Application: GTC Technology’s GT-BenZap is a benzene saturation technology that allows refiners to achieve the upcoming benzene limit required by EPA’s regulations under Mobile Sources Air Toxics Phase 2 (MSAT2). Benzene saturation is applied when the logistics of benzene recovery and production are unfavorable, or where the economy of scale for benzene production is not sufficient.
Description: GT-BenZap process features a reliable traditional design paired with a proven nickel-based catalyst. The process consists of hydrotreating a narrow-cut C6 fraction, which is separated from the full-range reformate to saturate the benzene component into cyclohexane.
The reformate is first fed to a reformate splitter where the C6 heart cut is separated as a side-draw fraction, while the C7+ cut and the C5– light fraction are removed as bottom and top products of the column.
The C6 olefins present in the C6 cut are also hydrogenated to paraf-fins, while the C5– olefins removed at the top of the splitter are not, thus preserving the octane number. The hydrogenated C6 fraction from the reactor outlet is sent to a stabilizer column where the remaining hydro-gen and lights are removed overhead. The C5– cut, produced from the splitter overhead, is recombined with the hydrogenated C6 cut within the GT-BenZap process in a unique manner that reduces energy con-sumption and capital equipment cost. The light reformate is mixed with the C7+ cut from the splitter column and together form the full-range reformate, which is low in benzene. GTC also offers a modular construc-tion opconstruc-tion and the possibility to reuse existing equipment.
Process advantages:
• Simple and reliable technology; low operating costs
• An economical alternative to platinum-based systems
• Ability to reduce the benzene in the reformate stream by over 99.9%
• Minimized impact to hydrogen balance and octane loss.
Installation: Three commercial licenses.
Licensor: GTC Technology US, LLC contact
Full-range
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Biodiesel
Application: Consumption of primary energy has risen substantially in recent years, and greenhouse gases (GHG) emissions have increased by a substantial amount. To counter this trend, there is a global strong em-phasis on regenerative energy such as biofuels to effectively reduce or avoid such emissions.
Description: The Lurgi biodiesel process is centered on the transesteri-fication of different raw materials to methyl ester using methanol in the presence of a catalyst. In principle, most edible oils and fats — both veg-etable and animal sources— can be transesterified if suitably prepared.
Transesterification is based on the chemical reaction of triglycerides with methanol to methyl ester and glycerine in the presence of an alka-line catalyst. The reaction occurs in two mixer-settler units. The actual conversion occurs in the mixers. The separation of methyl ester as the light phase and glycerine water as the heavy phase occurs in the settlers due to the insolubility of both products and the difference in density.
Byproduct components are removed from the methyl ester in the down-stream washing stage, which operates in a counter-current mode. After a final drying step under vacuum, the biodiesel is ready for use.
Any residual methanol contained in the glycerine water is removed in a rectification column. In this unit operation, the methanol has a puri-ty, which is suitable for recycling back to process. For further refinement of the glycerine water, optional steps are available such as chemical treatment, evaporation, distillation and bleaching to either deliver crude glycerine at approximately 80% concentration or pharmaceutical-grade glycerine at > 99.7% purity.
Economics: The (approximate) consumption figures—without glycerine distillation and bleaching—stated below are valid for the production of one ton of rapeseed methyl ester at continuous operation and nominal capacity.
Steam, kg 320
Water, cooling (t = 10°C), m3 25
Electrical energy, kWh 12
Methanol, kg 96
Catalyst (Na-methylate 100%), kg 5
Hydrochloric acid (37%), kg 10
Caustic soda (50%), kg 1.5
Nitrogen, Nm3 1
Installation: Lurgi has been building biodiesel plants for 20 years. Only in the last five years, Lurgi has contracted more than 40 plants for the pro-duction of biodiesel with capacities ranging from 30,000 to 250,000 tpy.
Licensors: Lurgi GmbH contact
Oil
Reactor 1 Reactor 2
Methanol recovery
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Biodiesel
Application: The RHT- Biodiesel process is optimized to produce biodiesel from palm oil, rape-seed oil, vegetable and animal products that contain fatty acids with even number of carbon atom (12 to 22). The lack of sulfur in the biodiesel enables complying with many international fuel specifications.
The biodiesel is comparable to petroleum-based diesel. Triglycerides are reacted with methanol, ethanol or higher alcohols to yield biodiesel within the acceptable boiling range. Methanol is most commonly used for the biodiesel production since it is the most cost-effective of alco-hols, and it can provide better economics for the biodiesel producers.
Biodiesel is produced by reacting vegetable oils and animal fats (triglyc-erides) with methanol in the presence of highly alkaline heterogeneous catalyst at moderate pressure and temperature. Pretreatment may be required if the vegetable oil has a high free-fatty acids content to optimize methyl esters yield. If free fatty acids are present in the feed, first step is esterfication of the free-fatty acid with metha-nol. However if the free-fatty acids concentrations are low, then this step can be deleted.
The triglycerides and methanol are converted by transesterfication reaction to yield methyl esters of the oils and fats, and glycerine is pro-duced as a byproduct. The glycerine is separated from the methyl esters (biodiesel) by phase separation via gravity settling. The methyl esters and glycerine are purified to meet the product specifications.
Description: In the simplified process flow diagram (1), the feed—veg-etable oil or animal fats—is pumped from storage and is mixed with methanol in the required molar ratio vegetable/methanol at moderate operating pressure. The feed is heated to the reaction temperature and is sent to esterification reactor. Free-fatty acids are pretreated if the con-centration exceeds 3% percent of the feed. The reactor contains an acid catalyst for this reaction and can remove 99.9 % of free-fatty acids from
the vegetable oils. (Note: the pretreatment is only required when the feed contains free-fatty acids; otherwise, this step can be omitted.
The effluent from the first reactor (if free-fatty acids are present) or the heated feed is sent to the transesterfication reactor, where 3 moles
Esterification
of the separator, and is water washed. The washed biodiesel product is taken from the top of the drum. Water washing removes excess metha-nol from the reaction products, which is recovered by normal distillation;
the pure methanol is recycled back to the reactor. The bottoms from the separator/settler are sent to the purification unit to remove impurities and residual methanol, which is recycled back. Pure glycerine product is sent to storage.
Fig. 2 is an alternate flow scheme; a spare transesterification reactor is added to remove glycerine from the reactor to sustain reaction rates.
Once the reaction rates are reduced the reactor is switched and washed with hot solvent to remove residual glycerine and biodiesel. This extra reactor patented mode of operation provides higher reactions rates and onstream capability while enhancing yield and productivity. Glycerine purity can exceed 99.8% after distillation.
Reaction chemistry: Transesterification reactions:
Triglycerides + 3 Methanol ➞ Methyl Ester of the oil (biodiesel) + Glycerol Comparision of the Diesel/Biodiesel Properties
Fuel Property Diesel Biodiesel
Fuel standard ASTM D 975 ASTM P S 121
Fuel composition C10–C21 HC C12–C22 FAME Lower heating value, Btu/gal 131 117
Kinemetic Vis @ 40°C 1.3–4.1 1.9–6
SG at 60°F 0.85 0.88
Water, wppm 161 500
Carbon 87 77
Hydrogen 13 12
Oxygen 0 11
Sulfur, wppm 15–500 0
Bp, °F 380–650 370–340
Flash Pt, °F 140–175 210–140
CAPEX ISBL plant: USD/ton Biodiesel 235–265
Steam, lb/h 368
Water, cooling gpm 64
Power, kWh 9
Licensor: Refining Hydrocarbon Technologies LLC contact
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