Search Results (2)

In this study, penicillin residue (PR) was used to prepare bio-oil by hydrothermal liquefaction. The effects of homogeneous (organic acid and alkaline catalysts) and heterogeneous catalysts (zeolite molecular sieve) on the yield and properties of bio-oil were investigated. The results show that there are significant differences in the catalytic performance of the catalysts. The effect of homogeneous catalysts on the bio-oil yield was not significant, which only increased from 26.09 (no catalysts) to 31.44 wt.% (Na₂CO₃, 8 wt.%). In contrast, heterogeneous catalysts had a more obvious effect, and the oil yield reached 36.44 wt.% after adding 5 wt.% MCM-48. Increasing the amount of catalyst enhanced the yield of bio-oil, but excessive amounts of catalyst led to a secondary cracking reaction, resulting in a reduction in bio-oil. Catalytic hydrothermal liquefaction reduced the contents of heteroatoms (oxygen, mainly), slightly increased the contents of C and H in the bio-oil and increased the higher heating value (HHV) and energy recovery (ER) of bio-oil. FTIR and GC-MS analyses showed that the addition of catalysts was beneficial in increasing hydrocarbons and oxygen-containing hydrocarbons in bio-oil and reducing the proportion of nitrogen-containing substances. Comprehensive analyses of the distribution of aromatic, nitrogen-containing and oxygen-containing components in bio-oil were also performed. This work is beneficial for further research on the preparation of bio-oil by hydrothermal liquefaction of antibiotic fermentation residue. Full article

Mesoporous heteroatom molecular sieve MCM-41 bulk crystals with the crystalline phase were synthesized via a one-step hydrothermal method using an ionic complex as template. The ionic complex template was formed by interaction between cetyltrimethylammonium ions and metal complex ion [M(EDTA)]²⁻ (M = Co or Ni)]. The materials were characterized by X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, N₂ adsorption-desorption isotherms, and X-ray absorption fine structure spectroscopy. The results showed that the materials possess a highly-ordered mesoporous structure with a crystalline phase and possess highly uniform ordered arrangement channels. The structure is in the vertical cross directions with a crystalline size of about 12 µm and high specific surface areas. The metal atoms were incorporated into the zeolite frameworks in the form of octahedral coordinate and have a uniform distribution in the materials. The amount of metal complexes formed by metal ion and EDTA is an essential factor for the formation of the vertical cross structure. Compared to Si-MCM-41, the samples exhibited better conversion and higher selectivity for cumene cracking. Full article