Application: To produce high yields of benzene, toluene, xylenes and hydrogen from naphthas via the CCR Aromizing process coupled with RegenC continuous catalyst regeneration technology. Benzene and tolu- ene cuts are fed directly to an aromatics extraction unit. The xylenes fraction, obtained by fractionation and subsequent treatment by the Arofi ning process for diolefi ns and olefi ns removal, is ideal for para- xylene and orthoxylene production.
Description: This process features moving bed reactors and a continu- ous catalyst regeneration system coupled with a hard, smooth-fl owing catalyst. Feed enters the reactor (1), passes radially through the moving catalyst bed, exits at the reactor bottom and proceeds in the same man- ner through the 2–3 remaining reactors (2). The robust (latest genera- tion AR 501 & 505) catalyst moves downward through each reactor. Leaving the reactor, the catalyst is gas-lifted to the next reactor’s feed hopper where it is distributed for entry. After the last reactor, an inert gas lift system isolates and transports the catalyst to the recently-in- troduced RegenC regeneration section (3). Coke is removed; catalyst is returned to its original state and sent to the fi rst reactor; the cycle begins again. A recovery system (4) separates hydrogen for use in downstream units and the Aromizate is sent to a stabilization section. The unit is fully automated and operating controls are integrated into a DCS, requiring only a minimum of supervisory and maintenance effort.
Yields: (%) Feed Products TBP cut, °C 80 –150 Hydrogen 4.1 Paraffi ns 57 C5+ 87 Naphthenes 37 Benzene 8.5 Aromatics 6 Toluene 26.3 Xylenes 26.1 Total aromatics 74.3
Economics: The ISBL investment for a typical 25,000-bpsd CCR Aromiz- ing unit with a RegenC regenerator, 2004 Gulf Coast location.
Investment including initial catalyst inventory,*
US$ million 53
Typical utility requirements:
Fuel, 106 kcal/h 76
Steam, HP t/h (net export) (17)
Electricity, kWh/h 5,900
Catalyst operating cost, $/ton feed 0.5 * Exclusive of noble metals
��������� �������� ������������ ������������ ������� ���������� ������� ���������� ������������ ������� ����������� ��������� ������ ���� �������� ������ ���� � � � �
Commercial plants: Sixty-four CCR reforming units have been licensed; including seven plants in operation and four under design.
Licensor: Axens, Axens NA.
BTX aromatics
Application: An aromatics process based on extractive distillation, GT- BTX effi ciently recovers benzene, toluene and xylenes from refi nery or petrochemical aromatics streams, such as catalytic reformate or pyrolysis gasoline.
Description: Hydrocarbon feed is preheated with hot circulating sol- vent and fed at a midpoint into the extractive distillation column (EDC). Lean solvent is fed at an upper point to selectively extract the aromatics into the column bottoms in a vapor/liquid distillation operation. Nonaromatic hydrocarbons exit the column top and pass through a condenser. A portion of the overhead stream is returned to the column top as refl ux to wash out any entrained solvent. The balance of the overhead stream is the raffi nate product, requiring no further treatment.
Rich solvent from the bottom of the EDC�is routed to the solvent- recovery column (SRC), where the aromatics are stripped overhead. Stripping steam from a closed-loop water circuit facilitates hydrocarbon stripping. The SRC operates under vacuum to reduce the boiling point at the column base.
Lean solvent from the bottom of the SRC is passed through heat exchange before returning to the EDC. A small portion of the lean circulating solvent is processed in a solvent-regeneration step to remove heavy decomposition products, which are purged daily.
The process advantages over conventional liquid-liquid extraction processes include lower capital and operating costs and simplicity of operation. Advantages over other extractive processes include: superior solvent system, fewer equipment pieces, small equipment and expanded feedstock range. Design fl exibility allows use for grassroots aromatics recovery units or debottlenecking conventional systems in many revamp confi gurations.
Economics:
New unit Expansion of conventional BTX recovery unit
Feed, bpd 3,500 Lt. reformate 4,000 incremental
Capital cost, $MM 6.5 3.5
Simple pretax payout, yr 2.2 1.2
ROI, % 44 85
Commercial plants: Fourteen commercial licenses are in place.
Reference: “Benzene reduction in motor gasoline — obligation or op- portunity,” Hydrocarbon Processing Process Optimization Confer-
��������� ����������� ������������ ������ ���� ������� �������������� ������� ���������������� ������������ ���������� ������������� ������� �������� ������ ����� �����
ence, April 1997. “Improve BTX processing economics,” Hydrocarbon
Processing, March 1998.
Licensor: GTC Technology.
BTX aromatics
Application: To produce reformate, which is concentrated in benzene, toluene and xylenes (BTX) from naphtha and condensate feedstocks via a high-severity reforming operation with a hydrogen byproduct. The CCR Platforming Process is licensed by UOP.
Description: The process consists of a reactor section, continuous cata- lyst regeneration section (CCR) and product recovery section. Stacked radial fl ow reactors (1) facilitate catalyst transfer to and from the CCR catalyst regeneration section (2). A charge heater and interheaters (3) are used to achieve optimum conversion and selectivity for the endo- thermic reaction.
Reactor effl uent is separated into liquid and vapor products (4). Liquid product is sent to a stabilizer (5) to remove light ends. Vapor from the separator is compressed and sent to a gas-recovery section (6) to separate 90%-pure hydrogen byproduct. A fuel gas byproduct of LPG can also be produced. UOP’s latest R-270 series catalyst maximizes aromatics yields.
Yields: Typical yields from lean Middle East naphtha:
H2, wt% 4.3
Benzene, wt% 1.7
Toluene, wt% 29.9
Xylenes, wt% 30.4
A 9+, wt% 13.1
Economics: Capital investment per mtpy of feed:
US$ 50 –75
Utilities per metric ton feedrate
Electricity, kWh 12
Steam, HP, mt 0.16
Water, cooling m3 20
Fuel, MMkcal 0.13
Commercial plants: There are 173 units in operation and 30 additional
units in design and construction. Total operating capacity represents over 3.9 million bpd. Licensor: UOP LLC. ������������ ������������� ����� �������� ����� �������� ������������� ���������� �������� � � � � � � ���������������
BTX aromatics
Application: To produce petrochemical-grade benzene, toluene and xy- lenes (BTX) via the aromatization of propane and butanes using the BP- UOP Cyclar process.
Description: The process consists of a reactor section, continuous cata- lyst regeneration (CCR) section and product-recovery section. Stacked radial-fl ow reactors (1) facilitate catalyst transfer to and from the CCR catalyst regeneration section (2). A charge heater and interheaters (3) achieve optimum conversion and selectivity for the endothermic reac- tion. Reactor effl uent is separated into liquid and vapor products (4). The liquid product is sent to a stripper column (5) to remove light satu- rates from the C6– aromatic product. Vapor from the separator is com- pressed and sent to a gas recovery unit (6). The compressed vapor is then separated into a 95% pure hydrogen coproduct, a fuel-gas stream containing light byproducts and a recycled stream of unconverted LPG.
Yields: Total aromatics yields as a wt% of fresh feed range from 61% for propane to 66% for mixed butanes feed. Hydrogen yield is approxi- mately 7 wt% fresh feed. Typical product distribution is 27% benzene, 43% toluene, 22% C8 aromatics and 8% C9+ aromatics.
Economics: US Gulf Coast inside battery limits basis, assuming gas tur- bine driver is used for product compressor.
Investment, US$ per metric ton (mt) of feed 175–208
Typical utility requirements, unit per mt of feed
Electricity, kWh 0.013 Steam, MP, mt (credit) (0.7) Steam, LP, mt 0.13 Water, cooling, mt 19 Fuel, MMkcal 2 Boiler feedwater, mt 0.55
Commercial plants: In 1990, the fi rst Cyclar unit was commissioned at the BP refi nery at Grangemouth, Scotland. This unit was designed to
process 1,000 bpd of C3 or C4 feedstock at either high- or low-pressure over a wide range of operating conditions. A second unit capable of processing C3 and C4 feedstock was commissioned in 2000, and oper- ates at design capacities.
Reference: Doolan, P. C., and P. R. Pujado, “Make aromatics from LPG,”
Hydrocarbon Processing, September 1989, pp. 72–76.
Gosling, C. D., et al., “Process LPG to BTX products,” Hydrocarbon
Processing, December 1991. Licensor: UOP LLC. ����������� ������� � � � � � ���������� ������������������ � ������������ �������� ������� ����� ���� ������� ���������������