Poly Fuel
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AXENS OLIGOMERIZATION PROCESSES PolyFuel TM Technology is derived from Axens’ extensive industrial experience of converting low value LPG olefins into high quality car fuels by oligomerization using Polynaphtha TM and Selectopol TM . In a context of dwindling refinery margins limiting capital investment and unbalanced gasoline/diesel slates, Axens has developed a new technology named PolyFuel aimed at maximizing middle distillates production by converting light olefins from gasoline into distillate at minimum cost. PolyFuel can accept the full range C 5 -C 9 olefinic cut produced downstream of the FCC. The benefits will be maximized using the C 5 -C 6 olefinic cut that is less contaminated, particularly with nitrogen species, than the heavier FCC cut. In these conditions, a significant increase in run-length of the oligomerization catalyst can be achieved. In addition considering that C 5 and C 6 olefins are much more reactive to oligomerization and more concentrated than the heavier C 7 + olefins issued from the FCC, Axens has elected as a priority the processing of C 5 -C 6 olefinic cut as the optimum solution to maximize the profitability of the technology by: maximizing the amount of the oligomer product per ton of processed feed maximizing run-length of the catalyst minimizing the feed pretreatment PolyFuel is an innovative technology that utilizes the implementation of the first step Prime-G+ TM selective hydrogenation on the full range FCC gasoline as an ideal feed pretreatment to lower the diolefins and sulfur content of the light C 5 -C 6 cut recovered at splitter top. As Prime-G+ TM is a leading technology, its widespread use means PolyFuel can be installed for minimum pretreatment cost in a vast majority of refineries. To maximize refinery profitability PolyFuel feedstock can also include C 3 and / or C 4 fractions from FCC or from any cracking processes such as Coker or Steam Cracking or any other olefinic sources: FT effluent, product from paraffin dehydrogenation or alcohol dehydration. Pretreatments are adjusted depending on feed origin and the level of contaminants. Innovative PolyFuel technology is a tool to tackle unbalanced gasoline/middle distillates slates while reaching tighter products requirements. To address these challenges PolyFuel-K (K for Kerosene) can be used when high smoke point and good cold flow properties are targeted for jet fuel. PROCESS DESCRIPTION In the PolyFuel process, light olefins are oligomerized catalytically in a series of two fixed bed reactors. Conversion and selectivity are controlled by reactor temperature adjustment while the heat of reaction is simply removed by feed-effluent heat exchange (cf. Figure 1). The reactor section effluent is fractionated producing gasoline depleted in olefins and middle distillate fractions. The gasoline fraction is recycled to the reaction section to enhance middle distillate production. C5/C6 olefinic feed Reaction section Splitter Gasoline Middle Distillates Figure 1: General Flow Diagram of Axens PolyFuel Technology A spare reactor is provided to ensure a continuous operation of the process thus avoiding unwanted FCC shutdowns. The management of the reactors is optimized to maximize catalyst run-length. With the objective to produce high quality jet fuel, the PolyFuel-K process utilizes the IP 811 catalyst initially developed for Polynaphtha. Thanks to its high activity and stability, IP 811 can be operated at high severity to maximize the middle distillate fraction. IP 811 is regenerable several times allowing over 95% activity recovery. Catalyst regeneration can be performed in-situ or ex-situ. PolyFuel™-K CONVERSION OF LIGHT OLEFINIC STREAMS INTO KEROSENE
description
Poly Fuel
Transcript of Poly Fuel
AXENS OLIGOMERIZATION PROCESSES
PolyFuelTM Technology is derived from Axens’extensive industrial experience of converting lowvalue LPG olefins into high quality car fuelsby oligomerization using PolynaphthaTM andSelectopolTM .
In a context of dwindling refinery margins limitingcapital investment and unbalanced gasoline/dieselslates, Axens has developed a new technology namedPolyFuel aimed at maximizing middle distillatesproduction by converting light olefins from gasolineinto distillate at minimum cost.
PolyFuel can accept the full range C5-C9 olefinic cutproduced downstream of the FCC. The benefits willbe maximized using the C5-C6 olefinic cut that is lesscontaminated, particularly with nitrogen species, thanthe heavier FCC cut. In these conditions, a significantincrease in run-length of the oligomerization catalystcan be achieved. In addition considering that C5 andC6 olefins are much more reactive to oligomerizationand more concentrated than the heavier C7
+ olefinsissued from the FCC, Axens has elected as a prioritythe processing of C5-C6 olefinic cut as the optimumsolution to maximize the profitability of thetechnology by:
maximizing the amount of the oligomer productper ton of processed feed
maximizing run-length of the catalyst
minimizing the feed pretreatment
PolyFuel is an innovative technology that utilizes theimplementation of the first step Prime-G+TM selectivehydrogenation on the full range FCC gasoline as anideal feed pretreatment to lower the diolefins andsulfur content of the light C5-C6 cut recovered atsplitter top. As Prime-G+TM is a leading technology,its widespread use means PolyFuel can be installedfor minimum pretreatment cost in a vast majority ofrefineries.
To maximize refinery profitability PolyFuel feedstockcan also include C3 and / or C4 fractions from FCC orfrom any cracking processes such as Coker or SteamCracking or any other olefinic sources: FT effluent,product from paraffin dehydrogenation or alcoholdehydration. Pretreatments are adjusted depending onfeed origin and the level of contaminants.
Innovative PolyFuel technology is a tool to tackleunbalanced gasoline/middle distillates slates whilereaching tighter products requirements.
To address these challenges PolyFuel-K (K forKerosene) can be used when high smoke point andgood cold flow properties are targeted for jet fuel.
PROCESS DESCRIPTION
In the PolyFuel process, light olefins are oligomerizedcatalytically in a series of two fixed bed reactors.Conversion and selectivity are controlled by reactortemperature adjustment while the heat of reaction issimply removed by feed-effluent heat exchange (cf.Figure 1). The reactor section effluent is fractionatedproducing gasoline depleted in olefins and middledistillate fractions. The gasoline fraction is recycled tothe reaction section to enhance middle distillateproduction.
C5/C6olefinic
feed
Reaction section SplitterGasoline
MiddleDistillates
Figure 1: General Flow Diagram of Axens PolyFuel Technology
A spare reactor is provided to ensure a continuousoperation of the process thus avoiding unwanted FCCshutdowns. The management of the reactors isoptimized to maximize catalyst run-length.
With the objective to produce high quality jet fuel, thePolyFuel-K process utilizes the IP 811 catalystinitially developed for Polynaphtha. Thanks to its highactivity and stability, IP 811 can be operated at highseverity to maximize the middle distillate fraction.
IP 811 is regenerable several times allowing over 95%activity recovery. Catalyst regeneration can beperformed in-situ or ex-situ.
PolyFuel™-KCONVERSION OF LIGHT OLEFINIC STREAMS INTO KEROSENE
PolyFuel oligomerization technology provides a low costoption for retrofitting existing Polynaphtha units.
If foreseen at the design stage, it may be envisioned tooperate the unit both with LPG feed and/or C5-C6
olefinic feed with adjustment of the gasoline/middledistillates ratio to maximize either gasoline or middledistillates production depending on market demand.
Besides the standard stand-alone version, PolyFuel canbe used within the FlexEneTM concept which is Axensinnovative combination of FCC and oligomerizationprocesses. This combination enhances product flexibilityby controlling the balance of propylene, gasoline andmiddle distillates production with a low additionalcapital investment relative to the FCC complex. Thisflexibility is achieved via a selective oligomerization ofan appropriate selection of light FCC alkenes (olefins)for recycle and further cracking in the FCC thusincreasing the desired product slate.
A typical flow scheme of PolyFuel integrated in theFlexEne concept is presented in Figure 2.
Figure 2: Oligomerization within FCC Block
KEY PROCESS FEATURES
The PolyFuel-K process displays the following features:
Moderate investment and utilities consumption
Continuous operation
Environmentally friendly solid catalyst regenerableseveral times
Easy unit monitoring by exotherm control
Versatile product range
High quality jet fuel after hydrotreament
PERFORMANCES AND PRODUCT QUALITY
Light olefin conversion typically ranges between 80 and90% depending on feedstock quality and productdistribution.
The distillate product is mainly composed of olefinsand is typically sent to an existing hydrotreatment unitto comply with Jet A1 specification as per Table 1.
C5-65°C FCC cut PolyFuel-K
Middle distillates yield wt% ascompared to feed olefins 70 %
Hydrotreated jet fuelFreezing point < - 70°CSmoke point 35 mm
Table 1: PolyFuel-K yield and Product Quality
The olefin and sulfur depleted gasoline fraction istypically sent directly to the gasoline pool.
Jet fuel characteristics such as oxidation stability,freezing point and smoke point are excellent afterhydrotreatment of the product. Jet fuel is also low insulfur and in aromatics.
The following table provides investment (ISBL) andoperating costs data for PolyFuel-K.
PolyFuel-K
ISBL cost, MM USDUS Gulf Coast 2011
16
Feed rate, BPSDFeed origin
10,000FCC LCN
Utilities cost, $/T of feedCatalyst cost, $/T of feed
150.7
Table 2: Economics – Typical case
COMMERCIALIZATION
PolyFuel-K technology is the result of more than 50years of commercial experience in the fields of olefinsconversion into fuels. This experience is based on 20Selectopol and Polynaphtha units licensed all over theworld by Axens. The combination of proventechnology elements in a patented configuration, makesPolyFuel-K the candidate of choice to address a clearmarket demand towards middle distillates. Used withinthe FlexEne concept, flexibility towards propylenemaximization can also be targeted.
PolyFuel belongs to Axens core technologies forupgrading FCC and Steam Cracker olefinic streams,these include: Alkyfining® (selective hydrogenation ofdiolefins), dedicated adsorbents (AxSorb™ series) andEtherification.
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