scholarly journals Review: Effects of wood quality and refining process on TMP pulp and paper quality

BioResources ◽  
2011 ◽  
Vol 6 (3) ◽  
pp. 3569-3584
Author(s):  
Bin Li ◽  
Haiming Li ◽  
Quanqing Zha ◽  
Rohan Bandekar ◽  
Ahmed Alsaggaf ◽  
...  

For the thermomechanical pulping (TMP) process both wood chip quality and the refining process have important effects on the resulting pulp and paper quality. Properties of wood raw material give a framework for final pulp properties. During TMP refining the specific energy consumption and refining intensity strongly impact fibre and pulp qualities. Increasing specific energy consumption benefits the development of fibres and improves their properties. However, high intensity refining tends to shorten the fibres and produces more fines content when compared with low intensity refining. This review focuses on the influence of key variables of chip qualities and the refining process on TMP pulp and paper qualities.

2011 ◽  
Vol 204-210 ◽  
pp. 2087-2092
Author(s):  
Li Rong Lei ◽  
Zhi Wen Huang ◽  
You Ming Li

Several kinds of fibre materials including waste paper, wheat straw, bamboo and hardwood pulp were refined by using medium consistency refiner (MC refiner) at pulp consistency of 6-10%, and fibre fractions classification and length distribution after refining, paper physical properties and specific energy consumption during refining were compared with the refining process by using traditional low consistency refiner (LC refiner) at pulp consistency of 3-4%. The objective of this study is to investigate the effect of pulp consistency on refining response of the fibre materials. Results show that refining at consistency of 6-10% with the MC refiners effectively preserves fibre length, and the pulp after refining contains higher proportion of long fibre fractions in comparison with the pulp refined at consistency of 3-4% with LC refiners. It is also found in the experiments that physical properties of the paper made from the pulp refined at consistency of 6-10% with the MC refiners obviously enhance, and specific energy consumption during refining reduces by 30% compared with the refining at consistency of 3-4% with LC refiners.


Author(s):  
Vivek R. Gandhewar

Among all the metal industries, the iron and steel industries are the most energy intensive sectors in India. Worldwide the use of induction furnaces in steel industries especially in foundries has increased exponentially. A great deal of research is dedicated to identify the factors that affect the performance of the furnace. It is observed that quantity of molten metal produced per batch, average time required for production per batch, electricity consumption per ton ,raw material in ratio, power supply on and off time, thickness of refractory lining are some of the crucial factors that are responsible for improving the productivity of Induction Furnace. This paper presents the results of a study where an attempt is made to optimize the specific energy consumption and alternatively productivity. The correlation between various parameters was found in order to optimize the results. To get the optimum results TOPSIS was applied .Finally, the results of the study confirm the common connotation that less specific energy consumption leads to more productivity. Academicians and practitioners could use the results as a guideline for studying effects of various induction furnace parameters


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.  


2021 ◽  
Vol 13 (10) ◽  
pp. 5617
Author(s):  
Raman Kumar ◽  
Sehijpal Singh ◽  
Ardamanbir Singh Sidhu ◽  
Catalin I. Pruncu

This paper’s persistence is to make an inclusive analysis of 268 documents about specific energy consumption (SEC) in machining operations from 2001 to 2020 in the Scopus database. A systematic approach collects information on SEC documents’ primary data; their types, publications, citations, and predictions are presented. The VOSviewer 1.1.16 and Biblioshiny 2.0 software are used for visualization analysis to show the progress standing of SEC publications. The selection criteria of documents are set for citation analysis. The ranks are assigned to the most prolific and dominant authors, sources, articles, countries, and organizations based on the total citations, number of documents, average total citation, and total link strength. The author-keywords, index-keywords, and text data content analysis has been conducted to find the hotspots and progress trend in SEC in machining operations. The most prolific and dominant article, source, author, organization, and country are Anderson et al. “Laser-assisted machining of Inconel 718 with an economic analysis”, the Int J Mach Tools Manuf, Shin Y.C., form Purdue University Singapore, and United States, respectively, based on total citations as per defined criteria. The author keywords “specific cutting energy” and “surface roughness” dominate the machining operations SEC. SEC’s implication in machining operations review and bibliometric analysis is to deliver an inclusive perception for the scholars working in this field. It is the primary paper that utilizes bibliometric research to analyze the SEC in machining operations publications expansively. It is valuable for scholars to grasp the hotspots in this field in time and help the researchers in the SEC exploration arena rapidly comprehend the expansion status and trend.


Membranes ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 173
Author(s):  
Abdeljalil Chougradi ◽  
François Zaviska ◽  
Ahmed Abed ◽  
Jérôme Harmand ◽  
Jamal-Eddine Jellal ◽  
...  

As world demand for clean water increases, reverse osmosis (RO) desalination has emerged as an attractive solution. Continuous RO is the most used desalination technology today. However, a new generation of configurations, working in unsteady-state feed concentration and pressure, have gained more attention recently, including the batch RO process. Our work presents a mathematical modeling for batch RO that offers the possibility of monitoring all variables of the process, including specific energy consumption, as a function of time and the recovery ratio. Validation is achieved by comparison with data from the experimental set-up and an existing model in the literature. Energetic comparison with continuous RO processes confirms that batch RO can be more energy efficient than can continuous RO, especially at a higher recovery ratio. It used, at recovery, 31% less energy for seawater and 19% less energy for brackish water. Modeling also proves that the batch RO process does not have to function under constant flux to deliver good energetic performance. In fact, under a linear pressure profile, batch RO can still deliver better energetic performance than can a continuous configuration. The parameters analysis shows that salinity, pump and energy recovery devices efficiencies are directly linked to the energy demand. While increasing feed volume has a limited effect after a certain volume due to dilution, it also shows, interestingly, a recovery ratio interval in which feed volume does not affect specific energy consumption.


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