Processes

 

Büten-1 Production Process:
Butene-1 is obtained from ethylene by the selective dimerization reaction. The catalyst system is a derivative of titanium and prevents the isomerization of butene-1 to butene-2.
The polymerization purity ethylene is used in the process. The Alfabutol process is simple. Since the working temperature is low (50-60 ° C), there is no need for a heating medium in the reaction section; keep the reactants in liquid phase

a low working pressure is sufficient for Use solvents in the reaction and process.
indestructible; no special or expensive materials are required (construction only

carbon steel is used). Polymerization purity ethylene (in gaseous form) is fed through a dispersant to the reactor in liquid phase conditions. Catalyst is continuously introduced into the reactor solution, where ethylene undergoes the dimerization reaction in the liquid phase. The reaction heat is removed by a conventional air or water-cooled pumping system. The product is taken from the bottom of the reactor; It is in liquid form and mixed with spent catalyst.

The spent catalyst in the product stream is separated in the catalyst removal section and

thrown away (for example, sent to the incinerator); hydrocarbons are divided by fractionation.
goes. There are two columns here. In the first, unreacted ethylene is separated and returned to the reactor. Pure butene-1 is taken from the top of the second column and oligomers (predominantly C6 olefin) from the bottom.

 

Büten-2 Production Process:

It is a process in which butene-2 ​​and ethylene are produced from propylene by the reaction of triolefin. Propylene, of ethylene and nbutylenes; or other triolefin processes where ethylene, propylene and C5 - C7 olefins are obtained from butylenes.

The propylene (and returning propylene) is heated and fed into the fixed bed metathesis reactor.
fed. In the metathesis reactor, 2 moles of propylene are converted into 1 mol of ethylene and 1 mol of butene-2. The small amount of coke accumulating on the catalyst is cleaned by a periodic regeneration process. The reactor stream passes to the fractionation column; where ethylene separates, unreacted propylene returns and the butylene product passes into the next fractionation. The recycled propylene separates from the propane contained in the previous fractionation column and goes to the reactor. The small amount of C5 + olefins formed in the reaction is separated from the butylene stream and butylene is removed from the top of the arm.
Commercially pure (93%) propylene, 30% ethylene, 58% butylenes (90% butene-2), 9%
propane by-product (80% propane) and

3% C5 + weights are obtained.

Propylene is made by pyrolysis or supplied from the refinery; its concentration can vary over a wide range. The higher the propylene concentration in the feed stream, the higher the efficiency.

 

Alcohol Production Process:

Ethylene, aluminum, hydrogen, solvents, air and water ethylation, oxidation and
It is a process in which even-numbered straight-chain alpha-alcohols are produced by hydrolysis reactions.
Very pure alumina or alum is also produced as a by-product in the process.
Aluminum powder is mixed as slurry in a suitable solvent and
It is hydrogenated with dry hydrogen in the environment with triethylaluminium (TEA). The resulting product, diethylaluminium hydride, reacts with ethylene to form triethylaluminum. For each mole introduced into the polymerization, 2 moles of triethylaluminum are returned to the hydrogenation stage.

(TEA) reacts with ethylene to form high molecular weight alkylalumines. By decomposition after polymerization, a mixture of alkyl chains from C2 to C22 is obtained. The proliferative reaction is very exothermic; As the proliferating chain and (TEA) react violently with water, the heat released is transferred by a hydrocarbon. For optimum efficiency, the reaction is done at high pressure and low temperature.

The product that grows is converted into alkoxides by oxidizing with dry air under controlled conditions. The oxidation reaction is very exothermic and gives esters, ethers, oxides, aldehydes as byproducts; these are removed with an excess of solvent before hydrolysis.
Hydrolysis: Purified alkoxide is converted into crude alcohols and alumina sludge by reacting with water. After a purification process, the water is separated by drying and 75% Al2O3 CATAPAL alumina with high purity is obtained. When a high purity alum solution is desired, the hydrolysis reaction is carried out with 98% sulfuric acid.
Fractionation: Crude alcohols are dried and distilled; By fractionation, each alcohol can be obtained individually or collected as binary mixtures. High molecular weight alcohols are distilled in vacuum.

 

Ammonia Production Process:

It is a process where ammonia is obtained from natural gas by methanation reaction. Other hydrocarbons can also be used as raw materials.
After mixing with the return hydrogen, the natural gas is heated and sent to the desulfurizer to desulfurize it, through which the saturator passes; Meanwhile, while heating the natural gas coming from the feed tank, it cools down somewhat.
In the saturator, it mixes with the hot circulating process condensate, the outgoing stream,
the steam / carbon ratio is 2.8 / 1, mixed with a little more steam and hot
In the first reformer, the gas is brought to a temperature of 700-800 ° C and a pressure of 28-45 bar by preheating. The gas mixture is fed to a second reformer unit and the process
heated by air, here its temperature reaches 900-950 ° C. Hot gas is cooled
(by producing superheated high pressure gas) and enters high temperature (HT) and low temperature (LT) converters (5,6); In these units, most of the carbon monoxide turns into carbon dioxide. The cooling process of the process gas in HT and LT converters is provided by heating the circulation water fed to the saturator.

The heat of the gas leaving the LT converter is used for preheating the high pressure boiler feed water (BFW = boiler feed water).

The cold gas exiting the LT converter is taken into a CO2 removal unit;
from here directly to the synthesis gas compressor and then to the methanator
expense. This layout minimizes the need for outside heat. The process gas is dried and comes to the synthesis unit. Conventional catalysts are used in synthesis production. Any ammonia converter unit can be used. After the hot gases leaving the converter are cooled by high pressure boiler feed water and converter feed gas, they pass to the refrigeration unit, from which ammonia is obtained in pure form. The side stream from the circulator comes to a simple refrigeration unit. Here, the unreacted parts condense and leave for use as fuel, while the hydrogen returns to the circulation pump.
Production prices depend on the natural gas price and capital. Raw material and auxiliary material (fuel) cost varies according to the flow chart of the factory and geographic location.

 

Ammonium Nitrate Production Process:

It is a process in which ammonium nitrate is obtained by the neutralization reaction of nitric acid with ammonia; The product is 99.8% (by weight) ammonium nitrate (AN) solution. In the carnit process, there is no need for external heat, energy efficiency is high and capital is low.
Nitric acid and ammonia gas react in a highly reversible flow system.

inserted; the working pressure is kept higher than the vapor pressure of the solution. No process steam is produced. By adjusting the return rate, the solution return stream is cooled (by a series of heat exchangers), keeping the temperature under control. The hot return solution exits the reactor at 185-190 ° C, flows into the heat exchanger where it releases its heat; This heat is used in the production of 99.8% product solution. Other modifiers in the system are evaporators and they give export steam with 95% solution. In the system

The solution is slightly ammonia. Free ammonia in the product is neutralized by injection of a small amount of nitric acid before pressure reduction. The carnite process is characterized by an isobaric concentration process.

pressure reduction and self-regulation of the adiabatic jet. There is no gas flow; The ammonium nitrate content of the liquid stream is at the level of 400 ppm by weight. The process's own energy is sufficient up to 45% acid solution; Higher concentrations of export steam are obtained.

 

Aniline Production Process:

It is a reaction from phenol in which aniline is produced by the ammonolysis reaction.

After the phenol taken from the tank is mixed with excess ammonia, it is evaporated, heated and fed to a fixed bed adiabatic reactor. Phenol and ammonia react with the catalyst in the reactor to form aniline and water. The gas stream leaving the reactor is partially condensed, the liquid and gas phases are separated. The gas phase is unreacted ammonia; it is compressed and recycled. The liquid part is distilled after the ammonia has been removed and very pure aniline is obtained. A small amount of unreacted phenol is recovered as the aniline-phenol azeotrope and returned to the reaction. The most important feature of the process is the Halcon SD catalyst; phenol to stoichiometric efficiency
converts to ammonia at a very close level. Therefore, the purification process is very simple and the resulting aniline is exceptionally pure. The life span of a catalyst is quite a long time, like seven years.
Another feature of the process is to change the proportions of the reactants.

is to allow. Thus, predominant production of the by-product diphenylamine is possible. An additional purification system is required to obtain very pure diphenylamine. Even in such an operating state, the life span of the catalyst does not change.
The required capital is much lower than for technology operating on the basis of nitrobenzene reduction; A factory with a capacity of 50 000 t / year was established for 12.6 million dollars (1985). Excessive phenol content, where very pure aniline production is desired

This process is preferred when it is desired to produce with a small amount of capital. Another advantage of using phenol as a raw material is that the hazardous nitriding reaction and acid cleaning stage found in conventional benzene-based technologies.
it is the absence of mesinin. Therefore, there are very few waste problems.

 

Polyethylene Production Process:

High pressure gas phase polymerization from ethylene, low density
It is a calcic process in which polyethylene is obtained.
Ethylene gas is first compressed in the front compressor up to 250-300 atmospheres, the second
sent to the compressor. Pressure here

It is raised to 3500 atmospheres. The pressure of the reactor depends on the design of the factory, the type of catalyst and the grade of the desired product. The compressed ethylene is polymerized in the tube reactor after a preheating. Unreacted ethylene at the exit of the reactor is sent to two separators with medium and low pressure. This ethylene is returned to the pre-separator and second compressor via a booster.

The resulting polyethylene is fed into an extruder; Here necessary additives are added and the final product is granulated. The polymerization rate is very high due to the type of reactor used. Expenses of auxiliary materials such as water, steam and electricity are low and operating flexibility is extraordinary. The quality of the product obtained is very good. Factories are designed to operate in complete safety.

 

LLDPE Production Process:

It is a process where linear low density polyethylene and high density polyethylene are obtained by gas phase polymerization at low pressure from ethylene. In a fluidized bed reactor, using suitable solid catalysts, gas phase polyethylenes covering a wide range can be produced. The product is dry, flows easily and is in the form of granules that do not contain fine particles. Melting index and molecular weight
its distribution is controlled by the choice of specific catalysts and operating conditions. The density of the polymer in the product

adjusted by the amount of co-monomer. Catalyst efficiency is very high; This property eliminates a catalyst separation after the reaction.

The feature of the process minimizes environmental pollution, fire and explosion hazards.
is keeping level; therefore it is very easy to operate and maintain.
Gas ethylene, co-monomer and catalyst are introduced into the reactor; in the reactor, growing
there is a fluid-bed formed by polymer particles; 20 kg / cm2

pressure and works around 100 ° C. The reaction gas flowing into the reaction bed is circulated by a single stage centrifugal compressor; Thus, the polymerization reaction
While providing the necessary raw material, reaction heat is removed from the bed.
The circulation gas is cooled through a heat exchanger. The granular product flows intermittently into the product discharge tanks. Here, unreacted gas is separated from the product. The extracted gas is compressed and sent back to the reactor. Hydrocarbons remaining in the product are swept away with nitrogen. The granular product is formed into pellets in a low energy system.
The density of the polymer is easily controlled in the range of 0.915-0.970.
The molecular weight distribution is narrow or medium width, relative to the catalyst.

The melt flow can be varied from 1 to over 200.