Utilization of Bagasse Energy in Thailand

Bagasse, a biomass fuel, is the waste generated by the sugar-making process from sugar cane. Sugar making is one of the most important agricultural-produce processing industries for developing countries in Southeast Asia, Latin America and Africa. As sugar producing plants need electric power and process steam, co-generation using bagasse as an alternate fuel for petroleum has been in use for some time. Thailand recently became one of the largest sugar exporters by enlarging plant capacities and improving equipment, thus reducing its production cost. In addition, the Thai government promotes power generation using bagasse as a means to combat global warming by raising the purchase price of the surplus power. The industry is in the process of further raising the plant capacity, and improving the power-generating efficiency. This will enable a plant to generate more electric power than its in-plant need so that the surplus power can be sold to the commercial grid. It also plans to become a local power supplier during off-season of sugar making by adding a condensing turbine generator. A typical Thai sugar plant of the latest design generates steam of 4Mpa at the bagasse boiler outlet with the temperature of 400°C at 84% boiler efficiency. With the bagasse LHV of 7,540 kJ/kg and that of fuel oil 41, 840 kJ/kg, and taking 90%as oil-burning boiler efficiency, 5.95 kg of bagasse would replace 1 kg of oil. The Kyoto Mechanism defines CO₂ generation by fuel oil as 2.65 kg per liter. Using 0.85for the specific gravity of fuel oil, the amount of CO₂ generation will be 3.12 kg-CO₂/kg. Therefore, CO₂reduction per ton of bagasse in terms of fuel oil will be: 3.12/5.95 =0.524 kg-CO₂/kg-bagasse. As 1 kg of bagasse generates 2 kg of steam, the CO₂reduction of a 100t/h steam boiler will be112,660 ton/year for an annual operation of4,300 hours, as follows. 0.524 × 100/2 = 26.2 t-CO₂/h, 26.2 × 4,300 =112,660 t-CO₂/year. This revised version was published online in August 2006 with corrections to the Cover Date.     

Analysis of the hydrocyclone stock cleaning process for wasted fibre in a paper mill

The main objective of this project was to evaluate the possibility of reducing the quantity of fibre wasted at one of many hydrocyclone (centrifugal) cleaning processes in a paper mill. It was found that the application of elutriation water to both the tertiary and quaternary cleaners was essential to minimise the fibre discharged to the sewer, and the pressure of this elutriation water had a dramatic effect of reducing the fibre wastage. Accordingly, it has been shown that 150–160 kPa as the optimum pressure range to apply elutriation water to minimise the product grade fibre wasted whilst sending undesired shive fibre to the sewer. Also, monitoring of the press uhle box wastewater revealed that the paper mill has the potential to make substantial cost savings by reducing the waste stream. Further investigation is necessary to determine the types of fibre that are being wasted, and the viability of a screen to recycle the wasted fibre to the process. However, these fibres may be unsuitable to reuse in the process and alternative uses must be found.     

钢厂热锯机噪声控制方案

某钢厂热锯机的工作噪声问题严重影响附近居民的日常生活，急需解决。根据其发声机理，通过采取对圆盘锯边缘开槽，安装吸隔声罩，对锯片增加阻尼材料，夹紧工件等措施取得了较好的降噪效果。     

固硫剂制备工艺探讨

探讨了循环流化床锅炉脱硫方法中固硫剂的制备工艺，对几种石灰石破碎设备及工艺进行了分析比较，通过柱磨机粉磨石灰石的工业试验，了解其产品粒度分布，从而择优确定固硫剂制备工艺流程。     

Electrochemical treatment of olive mill wastewater: Treatment extent and effluent phenolic compounds monitoring using some uncommon analytical tools

Problems related with industrials effluents can be divided in two parts: (1) their toxicity associated to their chemical content which should be removed before discharging the wastewater into the receptor media; (2) and the second part is linked to the difficulties of pollution characterisation and monitoring caused by the complexity of these matrixes. This investigation deals with these two aspects, an electrochemical treatment method of an olive mill wastewater (OMW) under platinized expanded titanium electrodes using a modified Grignard reactor for toxicity removal as well as the exploration of the use of some specific analytical tools to monitor effluent phenolic compounds elimination. The results showed that electrochemical oxidation is able to remove/mitigate the OMW pollution. Indeed, 87% of OMW color was removed and all aromatic compounds were disappeared from the solution by anodic oxidation. Moreover, 55% of the chemical oxygen demand (COD) and the total organic carbon (TOC) were reduced. On the other hand, UV- Visible spectrophotometry, Gaz chromatography/mass spectrometry, cyclic voltammetry and 13 C Nuclear Magnetic Resonance (NMR) showed that the used treatment seems efficaciously to eliminate phenolic compounds from OMW. It was concluded that electrochemical oxidation in a modified Grignard reactor is a promising process for the destruction of all phenolic compounds present in OMW. Among the monitoring analytical tools applied, cyclic voltammetry and 13 C NMR are among the techniques that are introduced for the first time to control the advancement of the OMW treatment and gave a close insight on polyphenols disappearance.     

用造纸污泥制备改性木质素磺酸钠

以甲醛作改性剂，用造纸污泥制备改性木质素磺酸钠，通过正交实验考察了各种因素对改性木质素磺酸钠减水性能的影响。实验结果表明：木质素磺酸钠进行羟甲基化反应时，在10g粗品木质素中加入甲醛7mL、反应温度为45℃、反应液pH为10—11的最佳条件下，改性木质素磺酸钠的减水率为25．2％。经测试，改性木质素磺酸钠的各项性能指标均达到普通减水剂的国家标准要求。     

低纬高原大气电场特征及其在预警中的应用

通过对2006年7月- 2007年6月云南地闪定位网探测资料和玉溪大气电场仪资料分析,研究了高原晴天大气电场和雷暴天气过程的电场演变特征.结果表明:高原晴天大气电场具有明显的日变化和月变化特征.低纬高原地区雷暴云具有偶极性和三极性两种结构,但大多数雷暴具有偶极性电荷结构,不同电荷结构的雷暴云的放电特征不同,偶极性时主要为负地闪,地闪活动较活跃；三极性时主要是正地闪,地闪活动较少.根据雷暴云近地面电场变化特征,探讨了大气电场仪预警地闪的方法,首次提出极性变化预警法,其命中率和提前预警时间都明显优于阈值预警法.     

造纸工业总排水及漂白废水中AOX监测方法的研究

运用TOX测定仪对造纸工业废水及漂白废水中AOX(可吸附有机卤素)测定;水样用硝酸调pH＜2后,以双根活性炭玻璃填充柱连续吸附;将吸附有机物的活性炭在氧气流中燃烧热解、用微库仑法测定其卤化氢.样品前处理比现行活性炭振荡吸附法样品及试剂用量少、快速、重现性好.方法测定浓度下限为3.73μg/L.     

Dioxin formation in pulp and paper mills of India

Samples of effluents, sludge, pulp, final products (paper) and soil were collected from the identified pulp and paper mills in India. The samples were analysed for 2,3,7,8-tetrachloro-dibenzo-p-dioxin (2,3,7,8-TCDD) and other dioxin congeners and precursors. Pulp and paper mills using chlorine for the bleaching process showed the presence of 2,3,7,8-TCDD in effluent samples. In the effluent and pulp samples from mills where chlorine dioxide was used as a bleaching agent, the 2,3,7,8-TCDD congener ranged from below the detection limit 0.05 to 0.12 ngL⁻¹/ngg⁻¹. The relative standard deviation of reproducibility and the percent recovery of 2,3,7,8-TCDD were 2.07 and 82.4% in pulp and 2.8 and 92% in effluent, respectively. The 1,3,6,8-TCDD was the only other major dioxin congener found in the treated and untreated effluent and sludge samples. However, dichlorobenzene, trichlorophenyl, and hexachlorobiphenyl were detected in all samples. The formation of dioxins can be minimised by replacing chlorine with chlorine dioxide in bleaching processes in pulp and paper mills.     

The removal of lignin and phenol from paper mill effluents by electrocoagulation

This study aims to investigate the treatment of paper mill effluents using electrocoagulation. Removal of lignin, phenol, chemical oxygen demand (COD) and biological oxygen demand (BOD) from paper mill effluents was investigated at various current intensities by using different electrodes (Al and Fe) and at various electrolysis times (1.0, 2.5, 5.0 and 7.5min). It was observed that the experiments carried out at 12V, an electrolysis time of 2min and a current intensity of 77.13mA were sufficient for the removal of these pollutants with each electrode. The removal capacities of the process using an Al electrode were 80% of lignin, 98% of phenol, 70% of BOD, and 75% of COD after 7.5min. Using an Fe electrode the removal capacities were 92%, 93%, 80% and 55%, respectively. In addition, it was found that removal of lignin, phenol, BOD and COD increased with increasing current intensity. In the experiments carried out at different current intensities, higher removal can be explained through a decrease in intra-resistance of solution and consequently an increase at the transfer speed of organic species to electrodes. It was also found that Al electrode performs higher efficiency than Fe electrode except for COD removal. However, the time required for removal of BOD was more than that of COD. The results suggest that electrocoagulation could be considered as an effective alternative to paper mill effluents treatment.