Previous Pyrolysis Work

Until fairly recently, no significant publications were produced on rapid or flash pyrolysis of waste plastics harnessing a FFR. A review of FFR developments is therefore given below regarding coal or biomass applications. 

Badzioch [I] summarized the volatile yields in the pioneering studies carried out at relatively low temperatures in a publication on rapid pyrolysis containing three introductory 

Feedstock Recycling and Pyrolysis of Waste Plastics Converting Waste Plastics into Diesel and Other Fuels Edited by J. Scheirs and W. Kaminsky 2006 John Wiley Sons, Ltd ISBN 0-470-02152-7 

High heating rates were applied in fluidized-sand-bed experiments by Pitt [2] who studied the kinetics of volatile product evolution from coal. He measured evolution rates in a fluidized carbonizer at temperatures from 300 to 650°C, over a time period 10 s to 100 min. 

Edinger et al. [4] studied rapid decomposition of coal in a transport-type reactor, with residence times 8-40 ms (COED-FMC). They found that pyrolysis atmosphere affects the products. Coal particles never reached the reactor temperature, even at the lowest particle transfer rate 59% of the coal volatilized when the reactor temperature was 1300°C. This is far above the 41% indicated by the ASTM volatile-matter determination. 

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In our previous work [4, 5], results on the catalytic pyrolysis of R22 over Cu-promoted catalysts were reported. In this work, various metal fluoride catalysts were introduced to improve the relatively poor yield of TFE. 

The work of Purnell and Walsh67 will now be compared with previous studies of this decomposition. Hogness et al.12 were the first to undertake a systematic investigation of the kinetics of the SiH4 pyrolysis. They followed the course of the reaction by measuring the increase in total pressure and assumed a stoichiometry corresponding to... 

Previous studies in conventional reactor setups at Philip Morris USA have demonstrated the significant effectiveness of nanoparticle iron oxide on the oxidation of carbon monoxide when compared to the conventional, micron-sized iron oxide, " as well as its effect on the combustion and pyrolysis of biomass and biomass model compounds.These effects are derived from a higher reactivity of nanoparticles that are attributed to a higher BET surface area as well as the coordination of unsaturated sites on the surfaces. The chemical and electronic properties of nanoparticle iron oxide could also contribute to its higher reactivity. In this work, we present the possibility of using nanoparticle iron oxide as a catalyst for the decomposition of phenolic compounds. 

The usual sources used for the homolytic aromatic arylation have been utilized also in the heterocyclic series. They are essentially azo- and diazocompounds, aroyl peroxides, and sometimes pyrolysis and photolysis of a variety of aryl derivatives. Most of these radical sources have been described in the previous review concerning this subject, and in other reviews concerning the general aspects of homolytic aromatic arylation. A new source of aryl radicals is the silver-catalyzed decarboxylation of carboxylic acids by peroxydisulfate, which allows to work in aqueous solution of protonated heteroaromatic bases, as for the alkyl radicals. 

The same has been observed by Dodson and Klose in previous work where cis- and trans-1,2-diphenylcyclopropane were formed by pyrolysis of 2,3-diphenylthietane 1,1-dioxide at 230°C. Analogous results have been achieved by both photolysis and thermolysis of l-phenyl-2-benzoylthiethane 1,1-dioxide to a cis-trans mixture of l-phenyl-2-benzoylcyclopropane. ... 

It has been shown earlier (3) that the aromatic carbon rendered hydroaromatic by reduction is quantitatively devolatilized, and virtually all the freshly created hydroaromatic carbon forms tar (12) with little extra carbon liberated as a gas. In the present work some of the previously reduced samples as well as one recently prepared have been studied with special emphasis on the volume and composition of the gas. The essential data on the reduced samples and the results of pyrolysis are presented in Table V. 

In cases where R1 is a stabilizing group (entries 1-11) conventional pyrolysis is satisfactory, but the use of FVP has allowed the extension of the reaction to cases with R1 = H or alkyl (entries 13, 18-20) where conventional pyrolysis does not work. For R1 = C02Et, simply increasing the furnace temperature leads to loss of the ester group to give terminal alkynes and 1,3-diynes (entries 15, 17) as already noted in Section IV.B. The E-Z isomerization which occurs for styrylalkynes at higher temperatures (entry 20) was also noted previously in Section II.C. 

Fig. 5.2(A) presents the pyrolysis mass spectrum for the soil extract. In previous work (ref. 358,359,365) it was shown that complex organic materials like polysaccharides, proteins, lignins, and soil humic fractions have characteristic peaks yielding a typical pattern, which give preliminary information about the composition of the pyrolysis fragments. Thus, characteristic peaks for polysaccharides were observed at 60, 68, 82, 84, 96, 98, 110, 112, and 126 m/z, which were also present in the soil extract. They were shown to be related to acetic acid, furan, methylfuran, hydroxyfuran, furfural, furfuryl alcohol, methylfurfural, methoxy-methylfuran, and a typical pyrolysis fragment of polysaccharides with hexose and/or deoxyhexose units, respectively.

Previous studies of the decomposition of cellulose reported Ea for absorbent cotton as 54.3 kcal/mol at a high-temperature range of 270-310 °C (23). For temperatures below pyrolysis, Ea = 20 kcal/mol reflects the low-temperature degradation effects of loss of H and OH from adjacent carbon atoms in cellulose (dehydration) and the concomitant creation of C=C bonds (24). In another work Ea = 21 kcal/mol was estimated from Arrhenius plots of the degree of polymerization versus time for cellulose heated in air at 150-190 °C (25). 

Although previous researchers have studied the effects of cations on the pyrolysis of carboxyl groups, most of the work has been concerned with weight loss as a function of temperature and/or the evolution of carbon oxides. Little work has been concerned with direct determination of the kinetics of decarboxylation. Table VIII... 

Earlier workers have identified some of the products of 1-butene pyrolysis (3,4). In this work, several previously unreported products were found along with many of those previously noted. Acetylene was observed among the products from 1-butene as well as 2-butene in yields that paralleled the formation of ethylene. Yields varied from a trace at low temperatures to between 5%-10% of the total C2 product at the highest temperatures. Methylacetylene + propadiene (MAP) yield varied in a similar manner for 1-butene pyrolysis ranging between 2% and 20% of the C3 product. In 2-butene pyrolysis, the MAP yield comprised approximately 10% of the C3 product in all of the runs. 

We implement a modified version of the reconstruction method developed in a previous work to model two porous carbons produced by the pyrolysis of saccharose and subsequent heat treatment at two different temperatures. We use the Monte Carlo g(r) method to obtain the pair correlation functions of the two materials. We then use the resulting pair correlation functions as target functions in our reconstruction method. Our models present structural features that are missing in the slit-pore model. Structural analyses of our resulting configurations are useful to characterize the materials that we model. 

Very recently, the gas phase pyrolysis (155-200°) of methyl azide at low conversions (< 1%) was studied . Nitrogen was the major non-condensable gas, in addition to small amounts of hydrogen (6% at lowest initial pressure of azide to less than 1% at the highest pressure) and methane (<2%). Ethane, ethylene, ammonia and hydrazoic acid were not detected, although the ethane, ethylene and hydrazoic acid determinations were subject to some uncertainty. Two solid white products were also obtained which were not characterized. The results showed that the thermolysis of methyl azide is of first-order, homogeneous and free from chains, in agreement with previous work . The Arrhenius activation parameters (see Table 1)... 

Several studies about pyrolysis and gasification of krafl black liquor from cooking of wood can be found in literature, but there are scarcely data for black liquor coining from alkaline pulping of straw. The aim of this research is to provide more infoimation about the thermochemical conversion of this residue. Studies [1] about CO3 gasification kinetics of alkaline black liquor from straw have been previously carried out in thermobalance by our research group. The present work is focus on the... 

As it has been pointed out in the previous paragraph, the aim of the present work is to provide more information about the behaviour, during pyrolysis and gasification of the alkaline black liquor from the pulping of straw. All experiments were performed in a fixed bed reactor on a laboratory scale plant. 

Although these results were obtained from the same starting material, they point out an important difference if they are compared to those presented in this paper. In Fig. i it can be noticed that the main pyrolysis gas products obtained in the present research work were CO and CO. These different results can be explained by the fact that in the present work the material processed was completely dry, while in the cited previous work [3] the processed material had an important humidity weight percentage (63%). This water leads up to the following reactions happen. 

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