Novel approach to convert non-self drying palm stearin alkyds into environmental friendly UV curable resins

UV curable coating is a form of green technology that reduces or eliminates completely the emission of volatile organic compounds (VOC) and is in line with the current global call in preserving nature. The objective of this project is to produce UV curable resins from non-self drying palm stearin alkyds by the incorporation of maleic anhydride (MAH) which could introduce more unsaturation into the main chains of alkyds. Four alkyds with different level of unsaturation were prepared and the successful incorporation of MAH was confirmed by FTIR and ¹H NMR analyses. Methyl methacrylate (MMA) was used as the reactive diluents, and benzophenone as the UV-photoinitiator. The UV-cured coatings were tested using standard methods adopted from ASTM, and results showed that coatings of maleated alkyds exhibited good film properties. This novel approach has succeeded in converting a non-self drying palm stearin alkyd into UV-curable resins.     

基于无线通信的人机协同车间数字化制造模式

网络环境下的数字化制造的成功与否不仅取决于企业上层管理的数字化和信息化,也取决于车间底层的数字化和信息化.后者在一定意义上更加困难:普通机床造成信息盲区,车间布线困难,调度的不确定性等,传统的FMS排斥人的参与,文章提出一种基于无线通信技术的人机协同车间数字化制造模式:它是一个三层结构,即基于有线和无线局域网的管理层、掌握车间数字助理的现场调度员层和采用掌上数控系统的数控机床和普通机床的设备层;车间数字助理通过802.11x和管理层与设备层通信;数控系统由掌上部分和嵌入机床的固定部分组成,彼此通过蓝牙通信.采用Windows CE.NET作为车间数字助理和数控系统的操作系统平台.采用人机协同的多Agent调度策略.新的数控系统把以机器为中心的操作模式改为以人为中心,一人能同时操作多台不同类型的数控机床,构成一个人机协同工作的加工单元,比传统的FMS更灵活、更可靠.     

Dynamic modeling and simulation of a palm wastes boiler

A state-space dynamic model for a palm wastes boiler is being developed and simulated. The unique feature of this boiler is that it uses wastes in the form of fiber and shell from the palm oil processing as its fuels. Specific characteristics of oil palm waste boilers are non-uniform fuel feed, compositions, sizes and moisture content of the fuel. These features introduce additional dimensions to the difficulty of boiler control. The superheated steam produced is used to generate electricity, which drives numerous motors and other equipment for palm fruit processing thus causing severe interactions between the power plant and other parts of the mill. The main work of this paper is the development of a dynamic model and simulation of the boiler. The boiler unit can be divided into several sections for analysis viz., the furnace, superheater, drum, risers, and downcomer. A tenth-order, physical, linearized process model was developed. The linearized model consists of ten first-order simultaneous equations and is represented by a (10 x 10) state matrix and (4 x 10) input matrix in the state space form.     

Prediction of gaseous products from biomass pyrolysis through combined kinetic and thermodynamic simulations

Due to the nonhomogeneous characteristics of biomass constituent, it has been known to be difficult to apply directly any simulation work to the pyrolysis of biomass for a precise prediction of gaseous products. In this study, two computation codes (HSC Chemistry for thermodynamic and Sandia PSR for kinetic simulations) were employed, to consider the integrated effects of thermodynamic and kinetic phenomena occurring in biomass pyrolysis on the distribution of gaseous products. The principle of simulation applied in this study was to extract substitutable gas phase compositions from HSC calculations, which were predicted thermodynamically. Then, the gas phase compositions were inputted into the Sandia PSR code to consider the potential constrains of kinetics involving in the pyrolysis and finally to get the distributions of gas products which should be closer to the realistic situation. Palm oil wastes, a local representative biomass, were studied as sample biomass. The gaseous products obtained from HSC calculations were mainly H₂, CO₂, CO, CH₄ and negligible C₂₊ hydrocarbons. After applying these products into PSR program, the final products developed into H₂, CO₂, CO, CH₄, C₂H₂, C₂H₄, C₂H₆ and C₃H₈ which are more realistic products in the modern fast pyrolysis.     

Esterification of palm fatty acid distillate (PFAD) in supercritical methanol: Effect of hydrolysis on reaction reactivity

This study demonstrated the potential use of local palm fatty acid distillate (PFAD) as alternative feedstock for fatty acid methyl esters (FAMEs) production and the possibility to replace the conventional acid-catalyzed esterification process (with H₂SO₄), which was industrially proven to suffer by several corrosion and environmental problems, with non-catalytic process in supercritical methanol. At 300 °C with the PFAD to methanol molar ratio of 1:6 and the reaction time of 30 min, the esterification of PFAD in supercritical methanol gave FAMEs production yield of 95%. Compared with transesterification of purified palm oil (PPO) in supercritical methanol, the production of FAMEs reached the maximum yield of only 80% at 300 °C with higher requirement for methanol (1:45 PPO to methanol molar ratio). Compared with the conventional acid-catalyzed esterification of PFAD, only 75% FAMEs yield was obtained in 5 h. The presence of water in the feed (between 0 and 30% v/v) was found to lower the yield of FAMEs production from PFAD significantly. This negative effect was proven to be due to the further hydrolysis of FAMEs, which nevertheless can be minimized when high content of methanol was used.     

稳步提升 Palm Centro深度评测

从Centro工程机评测发布到港行正式上市,Palmer们对Centro的关注度一直很高。有赞同的——Centro的时尚设计摒弃了Treo系列一贯的呆板厚重;也有鄙视的——作为低端廉价的新机型,并没有去更新系统满足广大Palmer的诉求,Palm似乎处于穷途末路之中。不论Palm的经营策略是否时过境迁,对于这款Palm最新的智能手机,我们还是应该给予更多的关注。     

Development of a rheological method to characterize palm oil crystallizing under shear

To follow palm oil crystallization under shear, a new rheological method was developed. This method can be split up into two parts: In the first part, continuous shear is applied for a pre‐defined period and crystallization is monitored by measuring the apparent viscosity as a function of isothermal time under shear. In the second part, shear is halted and oscillation is applied during 30 s, thus recording moduli and phase angle. These moduli and phase angle are then characteristic of a sample crystallized under shear during this pre‐defined period. After repeating this procedure for increasing shearing periods in the first part, complex modulus and phase angle were plotted as a function of isothermal time under shear. The thus obtained results were compared with crystallization data obtained via time‐resolved X‐ray diffraction and polarized light microscopy.     

Fractionation of Palm Kernel Oil by Short Path Distillation

Fractionation of palm kernel oil （PKO） by short path distillation （SPD） at two feed flow rates （135 g/h and 195 g/h） and six distillation temperatures, TD,s （200, 210, 220, 230, 240 and 250 ℃） was investigated. Other distillation parameters, such as vacuum pressure （0.001 mbar）, blade rotation speed （400 rpm） and temperature of the feed material （60 ℃） were kept constant. The fractionated products, known as residue and distillate, were analysed for physico-chemical properties including fatty acid composition （FAC）, triacylglycerol （TAG） composition, slip melting point （SMP）, thermal analysis by differential scanning calorimetry （DSC） and solid fat content （SFC）. Product yield was measured as well. Crystallisation behaviour of PKO and the fractionated products were studied by measurement of isothermal crystallisation, Tc,. at 0, 5, 10, 15, 20 and 25 ℃. The distillates, collected at all fractionation temperatures, were enriched with caprylic, capric and lauric acids. These fractions were also concentrated with low molecular weight and C36 TAGs. Distillates obtained at higher TDis （230-250 ℃） exhibited higher in SMP and SFC. On the other hand, the residual oils collected at all fractionation temperatures contained higher amount of long-chain fatty acid and palmitic acid. These fractions were enriched with high molecular weight TAGs. Residues obtained at lower Tois （200-220 ℃） were low in SMP and comparable SFC with PKO. Changes in fatty acid and TAG composition resulted in different crystallisation behaviour of the fractions. Distillates collected at all fractionation temperatures crystallised in a sharper peak while residues obtained at higher T Dis （230-250 ℃） showed broader crystallisation peaks, as shown by the DSC thermograms.     

Electron spin resonance spectroscopy for evaluation of early oxidative events in semisolid palm oil

Electron spin resonance (ESR) spectroscopy was applied to study early oxidative events in semisolid palm oil in bulk. Oil was stored at mildly accelerated conditions of 50°C for 7 days and the free radical formation was followed with the addition of spin trap N‐tert‐butyl‐α‐phenyl‐nitrone. Dissolution of the oil samples in isooctane prior to ESR measurements stabilized the ESR signal allowing the changes in relative free radical concentrations during oil storage to be monitored. Formation of lipid hydroperoxides as primary lipid oxidation products was found to correlate with the tendency for the formation of free radicals in the oil during the storage and accordingly, ESR spectroscopy may be used to detect the early events in lipid oxidation in palm oil. However, the interference of added rosemary extract (RE) in ESR analyses was seen as an increased ESR signal while the efficiency of RE as antioxidant in palm oil was confirmed by isothermal DSC. Practical applications : ESR spectroscopy may be used to evaluate early events of oxidation in semisolid oils such as palm fat, which is widely used in food industry.     

Determination of 3‐MCPD esters in edible oil – methods of analysis and comparability of results

The discovery of fatty acid esters of 3‐chloropropane‐1,2‐diol (3‐MCPD) in edible oil products initiated food monitoring campaigns in many EU Member States. As the determination of 3‐MCPD esters was new to most laboratories, questions on the reliability of the produced analysis data were raised. In response to this, the Institute for Reference Materials and Measurements (IRMM) of the European Commission's Joint Research Centre (JRC) organised a proficiency test on the determination of 3‐chloropropane‐1,2‐diol esters (3‐MCPD esters) in edible oils. The aim of this proficiency test was to scrutinise the capabilities of official food control laboratories, private food control laboratories as well as laboratories from food industry to determine the 3‐MCPD esters content of edible oils. The study was carried out in accordance with “The International Harmonised Protocol for the Proficiency Testing of Analytical Chemistry Laboratories” and ISO Guide 43. The test materials dispatched to the participants were: refined palm oil, extra virgin olive oil spiked with 3‐chloropropane‐1,2‐dioleate and 3‐MCPD standard solution in sodium chloride. Altogether 41 laboratories from 11 EU Member States, Switzerland and Macedonia subscribed for participation in the study. The analysis task was to determine the 3‐MCPD esters content as total 3‐MCPD content of the test samples. Participants were free to choose their analysis methods. In total, 34 laboratories reported results to the organisers of the study. The performance of laboratories in the determination of 3‐MCPD esters in edible oils was expressed by z‐scores. About 56% of the participants performed satisfactorily in the determination of 3‐MCPD esters in palm oil and 85% for the spiked extra virgin olive oil test sample. The study revealed that the direct transesterification of the sample without the prior removal of glycidol esters might lead to strong positive bias.