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We report the practical, scalable synthesis of a range of N-methyl allylic amines. Primary and secondary allylic alcohols underwent a regioselective Mitsunobu reaction with readily accessible N-Boc ethyl oxamate to deliver the corresponding N-Boc allylic amines, including in enantiopure form via stereospecific substitution. Subsequent N-methylation and Boc deprotection without chromatography yielded the amine products as hydrochloride salts. This method solves the problem of converting commercially available alcohols into often volatile N-methyl allylic amines, many of which have limited commercial availability.

Pyrolysis is carried out by means of a packed bed, heated along the lateral surface at a moderate temperature (about 585 K), of a significant number of nut shells (pine, macadamia and Brazil nuts, hazelnut, walnut, almond, coconut, chestnut, peanut, and pistachio) and fruit stones (olive, nectarine, peach, plum, cherry, and apricot). With the exception of pistachio shells, the residues own fixed carbon (and C) and lignin/extractive contents higher than those of wood. The SEM images of chars reveal a nonporous vesicular or foamed tissue generally crossed by a very few large hollow vessels surrounded by bundles of small void fibers and/or hosting elongated rolled elements again of much smaller size. The EDX analysis indicates that the deposits, scattered on the charred tissue, are generally rich in potassium. As a consequence, secondary reaction activity is enhanced and, compared with wood, pyrolysis-induced overheating is always higher. However, despite the similarities, feedstock differences during pyrolysis are remarkable, as testified by maximum temperature overshoots between 60-225 K (versus 50K for wood) and severe pyrolytic runaway established only for about half of the samples.

Packed-bed pyrolysis is carried out of beech wood preliminarily impregnated with potassium compounds (KOH, KCl, KC2H3O2, and K2CO3) for ion percentages corresponding to 0-1.8 wt %. The study is mainly aimed at examining the influence of the chemical state of potassium on the global thermicity of packed-bed conversion never examined before. The lowering of primary decomposition temperatures and the enhancement of secondary decomposition of tarry vapors is associated with a remarkable increase in the global exothermicity of the process which highly modifies the conversion conditions and product distribution. Maximum temperature overshoots over a large part of the bed, with respect to the programmed value of 605 K, reach 100-150 K and correspond to minima in the char yields. The quantitative effects are dependent on the content and chemical state of potassium which exerts its action via first the alkaline pretreatment and then catalysis. Moreover, thermogravimetric curves show that the diminution in the primary decomposition temperature is directly related to the K content and the basicity of the additive.

The influence of the loaded zinc chloride content (0–11 wt %, dry sample basis) on the pyrolysis of beechwood particles packed in a bench-scale bed was studied. Given an external heating temperature of 655 K, the temporal profiles of the thermal field showed maximum values progressively increasing from 683 to 790 K as the catalyst content was increased from 0 to about 5 wt %. Based on cumulative char and water yields increasing from about 51 to 70 wt % and yields of condensable organics decreasing from about 35 to 15 wt %, the enhancement in the global exothermicity of the conversion process can be attributed to the successive predominance of dehydration with cross-linking reactions over depolymerization reactions. The exothermic effects were found to be qualitatively similar to but quantitatively lower than those associated with a sulfuric acid treatment. For higher acid contents and both additives, the noncatalytic effects associated with their loading were also found to contribute significantly to the ...

Fir wood pyrolysis is carried out for extracted, KOH and KCl impregnated, and impregnated-extracted samples. For Kþ concentrations in wood of 0.14% (dry mass basis), the effects of KOH are quantitatively higher, but both additives produce a significant diminution in the yields of hydroxyacetaldehyde, furfural, and sugars, the decomposition temperature, and the conversion time. Water extraction of KCl impregnated samples is apt to reproduce again the characteristics of extracted wood pyrolysis. Instead, water extraction of KOH impregnated samples only reports the yields of hydroxyacetaldehyde, acetic acid, and hydroxypropanone to the original values whereas differences in the other variables, especially characteristic times and temperatures and levoglucosan yields, remain very large. Therefore, the action of the impregnated Kþ compounds during wood pyrolysis can be attributed to both irreversible modifications in the wood structure during impregnation, whose entity depends on the basicity of the aqueous solution, and intrinsic action of the Kþ ion on the activity of the decomposition reactions.

The acid-catalyzed pyrolysis of corncobs is investigated for the production of chemicals (in particular furfural) and bioproducts. Particles, preimpregnated with H2SO4 concentrations up to about 4%...

Packed-bed pyrolysis (heating temperature 800 K) is studied of beech and fir wood, several agro-industrial residues (corn cobs and stalks, olive husks, wheat straw, hazelnut and almond shells, orange peels, grape residues, artichoke stems, brewer's spent grain, and pruning cuts from cherry, olive, vine, and poplar trees) and cellulose, aimed at determining the potentially most promising feedstock for the production of furfural. Parameters associated with conversion dynamics are mainly affected by the packed-bed density (0.1-1.1 g/cm3) whereas products mainly depend upon the feedstock chemical composition. In particular, the yields of condensable organic products increase with the holocellulose content (10-85%) up to 25-40% (dry sample mass basis). The higher yields of furfural (dry organics mass basis), in the range 2-0.8%, are obtained from feedstocks with significant contents of cellulose/ pentoses (corn cobs, almond shells, hardwoods such as beech, cherry, olive, and poplar woods, orange peels, corn stalks, and hazelnut shells), while interesting quantities (approximately 1-0.4%) of 2(5H)-furanone are observed in all cases. As expected, the highest yields of hydroxyacetaldehyde and levoglucosan (about 8 and 3%) are produced from fir wood. On the other hand, some agro-industrial residues (hazelnut and almond shells and olive husks), apart from acetic acid, also produce high yields of phenolic compounds.

Weight loss curves of wood fast pyrolysis oils in air have been measured, under controlled thermal conditions, carrying out two separate sets of experiments. The first, which has a final temperature of 600 K, concerns evaporation/cracking of the oil and secondary char formation, processes associated with sample swelling and solidification. After collection and milling, in the second set of experiments, heterogeneous combustion of the secondary char is carried out to temperatures of 873 K. Although the details of the rate curves appear to be dependent on the commercial process (BTG, Dynamotive, Ensyn, Pyrovac) applied to produce the oil, the same qualitative features are observed in all cases. Secondary char formation and sample modification begin for temperatures of about 460-490 K. Moreover, a conceptual reaction mechanism, consisting of six main zones, can always explain the low-temperature (e600 K) devolatilization characteristics. Similar to primary char produced from wood pyrolysis, secondary char exhibits weight loss curves that present a devolatilization stage and a combustion stage, but with a significantly lower reactivity, as a consequence of a physical structure completely lacking micropore networks.