Hydro-pyrolysis

Virgin Bitumen Vis- breaking Products Maltenes Hydro- pyrolysis Products... 

As well as these reactions, large coal molecules undergo pyrolysis and hydro-pyrolysis to smaller molecules. 

Fig. 5.2 The main crop-to-energy chains. BtL Biomass-to-Liquid, GtL Gas-to-Liquid, ETBE Ethyl tert-butyl ether, MTBE Methyl tert-butyl ether, MeOH Methanol, DME Dimethyl ether. Pyrolysis oil, HTU-Diesel (Hydro Thermal Upgrading), ethanol and hydrogen from ligno-cellulosic species are not considered here because of their minor practical relevance in the near future...

Alternative pathways, also discussed in part in the various chapters, include (catalytic) pyrolysis, flash or fast processes for wet biomass without pre-drying, hydro-thermal upgrading (HTU), conversion of solid biomass more or less directly into a natural-gas equivalent called substitute natural gas (SNG), or even to hydrogen. 

Pyrolysis of Esters of Carboxylic Acids Hydro-acyloxy-elimination... 

Pyrolysis of Alkali-Metal Organometallic Compounds Hydro-metallo-elimination... 

Pyrolysis of (3-Hydroxy Olefins O-Hydro-C-allyl-elimination... 

Figure 4. Chromatogram of cellulose pyrolysis tar after reduction with NaBHa, unknown b, 1,6-anhydro-p-n-glucopyranose c, 1,6-an-hydro-p-v-glucofuranose d, 3-deoxyhexitols e, d-glucitol f, oligosaccharide derivatives...

Different procedures have been established chemical vapor deposition [5, 16], powder sintering combined with pressing [1, 2, 6, 7, 12, 17-25], sputtering [9, 26], flux and melt grown [10, 27, 28], chemical deposition [11, 14, 29, 30], sol-gel techni-ques [31], mechano-chemical pro-cessing [32], forced hydrolysis [33,34], spray pyrolysis [35-41], and thermal and hydro- thermal oxidation [3, 4, 8, 10, 17,42-58]. 

In recent years, we have seen an explosive interest in nanomaterials, in particular in nanofibers, nanofilaments, and nanotubes of the very different chemical composition. The interest arises from the specific mechanical and physicochemical properties of these nano objects, which allow them to be used, for example, as specific adsorbents, catalyst supports, reinforcing components of composite materials, and so on. The most cited generic types of nanomaterials are carbon nanofilaments and nanotubes. Numerous methods for preparing these carbon materials are known. However, the simplest method seems to be thermal pyrolysis of various carbon contain ing precursors (e.g., carbon monoxide, saturated and unsaturated hydro carbons, etc.) in the presence of special catalysts that are typically nanosized particles of nickel, cobalt, iron metals, or their alloys with different metals. 

The other components are C5+ olefins and dienes and in particular cycto-pentadiene which easily dimerises to a Cio compound di-cyclo-pentadiene). As well as a strong odour, these materials readily polymerise to form gum in the gasoline and the raw pyrolysis gasoline is usually hydro-treated prior to use. In some cases, these C5 dienes are extracted and used to form low melting resins. One approach to upgrading the pyrolysis gasoline stream is shown in Figure 5.5 . 

For some widely practiced processes, especially in the petroleum industry, reliable and convenient computerized models are available from a number of vendors or, by license, from proprietary sources. Included are reactor-regenerator of fluid catalytic cracking, hydro-treating, hydrocracking, alkylation with HF or H2SO4, reforming with Pt or Pt-Re catalysts, tubular steam cracking of hydrocarbon fractions, noncatalytic pyrolysis to ethylene, ammonia synthesis, and other processes by suppliers of catalysts. Vendors of some process simulations are listed in the CEP Software Directory (AIChE, 1994). 

E. Hakejova et al. [12], studied the pyrolysis of individual hydrocarbons, and of naphtha, kerosene, gas oil, and hydro-cracking fractions, as well as their copyrolysis with hex-adecane, heptane, iso-octane, cyclohexane, and also with heavier feedstocks, i.e. dewaxing... 

In a related reaction, pyrolysis of aUylic ethers that contain at least one a hydro-... 

The title compound was initially synthesized by the pyrolysis of Re3H3(CO)i2 at 190° in hydrocarbon solution. Treatment of the complex with carbon monoxide at atmospheric pressure gradually converts it into higher carbonyls, as indicated in the reaction sequence below. At slightly elevated temperatures, the reaction is much faster and hydrogen is evolved. The suggestion that the reverse transformation might be possible led to the current synthesis. The direct hydro-... 

Decomposition of a compound by the action of heat alone is known as pyrolysis. This word is taken from the Greek pyr, fire, and lysis, a loosing, and hence to chemists means cleavage by heat compare hydro-lysis, cleavage by water. ... 

High temperature (800°C), pressure-free hydrothermal treatment of carbosil prepared by pyrolysis of methylene chloride was studied in the paper [38]. The results of hydro-thermal treatment of such adsorbents under the conditions without pressure (800°C) and high pressure of water vapour (250-500°C) are presented in another paper [59]. 

Acetylene hydro- chlori- nation Ethylene dicliinrido Itula need acetylene/ ethylene process ( rude oil pyrolysis und in ethylene Fluidized I red dichloridc, > Fixed bed set Hydro- chloric aeitl cotes... 

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