Issue 17, 2012 - Review of high-value development and utilization of 2-butene (Part II)

With the successive completion and operation of ethylene projects in China, coupled with the rapid growth of the processing capacity of the refinery catalytic cracking unit, the total amount of C4 fractions in 2011 has exceeded 10 million tons, and how to rationally use C4 resources has attracted widespread attention
.
At present, a lot of research has been done on the utilization of 1-butene, butadiene and isobutylene in C4, but the utilization of 2-butene has been less
explored.
With the construction of MTBE production equipment, especially after precision fractionation of 1-butene, the content of 2-butene in by-product C4 reaches more than 80%, and a large amount of 2-butene needs to be developed and utilized
at a high value.

(Continued from the 17th edition of the 16th issue)
Fourth, butadiene is produced by oxidative dehydrogenation of butene

The B-02 ferrochrome-free catalyst adiabatic fixed bed reaction process developed by Beijing Institute of Fashion Technology adopts a reaction process in the synthetic rubber plant of Yanhua Company, and the yield of butadiene is 65.
8%
under the condition of butadiene: oxygen: water = 1:0.
65:16 。 Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences and Jinzhou Petrochemical Company researched and developed the butene oxidative dehydrogenation process, using W-201 iron-based catalyst, filling 9~10 tons of catalyst in the fluidized bed of the baffle with a diameter of 2600 mm, the airspeed of butene is 250~350 h-1, the reaction temperature is 370~385 °C, the average conversion rate of butene is about 80.
1%, and the average yield of butadiene is 70.
9%.

5.
Synthesis of sec-butanol from 2-butene

Germany's Texaco company's 2-butene direct hydration technology, using solid sulfonated resin as catalyst, at 150~170 °C, 5~7 MPa, to generate sec-butanol
.
Sinopec has developed the process of n-butylene direct hydration to sec-butanol and the XZ type high-temperature resistant resin catalyst supporting this process, which is characterized by good separation effect of crude products and long
service life of the catalyst.

6.
Secondary butyl acetate is produced from 2-butene

The n-butene method for the production of sec-butyl acetate in Japan in 1992 uses cation exchange resin as a catalyst, using a fixed-bed tubular reactor, the acidene mass ratio (1~2):1, acetic acid liquid airspeed 0.
1 ~10 h-1, olefin conversion > 90%, and the selectivity of sec-butyl ester is 89.
5%~96.
6%.

If solidified heteropoly acid is used as a catalyst, its effect is better than that of cation exchange resin
.

7.
Synthesis of methyl ethyl ketone from 2-butene

The liquid phase oxidation of n-butene can generate methyl ethyl ketone in one step, reducing the traditional hydration dehydrogenation production step
.
Catalytica of the United States has developed a new process OK (Olefin to Ketone) for the one-step oxidation of methyl ethyl ketone, the conditions are moderated, the redox reaction is completed in one step, and the halogen-free catalyst system is used, and the equipment can be made of
stainless steel.

China's 200,000 tons of ethylene from Fushun Petrochemical and 220,000 tons of ethylene plant in Xinjiang Dushanzi are used to produce methyl ethyl ketone, and Maoming Petrochemical's 1 million tons of ethylene plant plans to use 2-butene to produce methyl ethyl ketone
.

8.
Synthesis of pentanaldehyde from 2-butene hydroformylation

The process of butene carbonyl synthesis reaction to valeraldehyde belongs to atomic economic reaction, which is recognized as a representative of green chemical industry, and is a hot research field at home and abroad and a key technology
in the chemical industry 。 The industrialized butene hydroformylation process includes: (1) high-pressure cobalt method, using the hydrocarbonyl cobalt coordination compound HCo(CO)4 or the hydrocarbonyl cobalt coordination compound with tertiary phosphine ligand as the catalyst, and the hydroformylation reaction is carried out at 5.
0~35MPa, and the product is low in positive/heterogeneous ratio; (2) Low-pressure rhodium method, HRh(CO)2(PPh3)2 with triphenylphosphine as ligand or water-soluble HRh(CO)(trpps)3 with m-triphenylphosphine trisulfonate (tpps) as ligand as catalyst, the reaction pressure is usually 1.
5~3.
0MPa, and the product positive/heterogeneous ratio is high
。 Especially when HRh(CO)(tpps)3 is used as a catalyst, due to the introduction of water-soluble ligand tpps, it is soluble in water, and the catalyst in the aqueous phase and the products of the organic layer can be automatically separated after the reaction, which solves the problem of separation of products and catalysts in homogeneous catalysis, and opens up a new way to prevent the loss of active components of the catalyst, and has been successfully industrialized
abroad.

Domestic Sichuan University, Lanzhou Institute of Chemistry, Physical Chemistry, Dalian Institute of Physical and Chemical Engineering, etc.
have carried out in-depth research on the synthesis of C4 hydroformylation of pentanaldehyde, among which Sichuan University in the water-soluble phosphine-rhodium catalyst HRh(CO)(tpps)3 synthesis research earlier, Lanzhou Institute of Chemical Physical Chemistry through Aspen Plus software, simulation of butene hydroformylation to valeraldehyde continuous reaction-separation process, determine the simulation process flow, In addition, a mold test device composed of a vertical upgrade tandem kettle reactor and a thin film evaporator was built, and the process flow
of hydroformylation to valeraldehyde was opened up through cold mold and hot mold, 320h test and 1000h continuous operation test.
However, the above catalytic system has high reactivity to 1-butene and n-valeraldehyde, low reactivity to 2-butene, and poor selectivity
of n-valeraldehyde.

9.
Aromatization

The light hydrocarbon aromatization process mainly targets alkane, olefin and naphthenic raw materials
with carbon numbers C3, C4 and C5.
The catalysts used in various light hydrocarbon aromatization processes are basically ZSM-5 type zeolite
modified by non-noble metal elements such as gallium and zinc.
It is generally believed that the aromatization reaction of various light hydrocarbons is completed on the B acid center and the L acid center of the above catalyst, and the reaction steps are as follows: (1) ethylene, propylene, butene and pentene are generated by dehydrogenation, cracking or polymerization cracking reaction on the acid center, which are the building blocks of aromatic hydrocarbon molecules and belong to endothermic reactions; (2) After low-carbon olefin molecules generate C6~C9 olefins by oligomerization (dimerization and trimer) on the center of B acid, aromatic molecules with six-membered rings are generated by isomerization and cyclization reactions, which belongs to strong exothermic reactions; (3) The aromatic precursors are dehydrogenated at the acid center to generate aromatic hydrocarbons such as benzene, toluene and xylene, which belong to the endothermic reaction
.

The alpha process uses the pyrolysis C4 extract and pyrolysis C5 extract discharged from the ethylene plant as raw materials, and has high olefin content (olefin content is 30%~60%)
.
A set of 3500 BPSD industrial plant of Alpha process has been operating on Mizujima Island in Okayama, Japan since 1993, with a reaction pressure of 0.
2~0.
5MPa, aromatic hydrocarbon yield of 50%~65%, aromatic hydrocarbon distribution of benzene 14%, toluene 44%, xylene 30%, C9+ aromatic hydrocarbon 13%.

Because of the high olefin content of the feedstock, the reactor inlet temperature of the alpha process is relatively low (generally around 480°C), but the one-pass operation cycle of the catalyst is relatively short
.

The nano-forming process has been successfully industrialized in China, and two fixed-bed reactors are used to switch the operation mode and produce "triphenyl"
from C4 liquefied gas/pyrolysis C5 as raw material.
The feasibility
of civil liquefied gas, pre-MTBE liquefied gas feed (high olefin), cracked C5 feed, liquefied gas feed and aromatic hydrocarbon residual oil mixed feed has been verified on industrial plants.
When civil liquefied gas is used as raw material, the actual liquid phase yield on industrial equipment can reach more than
55%.
When C4 liquefied gas or pyrolysis C5 with high olefin content is used as raw material, the actual liquid phase yield on the industrial device can reach 60%~65%.

Although the raw materials used are different, the distribution of aromatic hydrocarbon products obtained under the same reaction conditions is roughly the same (benzene 18%~22%, toluene 40%~45%, xylene 20%~25%, C9+ aromatic hydrocarbons 8%~10%)
.
Nano-forming process catalyst DLP-1 uses nano-ZSM-5 molecular sieve with many orifices, short intracrystalline pores and low intramolecular diffusion resistance as the parent body, which has strong anti-deactivation ability and easy regeneration of carbon deposits, and has been operating in the first 100,000-ton industrial test device for nearly 1.
5 years and is undergoing technology promotion work
.

10.
Alkylation

Alkylated oil is produced by H2SO4, HF and other liquid acids catalyzed isobutane and butene alkylation reaction, equipment corrosion and environmental pollution is quite serious, many production equipment has not been started
.
Although patent CN98116429 discloses a local method for catalyzing the alkylation of isobutane and butene with a solid superacid, CN94120022, CN94120018 discloses a local method for catalyzing the alkylation of isobutane and butene with solid heteropoly acids to produce alkylated oil, but due to production technology and cost problems, it is difficult to achieve industrialization
.

(End of full text)

2-butene comprehensive utilization optimization
★2-butene hydrosaturation is a high-quality ethylene cracker, but high hydrogen consumption;
★ The technology for producing ethylene, propylene and aromatics from 2-butene is mature, but the investment is high and economies of scale are required;
★ The production of fine chemical products from 2-butene is highly
profitable.
2-butene oligomerization to produce C8 olefin or hydroformylation to valeraldehyde, the added value of the product is high, the downstream market space is large, and the investment is relatively low
.