Pyrolysis products value

The reaction of BPA in water at 386°C and pr = 0.8 is summarized in Figure 1 and led to benzyl alcohol and benzaldehyde as well as the neat pyrolysis products. BPA conversion was approximately 0.8 after 40 min. Aniline was the major product with a yield of 0.5 after 40 min. Toluene, a primary and major product of neat pyrolysis, had a yield near 0.2. This was roughly equal to the yield of benzyl alcohol, which had a maximum value of 0.15 at 30 min the yield of benzyl alcohol decreased after 30 min. The reduced yield of toluene relative to neat pyrolysis and the presence of benzyl alcohol indicate that water reacted with BPA. 

Because of the ease of formation of these flammable pyrolysis products, polyesters have LOI values of 20-22 vol% (see Table 2.4), and hence, burn readily and because of the styrene content, give heavy soot formation. As these resins are cured at room temperature, bromine-containing flame retardants, which would decompose in melt-processed, thermoplastic polymers, may be effectively used. 

Some pyrolysis products have high value. These are mainly monomers, such as methylmethacrylate, caprolactam (the monomer of PA 6), tetralinorethylene, or styrene. Others are comparable to standard prodncts with specifications of naphtha, kerosene, or gas-oil. Snch fractions have a well-known market, as follows from Table 1.7. 

For the processes of different reactor types, kiln and retort pyrolysis processes are characterized by a relatively low capital investment. However, they suffer from unfavorable economics, due to the high processing costs compared with the value of the oil product obtained. Also, the characteristics of this process are relatively long residence times of waste in the reactor, poor temperature control due to large temperature gradients across their internal dimensions, fouling walls of the reactor by carbon residue and low liquid product quahty due to the production of a diverse number of pyrolysis products. 

The prominence of car soot and crankcase oil PAHs in sediments supports the suggestion that road runoff and runoff via the sewer system, and not atmospheric deposition, is the main pathway for PAH input to the Harbor sediments. This is also reflected by the similarity in the isotopic values of the PAHs in the sewage and sediment samples (Figure 21). Input of road sweep materials to the sediments was also supported by the presence of asphalt-like particulates similar to those observed in the open-road sweeps. Due to the absence of major industries in the St. John s area, sewage is dominated by domestic sources. Sewage PAH content is, therefore, predominantly derived from aerially deposited pyrolysis products, car emissions, crankcase oil by direct... 

The vacuum pyrolysis of (CF3)3Sb in the temperature range of 298-1100 K was aimed to prepare CFj radicals . The PE spectra of pyrolysis products formed at different temperatures are shown in Figure 7. From these spectra there is no evidence for the formation of CF3 whose lEj is expected between 9.25 and 10.10 eV °. However, production of CFj species seemed to be hkely at 1100 K on the basis of some characteristic IE values. Another pyrolysis product, C2F4, was also identified by the analysis of vibrational fine structure and other spectral features. 

A range of chemicals can also be produced from specialities such as levoglucosan to commodities such as resins and fertilisers as summarised in Table 7. Food flavourings are commercially produced from wood pyrolysis products in many countries. All chemicals are attractive possibilities due to their much higher added value compared to fuels and energy products, and lead to the possibility of a bio-refmery concept in which the optimum combinations of fuels and chemicals are produced. 

Raveendran, K. and Ganesh, A. "Heating Value of Biomass and Biomass Pyrolysis Products", Fuel, v-75, n-15, pp.1715-1720, 1996,... 

Raveendran, K., Ganesh, A. (1996). Heating value of biomass and biomass pyrolysis products. FuellS, 1715-1720. 

This paper uses pyrolysis products from an air-blown, fluidized-bed reactor designed to produce liquids for use in adhesives as an illustration of what might be produced, separated and sold commercially for higher value. Guidelines for chemicals production and product recovery are suggested for pyrolysis processes in general. Recommended research and development topics to aid commercialization and increase chemical product recovery and project cash flow are presented. 

ITie first step on the way to the decision if fast pyrolysis is a suitable technique for biomass waste exploitation is to take a serious look at the mass balance. In almost every case bio-oil is the pyrolysis product with the highest commercial value no matter weather it is used as bio-fuel for power and heat production or as chemical feedstock. 

Approximately 50% of the pyrolysis product boils below the initial boiling point of the diesel fuel, which is entirely consistent with the specific gravity and viscosity results. The pour point (-39 C) of the product was also considerably lower than a number 2 diesel fuel (-27 C). It is lower than the average value (-2rC) of diesel fuel in the Great Lakes and Eastern Region of Canada and similar to the average value (-39 C) in the Western Region of Canada. 

Table I. Yield (wt% on the o.d. wood basis) of grey alder Almis incana) wood catalytic pyrolysis products and the heating value of their volatile components. 

For flaming combustion, the - AH and the rate of producton of the volatiles are important. The latter value could be determined by thermogravimetry and its derivative under simulated pyrolysis conditions, which indicate the progress and the rate of weight loss. Figure 26 shows the dynamic TG of cottonwood and its components and indicates that lignin contributes mainly to char, whereas cellulose and hemicelluloses form mainly the volatile pyrolysis products that are responsible for the flaming combustion. These data also indicate that wood shows the collective thermal properties of its components. 

The heats of combustion of the volatile pyrolysis products released at various stages of volatilization were determined from untreated and chemically treated ponderosa pine (64). Fire-retardant treatments reduced the average heat of combustion for the volatile pyrolysis products released at the early stage of pyrolysis below the value associated with untreated wood at comparable stages of volatilization. At 40% volatilization, untreated wood had released 29% of its volatile products heat of combustion treated wood had only released 10-19% of its total heat. Of all the chemicals tested, only NaCl, which is known to be an ineffective fire retardant, did not reduce the heat content. This reduction in heat content of the volatiles was confirmed by using thermal evolution analysis (TEA) (55). 

The pyrolysis time (THT) in this example is 1.0 s. At temperatures up to 560° C, process (2) will dominate the pyrolysis, while at temperatures higher than 560° C, the pyrolysis will be dominated by process (1). If the pyrolysis products for process (1) are different from those for process (2), it can be seen that a small variation in the temperature profile may significantly modify the analytical results producing more of the products from process (1) or more from process (2). Therefore, the importance of TRT is more significant when rapid degradation reactions occur during pyrolysis. Equal TRT values are essential for the reproducibility of analytical pyrolysis mainly for fast processes. 

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