Pyrolysis And Liquefaction Study Of Seeds Of Mustard Family Plants

Biodiesel has better properties than that of petroleum diesel such asbiodegradable, non-toxic, renewable and essentially free of sulfur and aromatics. Thedevelopment of feedstock for biodiesel production has received considerable attentionin recent years. Use of edible oil plants such as canola and corn to produce biodieselin China is severely hindered in view of higher food price and large demand as food.Therefore, non-edible oil plants become very promising alternative feedstock forbiodiesel production. In this study, non-edible se eds of brassicaceae family—fieldpennycress, lepidium apetalum, orychophragmus violaceu, are selected as the researchobject, which includes relatively high oil content and stronger tolerance of fallowlands; Because rapeseed production of biodiesel technology in the USA and EU ismature, rapeseed is mostly selected only for comparison. This study usesthermogravimetricanalyzer and fluidized bed to analyze pyrolysis characteristics andliquids （pyrolysis oil） from proteinaceous seeds, the main work and results of fourkinds of mustard family plants are as follows:（1） Based the fatty acid （FA） selection criteria of biodiesel feedstock employedin the current study, the FA compositions of crude vegetable oils of4species ofmustard family plants are analyzed, we find field pennycress can be selected forfurther investigation because of similar FA profile of rapeseed oil, but lepidiumapetalum and orychophragmus violaceus are chosen for further studyas an antagonistto these limits.（2） Proximate analysis, ultimate analysis and HHV of seeds are obtained byexpeiments to provide basis data for pyrolysis characteristics study; Recovery of ironpowder is investigated from industrial solid waste, has been used as catalyst mainly tofavour biomass cracking reactions, since α-Fe₂O₃is its main component, the resultsshow the content of catalytic components α-Fe₂O₃, Fe₃O₄, TiO₂and Ti.（3） Non-isothermal kinetic experiments are carried out using a thermogravimetricanalyzer （TGA） with N₂for thermal degradation of seeds and seeds/iron powder, theresult shows: the decomposition processes of four kinds of proteinaceous seeds appearone obvious stage; in the presence of iron powder, the main DTG peaks of these occur at5¹5℃lower than before, and iron powder has a great influence on rapeseedcompared with other seeds; the main DTG peak of orychophragmus violaceus seedoccurs at6℃higher than before, which iron powder could hinder its decomposition.（4） The Coats-Redfern, Ozawa and Kissinger methods determine the kineticsparameters on thermal degradation, the results show: an apparent activation energy Eof35⁵5kJ/mol is obtained for the selected seeds by Coats-Redfern method, in thepresence of iron powder, E of seeds of field pennycress, lepidium apetalum andbrassica campestris obviously decreases, especially rapeseed, the decreased degree isthe largest; E of orychophragmus violaceus seed increases a little；E of110¹50kJ/mol is obtained by Ozawa and Kissinger methods.（5） We carried out fast pyrolysis of pennycress seeds in a fluidized-bed reactor ina quartz sand medium fluidized with nitrogen, with pyrolysis oil collected at acondensation，and at the pyrolysis temperature of500℃, not only can high-carbon,high-energy liquid fuel intermediates of pyrolysis oil be produced but also theseliquids are low-oxygen, low water content, neutral acidity. In the present of a catalystNa2CO3（1wt%）, viscosity index of oil can be reduce by30%, improving the pyrolyticoil quality.