Xylene (English dimethylbenzene) is an anemic, clear fluid with a fragrant odor. It is a thing in which 2 hydrogens on the benzene ring are changed by methyl groups. The boiling point is 137-140 ° C. Xylene is divided right into ortho Xylene, m-xylene, and p-xylene are 3 isomers. In industry, xylene defines the mix of those isomers as well as ethylbenzene. The top qualities are typically exceptional and likewise first-grade products with a purification variety of 3 ° C as well as likewise 5 ° C for cleansed water. It can be arbitrarily combined with ethanol, chloroform or ether, and insoluble in water. Commonly utilized in organic solvents as well as artificial medications, coverings, materials, dyes, nitroglycerins along with chemicals. Xylene is moderately unsafe in addition to additionally cancer causing somewhat. Xylene air contamination primarily originates from synthetic fibers, plastics, gas, rubber, ingredients of numerous coverings, numerous adhesives, water-proof products, as well as furthermore from shedding gas of gas as well as tobacco leaves.
Xylen Property
Melting point
-34 °C
Boiling point
137-140 °C (lit.)
density
0.86 g/mL at 25 °C (lit.)
vapor density
3.7 (vs air)
vapor pressure
18 mm Hg ( 37.7 °C)
refractive index
n20/D 1.497(lit.)
Fp
77 °F(lit.)
storage temp.
Flammables area
solubility
Chloroform (Soluble), Methanol (Slightly)
form
Liquid
color
APHA: ≤10
Odor
char. sweet odor
explosive limit
7%
Water Solubility
<0.1 g/L (20 ºC)
Xylen Uses
Xylen is utilized as a solvent in the printing, rubber, paint and also leather industries. Aircraft gas, fuel, and cigarette smoke contain small amounts. Utilized as a fragrance ingredient and also solvent in the cosmetics industry.
Xylen is commonly made use of as natural solvents as well as resources for synthetic medicines, coverings, materials, dyes, nitroglycerins as well as pesticides.
Xylen solvent, resolution of water in several organic compounds, microscope cleaner. Cleaning up agent for silicon components and also thermistors, and so on. When made use of as a chemical basic material, each isomer can be separated in advance. The blend is mostly utilized as a solvent for paint finishes and as an additive for aviation fuel.
Xylen's Coproduction Approach
Para-xylene is produced in a countercurrent simulated moving bed using a feedstock containing a mixture of Xylen and ethylbenzene that has previously removed hydrocarbons containing 9-10 carbon atoms, the feedstock having the following weight composition:
EB: Ethylbenzene 5.6%
PX: Paraxylene 22.6%
MX: m-xylene 49.9%
OX: o-xylene 21.9%.
The pilot plant used in this example consisted of 24 beds 1.1 meters long and 0.021 meters in diameter. Each column was loaded with 344 grams of barium-exchanged X zeolite with a moisture content of 5.5% expressed as loss on ignition at 900°C. The operating temperature is 175°C, the suction pressure of the circulating pump is maintained at 10 bar, all streams are continuously injected or discharged under flow control, except that the intermediate raffinate is continuously discharged under pressure control, and the flow rates of injection and discharge are all at Expressed under ambient pressure conditions and 20°C. The raffinate (R2) and the middle fraction R1 (middle raffinate) are withdrawn continuously. The total number of beds is 24. There are 5 beds between desorbent injection and raffinate discharge, 9 beds between extract discharge and material injection, 5 beds between material injection and intermediate raffinate discharge, intermediate raffinate discharge and There are 3 beds between raffinate discharge and 2 beds between raffinate discharge and desorbent injection.
The operating conditions are as follows:
Material: 3.24 liters/hour
Solvent: 5.52 l/h desorbent (99.06% p-diethylbenzene and 0.94% other C10 aromatic hydrocarbons)
Extraction: 3.27 liters/hour
Intermediate raffinate (R1): 4.29 liters/hour
Raffinate (R2): 1.2 liters/hour
Circulation flow (in segment 1): 16.4 l/h
The R2/R1 ratio is 0.28.
The switching time (period) of the valve is 70.8 seconds.
After distillation of p-diethylbenzene, the resulting extract was withdrawn continuously to give a stream of 0.71 liters/hour of 99.7% pure p-xylene.
1.2 liters/hour raffinate carries out distillation, obtains fluid flow rate 0.13 liters/hour, and its weight composition is as follows:
EB: Ethylbenzene 0.1%
PX: p-xylene 1.7%
MX: m-xylene 73.9%
OX: o-xylene 24.2%.
The crystallization section consists of two static crystallizers with alternating cooling and heating periods as crystals are formed. A refrigeration unit was used to generate meta-xylene crystals at -60 °C. After crystallization, the mother liquor is drained off. The meta-xylene crystals were washed with very high purity molten meta-Xylen while purification was performed by partial melting at -45°C.
The meta-xylene crystallization yield was 29%.
The amount of p-xylene produced by all units was 25 times that of m-xylene, namely 0.71 l/h and 99.7% p-Xylen and 0.028 l/h and 99.0% m-xylene respectively.
Xylen Separation Method
Report one
Add xylene raw material D as well as 2% volume proportion catalyst H in mixer 1, mix evenly at regular temperature level, as well as dissolve each other; After mixing, enter o-xylene separation tower 2 furnished with stainless steel wire corrugated packing at 7L/h, tower The temperature of the pot is 149 ° C, the stress of the tower kettle is ≤ 0.02 Mpa, and the reflux proportion at the top of the tower is 15.3. The ortho-xylene product E is divided from the tower kettle, and also part E is reboiled by the tower pot reboiler 6, as well as returns to the o-xylene splitting up tower 2, the tower overhead steam A has stimulant, ethylbenzene, p-xylene, m-xylene; the tower overhead vapor A goes into the tower top reflux intermediate container 4 after being cooled down by the colder 3, as well as a part of it is injected into the tower leading reflux intermediate container 4 through the pump 5 as reflux Part of the top of the o-xylene separation tower 2 is utilized as extract A; extract A gets in the ethylbenzene separation tower 7 at 4L/h, the temperature level of the tower base is controlled at 149 ° C, the stress of the tower bottom is ≤ 0.02 Mpa, as well as the top of the tower is refluxed Ratio 161, p-xylene as well as m-xylene F are divided from the tower kettle, part of F is reboiled by the tower kettle reboiler 11, and then returns to the ethylbenzene separation tower 7, heavy steam B is distilled from the top of the tower; vapor is distilled from the top of the tower B is cooled right into a liquid by cooler 8 and enters the leading reflux intermediate container 9, a part of which is pumped back to the top of the ethylbenzene separation tower 7 with a pump 10, as well as a component is utilized as the overhanging distillate B; the overhanging distillate B gets in the urging Representative recovery tower 12, the temperature of the tower kettle is managed at 136 ° C, the stress of the tower kettle is ≤ 0.01 Mpa, the top reflux proportion is 8, the ethylbenzene product G is divided from the tower pot, part of G is reboiled by the tower kettle reboiler 15, and returned to the accelerator Recuperation tower 12, the heavy steam C distilled from the top of the tower is cooled right into liquid by cooler 13, gets in the intermediate storage tank 14, a component is returned to the top of the driver recuperation tower 12 with a pump 16, and a part is made use of as the top extract C, C is a healing accelerator without Xylen and also ethylbenzene, which can be utilized once again.
Report two, An approach for dividing p-xylene from a xylene mixture, comprising the steps of:
a) Catalytic hydrogenation: feed the blended xylene resources and flowing hydrogen right into Activator 1 at the same time, regulate the response stress in Reactor 1 to 6.0 MPa, the reaction temperature level is 250 ° C, and also the quantity proportion of hydrogen hydrocarbons is 500. Under the action, the mixed xylene resources undertakes discerning isomerization-hydrogenation reaction under the condition of hydrogenation, as well as produces a stream consisting of 1,4-dimethylcyclohexane after the response; the hydrogenation driver is Y Type molecular filter, wherein Cr content is 5wt%;.
b) Rectification separation: The stream having 1,4-dimethylcyclohexane produced symphonious a) is sent out to the rectification splitting up device for rectification. The correction separation system takes on a plate rectification tower, and the stream is from the rectification The middle part of the tower gets in, 1,4-dimethylcyclohexane spurts from the top of the tower, and unreacted xylene is discharged from the bottom of the container and went back to the reactor as a resources. A condenser is set up on top of the correcting tower, as well as a For the reboiler, the operating temperature level on top of the tower is 90 ° C, the operating stress is 0.1 MPa, and the operating temperature at the end of the tower is 120 ° C;
. c )Dehydrogenation response: After correction and also splitting up, 1,4-dimethylcyclohexane enters the second activator, the response pressure in the 2nd activator is controlled to 1.0 MPa, the reaction temperature is 400 ° C, as well as the hydrogen/hydrocarbon molar proportion is 5, under the impact of a dehydrogenation stimulant, 1,4-dimethylcyclohexane creates p-xylene through a dehydrogenation response, and the catalyst made use of in the dehydrogenation response is a supported stimulant having shift metal Ni;.
d) Separation and also filtration: The p-xylene obtained symphonious c) is fixed to separate unreacted 1,4-dimethylcyclohexane to acquire the finished p-xylene, and also the separated unreacted 1,4- Dimethylcyclohexane is returned to reactor two.
The purity of the Xylen product was figured out to be 99.8%.
About Products: If you need Xylen, a cosmetic raw material, please contact our service staff directly, and we will provide you with high-quality products at the best price. As an experienced Xylen manufacturer and supplier, ZSpharmac will provide Xylen raw materials to customers all over the world for a long time. Over the years, the company has been adhering to the spirit of “integrity management, strict quality control, customer first”, and has won unanimous praise from domestic and foreign customers.
Company Profile and Corporate Culture
Company Profile：
ZhiShang Chemical is owned by ZhiShang Group is a professional new-type chemicals enterprise combined into research and development, production and sales .
The company’s competitive product is pharmaceutical raw materials and intermediates (especially carbohydrate derivatives Series), In recent years, the company has made a major breakthrough in food and feed additives, plant extraction, industrial chemicals industry .
The company insists on the spirit of “sincere management, strict quality control, customer as god” , get consistent high praise from customers at home and abroad.
Corporate Culture：
OUR MISSION Help China Chemicals to benefit the happiness of human life OUR VISSION Become the most trusted chemical supplier in the world OUR BUSINESS PHILOSOPHY Striver – oriented, enrich employees, customer first, deep service, seek development OUR VALUES Be prepared for danger in times of peace, forge ahead actively, unity and cooperation, and be brave to fight
About Us
The production base is located in Zhangqiu chemical industry park and Tai’an high-tech chemical industry park. laboratory and workshop in strict accordance with the GMP standard and the product fit national ISO9001 and ISO2000 standards.
“Zhishang” products are exported to Europe, North and South America, the Middle East, Asia Pacific and Africa area, so as to establish a long-term and stable cooperation relationship with customer in the world.
Company Info
Business Type: Manufacturer
Product Range: Cosmetic raw materials
Products/Service:Cosmetic raw materials (flavors and fragrances,antioxidant products, moisturizing and hydrating, whitening agents, cosmetic additives)
Factory Location : Diao Town Industry Park, Zhangqiu City, Jinan City, Shandong Province, China.
Service
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FAQ
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We will make samples before mass production, and after sample approved, we’ll begin mass production. Doing 100% inspection during production, then do random inspection before packing.
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You can get free samples for some products,you only need to pay the shipping cost or arrange a courier to us and take the samples. You can send us your product specifications and requests,we will manufacture the products according to your requests.
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Our MOQ is 1kg. But usually we accept less quantity such as 100g on the condition that sample charge is 100% paid.
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Different quantity has different discount.
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1. ≤50kg, Express delivery recommended, usually called as DDU service;
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