水性聚氨酯的制备

要制得性能优良的木器用水性聚氨酯乳液,要从制备水性聚氨酯用的原料聚酯二元醇入手,文章设计分子量为1000的聚酯二元醇,它使用邻苯二甲酸酐和己二酸以摩尔比40∶60混合后再与乙二醇反应,制得的水性聚氨酯乳液,其化学稳定性、涂膜硬度,相对于单独用脂肪族聚酯二元醇制备的水性聚氨酯的性能要优。     

Effect of support type and synthesis conditions on the oxygen reduction activity of RuxSey catalyst prepared by the microwave polyol method

Ru_xSe_y nanoparticles supported on different carbon substrates were synthesized by microwave heating of ethylene glycol solutions of Ru(III) chloride and sodium selenite at different pH and Ru/Se mole ratios. The resulting catalysts were used for the electrochemical oxygen reduction reaction (ORR) in acidic solution. The electrochemical activity was highest for the supported catalyst synthesized at pH 8. Increasing the Se concentration of the catalyst up to 15 mol% increased the catalytic activity for the ORR; at this Se concentration, the activity of the catalyst was considerably higher than that observed for pure Ru catalyst synthesized at exactly the same conditions. The influence of the type of carbon support on the activity of the electrocatalyst was also investigated. Among the different supports, including carbon black (Vulcan XC-72R) (C1), and nanoporous carbons synthesized from resorcinol- (C2) and phloroglucinol-formaldehyde (C3) resins, the Ru_xSe_y catalyst supported on C3 exhibited highest activity for ORR.     

用于可焊性漆包线漆的聚酯多元醇的合成及性能测定

发展了一种聚酯多元醇,可望应用于制备新型的直焊性耐热漆包线漆。采用间苯二甲酸、己二酸、乙醇胺或乙二醇、三乙醇胺或甘油,通过熔融共缩聚合成一系列聚酯多元醇,然后用甲醚化氨基树脂及溶剂混合、配制成溶液,再涂制成漆包线。研究结果表明系列聚酯多元醇的分子量、酸值均符合漆包线漆制备的技术要求;采用乙醇胺代替乙二醇、三乙醇胺代替甘油在聚酯多元醇的合成反应中具有较高的缩聚反应活性,由此制备的聚酯多元醇具有在350℃至400℃的范围内更快速分解和分解残渣较少的特点,采用此聚酯多元醇作为主要成分、涂制的漆包线在400℃至460℃范围内下可直焊,介质损耗曲线的拐点温度可达到162℃、意味着耐热等级较高。     

折叠带蒂髂腹股沟皮瓣修复手掌洞穿性缺损的围手术期护理

目的探讨带蒂髂腹股沟皮瓣折叠修复手掌洞穿性缺损的围手术期护理。方法2004～2008年,12例手掌洞穿性缺损应用带蒂髂腹股沟皮瓣折叠修复,采取心理护理、皮瓣受区、皮瓣供区准备、皮瓣血运监测、皮瓣固定护理、体位护理、饮食控制等围手术期护理。结果皮瓣全部成活,康复顺利,无并发症发生。结论该围手术期系统护理策略对带蒂髂腹股沟皮瓣折叠修复方法修复手掌洞穿性缺护理是安全有效的护理方法。     

Environmental and economic feasibility of palm oil biodiesel in the Mexican transportation sector

This study analyses the environmental and economic feasibility of producing palm oil-based biodiesel in Mexico in order to substitute of diesel fuel consumption using B5 until 2015 and B10 from 2016 to 2031 in the transportation sector. Two scenarios were created by projecting demand and costs for biodiesel as well as greenhouse gases emissions reduction over the next 26 years. In the environmental section, avoided emissions of Particulate matter, Total Hydrocarbons, Carbon Monoxide, Sulphur Dioxide, and Carbon Dioxide as well as the increase in Nitrous Oxide emissions were estimated for each scenario. In the economic section, a cost–benefit analysis of biodiesel substitution was implemented, and mitigation costs of Carbon Dioxide were estimated. Our results show that the feasibility of palm oil biodiesel use is directly related to the implementation of fiscal incentives, such as the exemption from tax (Special Tax on Production and Services).     

Implementation of biofuels in Malaysian transportation sector towards sustainable development: A case study of international cooperation between Malaysia and Japan

Modern transportation nowadays has evolved into an important economic activity for human civilisation. Even though various alternative energy solutions have been put forward to reduce the dependency on fossil fuels, biofuels remain one of the few options which are capable of replacing the roles of fossil fuels in transportation sector without suffering from major economic losses. Malaysia with a huge supply of palm oil for biofuels production is intended to implement mandatory biodiesel blends in its transportation sector in 2011 in order to achieve its carbon reduction commitment towards a more sustainable development. This implementation was originally targeted to start in 2009 but had to be postponed due to several obstacles such as expensive cost, lack of sufficient infrastructure and low public demand. On the other hand, Japan is also trying to fulfil its carbon reduction obligation as outlined under Kyoto Protocol with the usage of biofuels to replace fossil fuels in the transportation sector. However, it lacks sufficient biofuels supply to support its high transportation energy demand. In this case study, the mutual cooperation between Malaysia and Japan in the implementation of biofuels in transportation sector will be studied and analysed in order to overcome the challenges presented in both countries. It is hope to ascertain potential cooperation opportunities amongst those two countries to promote biofuels energy as Malaysia is rich in natural resources whilst Japan has the relevant expertise and technology. It is believed that the strengths from one country can help to cover for the weaknesses from the other and vice versa via closer bilateral partnership which will be extremely crucial when dealing with global energy issues. Ultimately, it is hope that this case study will enable both Malaysian and Japanese government to achieve their renewable energy target in domestic transportation sector.     

Performance optimization of microbial electrolysis cell (MEC) for palm oil mill effluent (POME) wastewater treatment and sustainable Bio-H2 production using response surface methodology (RSM)

Microbial electrolysis cells (MECs) are a new bio-electrochemical method for converting organic matter to hydrogen gas (H₂). Palm oil mill effluent (POME) is hazardous wastewater that is mostly formed during the crude oil extraction process in the palm oil industry. In the present study, POME was used in the MEC system for hydrogen generation as a feasible treatment technology. To enhance biohydrogen generation from POME in the MEC, an empirical model was generated using response surface methodology (RSM). A central composite design (CCD) was utilized to perform twenty experimental runs of MEC given three important variables, namely incubation temperature, initial pH, and influent dilution rate. Experimental results from CCD showed that an average value of 1.16 m³ H₂/m³ d for maximum hydrogen production rate (HPR) was produced. A second-order polynomial model was adjusted to the experimental results from CCD. The regression model showed that the quadratic term of all variables tested had a highly significant effect (P < 0.01) on maximum HPR as a defined response. The analysis of the empirical model revealed that the optimal conditions for maximum HPR were incubation temperature, initial pH, and influent dilution rate of 30.23 ^°C, 6.63, and 50.71%, respectively. Generated regression model predicted a maximum HPR of 1.1659 m³ H₂/m³ d could be generated under optimum conditions. Confirmation experimentation was conducted in the optimal conditions determined. Experimental results of the validation test showed that a maximum HPR of 1.1747 m³ H₂/m³ d was produced.     

Dry Fractionation Approach in Concentrating Tocopherols and Tocotrienols from Palm Fatty Acid Distillate: A Green Pretreatment Process for Vitamin E Extraction

Palm fatty acid distillate (PFAD) is a rich source of vitamin E. As compared to other vegetable oil, PFAD has higher tocotrienol (70–80%) over tocopherol content, which makes it a valuable source for vitamin E extraction. Current vitamin E extraction methods are not sustainable due to the intensive usage of chemical and high operational cost. Hence, the present study investigated for the first time using dry fractionation process as a green and economical pretreatment method for separating solid fraction (stearin) and liquid fraction (olein) in order to concentrate vitamin E from PFAD in olein fraction. We examined the dry fractionation conditions: crystallization ending temperature (36–44 °C), cooling rate (0.3 and 1.5°C min⁻¹), stirring speed (20–125 rpm), and holding time (0–60 min) on the composition of unsaturated and saturated fatty acids as well as vitamin E content in liquid fraction (olein) and solid fraction (stearin) using gas chromatography and high performance liquid chromatography, respectively. In most of these conditions, vitamin E was ultimately higher in olein fraction as compared to stearin fraction, which is correlated with the high degree of unsaturation. Under a cooling rate of 0.3°C min⁻¹, 90 rpm stirring speed, and ending crystallization of 38 °C, the highest vitamin E rich olein fraction was attained with 1479 ± 10.51 ppm in 50 g olein fraction as compared to 1366 ± 7.94 ppm in 500 g of unfractionated PFAD.     

Environmental impact assessment of bio-hydrogenated diesel from hydrogen and co-product of palm oil industry

Bio-hydrogenated diesel (BHD) is a second generation biofuel that can be produced from vegetable oil and hydrogen via hydroprocessing. BHD is considered as one of alternative and renewable energy. This work presents evaluation of environmental impacts of BHD produced from palm fatty acid distillate (PFAD) compared to fatty acid methyl ester (FAME). Greenhouse gas emission, energy consumption, and overall environmental impacts are assessed. System boundary is from palm oil cultivation to BHD production. The functional unit is defined as 1 kg of fuel produced at the plant. The results indicate that energy consumption of BHD-PFAD is 1.18 times higher than that of BHD-FAME, while giving GHG emission 13.56 times lower than that of BHD-FAME. The results of overall environmental impacts indicated that BHD-PFAD was 3.58 greater than that of BHD-FAME.     

In-situ methane enrichment of biogas from anaerobic digestion of palm oil mill effluent by addition of zero valent iron (ZVI)

Palm oil mill effluent (POME) is a wastewater effluent that is generated from palm oil milling. Treatment of POME, especially using biological treatment methods, is a challenge as it contains high amounts of organic and sulfur compounds, and it is highly acidic. In this research, the effects of zero-valent iron (ZVI) on the enhancement of methane production from POME via anaerobic digestion were investigated. Furthermore, to identify the reactor operation modes that were suitable for the addition of ZVI, anaerobic digestion of POME was tested in three reaction configurations: batch reactor, fed-batch reactor, and continuous stirred-tank reactor (CSTR). In the batch mode, where acidic POME was fed with 16 g/L of ZVI dose just once, methane production increased by 74%. However, as the oxidation of ZVI under anaerobic conditions led to the production of hydroxyl ions, the pH of the medium continuously increased from approximately 7 to 9, which is not suitable for methanogenesis. In the fed-batch mode that involved intermittent feeding of acidic POME, the pH of the culture media was maintained at 6.8. This is because the extra hydroxyl ions generated from the oxidation reaction of ZVI tended to neutralize the acids in the feeding substrate. In addition, ZVI promoted the production of methane from POME and increased the average methane content in biogas from 62% to 76%. In the CSTR mode, which involved continuous feeding of acidic POME, ZVI increased methane production by 86% (from 1.79 to 3.32 L/day), methane content in biogas from 60 to 75%, and total chemical oxygen demand (tCOD) removal efficiency from 78 to 89 to 88–95%. Thus, the addition of ZVI can be a potential strategy for in-situ methane enrichment of biogas by anaerobic digestion of POME. This is because ZVI acts as a buffer for acid generation and provides extra electrons, ferrous ions, and ferric ions, which promote key microbial activities in the anaerobic digestion process.