Issue 16, 2012 - Review of 2-Butene High-value Development and Utilization (Part I)

With the 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 use of 1-butene, butadiene and isobutylene in C4, but the use of 2-butene (also known as n-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.

1.
Propylene made of 2-butene

1.
Propylene produced by 2-butene and ethylene/1-butene translocation reaction There are many
reports on the production of propylene by ethylene and 2-butene
translocation reaction.
Among them, the mature technologies mainly include ABB Lummus OCT technology and IFP's CCR-Meta-4 process
.

ABB Lummus' OCT technology mainly uses ethylene and 2-butene translocation reaction to produce propylene
.
Ethylene and butene are mixed into a fixed-bed reactor, ethylene and 2-butene react under the action of a catalyst to generate propylene, while isomerizing 1-butene to 2-butene, the logistics from the translocation reactor fractionation into high-purity, polymeric-grade propylene, unconverted ethylene and butylene cyclic back into the reactor
.
The one-pass conversion of butylene in this process > 60%, the total conversion rate of n-butylene is 85%~92%, and the selectivity of propylene > 98%.

The remaining C4 by-product of Shanghai SECCO's 900,000-ton ethylene plant uses this technology to produce propylene
.

IFP's CCR-Meta-4 process uses a highly active rhenium-based catalyst, and the crude C4 logistics in the reactants are converted into propylene and isobutylene-rich logistics in three steps: first, selective hydrogenation of butadiene and C4 alkynes, simultaneous hydroisomerization of 1-butene; Second, isobutylene is removed by distillation or etherification with methanol to generate MTBE; Third, the translocation of rich 2-butene and ethylene is converted into propylene
.
In this process, the translocation reactor operates at 35°C and at a pressure of 6 MPa, and the total conversion of 2-butene is increased by C4 fraction cycling, the total conversion of 2-butene reaches 90%, and the selectivity of propylene is about
95%.
CNPC in Taiwan applies the technology
.

Shanghai Petrochemical Research Institute has developed S-OMT to increase propylene production, under the action of transition metal oxides, under the conditions of 300 °C, 3.
0 MPa, C4 weight airspeed 2.
4h-1 through 2-butene and ethylene disproportionation to increase propylene, catalyst selectivity > 96%, initial conversion rate of 2-butene > 70%, total conversion rate of 2-butene cycle > 90%, has signed an agreement with Yanshan Petrochemical.
The first 200,000-ton industrial plant is expected to be industrialized
in Yanshan Petrochemical in 2012.
In addition, Dalian Institute of Chemical Physics uses supported MgMo/MCM22 zeolite catalyst for ethylene and 2-butene disproportionation reaction to produce propylene, on the fixed bed reactor, under the condition of 60~70 °C, 1.
0MPa, ethylene / 2-butene = 1.
5~3 (mol), the conversion rate of 2-butene is 60%~90%, and the selectivity of propylene is more than
90%.

2.
The recombinant part of the cracking of butene and light naphtha by 2-butene catalytic cracking
Fina Company converted the recombinant part of butene and light naphtha into propylene by silica zeolite catalyst under the conditions of 547 °C, 101.
3kPa and airspeed 10h-1, and the mass yield of propylene could reach 39.
9%.

If the process is combined with a device with excess butene (such as the residual liquid of an MTBE unit) to produce propylene, the conversion of linear butene mixtures into propylene is more economical than isomerization to isobutylene
.

Lurgi's Propylur process uses a selective heterogeneous ZSM-5 zeolite catalyst to convert C4 and above olefins (butene, pentene, hexene, etc.
) into propylene
by fixed bed catalytic cracking at 500 °C and 0.
1~0.
2 MPa.
The total conversion rate of olefins is about 83%, and the typical product yield is 42% propylene, 31% butylene and 10%
ethylene.
This technology has a lower investment cost than fluidized bed catalytic cracking and is easy to operate, which can be used as an alternative to translocation technology to increase propylene production
.

KBR's SUPERFLEXTM technology converts low-value olefin-rich materials such as mixed butene, pentene, FCC light oil and coking gasoline into high-value propylene and ethylene products, feedstocks can come from steam cracking or cracking processes in various refineries, with a total olefin content of 50%~60%.

The SUPERFLEX catalytic olefin process is a fluidized catalytic cracking (FCC) process in which the catalyst is continuously regenerated and typically does not require raw material pretreatment
.
The technology can be used in stand-alone production plants or integrated into existing olefin plants
.
The first set of industrial application equipment is in Sasol, South Africa, China's Jilin Chemical is the second manufacturer to obtain SUPERFLEX technology patent authorization, the device uses C4/C5 raw materials, propylene design capacity of 200,000 tons
.

Shanghai Petrochemical Research Institute, Beijing Research Institute of Chemical Industry, University of Petroleum, Dalian Institute of Chemical Physics, Lanzhou Institute of Chemical Physics, etc.
have carried out research on
catalytic cracking of C4 fractions 。 The OCC technology developed by Shanghai Petrochemical Research Institute adopts ZSM-5 catalyst, with the mixed C4 ~ C8 or ethylene plant cracking C4 fraction of the refinery catalytic cracking unit as raw materials, using a fixed bed reactor, under the conditions of atmospheric pressure, 550 °C and liquid volume feed airspeed of 15h-1, the conversion rate of C4 olefins is 68.
0%, the selectivity of propylene is 50.
4%, the propylene yield is 34.
3%, the catalyst regeneration cycle is 20 days, and a 60,000-ton industrial demonstration plant has been built in Zhongyuan ethylene
。

Second, 2-butene hydrogenation to produce ethylene cracker

2-butene hydrosaturated to generate n-butane, n-butane cracking triene yield of 62.
28%, which can make ethylene cracking raw materials lighter and high-quality, and improve the economic benefits of
ethylene enterprises.

Fushun Petrochemical Research Institute used Fylj-1 noble metal catalyst to hydrogenate C4 olefins.
Qilu Petrochemical Research Institute used Pd-Al2O3 catalyst for C4 olefin hydrogenation.
The Institute of Stone Sciences hydrogenated and saturated the catalytic cracking C4 fraction to produce ethylene pyrolyse
.
The C4 fraction hydrogenation catalytic cracking of Northwest Research Institute of Chemical Industry is improved on the basis of dry gas hydrogenation catalysts JT-4 and JT-1G, with a hydrogenation temperature of 220~280 °C in the first stage and a hydrogenation temperature of 260~380 °C in the second stage; The pressure is 2~3MPa, the liquid-air velocity is 1~2 h-1, the hydrogen-oil ratio is 300~400, and its hydrogenation saturation rate is 99%.

The hydrogenation of C4 fraction of Lanhua Research Institute adopts high nickel catalyst, the inlet temperature of the reactor is 30 °C, the air speed is 3.
0~4.
0 h-1, and the reaction pressure is 2.
5 MPa
.
The pretreatment of raw materials requires adsorption dehydration, hydrogen sulfide and arsenic
removal.
The technology has been industrialized in Lanzhou Petrochemical Company, providing feedstock
for a 20,000-ton maleic anhydride plant.
Sinopec Tianjin Branch Research Institute has developed a low-temperature hydrogenation catalyst for supported C4 fractions, which saturates the remaining C4 of ethylene at low temperature, without pretreating the remaining C4 of ethylene, and the catalyst is regenerated and used repeatedly, and has completed the design
of 150,000 tons of process package.

Third, 2-butene oligomerization to produce high carbon olefins

The basic raw materials for the synthesis of C7~C12 olefins are ethylene, propylene and butene, although ethylene oligomerization is a mature process, with the price difference between ethylene, propylene and n-butylene further expanding, butene has become a more economical raw material
for the production of high-carbon olefins.
Butene oligomeric catalysts include solid phosphoric acid catalysts, zeolite catalysts, supported metal oxides or metal salt catalysts
.

Oligomerization technology of solid phosphoric acid UOP's InAlkTM process uses solid phosphoric acid (SPAC) as a catalyst and mixed butylene or butylene and propylene mixture as raw material, and the octane number of oligomerized or stacked gasoline oligomerized gasoline produced can reach the level of isobutane alkylated oil, and there are currently 330 sets
of oligomerization and stacking devices using this process 。 Since 1986, Shanghai Petrochemical Institute has been conducting research on low-carbon olefin oligomerization, and has developed T-99 butene oligomerized solid phosphoric acid catalyst, which has improved its reactivity and mudging resistance compared with traditional catalyst SPAC, and has been successfully applied in butene oligomerization industrial plants, but there are still shortcomings
such as many catalyst preparation steps, poor repeatability and non-renewable.

Oligomerization technology of zeolite catalyst Mobile's MOGD process uses ZSM-5 mesoporous zeolite with a silicon-aluminum ratio of 79 as the catalyst, using a fixed-bed reactor, and the product is mainly gasoline
.
The Institute of Fossil Sciences developed a new SKP zeolite catalyst for butene reaction.
Shanghai Petrochemical Institute conducted experimental exploration
of butylene oligomerization to C8 olefins using molecular sieve as catalyst.

Oligomerization technology of supported catalysts The Octol process developed by UOP & Hulls has a catalyst of SiO2-Al2O3/Ni (Co, Ge, Sn, Pb, Zn, Cu), which is used as a raw material from the extraction solution of the n-butene-rich MTBE device or other C4 fractions of poor isobutylene, with a butylene conversion rate of ≥ of 90% and a selectivity of C8 olefins of 85%.

。 The Academy of Petrochemical Sciences used C4 after the ether of MTBE device as raw material and SiO2-Al2O3/NiO as catalyst for oligomerization reaction at 100~140 °C and 3.
8~4.
0MPa, C4 = one-pass conversion rate of 74.
7%, and C8 olefin selectivity 75.
4%.

Dalian University of Technology has developed a series of Al2O3-supported sulfate catalysts, when the Ni content is 8%, nickel sulfate is distributed in a single layer on Al2O3, and the catalyst has the highest acidity and oligomeric catalytic activity
.

(To be continued, next to issue 17)