Diesel hydroprocessing

Transcription

1 Diesel hydroprocessing

2 Optimizing your diesel production

3 32 Optimizing your diesel production As an increasing number of countries move towards requirements for low and ultra-low sulfur diesel with a high cetane number, the refining industry faces a double-edged challenge in terms of meeting the ever stringent specifications for diesel fuel, while simultaneously producing more diesel product from lower quality feedstocks. The market for clean and ultra-clean fuels continuously calls for a variety of improved diesel hydrotreating catalysts and processes. Many of the low-pressure diesel hydrotreaters are being revamped, and new high-pressure units are built in order to meet the latest diesel specifications. Whether it is extracting more diesel product from each barrel of oil, creating higher quality of the middle distillate product or meeting the growing demand for processing of renewable feeds, our global network of industry-leading scientists and catalyst specialists will meet your requirements.

4 4 Optimizing your diesel production More than 50% of all the ultra-low sulfur diesel units worldwide use catalysts from Topsoe >50% High-performance catalysts and technology Topsoe has been at the forefront of the hydroprocessing catalyst technology for many years, and today, we are the market leader within the field of catalysts, licensed technology and reactor internals for the production of Ultra-Low Sulfur Diesel (ULSD). Our HydroTech solutions for hydroprocessing offer you the opportunity to meet all legislative requirements when producing clean fuels. HydroTech includes a broad catalyst portfolio and advanced innovative hydroprocessing technologies, supported by consultancy services from our experienced engineers. Using our extensive knowledge of hydroprocessing, we are able to optimize operating conditions and catalyst loadings, thereby minimizing investment costs and utility consumption. Our HydroTech solutions within diesel hydrotreating consist of the following technologies: production of ultra-low sulfur diesel dewaxing of diesel cetane improvement saturation of aromatics hydroprocessing of renewable feeds

5 5 Optimizing your diesel production Up to 40% activity increase when using HyBRIM catalysts up to BRIM and HyBRIM catalyst technology Topsoe BRIM catalysts have proven to be leading for the production of clean transportation fuels. By virtue of the unique method of catalyst preparation, they exhibit a high activity and stability at all pressure levels on straight-run feed, as well as on cracked feedstocks. With the invention of our HyBRIM catalyst preparation technology, we have added new products to our portfolio that can help you reach your targets even more efficiently. HyBRIM combines the existing BRIM technology with an improved catalyst preparation step, resulting in an increased activity. The HyBRIM catalysts exhibit the same high stability that our customers have come to expect from all of our BRIM catalysts. HyBRIM catalyst 40%

6 State-of-the-art diesel catalysts

7 7 State-of-the-art diesel catalysts Topsoe offers our cobalt molybdenum (CoMo) catalysts for low-medium pressure applications and our nickel molybdenum (NiMo) catalysts for high pressure applications. Cobalt molybdenum catalysts Topsoe cobalt molybdenum (CoMo) catalysts are recommended for low and ultra-low sulfur diesel services, often being operated in low to medium pressure (20-50 bar/ psi) applications with high nitrogen feedstocks. Frequently, hydrogen consumption in these applications is critical. Currently, our CoMo series consists of the following catalysts listed with increasing activity: TK-568 BRIM < TK-570 BRIM < TK-578 BRIM Figure 1: Active structure, the metal slab, of a working NiMo catalyst TK-568 BRIM is our cost-efficient CoMo catalyst, especially developed for a lower fill cost option. The low density formulation has been designed for units processing average severity feeds, while meeting ULSD product specifications and still providing a stable performance during operation. For processing cracked stock fractions, and hence more difficult feeds, TK-570 BRIM is well suited with its excellent HDS activity. The enhanced pore structure combines a moderate density with an activity that has shown to provide an outstanding performance. TK-578 BRIM is the recommended catalyst when high activity and high stability is required, leading to a cost-effective life cycle for demanding ULSD services with high levels of cracked stock. Its improved activity can be utilized to increase cycle length to process tougher feeds or to increase feed rate. Figure 2: Active structure, the metal slab, of a working CoMo catalyst

8 8 State-of-the-art diesel catalysts Case story: Increased capacity with TK-578 BRIM Aiming for a long cycle length and producing less than 10 ppm sulfur diesel with the highest possible throughput, this US refiner operates a 20,000 BPSD diesel hydrotreating unit. After two successful cycles with TK-576 BRIM (previous generation CoMo catalyst) and TK-578 BRIM over a six-year period, the client decided to continue with TK-578 BRIM due to its proven success. This catalyst made it possible to increase the annual throughput from 14,000 to 20,000 BPSD, corresponding to an annual profit gain of approx. 18/$24 mil. Feed properties Feedstock type Unit SG/ API 0.85/34.5 Final boiling point, ( C/ F) 350/660 Sulfur, wt % 0.25 Operation conditions SR VGO/Kero + 35% LCO 0.8 (TK-578 BRIM )/ -1 LHSV, hr 0.7 (TK-576 BRIM ) H 2 inlet pressure, (barg/psig) 42/610 Product properties Sulfur, wt ppm < TK-578 BRIM TK-576 BRIM Temperature, C Temperature, F Run days Figure 3: The result of the upgrade to TK-578 BRIM is clearly observed on the normalized WABT. The start-of-run (SOR) temperature is more than 5 C (9 F) lower than the cycle loading with TK-576 BRIM. The customer says: It was essential for us to find a catalyst capable of producing ultra-low sulfur diesel with minimum catalyst deactivation throughout the cycle. We found that Topsoe came out the strongest on quality, with impressive scientific research behind their catalyst, and the performance of TK-578 BRIM exceeded our expectations with respect to cycle length and capacity.

9 9 State-of-the-art diesel catalysts Nickel molybdenum catalyst Topsoe NiMo catalysts are recommended for the production of ULSD at high operating pressures (> 50 bar/750 psi), especially when sufficient hydrogen is available. NiMo catalysts are the optimal solution when targeting high activity and volume swell. NiMo catalysts are preferable to CoMo catalysts at: high-pressure operations lower content of feed nitrogen lower feed rate. Currently, our NiMo series consists of the following catalysts listed with increasing activity: TK-563 BRIM < TK-569 HyBRIM < TK-609 HyBRIM Topsoe cost-efficient solution developed for removing nitrogen and sulfur at a higher pressure operation are TK-563 BRIM and the TK-569 HyBRIM. The formulation has been designed for units processing lower severity feed, while meeting low sulfur product specifications and stable hydrodenitrogenation (HDN) during operation. Our highest activity catalyst, ideally suited for treatment of very difficult feedstocks including all cracked material, is the TK-609 HyBRIM. It is designed to maximize nitrogen removal, increase volume swell and hydrogenation of the aromatic compounds, while minimizing the deactivation rate to provide a long cycle. The higher activity can be utilized to obtain longer cycles to process tougher feeds or to improve the yield structure.

10 10 State-of-the-art diesel catalysts Case story: Comparison of TK-609 HyBRIM and TK-607 BRIM Feed properties Unit Pilot plant results in Figure 4 demonstrate that TK-609 HyBRIM provides on average 0.4 % additional increase in volume swell compared to previous generation NiMo catalyst TK-607 BRIM. This corresponds to 160 additional barrels of ULSD per day for a 40,000 BPSD unit, improving the annual revenue. The result of the upgrade to TK-609 HyBRIM in a commercial unit is also clearly observed on the normalized weighted average bed temperature (WABT) as shown in Figure 5. TK-609 HyBRIM provides a significant increase in the activity compared to our previous generation NiMo catalysts. Feedstock type LG/LCO 75/25 SG/ API 0.88/29 Sulfur, wt % 1.35 Nitrogen, wt ppm 385 Operation conditions Reactor inlet Pressure, (bar/psi) 80/1,160 LHSV, hr Temperature, ( C/ F) 336/ TK-609 HyBRIM TK-607 BRIM Volume swell, vol% Run hours Figure 4: Obtained volume swell with TK-607 BRIM and TK-609 HyBRIM at equal conditions, pilot plant data.

11 11 State-of-the-art diesel catalysts TK-609 HyBRIM Summer TK-607 BRIM Summer TK-609 HyBRIM Winter TK-607 BRIM Winter Normalized WABT ( ºC ) Normalized WABT ( ºF ) Cumulative feed processed across catalyst ( BBLS/LB ) Figure 5: Performance of TK-607 BRIM versus TK-609 HyBRIM at same conditions, commercial data.

12 Topsoe diesel hydroprocessing technologies

13 13 Topsoe diesel hydroprocessing technologies The importance of good distribution Efficient distribution of the reactants is mandatory in order to achieve ultra-low sulfur levels. Poor liquid distribution will contribute to channeling through the catalyst bed, resulting in inefficient utilization of the catalyst, development of hot spots and catalytic deactivation due to coke formation. The advantages of installing a Topsoe designed distributor tray are: custom-made design for the feedstock and operating conditions significantly more drip points than conventional trays uniform coverage of the entire cross-section area in the bed very low sensitivity to degree of tray levelness good distribution over wide range of conditions (high turndown ratios and higher than design throughputs) low vulnerability to plugging. Dewaxing for improved cold flow properties With the incentive of processing higher end-point feeds, tight oils or processing renewable feeds in the diesel hydrotreater, meeting cold flow properties is often a concern, especially in colder climates with strict winter specifications. Diesel Hydrogen HDS/HDN Dewaxed USLD Dewaxing The freezing point of the paraffins in the upper ULSD boiling range will mainly determine the cold flow properties and can cause the ULSD to become off-spec due to wax crystallization. Cold flow properties of diesel fuels can be improved by catalytic dewaxing. Fractionation We have developed an isomerization dewaxing technology to be utilized in grassroots and revamp scenarios of a diesel hydrotreating unit. The yield loss of the diesel fraction is reduced by up to 30% compared to conventional dewaxing technology. Our patent-pending technology within isomerization dewaxing

14 14 Topsoe diesel hydroprocessing technologies Full feedstock flexibility Our renewable fuels licensed technology HydroFlex provides solutions for converting renewable feedstocks into ULSD that can be blended with conventional diesel. With our catalysts, it is possible to process a wide range of renewable feedstocks. Our catalyst portfolio for renewable feeds includes a selection of specialty catalysts for biofuels hydroconversion, which make it possible to control the heat release and potential associated pressure drop build-up. We also have isomerization catalysts for the improvement of the cold flow properties and pour point where needed. TK-335, TK-337 and TK-339: Are all used in top of the reactor to control the highly exothermal reactions. Grading products are well suited for processing feed with high levels of phosphor lipids, as they need low HDS and HDN activity in order not to polymerize the phosphor lipids. TK-340: High selectivity toward the hydrogenation route compared to other catalysts, thus eliminating the formation of CO2 from the process. This selective conversion functionality provides a number of advantages as opposed to normal hydrotreating catalyst, utilizing both the hydrogenation and the decarboxylation route: Very small amount of CO2 is formed and thus little risk for the byproducts formation of CO and methane 6% higher liquid yield of diesel, which significantly improves the economics of the renewable fuels unit No need for additional amine scrubbing capacity for removing the CO2 in a co-processing unit and the possibility of completely eliminating the amine scrubber in a grass roots facility, thus reducing the installed cost for the unit. TK-341 and TK-351: Are both NiMo catalysts developed for HDO services, with TK-351 being most active. The catalysts are typically applied as second-stage catalyst in diesel hydrotreating units, processing mixtures of diesel and renewable fuels. The catalysts are characterized by high HDO activity and, at the same time, moderate activities of HDS, HDN and saturation. The high quality of renewable diesel produced with our technology allows you to blend green diesel with conventional diesel. Due to the very low sulfur content of renewable diesel, it may be blended with low quality fossil diesel and still meet product requirements. Any renewable oil can be hydrotreated in a stand-alone unit or co-processed with diesel in a refinery. The optimal solution depends on cold-flow properties, existing refinery capacity and location of the unit.

15 15 Topsoe diesel hydroprocessing technologies R R + 2 H 2 Aromatics saturation In case significant reduction in aromatics is required, i.e. to increase the cetane number, our high-pressure two-stage process for combined deep desulphurization and dearomatization, HDA, is available. Both stages in the process may be used separately, which makes the process ideal for upgrading of existing diesel units. The first stage uses a high-activity NiMo catalyst, whilst a sulfur tolerant noble metal catalyst is used in the second stage. Depending on the severity of the operation, three HDA catalysts are available: TK-907 < TK-911 < TK-915. These catalysts can tolerate several hundred ppm sulfur; however, as the activity strongly depends on the sulfur and nitrogen content in the feed, we normally recommend pretreating the feed to low levels (less than 20 wt ppm sulfur and nitrogen) in order to minimize the required HDA catalyst volume, thereby reducing costs. Reactivity of aromatics: Mono-aromatics << Di-aromatics Triaromatics This two-stage HDS/HDA process has demonstrated attractive product properties including color removal and stable performance on both straight-run and cracked gas oil feedstocks. Your partner in business For refineries all around the world, meeting future demands and legislation for ULSD will require continuous plant investments and improvements, as well as optimized operational excellence. For optimum design, in which the cost of new units is kept to a minimum and the best use is made of existing equipment, it is necessary to have a thorough understanding of the factors governing the removal of the most refractive sulfur compounds in diesel. We have identified the specific basic nitrogen compounds, which inhibit removal of the most refractive sulfur compounds, and this knowledge is used to define the optimum choice of catalyst for you. The choice of catalyst also affects other key diesel properties such as density, aromatic content and cetane number, as well as hydrogen consumption and the required treat gas/oil ratio. In addition, properly designed reactor internals are necessary in meeting ultra-low sulfur fuel requirements. With us, you will have a highly competent and reliable partner for today and for the future. We are known for our commitment to catalysis a commitment we share with you. To find out more about our diesel hydroprocessing technologies and catalysts, please visit or contact your local Topsoe representative.

16 The information and recommendations have been prepared by Topsoe specialists having a thorough knowledge of the catalysts. However, any operation instructions should be considered to be of a general nature and we cannot assume any liability for upsets or damage of the customer s plants or personnel. Nothing herein is to be construed as recommending any practice or any product in violation of any patent, law or regulation. Haldor Topsoe A/S Nymollevej Kongens Lyngby Denmark Tel topsoe.com Corporate Communications & Marketing