Development system, pyrolysis

In a previous publication (12,13) the development of pyrolysis models for gas and liquid feeds was discussed. In a more recent paper, Shu and Ross (14) described a generalized model for predicting the rate of thermal decomposition of naphthas. These models become key components of Braun s computational system. 

Di Primio Skeie use compositional data from closed system pyrolysis experiments to construct a compositional kinetic model of petroleum generation from the Draupne Formation. Although this, in itself, is not new, they developed the model in a format compatible with the data resolution used in PVT models that are familiar to reservoir engineers. Most importantly, they tuned their PVT models to the observed properties of actual petroleum accumulations observed in a well-defined portion of the North Sea. This represents a significant... 

It was recently demonstrated that compositional information from closed system pyrolysis of source rock samples, when properly calibrated, can be used to reconstruct the regional distribution of hydrocarbons as a function of migration and phase separation using PVT simulation software (di Piimio 2002). While this former study was performed using PVT software it indicated the need for the development of phase predictive kinetic models for the correct simulation of secondary migration in basin modelhng. 

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. 

Process development on fluidized-bed pyrolysis was also carried out by the ConsoHdation Coal Co., culminating in operation of a 32 t/d pilot plant (35). The CONSOL pyrolysis process incorporated a novel stirred carbonizer as the pyrolysis reactor, which made operation of the system feasible even using strongly agglomerating eastern U.S. biturninous coals. This allowed the process to bypass the normal pre-oxidation step that is often used with caking coals, and resulted in a nearly 50% increase in tar yield. Use of a sweep gas to rapidly remove volatiles from the pyrolysis reactor gave overall tar yields of nearly 25% for a coal that had Eischer assay tar yields of only 15%. 

Three recycling news items are very briefly reported upon a Canadian-developed pyrolysis technology that converts plastics scrap into alpha-olefins, a scrap-plastics-to-monomers system under construction in Scotland, and statistical forecasts on chemical recycling in Germany for 1996. 

Figure 11.1 shows the pyrogram of lead white pigmented linseed oil paint obtained at 610 °C with a Curie-point pyrolyser, with on-line methylation using 2.5% methanolic TMAH. The pyrolyser was a Curie-point pyrolysis system FOM 5-LX, specifically developed at FOM Amolf Institute (Amsterdam, the Netherlands), to reduce cold spots to a minimum. This means that the sample can be flushed before pyrolysis in a cold zone, and it also ensures optimum pressure condition within the pyrolysis chamber, thus guaranteeing an efficient transport to the GC injection system [12]. 

The best developed example of a material produced by VDP is poly(p-xylylene) designated as Parylene-N by the Union Carbide Corporation. Poly(/i-xylylene) was discovered by Szwarc12 in 1957 and then commercialized by Gorham at Union Carbide.13,14 (Scheme 1). Gorham has reported that di-p-xylylene is quantitatively cleaved by vacuum vapor-phase pyrolysis at 600°C to form two molecules of the reactive intermediate /i-xylylene, which subsequently polymerizes on the cold substrate. In a system maintained at less than 1 Torr, p-xylylene spontaneously polymerizes on surfaces below 30°C to form... 

---