Fuel properties and combustion performance of hydrochars prepared by hydrothermal carbonization of different recycling paper mill wastes

The incineration of high-moisture solid residues generated at the recycling paper mills represents an energetically unfavourable method of resource utilization. Alternatively, hydrothermal pre-treatment is considered. In this study, low-value paper sludges from three different recycling streams were hydrothermally carbonized at 205, 225, and 245°C for 3 h. The raw feedstocks and derived hydrochars were analyzed for energy properties, chemical characteristics, surface morphology, functional groups, and combustion performance employing energy densification and mass yield quantification, scanning electron microscopy, elemental analyzer, Fourier-transform infrared spectroscopy, and thermogravimetry. The increase in reaction temperature was reported to cause a decrease in mass yield and an increase in energy densification and calorific values corresponding to 5.98%–49.35% and 10.10%–58.51% for raw fibre rejects and final sludge-derived hydrochar, respectively. Hydrothermal carbonization (HTC) had a non-significant influence on the energy densification of primary clarifier sludge-derived hydrochar. Higher reaction temperatures favoured the rate of dehydration and decarboxylation, leading to hydrochars with lower H/C and O/C ratios, thereby enhancing the overall fuel properties. The low-nitrogen and low-sulphur fuels obtained validated the effectiveness of HTC treatment to produce high-quality cleaner solid fuel. The burnout temperature was mostly reduced with an increase in HTC temperature. At HTC-205 and 225°C, the ignition temperature and the combustion performance increased as a result of the HTC reaction mechanisms. HTC effectively recovered hydrochar with increased carbon content, improved energy densification, and good combustion adequacy. Hydrochar derived from recycling mills may play a role in the energy sector as a substitute for coal or in co-combustion at coal-fired power plants.     

Effect of carbonization temperature on the yield and porosity of char produced from palm shell

Several batches of chars were prepared from palm shell by carbonization in a flow of nitrogen using a fixed‐bed reactor. Palm shell was carbonized at temperatures of 500, 600, 700, 800 and 900 °C for 1 h to study the effects of carbonization temperature on char yield and its porosity. The prepared chars were characterized for the micropore volume using CO₂ adsorption while the meso‐ and macropore volumes were analyzed using a mercury porosimeter. The char yield was around 25% and is comparable with yields reported from other lignocellulosic materials. The results show that carbonization temperature has a significant effect on the micro‐ and mesopore volumes. However, it has negligible effect on the macropore volume. © 2001 Society of Chemical Industry     

水热炭化制备污泥生物炭的碳固定

采用水热炭化法将市政污泥与印染污泥在不同的水热温度下制备成生物炭,并着重分析了污泥生物炭的碳固定指标与水热温度的关系。结果表明,污泥泥质和水热温度对生物炭碳固定特性影响明显。市政污泥的水热炭化以脱羧为主,而印染污泥则以脱水为主。随着水热温度升高,两种生物炭中碳元素含量、炭产率和碳回收率均下降,但市政污泥生物炭中稳定碳的含量及其产率增加,稳定性提高,而印染污泥则呈现相反的变化趋势。这一结果指出,市政污泥生物炭的碳固定性能明显优于印染污泥,并且应进一步研究不同污泥泥质特征与炭化碳固定效果的关系。     

Effect of activation temperature on pore development in activated carbon produced from palm shell

A series of experiments were conducted to investigate the effect of activation temperature on pore development of activated carbon produced from palm shell. Activation of the samples was carried out at 800, 850 and 900 °C for different durations ranging from 10 to 180 min. The samples were characterized using N₂ adsorption for evaluation of micropores and the mercury intrusion technique for mesopore and macropore analysis. Within the range of activation temperatures studied, high burn‐off products derived from high activation temperatures tend to have larger micropore development. However, an increase in the activation temperature has no remarkable effect on mesopore and macropore development. © 2002 Society of Chemical Industry     

过程参数对纤维素水热碳化的影响

生物质废弃物是当今世界上的第四大能源,传统的焚烧处理方式不仅会污染环境,还会浪费能源。水热碳化是一种高效的废弃生物质资源化技术。考察了反应温度和停留时间对纤维素水热碳化碳分布的影响,并对碳化物的物理化学特性、微观结构进行了研究,以及从反应机理角度进行解释。结果表明,原料中的碳大部分都保留在了碳化物中,占71%～75%,其余部分被转移至液相和气相。随着温度和时间的增大,碳化物的产率降低,热值升高,O/C原子比降低。SEM显示当温度达到220℃时,碳化物表面开始形成微球结构,且随着温度和时间的增大,微球结构均一性、分散度越来越好。FTIR表明碳化物表面生成羟基和羰基等官能团,水热碳化过程中会发生脱水和芳香化反应。     

Comparative evaluation of palm oil color measurement using a prototype palm oil colorimeter

The color of refined palm oil and palm oil products is conventionally measured using the manually operated Lovibond^® Tintometer. In the present study, one manual/visual and three automatic colorimeters for the measurement of vegetable oil color were used for color measurements of refined palm oil. All colorimeters used were commercially available instruments except for an automatic palm oil colorimeter developed specifically for the measurement of palm oil color. The color values obtained from all four instruments were compared using the visually obtained readings as reference values. Results showed that all three automatic instruments gave correlation coefficients of greater than 0.9300 for red color measurements. In addition, the Student t-test showed no difference between the analysis of red color using the visual method and the palm oil colorimeter. This investigation concludes that, although it is extremely difficult to reduce the lack of precision in color measurement of palm oil, a properly designed and calibrated automatic instrument may still be the better choice because reproducibility and repeatability are required in all standard test methods. The palm oil colorimeter offers a ready and relatively inexpensive solution to the problem of color matches based on visual observations.     

Synthesis of urethane oils from palm oil and waste PET bottles

Waste PET bottles were depolymerized by propylene glycol at a weight ratio of PET to propylene glycol of 37.5 : 62.5, using zinc acetate as a catalyst. The glycolyzed product, consisting of oligomeric diols with a number–average molecular weight range of 240–1107, was obtained. It was further reacted with palm oil and tolylene diisocyanate to obtain urethane oils at hydroxyl to isocyanate ratios from 1 : 1 to 1 : 0.8, with and without methanol acting as a blocking agent. It was found that all the synthesized urethane oils were yellowish transparent liquids of low molecular weights. A lower isocyanate content or the presence of a blocking agent resulted in higher viscosity, higher molecular weight, and shorter drying time. The films of all synthesized urethane oils exhibited good hardness, excellent flexibility, and high impact strength. They also showed excellent water resistance, good acid resistance but only fair alkali resistance. Moreover, these prepared urethane oils had better adhesion compared with those of the commercial urethane oil. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Lubrication properties of trimethylolpropane esters based on palm oil and palm kernel oils

Due to the global drive towards biodegradable products, trimethylolpropane [2‐ethyl‐2‐(hydroxymethyl)‐1, 3‐propanediol] (TMP) esters based on palm and palm kernel oils were synthesized, their lubrication properties evaluated, and their potential as base stock for biodegradable lubricants assessed. Two types of TMP esters were considered: palm kernel (PKOTE) and palm oil (PPOTE) TMP esters, derived from palm oil and palm kernel methyl esters, respectively. Lubrication properties such as viscosity, viscosity index (VI) and pour point (PP) were determined according to methods of the American Society for Testing and Materials. Wear and friction properties were evaluated using a four‐ball test machine, while oxidative stability was studied with the Penn State Micro‐oxidation thin‐film test. High VI ranges between 170 to 200 were recorded for these base stocks. PP were relatively high, between 4 to —1 °C, but were improved to at least —33 °C in high oleic palm oil TMP esters. The effects of chemical structure and impurities on wear properties and oxidative stability were also studied. The presence of methyl esters was found to improve wear, but hydroxyl groups in mono‐ and diesters had negative effects at high concentrations. Differences in chemical structures of PKOTE and PPOTE were shown to affect friction and wear results. Both base fluids exhibit oxidative stability comparable to other high oleic base fluids.     

Hydrothermal carbonization of sawdust for hydrochar production to prepare solid fuels

Hydrothermal carbonization (HTC) of sawdust for producing hydrochar was optimized using response surface methodology (RSM). After optimization, the combustion behaviour and other relevant fuel properties of hydrochar that was obtained at the optimized conditions were studied. Additionally, the aqueous phase obtained at the optimized conditions was recycled as the reaction medium for producing hydrochar and the influence of the aqueous phase recycling on the hydrochar yield and properties was evaluated. The results indicated that the highest hydrochar yield of 84.23 wt.% under the predicted optimum conditions of temperature of 162.23°C, 2.51 h, feedstock loading of 10.71 wt.%, and catalyst loading of 7.99 wt.%. Furthermore, it was found that the use of recycled aqueous phase as the reaction medium led to an increase in the hydrochar yield, higher heating value (HHV), and energy yield, and difference in combustion behaviour was minor. Overall, this study filled the gap in HTC literature regarding the effect of catalyst on hydrochar production and provided a practical solution to treat the aqueous phase.     

Improvement of palm oil through breeding and biotechnology

The oil palm Elaeis guineensis is the highest oil-yielding crop and has the potential to become the major supplier of both edible oil and renewable industrial feedstock. The oil yield from wild groves is presently less than 0.5 t/ha/y. However, through breeding and selection, the oil yield of commercial plantations could reach as much as 8 t/ha/y. New planting materials also have the capability of better oil yields with high iodine value (IV), slow height increment, and larger kernels. The oil also contains considerable amounts of carotenoids (500–700 ppm), vitamin E (600–1000 ppm), and sterols (250–620 ppm). The oil yield of another oil palm species, E. oleifera, is approximately 0.5 t/ha/y with high contents of carotenoids (700–1500 ppm), vitamin E (700–1500 ppm), and sterols (3500–4000 ppm). The above traits could be improved through breeding and biotechnology. Biotechnological efforts at the Palm Oil Institute of Malaysia are directed toward the production of oil with high IV and high monounsaturated fatty acids for edible purposes and industrial uses. Isolation and manipulation of the genes involved in the biosynthesis of fatty acids are the main focus. The aim is to increase the efficiency of conversion of palmitate (C_16:0) to oleate (C_18:1). Levels of palmitate and oleate are controlled by the enzymes acyl-acyl carrier protein (ACP) thioesterase and β-keto acyl ACP synthase II. The chain termination reactions of C_16:0 and C_18:1 are independent, thus paving the way for the possibility of reducing palmitate levels by switching off the palmitoyl ACP thioesterase gene. Paper presented at the 88th AOCS Annual Meeting & Expo. May 11–14, 1997, Seattle, Washington, USA.     

Comparative study of the textural characteristics of oil palm shell activated carbon produced by chemical and physical activation for methane adsorption

The objective of this study is to relate textural and surface characteristics of microporous activated carbon to their methane adsorption capacity. Oil palm shell was used as a raw material for the preparation of pore size controlled activated carbon adsorbents. The chemical treatment was followed by further physical activation with CO₂. Samples were treated with CO₂ flow at 850 °C by varying activation time to achieve different burn-off activated carbon. H₃PO₄ chemically activated samples under CO₂ blanket showed higher activation rates, surface area and micropore volume compared to other activation methods, though this sample did not present high methane adsorption. Moreover, it was shown that using small proportion of ZnCl₂ and H₃PO₄ creates an initial narrow microporosity. Further physical activation grantees better development of pore structure. In terms of pore size distribution the combined preparation method resulted in a better and more homogenous pore size distribution than the conventional physical activation method. Controlling the pore size of activated carbon by this combined activation technique can be utilized for tuning the pore size distribution. It was concluded that the high surface area and micropore volume of activated carbons do not unequivocally determine methane capacities.     

Determination of cypermethrin in palm oil matrices

In this study, a new method was developed for the determination of cypermethrin residue in both crude palm oil (CPO) and crude palm kernel oil (CPKO) using GC with electron capture detector. In this method, the oil was extracted with acetonitrile. Aliquots were cleaned‐up using combined solid phase extraction (SPE), and a primary‐secondary amine in combination with graphitized carbon black. The SPE cartridges were first conditioned and then eluted with acetonitrile. Cypermethrin recoveries from the fortified CPO samples were 87–98% with relative standard deviation (RSD) values of 4–8%, while those for the fortified CPKO samples were 83–100% with RSD values of 3–10%. Since good recoveries were obtained with RSD values below 10% in most cases, the proposed methodology will be useful for the analyses of palm oil samples. The method was successfully applied to the analysis of cypermethrin in real palm oil samples from various parts of Malaysia. No cypermethrin residue was found among 30 samples analyzed.     

棕榈油市场分析

分析了2008年度的棕榈油市场发展状况,对2009年度的棕榈油市场进行了展望和预测。同时,对全球棕榈油库存及库存使用比以及在全球贸易中所占比例进行了分析。     

Synthesis of 2‐monoglycerides by alcoholysis of palm oil and tuna oil using immobilized lipases

Commercial immobilized lipases were used for the synthesis of 2‐monoglycerides (2‐MG) by alcoholysis of palm and tuna oils with ethanol in organic solvents. Several parameters were studied, i.e., the type of immobilized lipases, water activity, type of solvents and temperatures. The optimum conditions for alcoholysis of tuna oil were at a water activity of 0.43 and a temperature of 60 °C in methyl‐tert‐butyl ether for ～12 h. Although immobilized lipase preparations from Pseudomonas sp. and Candida antarctica fraction B are not 1, 3‐regiospecific enzymes, they were considered to be more suitable for the production of 2‐MG by the alcoholysis of tuna oil than the 1, 3‐regiospecific lipases (Lipozyme RM IM from Rhizomucor miehei and lipase D from Rhizopus delemar). With Pseudomonas sp. lipase a yield of up to 81% 2‐MG containing 80% PUFA (poly‐unsaturated fatty acids) from tuna oil was achieved. The optimum conditions for alcoholysis of palm oil were similar as these of tuna oil alcoholysis. However, lipase D immobilized on Accurel EP100 was used as catalyst at 40 °C with shorter reaction times (<12 h). This lead to a yield of ～60% 2‐MG containing 55.0‐55.7% oleic acid and 18.7‐21.0% linoleic acid.     

Co-metathesis reaction of crude palm oil and ethene

The co-metathesis reaction of crude palm oil with ethene in the presence of WCL₆/Me₄Sn, followed by termination of this reaction with methanol, gives terminal alkenes. The major metathesis products are 1-decene and methyl 9-decenoate.     

Temperature effect on the viscosities of palm oil and coconut oil blended with diesel oil

One of the major difficulties in using crude vegetable oils as substitute fuels in diesel engines is their relatively high viscosities. Increasing the temperature of the crude vegetable oil, blending it with diesel oil, or the combination of both offers a simple and effective means of controlling and lowering the viscosities of vegetable oils. This work reports viscosity data, determined with a rotational bob-and-cup viscometer, for crude palm oil and cononut oil blended with diesel oil over the temperature range of 20–80°C and for different mixture compositions. All the test oil samples showed a time-independent newtonian type of flow behavior. The reduction of viscosity with increasing liquid temperature followed an exponential relationship, with the two constants of the equation being a function of the volume percentage of the vegetable oil in the mixture. A single empirical equation was developed for predicting the viscosity of these fuel mixtures under varying temperatures and blend compositions.     

Continuous supercritical carbon dioxide processing of palm oil

Crude palm oil was processed by continuous supercritical carbon dioxide. The process reduces the contents of free fatty acids, monoglycerides and diglycerides, certain triglycerides, and some carotenes. The refined palm oil from the process has less than 0.1% free fatty acids, higher carotene content, and low diglycerides. Solubility of palm oil in supercritical carbon dioxide increased with pressure. A co-solvent improves the refining process of palm oil.     

Synthesis of civetone from palm oil products

Metathesis of ethyl oleate, catalyzed by WCl₆ and SnMe₄, provided diethyl 9-octadecenedioate (the desired starting material for the synthesis of civetone) in 99% yield. Dieckmann condensation of diethyl 9-octadecenedioate gave 2-ethoxycarbonyl-9-cycloheptadecenone (63% yield), the hydrolysis-decarboxylation reaction of which yielded civetone (93%). Identification of all products was by¹H nuclear magnetic resonance, infrared and mass spectroscopic data. This is the first report of the synthesis of civetone from palm oil-derived products.     

棕榈油在全球的贸易

深入阐述了棕榈油、月桂酸和工业油脂化学在马来西亚和印度尼西亚等生产大国的市场概况,进而看到棕榈油在全球的贸易。同时,也分析了棕榈油和月桂油在中国的市场状况和市场潜力,不管是对马来西亚还是整个世界来说,中国是非常重要的市场。