a problem your company is trying to address. That is a risk that is similar to, but different than, the risk taken by venture capitalists.
Caveat … I am not an expert on risk assessment. However, I am an expert in online research. The purpose of this series is to help you make more efficient use of online resources to achieve your objectives.
So, how do you identify companies with breakthrough technology? Well, if you are not a venture capitalist, whose job it is to identify such companies, it might be useful to see how venture capitalists go about this critical task.

TIPSTARTALAB                http://www.desulf.blogspot.com/search/label/TIPSTARTALAB
How to design a lab: Part 1 of a series of posts
“What happens if a big asteroid hits Earth? Judging from realistic simulations involving a sledge hammer and a common laboratory frog, we can assume it will be pretty bad.” -- Dave Barry (American Writer and Humorist best known for his weekly newspaper column. b.1947)
Designing a laboratory is a seriously complex task.  If you have never designed one, how do you even start?
One place to begin is reading what experts in the field have written.  And a possible first step on the path to discovering what experts have written could be an Amazon.com search.
TIP: On the Amazon.com Web, select the Book department.  Then enter the following Amazon.com search string: laboratory design

TIPSTARTALIBRARY     http://www.desulf.blogspot.com/search/label/TIPSTARTALIBRARY
Seriously? A Series of Tips on Setting Up a Research Library (Part 1)
“It is a curious fact that people are never so trivial as when they take themselves seriously.” -- Oscar Wilde (Irish Poet, Novelist, Dramatist and Critic, 1854-1900)
Individual researchers create their own personal libraries of technical literature. This can work well for small research organizations with just three or four researchers. Larger organizations need a more formal structure to support their research efforts.
This is the first in a series of posts designed to help you create a resource base which can help your researchers make more productive use of their valuable time.
We’ll begin by focusing on commercial databases.  To be honest, the first step should involve strategic planning, but since most people like to cut to the chase, the chase is where we’ll begin. The tedious stuff will come later.

TIPCASESTUDY http://desulf.blogspot.com/search/label/TIPCASESTUDY
TIAX LLC
Searching for ExxonMobil patents, I ran across one with a co-assignee named TIAX LLC (see below).  This caught my eye.  When a giant like ExxonMobil teams with a small firm like TIAX, it makes me want to learn more.
This post is the first of a series.  Besides exploring TIAX LLC, the series provide a case study on how to glean useful information about any small company of interest.

TIPLITERATURESEARCH             http://desulf.blogspot.com/search/label/TIPLITERATURESEARCH
Whaddya Know? Literature Search Method Case Study
To paraphrase Donald Rumsfeld, We don’t know what we don’t know.
That’s true. Unfortunate, but true.
Here’s another paraphrase from a great sage known as Anonymous … Sometimes, we don’t know what we DO know.
And that is the theme of this post … i.e., how do we know what we DO know?
A recent study on the integration of Building Information Modelling (BIM) with Additive Manufacturing (AM) illustrates the point.

TIPPATENT         http://www.desulf.blogspot.com/search/label/TIPPATENT
TIPS & TRICKS FOR PATENT SEARCHING – TABLE OF CONTENTS
As easy as it is to search patents online these days, there are nuances to the process. Over the past year or so, we at the Desulfurization Blog (http://desulf.blogspot.com) have posted tips and tricks that can help you improve your effectiveness in a patent search.
For your convenience, we have compiled a TOC-Table of Contents of these posts.
TIP: Click http://desulf.blogspot.com/search/label/TIPPATENT to visit ALL the patent searching tips that have appeared (and will continue to appear) in the Desulfurization Blog.

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Google® Better!
Jean Steinhardt served as Librarian, Aramco Services, Engineering Division, for 13 years. He now heads Jean Steinhardt Consulting LLC, producing the same high quality research that he performed for Aramco.

Follow Jean’s blog at: http://desulf.blogspot.com/ for continuing tips on effective online research
Email Jean at research@jeansteinhardtconsulting.com  with questions on research, training, or anything else
Visit Jean’s Web site at http://www.jeansteinhardtconsulting.com/ to see examples of the services we can provide

PTQ Q1 2022 and Catalysis 2022 Call For Articles

PTQ-Petroleum Technology Quarterly (www.digitalrefining.com) wants you to consider contributing to the Q1 2022 issue, and the Catalysis 2022 issue.
Subjects range from crude blending to heavy oil processing to sustainable technologies. Sustainable technologies, of course, is becoming an increasingly urgent topic in the oil & gas industry.

Here is the text of the email I rec’d with more details …

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EMAIL FROM PTQ re: CALL FOR PAPERS
We have listed below the subjects we are looking to cover in the upcoming Q1 2022 issue of PTQ, as well as the Catalysis 2022 issue, both of which will be distributed to 29,411 downstream industry personnel within every refinery, gas and petrochemical processing plant, operating, engineering and licensing company worldwide.
 
As usual, we are seeking contributions that describe practical applications of established technology in the form of case studies, along with details of new developments in the world of refining, gas and petrochemical processing technology. In the first instance, please send your editorial suggestions to Chris Cunningham, editor@petroleumtechnology.com

The Q1 (Jan, Feb, Mar) issue of PTQ will feature articles on:
• Crude Blending
• Sustainable Technologies
• Refinery/Petrochemicals Integration
• Corrosion/Fouling Control
• Steam Cracking
• Operational Excellence
• Heavy Oil Processing
• Catalyst Developments
• Plant Design & Engineering
• Hydroprocessing
 
AUTOMATION & CONTROL
• Analytical Instruments
• Wireless Technology
• Predictive Control Technology
• IIoT & Digital Solutions
• Data Management & Security
• Modelling & Simulation

SAFETY & ENVIRONMENTAL
• Emissions Control
• Flare Systems
• Energy Efficiency
• Process Safety
• Water/Wastewater Management
• SOx/NOx Control

The Catalysis issue will feature articles on:
• FCC Catalyst Developments
• Additives for FCC Processing
• Catalysts for Bottoms Cracking
• Regenerating and Recycling Catalysts
• Catalysts for Reforming Processes
• Hydroprocessing Catalyst Developments
• Tail Gas Treating Catalysts
• Catalysts for Desulphurisation
• Additives for FCC Processing
• Catalysts for Increased Olefins Output
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Google® Better!
Jean Steinhardt served as Librarian, Aramco Services, Engineering Division, for 13 years. He now heads Jean Steinhardt Consulting LLC, producing the same high quality research that he performed for Aramco.

Follow Jean’s blog at: http://desulf.blogspot.com/  for continuing tips on effective online research
Email Jean at research@jeansteinhardtconsulting.com  with questions on research, training, or anything else
Visit Jean’s Web site at http://www.jeansteinhardtconsulting.com/  to see examples of the services we can provide

Catalyze this: PTQ Catalysis 2021

PTQ Catalysis 2021 has just been published. PTQ-Petroleum Technology Quarterly publishes a journal every three months. It also produces separate annual publications focusing on other topics. Catalysis is one of those topics.

TIP: Visit www.eptq.com to subscribe to PTQ. The digital version is free. The print version costs.

Each issue of PTQ consists of several technical articles, as well as a Q&A section. The Q&A section consists of a number of technical questions from subscribers. Each question is answered by several experts from various companies.

TIP: Subscribe to PTQ, then browse the Q&A. When you find a Question of interest to you, read the Answers.

Bear in mind that each answer to any given question will be from the point of view of a particular company. Your advantage is that you can compare the technical answers offered by each company. You will have a range of options to solve your particular problem.

TIP: Each answer to a particular Question offers names and email addresses of the people answering the question. Take advantage of that fact. Email each of the people answering the Question for more information. Think long term. Even if you do not select a particular solution to your problem, you begin a relationship with someone who may help solve a future problem.

To illustrate, here is one Question with several answers from PTQ Catalysis 2021.

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Question: Is there a route for post-treating gasoline with minimal octane loss?

Answer: Olivier BOISIER, Technology Team Manager, Catalysts & Adsorbents Global Business Unit, olivier.boisier@axens.net ; Boris HESSE, Technologist, Catalysts & Adsorbents Global Business Unit, boris.hesse@axens.net  
For the post-treatment of FCC gasoline, fixed-bed HDT is by far the most trusted solution because of its low capex, its ease of operation, and its flexibility. This technology also allows for excellent octane retention provided there is combined use of smart schemes and highly specific catalysts capable of very high HDS rates with minimum olefins saturation. Axens offers both as part of the Prime-G+ trademark.
A smart scheme should take advantage of the particularities of the FCC gasoline, the most striking being that olefins are more concentrated in the light fraction of the gasoline while sulphur is more concentrated in the heavy fraction. The combination of the Prime-G+ SHU reactor with the Prime-G+ splitter capitalises on this and allows for the production of an olefins-rich, desulphurised naphtha, bypassing the HDS section and thereby preserving all the valuable light olefins. The formation of mercaptans in the HDS section through the addition of H2S to olefins is a critical matter when targeting ultra-low sulphur FCC gasoline (see Figure 2). Basically, each ppm of mercaptan that is formed inside the unit requires that an additional ppm of sulphur from the feed be removed, which can dramatically impact octane retention since the octane loss increases exponentially with the HDS rate. Axens offers several solutions, both catalytic and schematic, to tackle this problem. On the road to high octane, one should also lean on the operation of the FCC as it can have big consequences for both the absolute octane value of the FCC gasoline and octane retention in the post-treating unit. Higher FCC severity for instance generally makes for a more aromatic gasoline, which directionally has a higher octane value. The olefins distribution is modified as well which has an impact on octane preservation in the post-treating unit.
The challenge for catalyst manufacturers is to provide catalytic solutions addressing high octane retention along with high activity/contaminants tolerance as those parameters generally go in opposite directions. High activity/contaminants tolerance is key to long cycle lengths matching the FCC turnaround schedule and to important energy savings. With HR 845 for the SHU and the duo HR 806/HR 841 for the HDS boasting more than 1000 cumulated references, Axens has created benchmark catalysts for FCC gasoline post-treatment. Capitalising on the feedback from nearly 200 running units and relying on extensive R&D work conducted jointly with IFPEN, Axens is now bringing to the market a full range of new Prime-G+ catalysts: HR 855 for higher SHU activity, HR 856 for higher HDS selectivity and HR 866 for higher HDS activity.
These new catalysts will help refiners take on new challenges and enhance further their profitability, allowing them for instance to process more refractory/more contaminated feeds from both FCC and other sources (co-processing of coker naphtha, pyrolysis gasoline, and so on) and to reduce significantly both octane losses and hydrogen consumption.

Answer: Colin Baillie, Segment Manager, Environmental Additives, W. R. Grace & Co, Colin.Baillie@Grace.com ; George Hoekstra, President, Hoekstra Trading LLC, george.hoekstra@hoekstratrading.com
One way to minimise octane loss in post-treated gasoline is through adjusting the FCC process to optimise the properties of FCC gasoline, prior to the subsequent post-treatment.
FCC gasoline typically consists of >300 different molecules, composed of paraffinic, olefinic, and aromatic structures. Portions of these molecules subsequently undergo further hydrogenation reactions when posttreated, which leads to octane loss. The level of octane loss is strongly impacted by the specific olefins that are being saturated, for example saturation of linear olefins, branched olefins, and cyclic olefins will lead to different levels of octane loss, as will the carbon number of the olefins. This is because these olefinic species have different octane values, as do the resulting paraffins that are formed upon post-treatment. The sulphur content of the FCC gasoline and type of sulphur species (mercaptans, thiophenes, benzothiophenes) is also important, as it impacts the post-treatment severity (and therefore octane loss) that is required to achieve a target sulphur level.
W. R. Grace & Co. and Hoekstra Trading LLC have worked together to provide unique insight into how the FCC process can be optimised to reduce octane loss of post-treated gasoline. Detailed hydrocarbon analysis and sulphur speciation of FCC gasoline and the corresponding post-treated gasoline combined with Hoekstra Trading’s software allow the analysis of individual reactions occurring upon post-treatment, and ultimately the octane impact of those reactions. Tailored FCC catalyst and gasoline sulphur reduction technology can then be employed to optimise FCC gasoline properties for minimum octane loss of post-treated gasoline. Such analysis has revealed that improving gasoline octane/sulphur performance can be done quickly, with no capital investment, and with the potential to generate a significant increase in profitability.

Answer: Claus Brostrøm Nielsen, Senior Solution Specialist, Haldor Topsoe, clbn@topsoe.com
It is important to understand the molecular composition of FCC naphtha before looking at desulphurisation of cracked naphtha and octane loss. If we look at boiling points of the sulphur species, like mercaptans, thiophenes, and their derivatives, we can classify cracked naphtha into two broad ranges: light cracked naphtha (LCN) and heavy cracked naphtha (HCN). For better differentiation, it can be said that fraction boiling above 80–85°C (176–185°F) can be considered as HCN. Most of the sulphur in the LCN fraction is mercaptans. The refractive sulphur species are distributed in the HCN fraction.
The LCN fraction contains a large part of the total amount of olefins present in the FCC naphtha. Olefins with carbon number 4, 5, and 6 will be present in the LCN fraction, and olefins with higher carbon numbers will be present in the HCN fraction. This is important to know when going into design strategy for a post-treatment process specific for FCC naphtha. The main challenge in FCC gasoline post-treatment is to selectively remove sulphur molecules while avoiding saturation of olefins, which are a major contributor to octane number of gasoline. Saturated olefins have significantly lower octane than the corresponding unsaturated molecules. When increasing the sulphur removal, the olefin saturation and corresponding octane loss increase almost exponentially the closer you get to 100% HDS conversion.
Typically, post-treatment of FCC naphtha consists of a two-step process: selective hydrogenation of diolefins followed by a hydrodesulphurisation (HDS) step to convert the sulphur species. Selective hydrogenation is undertaken at a low temperature compared to downstream hydrodesulphurisation. Selective hydrogenation of cracked feed also transforms the light sulphur species into heavier sulphur-bearing molecules. With the transformation of lighter sulphur species like mercaptans into heavier sulphide molecules, an almost sulphur-free LCN fraction can be obtained. These heavier sulphide molecules will now end up in the HCN fraction. A typical layout of a post-treatment unit consists of a selective hydrogenation unit, a splitter column to separate LCN and HCN, and then a hydrodesulphurisation unit (HDS). The separation of LCN from HCN in the splitter, which follows the SHU section, ensures that we end up with LCN, which is sulphur-free, and HCN that needs to be hydrodesulphurised. The high octane of the LCN stream can therefore be retained, since no further hydrodesulphurisation is required. The HCN fraction is sent to the HDS section.
In the HDS section of the unit, hydrodesulphurisation of the HCN fraction takes place to meet the required sulphur specifications. Hydrotreatment catalysts with optimised activity and selectivity, which enable removal of sulphur to ultra-low levels while retain- ing high octane numbers, are the keys to a successful FCC gasoline post-treatment. Haldor Topsoe’s series of HyOctane catalysts is specifically developed for all steps in the FCC gasoline post-treatment applications and meets the requirements for optimised activity and selectivity which enable a profitable production of high-quality gasoline with minimum octane loss. The catalysts are designed with high selectivity, which minimises mono-olefin hydrogenation even at ultra-low sulphur levels down to 10 wtppm. This ensures that a high octane number is maintained in the final gasoline product.
The Haldor Topsoe licensed HOT process (HyOctane Technology) is developed to provide even better octane retention than today’s available technologies. The HOT process is a combination of unit layout, process conditions, and the HyOctane catalysts, and when combined together it can obtain an ultra-low sulphur gasoline product with significantly higher octane value than typically seen from other FCC gasoline post-treatment units.
The route to FCC gasoline post-treatment with minimal octane loss goes through the correct unit layout and selection of the optimum catalysts.

Answer: José A. Toledo, Technical Service Engineer, Albemarle, joseantonio.toledo@albemarle.com
FCC naphtha is the most common gasoline pool blend component, accounting for 30-50% of the overall gasoline blend, and is the biggest contributor with respect to sulphur.
With gasoline regulations focusing on product sulphur levels, post-treating FCC naphtha for reduced sulphur also impacts octane quality. However, because many refiners lack FCC pretreatment capacity, cat naphtha post-treatment remains a commonly applied solution. In any case, the key is to avoid large octane losses that occur due to saturation of olefins during conventional hydrodesulphurisation of full range cat naphtha. Other processing options are available depending on refinery choice but handling the different cat naphtha fractions (LCN, low boiling and ICN/HCN, intermediate/ high boiling) separately is one of the most common approaches. It is widely known that olefin and sulphur content distribution in full range FCC naphtha moves in opposite directions: most of the olefins, which are desired high octane contributors to the gasoline pool, are found in the lighter portion (LCN), while the majority of sulphur is concentrated in the intermediate and high boiling range (ICN/HCN) fractions.
By separating the lighter boiling range naphtha (LCN), a fraction is created wherein most of the sulphur compounds consist of light, low boiling point mercaptans and sulphides. These species are present in LCN in low concentration and are easy to desulphurise. Often, applying just sweetening processes is sufficient and allows for the preservation of olefins compounds and high octane. For deep removal of the refractory and more concentrated sulphur compounds (thiophenes) in heavier fractions of the FCC naphtha (ICN/HCN), a highly selective HDS that can specifically tackle difficult sulphur while minimising olefins saturation is required. Notably, by separating LCN from FCC naphtha, the concentration of sulphur in the heavier fractions (ICN/ HCN) increases compared to the full range naphtha itself, which makes it more challenging to treat. High activity RT catalysts, such as those manufactured by Albemarle and developed for ExxonMobil SCANfining, have demonstrated high selectivity (high octane retention) in ULSG units processing high sulphur feeds ranging from ICN to HCN blends when Tier III product sulphur level is required. In addition, refineries without fractionation capabilities that need to process full range FCC naphtha have also benefitted from the market-leading high selectivity of RT catalysts. On the process side, high improvements have been obtained in lowering octane losses by applying proficient post-treatment hydrotreating processes such as SCANfining II (second generation SCANfining). Commercial experience demonstrates that at 10 wppm product sulphur, SCANfining II saturates about half of the olefin content compared to the original SCANfining process.
The RT catalysts have also shown commercial success in other post-treatment gasoline hydrotreating processes, such as Axens’ Prime-G+.

Answer: Steven Zink, Principal R&D Engineer/Scientist, Honeywell UOP, Steven.Zink@honeywell.com
Assuming FCC pre-treat capacity installation is not an option, sufficiently low octane deltas on post-treatment of FCC gasoline can be achieved via sequential application of several key molecular management operations. Light mercaptan sulphur is catalytically sweetened out of the light-cut, highest octane olefin fraction, which is recovered as a distillate product in a gasoline fractionator, with a recovery rate that is subject to the gasoline pool sulphur specification. The hydrotreating catalyst processing the mid-cut should perform with a very high ratio of desulphurisation rate vs olefin hydrogenation rate, in one or two hydrodesulphurisation stages, depending on the feed sulphur content and the maximum tolerable octane loss. At 10 ppm or less sulphur specification (US Tier 3), this fraction will require polishing, due to olefin recombination with the hydrogen sulphide produced in situ. Catalytic polishing of the deeply desulphurised mid-cut, carried out at relatively higher temperatures where recombination is less thermodynamically favourable, should be leveraged as much as possible to retain more olefins. The hydrogen partial pressure should be kept only just high enough to achieve the desired extent of desulphurisation, to limit octane loss by olefin hydrogenation.
To limit the loss of olefins to recombination, the hydrogen sulphide partial pressure should be kept as low as possible via application of a well-maintained amine scrubber to the recycle gas. The heavy gasoline fraction contains the lowest concentration of olefins (more aromatic than olefinic) and the highest sulphur concentration. Such sulphur is also the slowest to convert, relative to the light-cut and mid-cut sulphur. Considering that the few olefins in the heavy fraction contribute the least to gasoline octane, the heavy fraction is best routed to a conventional naphtha hydrotreater, to enable greater production of high-octane reformate gasoline.

Answer: George Hoekstra, President, Hoekstra Trading LLC, george.hoekstra@hoekstratrading.com
Octane loss can be optimised with a good selection of feed properties, splitter cut points, HDS reactor conditions, HDS catalysts, FCC catalyst technology, and capital investments: • Feed properties: controllable variables are feed source (FCC naphtha and other naphtha streams), sulphur species distribution, olefinicity, iso/normal ratios for paraffins, iso/normal ratio for olefins, FCC naphtha cut points, and heavy tail composition. In one of our commercial field tests, a refiner modified feed composition to reduce octane loss from 8 RON to 5 RON when making 10 ppm sulphur gasoline. The change was implemented for normal Tier 3 operation.
• Splitter cut point: thiophenic sulphur should all be driven down into the HDS reactor while maximising C6- olefins in the overhead. Careful optimisation of this can save 2 RON octane versus ‘blind’ operation.
• HDS reactor conditions: reaction rates of sulphur, olefins, and aromatics are affected differently by changes in reactor operating variables and can by optimised using modern analytical methods and models to improve octane/sulphur performance. 
• HDS catalysts: we have tested competitive FCC gasoline post-treating catalysts from Axens, Albemarle, Haldor Topsoe, and a fourth supplier, side-by-side in a multi-client catalyst testing program, and ranked them on activity and octane/sulphur selectivity. Results are available to anyone in Hoekstra Research Report 6.
• FCC catalyst technology: FCC catalyst and additives directly affect the distribution of naphtha sulphur, olefins, and aromatic species. By looking at the FCC and its post-treater as an integrated unit, it is possible to increase the reactivity of rate-limiting sulphur compounds, increase the octane of the FCC naphtha, and reduce feed sensitivity to octane loss on hydrogenation. This can have a bigger effect than selection of the post-treating catalyst.
• Capital investments: one of our refineries performed a field test in 2017 showing unacceptably high octane loss when making 10 ppm sulphur gasoline. They did a $20 million revamp to reduce octane loss by 2.5 AKI with $27 million per year benefit. This small capital investment also enabled them to become a supplier of Tier 3 sulphur credits. Refiners considering investment in new units should consider improved, 21st century gasoline desulphurisation technologies.
The above optimisation steps are enabled by use of modern analytical methods, an industry-best octane model, and a process model that tracks the critical reactions affecting octane/sulphur performance, all of which were developed in a three-year, multi-client research programme and are available to anyone at negligible cost by contacting george.hoekstra@hoekstratrading.com , +1 630 330-8159. 
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Google® Better!
Jean Steinhardt served as Librarian, Aramco Services, Engineering Division, for 13 years. He now heads Jean Steinhardt Consulting LLC, producing the same high quality research that he performed for Aramco.

Follow Jean’s blog at: http://desulf.blogspot.com/  for continuing tips on effective online research
Email Jean at research@jeansteinhardtconsulting.com  with questions on research, training, or anything else
Visit Jean’s Web site at http://www.jeansteinhardtconsulting.com/  to see examples of the services we can provide