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Lignin was isolated from wheat straw via organosolv process and further transferred to monophenolic compounds via oxidative conversion. Wheat straw lignin (WSL) with purity at 91.4 wt% was acquired in the presence of heterogeneous and recyclable catalyst of Amberlyst‐45. WSL was characterized by infrared spectrometer (IR), nuclear magnetic resonance spectroscopy (NMR) including 1H NMR and 13C NMR spectra. The results showed that WSL possesses typical syringyl (S), guaiacyl (G), and p‐hydroxyphenyl (H) units, and it is mainly composed of S and G units. The product distribution was dependent on the composition of WSL. Derivatives from S and G units were found to be the main products. The oxidative conversion of WSL was performed by varying oxidant and catalyst. Both the formation of monophenolic compounds and aromatic aldehydes were enhanced by combining oxidants and catalysts. The composite catalyst composed of NaOH/NaAlO2 was effective for the oxidation of WSL in the presence of nitrobenzene and atmospheric pressure air. The total yield of monophenolic compounds reached up 18.1%, and yields at 6.3 and 5.7% for syringaldehyde and vanillin were achieved, respectively.

A catalyst loaded Ni-Fe using powder active carbon (PAC) and γ-Al2O3 as the support was prepared for hydrogen-rich syngas production from rape straw pyrolysis in a two-stage fixed reactor. EDX (Energy-dispersive X-ray spectroscopy), SEM (Scanning electron microscope) and N2 isothermal adsorption-desorption were used to characterize the catalysts. The results showed that the support of PAC-γAl2O3 was uniform with large specific surface area. The metals loaded on the support were well dispersed. The performance of Ni-Fe/PAC-γAl2O3 catalysts compared with single support catalyst NiO-Fe2O3/γAl2O3 (NFA) and NiO-Fe2O3/PAC (NFP) was studied. The results showed that the Ni-Fe/PAC-γAl2O3 catalysts showed a good catalytic activity which obviously enhanced the H2 gas yield to 54.23 g/kg Rape straw and reduced the tar yield to 4.06 g/kg. Meanwhile, Ni-Fe/PAC-γAl2O3 catalysts had a stronger ability to prevent the deactivation to keep a longtime stability than the single carrier catalyst.

In this study, impact of a rice straw-derived biochar on the anaerobic digestion of piggery wastewater was investigated under different ammonium “stress levels”. The results showed that the biogas yield was decreased from 1293.27mL to 402.31 mL and the COD removal rate was decreased from 70.68% to 38.13% with the NH 4 + -N concentration increasing from 900mg/L to 3500 mg/L. At no ammonium “stress level”, the COD removal rate was increased from 70.68% to 83.75%, and biogas yield was increased from 1293.27mL to 2306mL with the increase of biochar dosage from 0g to 15g. While with the addition of biochar increasing from 0g to 15g, the COD removal rate was increased from 38.13% to 70.38% and the biogas yield was increased from 382 mL to 1878 mL at high ammonium “stress level”. It indicated that the presence of biochar not only could promote biogas yield but also could release the ammonium inhibition.