Ablative pyrolysis

Many other recovery alternatives have been proposed that iaclude ion exchange (qv), pyrolysis, and wet combustion. However, these have not gained general acceptance. A limited number of calcium-based mills are able to utilize their spent pulpiag liquors to produce by-products such as lignosulfates for oil-weU drilling muds, vanillin, yeast, and ethyl alcohol (see PETROLEUM Vanillin). 

Table 2.7 lists techniques used to characterise carbon-blacks. Analysis of CB in rubber vulcanisates requires recovery of CB by digestion of the matrix followed by filtration, or by nonoxidative pyrolysis. Dispersion of CB within rubber products is usually assessed by the Cabot dispersion test, or by means of TEM. Kruse [46] has reviewed rubber microscopy, including the determination of the microstructure of CB in rubber compounds and vulcanisates and their qualitative and quantitative determination. Analysis of free CB features measurements of (i) particulate and aggregate size (SEM, TEM, XRD, AFM, STM) (ii) total surface area according to the BET method (ISO 4652), iodine adsorption (ISO 1304) or cetyltrimethylammonium bromide (CTAB) adsorption (ASTM D 3765) and (iii) external surface area, according to the dibutylphthalate (DBP) test (ASTM D 2414). TGA is an excellent technique for the quantification of CB in rubbers. However, it is very limited in being able to distinguish the different types of... 

Chemical reactivity differences may be calculated if for the transition state of a rate-determining step of a reaction a structural model can be given which is describable by a force field with known constants. We give only two examples. Schleyer and coworkers were able to interpret quantitatively a multitude of carbonium-ion reactivities (63, 111) in this way. Adams and Kovacic studied the pyrolysis of 3-homoadamantylacetate (I) at 550 °C and considered as transition state models the two bridgehead olefins II and III (112). From kinetic data they estimated II to be about 2 kcal mole-1 more favourable than III. 

The objective of this work is to synthesize and characterize zeolite-bentonite hybrid catalysts and perform test reactions in the pyrolysis of woody biomass in a dual-fluidized bed reactor. The aim is to produce catalytic materials which have good mechanical strength and are still able to de-oxygenate the pyrolysis oil. 

Large-scale gasification reactor technology based on EF gasification from (a) General Electric (GE Texaco process) and (b) Conoco-Phillips (E-Gas). (Adapted from Meier, D. Faix, O. Fast pyrolysis A route for energy and chemicals from wood—fluidized vs. ablative pyrolysis. In Wood and Biomass Utilization for the Carbon Uptake, Seoul National University, Seoul, 2005, pp. 55-68.)... 

Biorefineries New catalytic pretreatment of plant materials Valorization, pretreatment or disposal of co-products and wastes from biorefinery by catalytic treatments New and/or improved catalytic processes for chemicals production through the integration of the biorefinery concept and products into the existing chemical production chain New advanced catalytic solutions to reduce waste emissions (solid, air and, especially, water) New catalysts to selectively de-oxygenate products from biomass transformation Catalysts to selectively convert chemicals in complex multicomponent feedstocks New biomimetic catalysts able to operate under mild conditions Small catalytic pyrolysis process to produce stabilized oil for further processing in larger plants... 

In the mid-1980s, Wentrup and co-workers, using flash vacuum pyrolysis techniques, were able to obtain direct evidence for N2S (29) as an unstable, primary product in the pyrolysis of 5-phenylthiatriazole <86JOC1908, 88JA3458). 

Pyrolysis of di-l,2-dicyano[ris,a //-3,4-2H2]cyclobutane (6) at 257°C yields a 6 4 mixture of [trorts-3-2H1]acrylonitrile (7) and [ra-3-2H Jacrylonitrile (8). Despite the fact that a concerted cycloreversion seems to be the predominant process, it can also be rationalized that an initial bond cleavage to a diradical, which competitively undergoes bond fission and/or bond rotation, is able to give the same result.84 ... 

Another relevant example is the pyrolysis of cnt/ -2,7,7-trimethylbicyclo[3.1.1]hept-2-en-6-ol (21) at 430 =C, which produces a mixture of several products. Gas chromatographic separation gives, among many other compounds, 3,7-dimethylocta-3,6-dienal (23) and 3,7-dimethylocta-2,6-dienal (24) in 13 and 6% yield, respectively.107 As can be seen in the diradical 22, the C — C double bond is able to offer 71-stabilization to the secondary radical. For this reason, the 1,4-diradical is generated exclusively.107... 

The Py-MS experiments have provided detailed information on the labile organic structures found in the maceral concentrates. The utility of being able to obtain precise mass measurements is demonstrated in Table II where a small selection of peaks from the pyrolysis of the Brazil Block seam sporinite is listed. Note that at nominal m/z = 108 and 122 there are actually three distinct peaks corresponding to a quinone, an alkyl-phenol and a hydrocarbon. Normally with nominal mass pyrolysis data these peaks would only be assigned to alkyl phenols. All three peaks... 

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