Industrial Catalysts
Catalysts occupy an extremely important position in the modern chemical industry, with about 90% or more of chemical production processes using catalysts with the aim of speeding up reaction rates and improving production efficiency.
The budding period of industrial catalysts
The beginning of catalytic technology engaged in industrial scale production
The history of the catalyst industry is closely related to the development and evolution of industrial catalytic processes.
In 1740, J. Ward, a British physician, established a plant near London to burn sulfur and saltpeter to make sulfuric acid, followed by J. Roebuck in 1746, who built a lead chamber reactor in which the nitrogen oxide produced by saltpeter was actually a gaseous catalyst, which was the beginning of industrial scale production using catalytic technology.
The creation of industrial catalysts
Platinum catalysts
In 1831, P. Phillips obtained a British patent for the oxidation of sulfur dioxide to sulfur trioxide on platinum. In the 1860s, the Deacon process was developed for the oxidation of hydrogen chloride to produce chlorine gas using copper chloride as the catalyst, and in 1875 German E. Jacob built a contact plant for the production of fuming sulfuric acid in Kroetschnach and manufactured the required platinum catalyst, a pioneer in solid industrial catalysts. Platinum is an industrial catalyst and is still the catalytically active component in many important industrial catalysts.
In the 19th century, the catalyst industry had a small variety of products, all of which were produced in artisanal workshops. Because of the important role of catalysts in chemical production, their manufacturing methods have been considered secret since the introduction of industrial catalysts.
Foundation period of industrial catalysts
During this period, a series of important metal catalysts were made, the catalytic active component was expanded from metals to oxides, and the use of liquid acid catalysts was scaled up.
Basic Technology for Industrial Catalysts
Manufacturers began to use more complex formulations to develop and improve catalysts, and applied the principle that high dispersion increases catalytic activity to devise manufacturing techniques such as precipitation, impregnation, hot melt, and leaching, which became the basic technologies in the modern catalyst industry.
Diatomaceous earth carrier
The role of catalyst carriers and their selection have also received attention. The carriers selected include diatomite, pumice, silica, alumina, etc.
In order to adapt to the requirements of large fixed bed reactors, molding technology was introduced into the production process and catalysts in the form of strips and ingots were put into use.
During this period there was a large scale of production, but the variety was relatively homogeneous, and certain widely used catalysts entered the market as commodities, in addition to self-production. At the same time, the development of industrial practice drove the progress of catalytic theory.
In 1925, H.S. Taylor proposed the theory of active centers, which played an important role in the development of subsequent manufacturing technology.
Metal catalysts
In the early 20th century, plants for hydrogenation of grease to hardened oil with nickel as catalyst were established in England and Germany, and in 1913, the German Baden-Aniline Soda Company used magnetite as raw material by hot melting method and added additives to produce iron-based ammonia synthesis catalysts.
In 1923, F. Fischer succeeded in hydrogenation of hydrocarbons from carbon monoxide using cobalt as catalyst.
In 1925, M. Rainey, USA, obtained a patent for the manufacture of skeletal nickel catalyst and put it into production. This is a skeletal nickel obtained from Ni-Si alloy by leaching with alkali to remove silicon.
In 1926, Farben used iron, tin, molybdenum and other metals as catalysts to produce liquid fuels from coal and tar by high-pressure hydrogenation and liquefaction, a method called the Burgess method.
Iron catalyst catalyst
This stage laid the foundation technology for manufacturing metal catalysts, including the reduction technology of transition metal oxides, salts and partial extraction technology of alloys, etc. The material of catalysts was also expanded from platinum to cheaper metals such as iron, cobalt and nickel.
Oxide catalysts
Given that the platinum catalysts developed in the 19th century for sulfur dioxide oxidation were susceptible to poisoning by the arsenic in the feed gas, a process in which two catalysts were used in conjunction with each other emerged.
The less active iron oxide was used as the catalyst in the middle section of the German Mannheim plant, and the remaining sulfur dioxide was then converted with a platinum catalyst in the second section.
Vanadium Oxide Catalyst
At this stage, a loaded vanadium oxide catalyst with high resistance to toxicity was developed and used in the new contact sulphuric acid plant at Baden-Aniline Soda in Germany in 1913, with a lifetime of several years to ten years.
After the 1920s, vanadium oxide catalysts rapidly replaced the original platinum catalysts and became the bulk commodity catalyst. This change in sulfuric acid catalysts opened up a wide range of prospects for oxide catalysts.
Liquid catalysts
In 1919, the Standard Oil Company of New Jersey developed an industrial process for the hydration of isopropanol from propylene using sulfuric acid as the catalyst, with a plant built in 1920, and in 1930, Union Carbide built a plant for the hydration of ethylene into ethanol. All of these liquid catalysts were simple chemicals.
The period of great development of industrial catalysts
The scale of industrial catalyst production expanded and the number of varieties increased during this period. Around the time of World War II, the need for strategic materials led to the rapid development of the fuel and chemical industries and the mutual promotion of new catalytic processes, which led to the rapid development of the catalyst industry.
Catalytic cracking catalysts
In the 1950s, the development of rich Middle East oil resources and low oil prices led to the rapid development of petrochemicals. At the same time, several important product lines were formed in the catalyst industry, namely, petroleum refining catalysts, petrochemical catalysts and inorganic chemical catalysts centered on ammonia synthesis. These catalysts include catalysts made of metal-organic compounds for polymerization, multi-component oxide catalysts for high selectivity, highly selective hydrogenation catalysts, and structurally ordered molecular sieve catalysts. The progress of chemical science and technology has led to a rapid increase in the number of catalyst products.
Organometallic catalysts
(C2H5)3Al-TiCl4 catalyst
Most of the homogeneous catalysts used in the past were acids, bases or simple metal salts. 1953, K. Ziegler of Federal Germany developed (C2H5)3Al-TiCl4 catalyst for ethylene polymerization under atmospheric pressure, which was put into use in 1955; 1954, G. Natta of Italy developed (C2H5)3Al-TiCl3 system for propylene polymerization, which was built in Italy in 1957. It was put into use in 1957. Since the introduction of this complex homogeneous catalyst into the market as a commercial product, certain organometallic compounds have been produced in the catalyst industry. Nowadays, catalysts for polymerization have become an important production sector in the catalyst industry.
Selective catalysts
Activated alumina microspheres
In terms of production methods, due to the widespread use of impregnation, the production of various carriers with different properties has also become an important part of the industry, including different grades of alumina, silica and certain low specific surface area carriers. Due to the transplantation of fluidized bed reaction technology from petroleum refining industry to chemical production, modern catalyst plants have also started to produce microsphere type chemical catalysts by spray drying technology. An important achievement in homogeneous catalytic selective oxidation was the commissioning of a large plant for the direct oxidation of ethylene to acetaldehyde in 1960. This method of producing acetaldehyde with palladium chloride-copper oxide catalysts is called the Wacker method.
Hydrofinishing catalysts
Cobalt-Molybdenum Catalysts
In order to develop petrochemicals, a large number of catalysts for hydrorefining petroleum cracking fractions were developed, many of which were based on the metal hydrogenation catalysts of the previous period. In addition, nickel-sulfur catalysts and cobalt-molybdenum-sulfur catalysts were developed for cracked gasoline hydrodehydration to remove diolefins, as well as palladium catalysts for low temperature hydrogenation of alkynes and diolefins in the hydrocarbon liquid phase.
Molecular Sieve Catalysts
Molecular Sieve Catalysts
Following the achievements in the oil refining industry in the 1960s by utilizing the shape selectivity of molecular sieves, many important catalytic processes based on molecular sieve catalysts have been developed in the chemical industry since the 1970s.
Large-scale ammonia synthesis catalyst series
Nickel catalysts
In 1962, Kellogg Company (USA) and ICI (UK) developed loaded nickel catalysts with alkali or alkaline earth metal co-catalysts, which can be operated under pressurized conditions (3.3 MPa) without coking, thus contributing to energy saving in large ammonia plants. Hydrocarbon steam conversion catalysts, hydrodesulfurization catalysts, high temperature conversion catalysts, low temperature conversion catalysts, ammonia synthesis catalysts, methanation catalysts, etc. constitute a series of catalysts for ammonia plants.
Industrial catalytic renewal period
During this period, high-efficiency complex catalysts were introduced; catalysts for low-pressure operation were developed to save energy; solid catalysts were diversified in shape; new molecular sieve catalysts were introduced; mass production of environmental protection catalysts was started; and biological catalysts were emphasized.
High efficiency complexation catalysts
Rhodium catalysts
After platinum and palladium, about a century later, rhodium became another precious metal element used in the catalyst industry, and will be important in the development of carbon monochemicals.
Another major advancement in complexation catalysts is the development of high efficiency olefin polymerization catalysts in the 1970s, which are loaded complexation catalysts formed by titanium tetrachloride-alkylaluminum system loaded on magnesium chloride carrier, with very high efficiency, one gram of titanium can produce tens to nearly one million grams of polymer, so it is not necessary to separate the catalyst from the product, which can save the energy consumption in the production process.
Industrial applications of solid catalysts
Honeycomb wire carriers
In order to achieve the goal of increasing production load and saving energy, solid catalyst shapes have been increasingly diversified since the 1970s, with the emergence of catalysts such as trilobal and quadralobal catalysts for hydrogen refining, honeycomb catalysts for automobile exhaust gas purification, and spherical and spoke-shaped catalysts for ammonia synthesis. There are also new designs for the distribution of catalytic active components in catalysts, such as palladium/alumina catalysts for hydrofinishing of cracked gasoline segments, so that the active components are concentrated near the outer surface layer.
Industrial applications of molecular sieve catalysts
ZSM-5 molecular sieve catalysts
In the late 1970s, ZSM-5 molecular sieve catalysts were developed for the alkylation of benzene to ethylbenzene, replacing the previous aluminum trichloride, and in the early 1980s, ZSM-5 molecular sieve catalysts were developed for the synthesis of gasoline from methanol. Molecular sieve catalysts will have an important role in the development of resources and carbon monochemicals.
Industrial applications of environmental protection catalysts
Currently, environmental protection catalysts are among the three major areas in the catalyst industry, along with chemical catalysts (including catalysts used in the production processes of synthetic materials, organic synthesis and ammonia synthesis) and petroleum refining catalysts.
Industrial applications of biocatalysts
The use of biochemical methods in the chemical industry has increased, and since the 1970s, a variety of immobilized enzymes have been made for large-scale applications. The development of biocatalysts will cause a great change in the production of chemical industry.
