长输管道管沟成型施工技术

在简述长输管道管沟成型的方式和技术要点的基础上,从理论和实践两个方面对管沟埋深不够和管道损伤等质量通病进行分析论证,并提出相应的整改措施和质量控制方法。     

Electrical energy production and operational strategies from a farm-scale anaerobic batch reactor loaded with rice straw and piggery wastewater

A farm-scale biogas plant loaded with untreated rice straw and co-digested with raw pig wastewater was operated and monitored during a complete digestion cycle. One active anaerobic digester cell (6600 m³) containing 727 tons of rice straw, 285 tons of pig wastewater and approximately 1300 tons of water was operated for a total of 422 days. Cumulative energy production of 295 MWh and an estimated specific methane yield of 181 LCH₄/kgVS added was achieved. A direct correlation between daily power production and digester temperature was observed, with a maximum power production of 2.74 MWh/d. Mesophilic conditions were reached inside the digester during the summer months by recovering waste heat from the engine and recycling it through the leachate recirculation process.A slow start-up period of approximately 200 days was observed, but increased leachate recirculation rates (from 0.04 to >0.14 m³/m³straw-d) resulted in increased gas production that initiated the microbial growth phase in the digestion cycle. Although sufficient buffering capacity as well as macro- and micronutrients were supplied to the system by the pig wastewater, an overall straw (dry wt.) to wastewater ratio (wet wt.) of 1 to 1.4 is recommended to improve gas production and decrease the acclimation period. A raw economic assessment of the system shows an investment recovery time of 8.3 years. Improvements such as continuous leachate recirculation, a more efficient heat exchange system to maintain mesophilic conditions year round, and periodic addition of fresh wastewater and sludge acclimated to lignocellulosic material are recommended to achieve a more sustainable and profitable system.     

油菜秸秆在碳酸乙烯酯中液化工艺的研究

利用碳酸乙烯酯(EC)为液化剂在常压条件下对油菜秸秆进行了液化试验。选择甲烷磺酸(MSA)作为最优催化剂,探讨了反应温度、反应时间、物料量、催化剂量4个因素对液化得率及黏度的影响。采用二次回归正交旋转组合设计对其液化工艺进行了优化。结果表明:最佳液化条件为反应温度165℃,反应时间70 min,物料量15.5%,催化剂量3.2%。在此条件下,液化得率可达到92.89%。     

定向麦秸板制造工艺概述

阐述了生产定向麦秸板的意义,按生产工艺流程对每个工段进行了简要叙述,并对定向麦秸板生产的关键技术进行了讨论。     

秸秆饰面墙体砌砖成型机的设计及其应用分析

阐述了秸秆饰面墙体砌砖成型机的设计方案,具体包括基本结构及工作原理。为满足秸秆墙体砌砖在建筑用材上较高强度和密实度的要求,关键对于成型装置和进料装置进行了设计和装配,使一次挤压中得以实现二次进料以及隔层中玻纤维添加的连续过程。并将秸秆饰面墙体砌砖在主要性能指标上与水泥砖进行对比分析,剖析秸秆墙体砌砖的优势和竞争力,而且通过经济指标上具体产值和节能效益的计算,分析得出该设备及其产品较大的市场价值和发展前景。     

The efficient lignocellulose-based sorbent for oil spill treatment from polyurethane and agricultural residue of Vietnam

In this study, new and efficient sorbent with density 0.2 g/cm³ was fabricated by incorporating rice straw into polyurethane matrix to get an open cell structure material with high oil uptake capacity. The influences of various important factors such as amount of adding rice straw, size of rice straw particles, and adsorption time on oil adsorption capacity of new sorbent material were investigated. The results showed that the oil absorption rate occurred fast in first 15–30 min, then slowed down and reached saturation level after about 2 h of treatment. Oil adsorption capacity of the new sorbent material was relatively high, up to 12.0 g/g. In comparison with pristine polyurethane or lignocellulosic materials, the new sorbents had higher oil adsorption capacity. Some characteristics of the as-obtained sorbent, such as surface shapes and porosity, were also studied by SEM analysis.     

Evaluation of a hydrothermal process for pretreatment of wheat straw—effect of particle size and process conditions

BACKGROUND: Hydrothermal processes are an eco‐friendly processes that provide an interesting alternative for chemical utilization of lignocellulosic materials, in which water and crop residues are the only reagents. In this work the effect of process conditions (size distribution of the wheat straw, temperature and time) was evaluated against production of fermentable products. RESULTS: The use of milled wheat straw fractions as a raw material containing blends of different particle size distribution showed that the latter had an influence on the final sugars in the hydrolysate. Improved values of glucose (21.1%) and xylose yields (49.32%) present in the hydrolysate were obtained with treatment severity factors of 2.77 and 3.36, respectively. Mathematical models were developed aimed at establishing the effect of process conditions on monosaccharide concentration and its degradation in the liquor. CONCLUSION: This work shows that the use of wheat straw blends with various particle sizes has a significant effect on the extraction of fermentable products. The effect of treatment severity, which takes into account both processing time and temperature was also evaluated. These results are of importance for process design. Copyright © 2010 Society of Chemical Industry     

醌及氢化醌类化合物对麦草蒸煮的作用及其数学模型

本文研究了蒽醌（AQ）及其衍生物以及氢化蒽醌对麦草烧碱法蒸煮的作用，用微型计算机处理蒸煮结果，得到7个关于添加剂用量与蒸煮效果关系的数学模型，并对蒸煮过程进行了分析。研究结果表明，氢化蒽醌是比较适合麦草制浆的蒸煮添加剂。     

亚铵法红麻,麦草浆配抄挂面牛皮箱纸板试验研究

本文首先对红麻及麦草的化学组分进行了分析,通过亚铵法对红麻、麦草浆配抄挂面牛皮箱纸板的蒸煮、打浆抄片工艺进行了实验研究。结果表明:以红麻和麦草为原料采用亚铵法制浆可以抄造出符合部颁标准的挂面牛皮箱纸板。