scholarly journals Review: Reduction of energy consumption in TMP refining through mechanical pre-treatment of wood chips

2010 ◽  
Vol 25 (2) ◽  
pp. 156-161 ◽  
Author(s):  
Dmitri Gorski ◽  
Jan Hill ◽  
Per Engstrand ◽  
Lars Johansson
Keyword(s):  
Energy Consumption ◽  
Pilot Scale ◽  
High Ratio ◽  
Wood Chips ◽  
Chip Size ◽  
Weak Points ◽  
Pulp Properties ◽  
Pre Treatment ◽  
Reduction Of Energy Consumption

Abstract This review covers the effect of mechanical pre-treatment of wood chips on the energy consumption in refining and the quality of pulp. To understand the mechanisms of mechanical pre-treatment, a short description of relevant refining theory and reported effects of pre-treatment on wood morphology is given. Mechanical pre-treatment offers a chance to utilize the energy needed to defibrate chips in a more efficient way, minimizing the cyclic elastic deformations which are the main defibration mechanism in refining. Studies of fibre morphology indicate that compressive pretreatment mechanically introduces favorable weak points in the S1 and S2 fibre walls where defibration proceeds easier upon subsequent refining. Published results which cover the effect of the pretreatment on energy consumption and pulp properties are reviewed. Energy reduction of between 10% and 30% is reported in the literature. High ratio of volumetric compression is necessary. Pressurized conditions are required to ensure that the fibres are not damaged during the pre-treatment. Other effects of compressive pretreatment include a more uniform chip size and moisture content, better penetration of chemicals and removal of extractives from the chips. A list of equipment used for chip pre-compression is provided together with published results of pilot-scale and mill-scale operation.

scholarly journals Design of a Traffic-Aware Governor for Green Routers

2014 ◽  
Vol 2014 ◽  
pp. 1-12
Author(s):  
Alfio Lombardo ◽  
Vincenzo Riccobene ◽  
Giovanni Schembra
Keyword(s):  
Quality Of Service ◽  
Energy Consumption ◽  
Energy Saving ◽  
Analytical Model ◽  
Case Scenario ◽  
Proposed Model ◽  
Traffic Impacts ◽  
Reduction Of Energy Consumption

Today the reduction of energy consumption in telecommunications networks is one of the main goals to be pursued by manufacturers and researchers. In this context, the paper focuses on routers that achieve energy saving by applying the frequency scaling approach. The target is to propose an analytical model to support designers in choosing the main configuration parameters of the Router Governor in order to meet Quality of Service (QoS) requirements while maximizing energy saving gain. More specifically, the model is used to evaluate the input traffic impacts on the choice of the active router clock frequencies and on the overall green router performance. A case study based on the open NetFPGA reference router is considered to show how the proposed model can be easily applied to a real case scenario.

scholarly journals Harmonics and Reduction of Energy Consumption in Lighting Systems by Using LED Lamps

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3169 ◽  
Author(s):  
Natthanon Phannil ◽  
Chaiyan Jettanasen ◽  
Atthapol Ngaopitakkul
Keyword(s):  
Energy Consumption ◽  
Power Quality ◽  
Power Factor ◽  
Energy Savings ◽  
Light Emitting Diode ◽  
Total Power ◽  
Increase Energy Efficiency ◽  
Lighting Systems ◽  
Reduction Of Energy Consumption

This paper proposes the study and analysis of harmonics, energy consumption and power quality of light emitting diode (LED) lamps equipped in building lighting systems. LED lamps with external (LED MR16) and internal (LED light bulb) drivers are investigated using an experimental setup to compare the results. The power quality of both LED lamps is studied by using a power quality meter to measure the generated harmonic currents from various case studies. The case study is divided into four major cases: one LED lamp is turned on with one driver, two LED lamps are turned on using the two drivers, eight LED lamps are turned on with one driver, and eight LED lamps are turned on with the eight drivers. As harmonics are related to total power factor (PF), which affects the energy savings of the building, hence, a filtering circuit to reduce harmonic current has been designed and implemented to improve power quality and/or power factor of the system. The different cases of harmonic filter insertion at the input of an LED lamp’s driver are discussed and then compared with a lighting standard to show the effectiveness of the passive filtering technique used in the studied system. In addition, the obtained result can be applied to both newly built and retrofitted buildings that aim to use LED technology to increase energy efficiency and decrease energy costs, and could be a helpful guide for end-users and manufacturers in addressing and developing LED issues.

Properties of wood chips for thermomechanical pulp (TMP) production as a function of spout angle

Holzforschung ◽  
2011 ◽  
Vol 65 (6) ◽  
pp. 805-809 ◽  
Author(s):  
Lisbeth M. Hellström ◽  
Per A. Gradin ◽  
Per Engstrand ◽  
Øyvind Gregersen
Keyword(s):  
Energy Consumption ◽  
Patent Application ◽  
Specific Energy Consumption ◽  
Electrical Energy ◽  
Wood Chips ◽  
Thermomechanical Pulp ◽  
Spruce Wood ◽  
Cutting Rate ◽  
Pulp Properties ◽  
The Impact

Abstract Spruce wood chips were produced under well-controlled conditions in a laboratory wood chipper at spout angles of 30°, 40°, and 50° at a cutting rate of 20 m s-1 and with a nominal chip length of 25 mm. The chips were then refined under thermomechanical pulp (TMP) conditions in a pilot refiner plant. The pulp properties such as freeness, average fiber length, and shives content were determined and evaluated as a function of specific energy consumption. For a first stage refining and for a freeness value of 350 ml, a decrease in specific electrical energy consumption could be achieved by performing the wood chipping at a spout angle of 50° as compared to 30° which is the spout angle commonly used. A patent application regarding this method has been filed and is pending. It is realized that a freeness value is not directly indicative of any quality measure, such as, for example tensile index and light scattering coefficient but the obtained results can be interpreted to be promising. Further studies are needed regarding the impact of the modified chipping process.

Pressurised compressive chip pre-treatment of Norway spruce with a mill scale Impressafiner

2012 ◽  
Vol 27 (1) ◽  
pp. 56-62 ◽  
Author(s):  
Erik Nelsson ◽  
Christer Sandberg ◽  
Lars Hildén ◽  
Geoffrey Daniel
Keyword(s):  
Energy Consumption ◽  
Specific Energy ◽  
Specific Energy Consumption ◽  
Paper Mill ◽  
Pilot Scale ◽  
Thermomechanical Pulp ◽  
Extractive Content ◽  
Mill Scale ◽  
Pre Treatment ◽  
Longitudinal Fibre

Abstract Mill scale trials were performed to evaluate pressurised compressive chip pre-treatment with the Impressafiner installed in one of the thermomechanical pulp lines at Braviken paper mill (Holmen Paper AB). The aim of the study was to determine if earlier reported effects of the Impressafiner pre-treatment on spruce chips from pilot scale trials (i.e. energy reduction and extractives removal) could also be attained with the mill scale Impressafiner. The mill scale Impressafiner pre-treatment resulted in partial disintegration of chips into a material consisting of fragmented chips with cracks running along the longitudinal fibre axis. Splits or evidence for weaknesses were observed between the primary and secondary fibre walls of pre-treated chips. An increase in water uptake for pre-treated chips was also observed. The extractive content was reduced by up to 24% for pulps produced with pre-treated chips compared to pulps from untreated chips. Pulp produced from pre-treated chips had higher tensile- and tear indices, elongation and light scattering and lower freeness compared to pulps from untreated chips produced with the same total specific energy consumption. The total specific energy needed to reach a tensile index of 47 Nm/g was reduced by 120 kWh/bone dry ton (6%) with Impressafiner pre-treatment. A smaller refiner plate gap was needed to reach the same specific energy consumption for pre-treated chips compared to untreated chips.

scholarly journals Analysis of Energy Consumption and Optimization Techniques for Writing Energy-Efficient Code

Electronics ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 1192 ◽  
Author(s):  
Javier Corral-García ◽  
Felipe Lemus-Prieto ◽  
José-Luis González-Sánchez and Miguel-Ángel Pérez-Toledano
Keyword(s):  
Energy Consumption ◽  
Energy Efficient ◽  
Optimization Techniques ◽  
Raspberry Pi ◽  
Software Systems ◽  
Major Subject ◽  
Efficient Code ◽  
Reduction Of Energy Consumption ◽  
The Internet Of Things

The unprecedented growth of connected devices, together with the remarkable convergence of a wide variety of technologies, have led to an exponential increase in the services that the internet of things (IoT) can offer, all aimed at improving quality of life. Consequently, in order to meet the numerous challenges this produces, the IoT has become a major subject of research. One of these challenges is the reduction of energy consumption given the significant limitations of some devices. In addition, although the search for energy efficiency was initially focused on hardware, it has become a concern for software developers too. In fact, it has become an intense area of research with the principal objective of analyzing and optimizing the energy consumption of software systems. This research analyzes the energy saving that can be achieved when using a broad set of techniques for writing energy-efficient code for Raspberry Pi devices. It also demonstrates that programmers can save more energy if they apply the proposed techniques manually than when relying on other automatic optimization options offered by the GNU compiler collection (GCC). Thus, it is important that programmers are aware of the significant impact these techniques can have on an application’s energy consumption.

scholarly journals Techno-Economic Modeling of Biomass Pellet Routes: Feasibility in Italy

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1636 ◽  
Author(s):  
Antonio Pantaleo ◽  
Mauro Villarini ◽  
Andrea Colantoni ◽  
Maurizio Carlini ◽  
Francesco Santoro ◽  
...  
Keyword(s):  
Moisture Content ◽  
Production Costs ◽  
Wood Chips ◽  
High Moisture Content ◽  
High Moisture ◽  
Production Chain ◽  
Wood Processing ◽  
Pellet Production ◽  
Pre Treatment

Wood and agricultural biomass pellets boost the potential as bio-fuels toward power production in tertiary and residential sectors. The production of pellets, however, is a multi-stage process where the supply-processing phases and the overall energy input strongly depend on the characteristics of the input biomass. In this paper, we describe the key features of the market for pellets in Italy, including national production and consumption data, production costs and prices, the available energy conversion systems, and the current regulatory issues. Moreover, we outline the main technical, economic, and end-user barriers that should be addressed in order to foster the growth of Italian pellet production. Additionally, we propose a methodology to evaluate the profitability of the pellet production chain, by assessing the investment and operation costs as a function of the quality of the raw biomass. The approach is applied to a real case study of a small firm producing wooden frames along with dry wood chips as the main by-product, which can be utilized subsequently for pellet production. Moreover, in order to optimize the size of the pellet production plant, further biomass was purchased from the market, including wood pruning and agricultural residues, wood chips from forestry, and uncontaminated residues of wood processing firms. A sensitivity analysis of the main technical and economic parameters (including the cost and quality of raw material, pellet market value, investment and operational costs, and plant lifetime) indicated that the biomass market price considerably affects the profitability of pellet production plants, particularly where the biomass has a high moisture content. Therefore, a 20% increase in the price of biomass with a high moisture content leads to a 60% fall in profitability index, turning it into negative one. This is due in particular to the costs of pre-treatment and drying of biomass, as well as to the lower energy content of wet biomass. As a result, the use of forestry residues with high moisture and high ash content, high costs of collection/transport, and high costs of pre-treatment and drying is not financially competitive.

scholarly journals Energy and Quality Aspects of Freeze-Drying Preceded by Traditional and Novel Pre-Treatment Methods as Exemplified by Red Bell Pepper

2021 ◽  
Vol 13 (4) ◽  
pp. 2035
Author(s):  
Katarzyna Rybak ◽  
Oleksii Parniakov ◽  
Katarzyna Samborska ◽  
Artur Wiktor ◽  
Dorota Witrowa-Rajchert ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Freeze Drying ◽  
Bell Pepper ◽  
Drying Process ◽  
Drying Time ◽  
Statistical Point ◽  
Quality Aspects ◽  
Bell Peppers ◽  
Pre Treatment

Freeze-drying is one of the most expensive and most energy intensive processes applied in food technology. Therefore, there have been significant efforts to reduce the freeze-drying time and decrease its energy consumption. The aim of this work was to analyze the effect of pulsed electric field (PEF), ultrasound (US), and hybrid treatment (PEF-US) and compare them with the effect of blanching (BL) on the freeze-drying kinetics, energy consumption, greenhouse gasses emission, and physical quality of the product. The freeze-drying process was applied to red bell peppers after pretreatment operations. Results showed that application of BL, PEF, US, or PEF-US reduces freeze-drying time and decreases energy consumption. Among the tested methods, the combination of PEF performed at 1 kJ/kg and US was the most effective in reduction of greenhouse gas emission. BL samples exhibited the highest porosity, but from a statistical point of view, most of the PEF-US treated materials did not differ from it. The smallest color changes were noted for US pre-treated bell peppers (ΔE = 9.4), whereas BL, PEF, and PEF-US material was characterized by ΔE of 15.2–28.5. Performed research indicates the application of pre-treatment may improve the sustainability of freeze-drying process and quality of freeze-dried bell pepper.

China: "A Bee Has a Stripy Back, but No One Can Call It a Tiger"

2003 ◽  
pp. 61-75
Author(s):  
V. Guelbras
Keyword(s):  
Energy Consumption ◽  
Gdp Growth ◽  
International Demand ◽  
Real Size ◽  
Rates Of Growth

The article is devoted to verification of the Chinese GDP data. The author compares the rates of GDP growth with the rates of growth of energy consumption, transport turnover of goods, and numbers of projected and constructed objects in 1980-2000. The former was significantly lower during that period. He also analyses the level of using productive capacities and the quality of production. About 25-30% of industrial productive capacities are not used because there is neither national nor international demand for their low quality goods. The main conclusion of the article is that the Chinese GDP real size is about 20-30% less than official releases.

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