scholarly journals Two-stage agglomeration of fine-grained herbal nettle waste

2017 ◽  
Vol 31 (4) ◽  
pp. 515-523 ◽  
Author(s):  
Sławomir Obidziński ◽  
Magdalena Joka ◽  
Olga Fijoł

Abstract This paper compares the densification work necessary for the pressure agglomeration of fine-grained dusty nettle waste, with the densification work involved in two-stage agglomeration of the same material. In the first stage, the material was pre-densified through coating with a binder material in the form of a 5% potato starch solution, and then subjected to pressure agglomeration. A number of tests were conducted to determine the effect of the moisture content in the nettle waste (15, 18 and 21%), as well as the process temperature (50, 70, 90°C) on the values of densification work and the density of the obtained pellets. For pre-densified pellets from a mixture of nettle waste and a starch solution, the conducted tests determined the effect of pellet particle size (1, 2, and 3 mm) and the process temperature (50, 70, 90°C) on the same values. On the basis of the tests, we concluded that the introduction of a binder material and the use of two-stage agglomeration in nettle waste densification resulted in increased densification work (as compared to the densification of nettle waste alone) and increased pellet density.

Author(s):  
Marcin Mitrus ◽  
Agnieszka Wójtowicz ◽  
Tomasz Oniszczuk ◽  
Ewa Gondek ◽  
Leszek Mościcki

Abstract The aim of the work was to investigate the effect of extrusion-cooking process conditions on the structure and pasting properties of starch extrudates. In addition, the extrudates structure was observed using scanning electron microscopy (SEM) and confocal laser microscopy (CSLM). Wheat, corn and potato starch were extrusion-cooked with different process parameters (moisture content, screw speed, process temperature) in a single screw extruder. Results showed influence of the process parameters on extruded starches pasting properties. Viscosity measurements indicated that water content during starch extrusion is more important than process temperature. The extrudates structure observed with scanning electron and confocal laser microscopes showed that the main effect of extrusion-cooking was loss of the crystalline structure of the starch and the formation of a cellular structure of the extrudates. In extrudates processed at higher starch moisture content reduced the quantity and diameters of created cells was observed.


2021 ◽  
Author(s):  
Imran Ahmed ◽  
Asif Ali ◽  
Babar Ali ◽  
Mahdi Hassan ◽  
Sakhawat Hussain ◽  
...  

Abstract Pelletization of low value added biomass materials such as furfural residue (FR) and sawdust was performed by using a lab scale pelletizer. Effects of moisture content (MC), particle size and a binder on quality parameters (e.g. pellet density, strength and hardness) and on energy consumption were investigated. Quality of pellets was analysed and compared. MC was found to be the more dominant parameter affecting pellet density, strength and hardness of furfural residue pellets (FRPs) and sawdust pellets (SPs), followed by particle size and a binder. Highest particle density of 1.419 g/cm3 for FRPs (0.5–1.41 mm) and 1.243 g/cm3 for SPs (0.25–0.5 mm) was achieved at MC of 8% and 18%. Highest decrease in relaxed density was observed at MC of 13% for FRPs and 28% for SPs. True density of FRPs and SPs made from particles of 0.25–0.5 mm was found higher than 0.5–1.41 mm. The highest strength and hardness (6.29 MPa and 401.3 N/mm2) for FRPs was achieved at 5.5% MC and particles 0.25–0.5 mm. Optimum strength (6.03 MPa) and hardness (96.06 N/mm2) for SPs was obtained at 18% MC and particles 0.25–0.5 mm. The lowest energy consumption (16.16 J/g) for FRPs (0.25–0.5 mm) and 20.22 J/g for SPs (0.5–1.41 mm) was achieved at MC of 13% and 28%. Addition of binding agent to FR sawdust decreased energy consumption of FRPs and SPs. SPs quality was enhanced with the use of a binder. Heating value of FRPs were found higher than SPs.


1970 ◽  
Vol 26 (1) ◽  
pp. 16 ◽  
Author(s):  
S Balasubramanian ◽  
Rajkumar Rajkumar ◽  
K K Singh

Experiment to identify ambient grinding conditions and energy consumed was conducted for fenugreek. Fenugreek seeds at three moisture content (5.1%, 11.5% and 17.3%, d.b.) were ground using a micro pulverizer hammer mill with different grinding screen openings (0.5, 1.0 and 1.5 mm) and feed rate (8, 16 and 24 kg h-1) at 3000 rpm. Physical properties of fenugreek seeds were also determined. Specific energy consumptions were found to decrease from 204.67 to 23.09 kJ kg-1 for increasing levels of feed rate and grinder screen openings. On the other hand specific energy consumption increased with increasing moisture content. The highest specific energy consumption was recorded for 17.3% moisture content and 8 kg h-1 feed rate with 0.5 mm screen opening. Average particle size decreased from 1.06 to 0.39 mm with increase of moisture content and grinder screen opening. It has been observed that the average particle size was minimum at 0.5 mm screen opening and 8 kg h-1 feed rate at lower moisture content. Bond’s work index and Kick’s constant were found to increase from 8.97 to 950.92 kWh kg-1 and 0.932 to 78.851 kWh kg-1 with the increase of moisture content, feed rate and grinder screen opening, respectively. Size reduction ratio and grinding effectiveness of fenugreek seed were found to decrease from 4.11 to 1.61 and 0.0118 to 0.0018 with the increase of moisture content, feed rate and grinder screen opening, respectively. The loose and compact bulk densities varied from 219.2 to 719.4 kg m-3 and 137.3 to 736.2 kg m-3, respectively.  


Processes ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 32
Author(s):  
Waleed H. Hassoon ◽  
Dariusz Dziki ◽  
Antoni Miś ◽  
Beata Biernacka

The objective of this study was to determine the grinding characteristics of wheat with a low moisture content. Two kinds of wheat—soft spelt wheat and hard Khorasan wheat—were dried at 45 °C to reduce the moisture content from 12% to 5% (wet basis). Air drying at 45 °C and storage in a climatic chamber (45 °C, 10% relative humidity) were the methods used for grain dehydration. The grinding process was carried out using a knife mill. After grinding, the particle size distribution, average particle size and grinding energy indices were determined. In addition, the dough mixing properties of wholemeal flour dough were studied using a farinograph. It was observed that decreasing the moisture content in wheat grains from 12% to 5% made the grinding process more effective. As a result, the average particle size of the ground material was decreased. This effect was found in both soft and hard wheat. Importantly, lowering the grain moisture led to about a twofold decrease in the required grinding energy. Moreover, the flour obtained from the dried grains showed higher water absorption and higher dough stability during mixing. However, the method of grain dehydration had little or no effect on the results of the grinding process or dough properties.


Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 2008
Author(s):  
Samsul Rizal ◽  
N. I. Saharudin ◽  
N. G. Olaiya ◽  
H. P. S. Abdul Khalil ◽  
M. K. Mohamad Haafiz ◽  
...  

The degradation and mechanical properties of potential polymeric materials used for green manufacturing are significant determinants. In this study, cellulose nanofibre was prepared from Schizostachyum brachycladum bamboo and used as reinforcement in the PLA/chitosan matrix using melt extrusion and compression moulding method. The cellulose nanofibre(CNF) was isolated using supercritical carbon dioxide and high-pressure homogenisation. The isolated CNF was characterised with transmission electron microscopy (TEM), FT-IR, zeta potential and particle size analysis. The mechanical, physical, and degradation properties of the resulting biocomposite were studied with moisture content, density, thickness swelling, tensile, flexural, scanning electron microscopy, thermogravimetry, and biodegradability analysis. The TEM, FT-IR, and particle size results showed successful isolation of cellulose nanofibre using this method. The result showed that the physical, mechanical, and degradation properties of PLA/chitosan/CNF biocomposite were significantly enhanced with cellulose nanofibre. The density, thickness swelling, and moisture content increased with the addition of CNF. Also, tensile strength and modulus; flexural strength and modulus increased; while the elongation reduced. The carbon residue from the thermal degradation and the glass transition temperature of the PLA/chitosan/CNF biocomposite was observed to increase with the addition of CNF. The result showed that the biocomposite has potential for green and sustainable industrial application.


2021 ◽  
Vol 32 (2) ◽  
Author(s):  
Amir Erfan Eshratifar ◽  
David Eigen ◽  
Michael Gormish ◽  
Massoud Pedram

2020 ◽  
Vol 34 (05) ◽  
pp. 8600-8607
Author(s):  
Haiyun Peng ◽  
Lu Xu ◽  
Lidong Bing ◽  
Fei Huang ◽  
Wei Lu ◽  
...  

Target-based sentiment analysis or aspect-based sentiment analysis (ABSA) refers to addressing various sentiment analysis tasks at a fine-grained level, which includes but is not limited to aspect extraction, aspect sentiment classification, and opinion extraction. There exist many solvers of the above individual subtasks or a combination of two subtasks, and they can work together to tell a complete story, i.e. the discussed aspect, the sentiment on it, and the cause of the sentiment. However, no previous ABSA research tried to provide a complete solution in one shot. In this paper, we introduce a new subtask under ABSA, named aspect sentiment triplet extraction (ASTE). Particularly, a solver of this task needs to extract triplets (What, How, Why) from the inputs, which show WHAT the targeted aspects are, HOW their sentiment polarities are and WHY they have such polarities (i.e. opinion reasons). For instance, one triplet from “Waiters are very friendly and the pasta is simply average” could be (‘Waiters’, positive, ‘friendly’). We propose a two-stage framework to address this task. The first stage predicts what, how and why in a unified model, and then the second stage pairs up the predicted what (how) and why from the first stage to output triplets. In the experiments, our framework has set a benchmark performance in this novel triplet extraction task. Meanwhile, it outperforms a few strong baselines adapted from state-of-the-art related methods.


2017 ◽  
Vol 61 (1) ◽  
Author(s):  
Lihua Guo ◽  
Chenggang Guo ◽  
Lei Li ◽  
Qinghua Huang ◽  
Yanshan Li ◽  
...  

2008 ◽  
Vol 4 (6) ◽  
Author(s):  
Law Chung Lim ◽  
Wan Ramli Wan Daud

Advanced drying technology enables drying of rough rice and dedusting of rice husks to be carried out simultaneously in the same unit processor. This paper reports the efficiency of dedusting of rice husks in a two-stage inclined cross flow fluidized bed dryer and the drying kinetics of rough rice in a batch fluidized bed dryer as well as the conceptual design of a hybrid drying – dedusting unit processor. Experimental works had been carried out using rough rice (a Group D particle according to Geldart classification of powders) in a 2.5 m height two-stage inclined fluidized bed column of cross sectional area of 0.61m x 0.15m and a 3 m high batch fluidized bed dryer. The objectives of the study was to investigate the separation efficiency of dedusting of rice husks in the two-stage cross flow fluidized bed dryer and to study the drying kinetics of rough rice drying in the batch fluidized bed dryer. The experimental results showed that the dedusting separation efficiency at low superficial gas velocity gave unsatisfactory separation of merely 40% of rice husks. At higher superficial gas velocity, separation efficiency of rice husks as high as 93% was achieved. In addition, higher distributor inclination angle gave slightly improved separation efficiency. The drying kinetics showed that the residence time that is required to reduce the moisture content of rough rice to 18% (intermediate storage moisture content for second stage drying) is 3 minutes whereas the residence time that is required to reduce the moisture content to 13% (desirable final moisture content) is approximately 10 minutes regardless of the effect of kernel cracking. It was also found that higher drying temperatures gave higher drying rate. A conceptual design has been developed based on the results obtained in the studies. In order to maximize the heat utilization and to carry out two processes viz. dedusting and drying in one unit processor, it is suggested that drying – dedusting can be carried out in a multistage mode where drying is taken place at each stage while dedusting is taking place at the upper stage. This concept can be applied to a packed bed or a fluidized bed unit processor.


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