Pyrolysis oils chemical feedstock potential

In summary, pyrolysis is a tertiary recycling process that is used to break down large polymer molecules. In this process, the polymer samples are heated in an inert atmosphere, which causes the carbon-carbon bonds to break along the polymer backbone. This depolymerization step results in monomers (short-chained compounds) being formed. Generally, three types of products are formed from pyrolysis reactions gas, oil and char. All three have the potential to be nsed as a fnel or chemical feedstock. Depending on the feed polymer and the reaction conditions, different products can be obtained. The pyrolysis oil can either be used directly or can be nsed as a raw material for the petroleum industry [1-5]. 

While all pyrolysis oil production reactor systems produce similar materials, each reactor produces a unique compound slate. The first decision, especially for a potential chemical or fuel producer, rather than a reactor developer, is to determine what products to make and which reactor system to use. The operating parameters of any reactor system designed to produce pyrolysis oil, especially temperature, can be altered to change the pyrolysis oil product composition and yield. Different feedstocks will produce different pyrolysis oil compositions and by-products, e.g. amorphous silica from rice hulls or rice straw, fatty acids from pine. Finally, feedstock pretreatment and/or catalysis, or reactor-bed catalysis can be used to improve specific product yields (7). Reactor system developers need to examine what they can produce and make this information available to chemical manufacturers and suppliers/owners of biomass feedstocks. This assumes that analysis of die entire liquid product from thermal conversion can be made, including quantitative analysis for any compounds that are being considered for recoveiy. Physical characterization - pH, viscosity, solids content, etc.is also needed. However, what can be produced is of no value, if it cannot be recovered or used economically. This involves examining the trade-offs between yield and current commercial value, recovery costs, and potential commercial value,... 

Catalytic upgrading of pyrolysis oils or in situ catalytic upgrading of pyrolysis vapors can be carried out to provide mixtures of potential value as chemical feedstocks. Wheat straw hgnin was converted to ethylbenzene in a two-step sequence, first via pyrolytic depolymerization over a composite Re-Y/HZSM-5 (25) catalyst and subsequent conversion to ethylbenzene via treatment with EtOH... 

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