Ben Lin Dai

Urea (CO(NH2)2) Pretreatment Improve Biogas Production Performance of Rice Straw

To discuss the internal effect of urea (CO(NH2)2) pretreatment on anaerobic digestion biogas production of rice straw waste, a self-designed laboratory-scale continuous anaerobic biogas digester was used in this study. Anaerobic biogas slurry, urea pretreatment and anaerobic digestion were evaluated for biogas production from rice straw. The results showed that the peak value of biogas production was attained on the 17th day by using 6% urea pretreatment on rice straw. However, the highest CH4 content was 49.8% on the 15th day for the 8% urea-treated rice straw. The cumulative biogas production of 6% urea pretreatment was the highest, about 16 540 mL, which was followed by 2% urea (12 283 mL), 8% urea (9 883 mL), and 4% urea (5 668 mL).

Effect of CaCO3 Pretreatment on Methane Production from Anaerobic Digestion of Rice Straw

The chemical pretreatment of rice straw was achieved via the liquid-state dissolution of CaCO3. Pretreatment effects on the biodegradability and subsequent anaerobic production of methane were investigated. The results showed that the peak value of biogas production was attained of 4% CaCO3 pretreatment on the 20th day, which is 1 589 mL. The test daily methane content of different pretreatment conditions mainly ranges from 3.4% to 47.4%. The cumulative biogas production of 6% CaCO3 pretreatment was the highest, about 19 917 mL.

Anaerobic Fermentation Characteristic of Rice Straw Pretreated by HCl

The anaerobic fermentation characteristic of rice straw pretreated by HCl was studied. The results showed that the test pH values of different pretreatment conditions mainly range from 5.09 to 7.52. The peak value of biogas production was attained of 2% HCl pretreatment on the 20th day, which is 1 180 mL. The test daily methane content of different pretreatment conditions mainly ranges from 3.2% to 58.1%. However, the cumulative biogas production by using HCl pretreatment of rice straw during anaerobic fermentation is poor.

Optimization of Sodium Carbonate Pretreatment on Enzymatic Digestibility of Bioenergy Material: Miscanthus

Pretreatment is a critical step in the conversion of lignocellulose to fermentable sugars. In this work, Miscanthus straw was pretreated with ammonium carbonate (Na2CO3), which was shown by earlier works to be an effective pretreatment of grass stovers and other plant materials in the context of ethanol production. Here, we explored several key parameters including Na2CO3 concentration (2–6%), temperature (120–160°C), and reaction time (10–30 min) to evaluate their effects on enzymatic digestibility using response surface methodology. The best conditions were found to be Na2CO3 of 4.4%, temperature of 150.7°C, and reaction time of 20.0 min, under which glucose yield reached to 294.5 g/Kg biomass.

Diversity of Cell Wall Composition and Saccharides Production with NaOH Pretreatment in Bioethanol Material: Miscanthus

Miscanthus is a high yielding bioenergy crop. In this study, we selected four typical pairs of Miscanthus samples which presents different cell wall compositions. After different concentration pretreatment of NaOH (0.5%, 1.0%, 4.0%), four species shows significant difference in saccharine production. Much more xylose was extracted in the supernatant solution; the average glucose yield of all samples was about 2.0% in the concentration of 4.0%, which while the xylose yield was 12.0%. Direct enzymatic hydrolysis of the NaOH presoaked biomass was found to give higher glucose yields of 11–26%, and low xylose yields of 11–15%.Lower concentration of NaOH resulted in distinct differences in both glucose and xylose hydrolysis yields.

Preparation of Activated Carbon from Formic Acid Hydrolysis Residue by Chemical Activation of ZnCl2

Utilization of wheat straw for bio-based chemicals production is a research focus. In this work, experiments were conducted to study the preparation conditions of activated carbon from formic acid hydrolysis residue of wheat straw applying response surface methodology. The effects of activation reaction temperature, retention time and activator quantity on the decolorizing capacity of activated carbon were dealt with in this paper. Optimal preparation conditions were abtained by response surface methodology as followed: the content of ZnCl2 solution was 14.2%, reaction temperature was 798°C and retained time was 30 mins with a decolorizing capacity of 15.8 mL methylene blue. Results indicated that the technology was available.

Water Quality Assessment Based on Fuzzy Comprehensive Evaluation and Confidence Criteria

Considering that the limits with determined water quality classification using maximum degree criteria in traditional fuzzy comprehensive evaluation method, a improved fuzzy comprehensive evaluation method for water quality assessment is established based on confidence criteria. The method can effectively avoid the problems that include the water quality unclear classification and the unreasonable result, etc. Finally, the water quality of Chaping River is taken as a case study and the assessment results show that the sections in Chaping River water area can be described into 3 “category Ⅰ”, 5 “category Ⅱ” and 2 “category Ⅲ” states in 2008.