Effects of electron beam irradiation (EBI) on the content and structure of corn cob were evaluated in this study. Cellulose, hemicelluloses and lignin were separated and analyzed to investigate the structural changes in the pretreatment process. The results showed that EBI increased the removal of hemicellulose and lignin. Irradiation resulted in break and rearrangement between cellulose chains, the degree of polymerization (DP) of cellulose was reduced to the minimum (188) at 270 kGy, and part of cellulose was transformed from cellulose I to cellulose II. The thermal stability of the lignin extracted from pretreated corn cob decreased compared to that from raw sample. After the hydrolysis of the samples, the glucose yield and reducing sugar increased with the increasing irradiation dose and reached the maximum (44.3%) at 270 kGy after 48 h of enzymatic hydrolysis with an enzyme loading of 10 filter paper unit (FPU)/g of corn cob, which was 1.75 times of that of the untreated sample. The best yield of reducing sugar (267.9 mg/g corn cob) was obtained at 270 kGy after the hydrolysis with 2% sulfuric acid, which was 72.5% higher than the untreated sample.Keywords: Cellulose; Degree of polymerization; Electron beam irradiation; Hemicellulose; Hydrolysis; Lignin; Lignocellulosic biomass;

This study focused on the influence of inorganic salt (MnCl2, FeCl3, NaHCO3) or H2O2 combined with electron beam irradiation (EBI) at 90, 180, and 270 kGy on the content and structure of the three major components (cellulose, hemicellulose, and lignin) of corn cob in the pretreatment process. Acemonium cellulase (10 FPU/g of corn cob) were used to hydrolyze the pretreated samples for 96 h. The results indicated that the combined methods showed an obvious synergetic effect on the removal of hemicellulose and lignin and the reduction of degree of polymerization (DP) of cellulose, while the cellulose recovery decreased slightly during the treatment. Particularly, at the optimum conditions (2% NaHCO3 with EBI at 180 kGy), the highest 70.5% hemicellulose and 34.7% lignin removal were achieved with the DP of cellulose decreasing from 1081 of raw to 82. The results of Fourier-transform infrared spectra (FTIR) and scanning electron microscopy (SEM) analysis showed that the IR crystallinity index of cellulose decreased, and the structure was disrupted deeply after pretreatment due to the effective removal of the amorphous zone. After hydrolyzing the sample under optimum pretreatment conditions, the glucose yield was significantly higher than that of the controlled sample, which proved that an inorganic salt solution combined with EBI is an effective way to reduce the recalcitrance of lignocellulose biomass and improve the production of glucose.Keywords: Cellulose; Degree of polymerization; Electron beam irradiation; Enzymatic hydrolysis; Glucose; Inorganic salt; Lignocellulosic biomass

The influence of temperature and catalyst type on production of combustible gas during the air gasification of waste rigid polyurethane foam has been researched in a bench-scale plant. The results indicated that among ten selected catalysts, sodium hydroxide had the most positive effect on the yield of combustible gas. An orthogonal array experimental design based on four levels L16 (43) of three parameters was employed to optimize the gasification conditions. The results showed that the relative effectiveness of the parameters was ranked as: temperature > catalyst supplied > air gas flow rate. Subsequently, a series of process optimization experiments were conducted and the optimum operating conditions are found as follows: temperature was 1100 °C, catalyst supplied was 12.5 wt% of the raw material, and the air flow rate was 120 L/h.

•CaO has a significant performance on increasing N2 formation and decreasing NOx formation.•CaO, as catalyst, may promote the conversion of tar N to N2, and HCN to N2.•N2 is the predominant species in gas, NH3, HCN, NO and NO2 are also detected.•More than 50% tar N exists in the form of 4-[(4-aminophenyl)methyl]aniline.In this paper, we focus on the release of nitrogenous species from waste rigid polyurethane foam (WRPUF) during thermal conversion. Pyrolysis of WRPUF was experimentally studied to determine the effects of four operational parameters, temperature, particle size, sweeping gas flow rate and catalyst supplied, on the partitioning of the fuel nitrogen among nitrogen species. Experiments were performed using a bench-scale fixed-bed reactor and the important findings of this research include the following. (1) Five nitrogen-containing species, N2, NH3, HCN, NO2 and NO, were found in gas-phase product and N2 is dominant. (2) Tar N is retained as heterocyclic compounds, nitrile, or amine functional groups bonded to aromatic rings, and 4-[(4-aminophenyl)methyl]aniline is the main nitrogen-containing compound. (3) CaO has a good performance on increasing N2 production and decreasing NOx precursors. (4) The sweeping gas (Ar) flow rate and catalyst supplied were the most important parameters on affecting the N-containing species release. Whatever gaseous nitrogen, tar N or char N, they were significantly affected by sweeping gas flow rate, catalyst supplied or their interaction.