Pyrolysis development

CARBON NANOMATERIALS ON THE BASE OF CATALYTIC HYDROCARBON PYROLYSIS DEVELOPMENT AND PERSPECTIVE USE... 

Converting Waste Plastics into Liquid Fuel by Pyrolysis Developments in China... 

In order to effectively produce chemicals from biomass pyrolysis, developers need to think beyond the mindset of maximizing production of liquids and stuffing these liquids into a combustion device. The proper thought process should be that of a chemical engineer - what can I make from this and what do 1 then do with it (to become rich and retire early). For a few specific chemicals that are identified through analysis and are easy to recover, no additional research and development are needed other than scale-up the commercialization problems are market related. For most potential products, some additional help is needed. The following are suggested research and development topics ... 

D.S. Scott, J. Piskorz, D. Radlein and co-workers at the University of Waterloo are well known for their fluidized bed flash pyrolysis development, also known as the WPPP (Waterloo Past Pyrolysis Process). The WPPP actually includes four process options as follows ... 

In the early stages of pyrolysis development, Kellogg designed a conventional pilot plant reactor (T ) (0,25 to 1,5 seconds) in order to study... 

Occidental Flash Pyrolysis Developing Entrained flow 610 0.3 1.5 Bituminous 56 35 7 2 3... 

Chemical Evidence for PX Monomer. Estabhshing early on that PX is indeed the pyrolysis product, rather than the molecule formed by breaking only one of the original diben2yl bonds, the dimer diradical (5), would prove to be an important development. 

As a result of the development of electronic applications for NF, higher purities of NF have been required, and considerable work has been done to improve the existing manufacturing and purification processes (29). N2F2 is removed by pyrolysis over heated metal (30) or metal fluoride (31). This purification step is carried out at temperatures between 200—300°C which is below the temperature at which NF is converted to N2F4. Moisture, N2O, and CO2 are removed by adsorption on 2eohtes (29,32). The removal of CF from NF, a particularly difficult separation owing to the similar physical and chemical properties of these two compounds, has been described (33,34). 

Thermochemical Liquefaction. Most of the research done since 1970 on the direct thermochemical Hquefaction of biomass has been concentrated on the use of various pyrolytic techniques for the production of Hquid fuels and fuel components (96,112,125,166,167). Some of the techniques investigated are entrained-flow pyrolysis, vacuum pyrolysis, rapid and flash pyrolysis, ultrafast pyrolysis in vortex reactors, fluid-bed pyrolysis, low temperature pyrolysis at long reaction times, and updraft fixed-bed pyrolysis. Other research has been done to develop low cost, upgrading methods to convert the complex mixtures formed on pyrolysis of biomass to high quaHty transportation fuels, and to study Hquefaction at high pressures via solvolysis, steam—water treatment, catalytic hydrotreatment, and noncatalytic and catalytic treatment in aqueous systems. 

Occidental Petroleum Coal Conversion Process. Garrett R D Co. (now the Occidental Research Co.) developed the Oxy Coal Conversion process based on mathematical simulation for heating coal particles in the pyrolysis unit. It was estimated that coal particles of 100-mm diameter could be heated throughout their volumes to decomposition temperature (450—540°C) within 0.1 s. A large pilot faciUty was constmcted at LaVeme, California, in 1971. This unit was reported to operate successfully at feed rates up to 136 kg/h (3.2 t/d). 

In several important cases, new synthetic strategies have been developed into new production schemes. An outstanding example of this is the production of an entire family of terpene derivatives from a-pinene (29), the major component of most turpentines, via linalool (3) (12). Many of these materials had been produced from P-pinene, a lesser component of turpentine, via pyrolysis to myrcene and further chemical processing. The newer method offers greater manufacturing dexibiUty and better economics, and is environmentally friendly in that catalytic air oxidation is used to introduce functionality. 

American Ligurian, Inc. (Stanford, Connecticut) is marketing a pyrolysis process developed in Italy, which generates steam for hot water, air heating, dryers, kilns, and similar installations. A modular plant produces 8000 kg/h of steam from 1 tih of tires. The pyrolysis process produces 0.9 t of fuel ok, 270 t of steel, and 54 t of ash annually. Gas emissions meet the strictest environmental standards (16). 

Titanium disulfide can also be made by pyrolysis of titanium trisulfide at 550°C. A continuous process based on the reaction between titanium tetrachloride vapor and dry, oxygen-free hydrogen sulfide has been developed at pilot scale (173). The preheated reactants ate fed iato a tubular reactor at approximately 500°C. The product particles comprise orthogonally intersecting hexagonal plates or plate segments and have a relatively high surface area (>4 /g), quite different from the flat platelets produced from the reaction between titanium metal and sulfur vapor. The powder, reported to be stable to... 

Alternatives to oxychlorination have also been proposed as part of a balanced VCM plant. In the past, many vinyl chloride manufacturers used a balanced ethylene—acetylene process for a brief period prior to the commercialization of oxychlorination technology. Addition of HCl to acetylene was used instead of ethylene oxychlorination to consume the HCl made in EDC pyrolysis. Since the 1950s, the relative costs of ethylene and acetylene have made this route economically unattractive. Another alternative is HCl oxidation to chlorine, which can subsequently be used in dkect chlorination (131). The SheU-Deacon (132), Kel-Chlor (133), and MT-Chlor (134) processes, as well as a process recently developed at the University of Southern California (135) are among the available commercial HCl oxidation technologies. Each has had very limited industrial appHcation, perhaps because the equiHbrium reaction is incomplete and the mixture of HCl, O2, CI2, and water presents very challenging separation, purification, and handling requkements. HCl oxidation does not compare favorably with oxychlorination because it also requkes twice the dkect chlorination capacity for a balanced vinyl chloride plant. Consequently, it is doubtful that it will ever displace oxychlorination in the production of vinyl chloride by the balanced ethylene process. 

G in the presence of a catalytic amount of a Lewis base such as dimethylether, (GH2)20. In addition to the gas-phase pyrolysis of diborane, can be prepared by a solution-phase process developed at Union Garbide Gorp. Decaborane is a key intermediate in the preparation of many carboranes and metaHa derivatives. As of this writing, this important compound is not manufactured on a large scale in the western world and is in short supply. Prices for decaborane in 1991 were up to 10,000/kg. 

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