Papers by Author: Xin De Chen

Abstract: The effects of ethanol concentration, reaction time, solid-liquid ratio and temperature on auto-catalytic ethanol pulping reaction of corncob acid hydrolyzed residua were investigated. The relationships of those four factors and pulping selectivity(Y/K ratio) were also discussed. The optimal pulping conditions were determined, which were ethanol concentration 55%, reaction time 2.0h, solid-liquid ratio 1:10, temperature 175°C. The temperature has the most influential effect. Structures of corncob acid hydrolyzed residua and dry pulp were observed by electronic microscope. The process of pulping reaction and the delignification were also verified.

Abstract: Soybean meal, the residue of soybean extract oil, mainly consists of protein. It was used as the only additive of corncob hydrolysate to produce acetone, butanol and ethanol with C. acetobutylium CH012. Because of inhibitors existing in corncob acid hydrolysate, butanol concentration was obtained only 6.61gL-1 by fermentation. Acetone concentration was 5.1gL-1 which was higher than a normal ratio of starch and molasses ABE fermentation. ABE fermentation of corncob enzymatic hydrolysate resulted in a productivity of 0.28gL-1h-1 and a solvent yield of 0.30. It was suggested that soybean meal could be a potential economical protein provider for ABE fermentation. Furthermore, for all experiments, cultivate including strain inoculum developed and batch fermentation was done in calorstat which would be beneficial to apply in the hydrolyate ABE fermentation industry.

Abstract: Pyrolysis of high density polyethylene (HDPE) to polyethylene wax (PEW) in a 1 L continues stirred-tank reactor (CSTR) was studied at 360-420 °C with 5-240 min, yield of PEW was discussed and the properties such as the drop melting point and average molecular weight of wax were determined. The PEW had a melting point of 104-120 °C, and an average molecular weight of around 3000 with a good dispersity at 673 K. Moreover, the composition of wax determined by fourier transform infrared spectroscopy (FT-IR) indicated that it was less branched than commercial waxes.

Abstract: Waste plastics can be converted to diesel oil and lube base oil by thermal pyrolysis and dewaxing. ZEM-5, H-ZEM-5, Fe/H-ZEM-5 and Co/H-ZEM-5 catalyst were prepared. The influences of additive metals and type of molecular sieves on catalyst were discussed. The results showed that the additon of metallic components enhances the activity of catalyst, produces the low pour point diesel oil, and greatly reduces the pour point of lube base oil. The catalyst impregnated with Fe was more effective than one impregnated with Co. The qualities of oil production were also improved more with H-ZEM-5 than ZEM-5.

Abstract: Bifunctional Pt/HZSM-5, Pt/HBeta, Pt/HMCM-41 and Pt/HSAPO-11 catalysts were prepared using pseudoboehmite as a binder. The H₂-TPR profiles, scanning electron microscope (SEM) and brunauer-emmett-teller (BET) pointed out that reducibility of catalysts and textural properties. These bifunctional catalysts have been tested in long-chain olefins hydroisomerization. The experiments were carried out at 320 ^o C under 2.0 MPa of hydrogen and at 3.0 h^-1 WHSV. Complete hydrogenation of long-chain olefins was observed over Pt/HMCM-41 and Pt/HSAPO-11. Hydroisomerization reactions also occured in the case of Pt supported strong acidic molecular sieves (HZSM-5 and HBeta). The result suggests product distribution of long-chain olefins hydroisomerization is dependent on the balance between the acid and metallic functions in catalysts.

Abstract: A series of Cu-Fe-Co based catalysts prepared by co-impregnation method using different alkali additives was characterized by BET, XRD and FESEM-EDX and investigated under MAS from CO hydrogenation. The results showed that the catalyst Cu25Fe22Co3-Na3/SiO2 has the highest catalytic activity and selectivity of total alcohol and C5+OH. XRD and FESEM-EDX demonstrated the Na3 catalyst exhibited homogeneous distribution of elements and effective synergy effect between Cu and Fe components, thereby performed good catalytic performances for MAS from CO hydrogenation. The presence of a suitable content of alkali promoter was necessary for mixed alcohols synthesis from syngas.