| Bio-crude is composed of various oxygenated and nitrogenous compounds,especially heterocyclic compounds.Bio-crude has abundant heavy components according to the molecular weight distribution and boiling range distribution.The bio-crude upgrading process mainly includes catalytic liquefaction,hydrothermal catalytic upgrading,catalytic hydrotreating or thermal upgrading.Comparison of the effects of NaOH,NaCl and FeSO4·7H2O catalysts on the catalytic hydrothermal liquefaction of macroalga from E.prolifera.The use of NaOH and NaCl catalyst resulted in an increase of the bio-crude yield by 1.84 wt.%and 1.54wt.%,respectively.Then the ash mass balance and alkali metal mass balance could be calculated.Na was mainly distributed in aqueous phase with mass balance of 76.69%in the absence of NaOH.The bio-crude yield using aqueous phase as catalyst increased from 16.96wt%to 17.79wt%.Thermal decomposition of bio-crude from HTL of E.prolifera was studied under non-isothermal conditions by using TGA.Bio-crude thermal decomposition exhibited typical multi-step reaction characteristics.The first-step reaction was in the range of 353-553 K with corresponding?of 1.0-46.7%,while the second-step reaction was in the range of 553-753 K with corresponding?of 46.7-93.7%.The first step was a distillation or volatilization process only,and the involved chemical reactions such as cracking,ring-opening,dehydrogenation,condensation and polymerization mainly took place in the second step.The isoconversional methods was used to determining the Apparent activation energy E.All sets of E increased with increasing?.The most probable reaction model was determined by following the universal integral approach to the treatment of nine levels of?from 10 K/min TGA data.In the lower temperature range,the volatilization process was followed apparent 1-D diffusion kinetics.In the higher temperature range the global reaction followed apparent first-order reaction kinetics. |
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