Electric energy consumption in the cotton textile processing stages

Electric energy is one of the primary energy sources consumpted in cotton textile processing. Current energy cost rate is reported about 8–10% in the total production cost of an ordinary textile product manufactured in Turkey. Significantly important share of this energy cost is electric energy. The aim of this paper was to investigate unit electric energy consumption of cotton textile processing stages using real-time measurements method. Actual and estimated Specific Energy Consumption (SEC) values for electric energy was calculated in the cotton textile processing stages of spinning, warping–sizing, weaving, wet processing and clothing manufacturing. Actual electric energy consumption data are gathered from monthly records of the involved plant managements. Estimated electric energy consumption data is gathered through on-site measurement. Actual and estimated electric energy consumption data and monthly production quantities of the corresponding months are used to facilitate specific electric energy consumption of the plants. It is found that actual electric energy consumption amount per unit textile product is higher than the estimated electric energy consumption amount per unit textile product of each involved textile processing stages.     

An analysis of energy use and input costs for cotton production in Turkey

The aim of this study was to determine direct input energy and indirect energy in per hectare in cotton production and compare with input costs. The study also sought to analyse the effect of farm size. Data were collected from sixty five farmers using a face to face questionnaire. The sample farms were selected through a stratified random sampling technique. The results revealed that cotton production consumed a total of 49.73 GJha⁻¹ of which diesel energy consumption was 31.1% followed by fertilizer and machinery energy. Output–input energy ratio and energy productivity were 0.74 and 0.06 kg of cotton MJ⁻¹, respectively. Cost analysis showed that net return per kilogram of seed cotton was insufficient to cover costs of production in the research area. The most important cost items were labour, machinery costs, land rent and pesticide costs. Large farms were more successful in energy productivity, use efficiency and economic performance. It was concluded that energy management at farm level could be improved to give more efficient and economic use of energy.     

Kinetics of cotton cellulose hydrolysis using concentrated acid and fermentative hydrogen production from hydrolysate

The kinetics of cotton cellulose hydrolysis using concentrated sulfuric acid and the performance of fermentative hydrogen production from the hydrolysate in the batch system was carried out in this study. Effects of sulfuric acid concentrations, cotton cellulose concentrations and operating temperatures on the cotton cellulose hydrolysis were investigated. It was found that cotton cellulose can dissolve completely in sulfuric acid concentration above 55% (by volume) at room temperature. The reduced sugar yields were varied from 64.3 to 73.9% (g R-sugar/g cotton cellulose) with the initial cotton cellulose concentrations of 30-70 g/L at a temperature of 40 °C.The reduced sugar concentrations and the initial pH of biohydrogen production were investigated at 37 °C. It was found that the optimal values of the hydrogen yield and substrate utilization were 0.95 mol H₂/mol R-sugar and 98% with an initial pH of 8.2, when substrate concentration was fixed at 20 g R-sugar/L. The maximum hydrogen yield was 0.99 mol H₂/mol R-sugar at a substrate concentration of 15 g R-sugar/L. Using the Gompertz Equation Model simulation, the maximum hydrogen production rate was 253 mL H₂/h/L at a substrate of 30 g/L and initial pH of 8.4.     

Bioenergy production from cotton straws using different pretreatment methods

Cotton straws are one of the most produced agricultural wastes in Turkey and getting attention by not being consumed as animal feed or an industrial stock and having a huge potential in clean energy production. In this study, different pretreatment methods for the conversion of cotton straw to sugar then biohydrogen and biomethane production from cotton straw were examined. The energy potential of cotton straw in case of an evaluation of these biomass residues was also determined using fuel cell technology. Acid pretreatment provided the highest yield in biogas formation as well as sugar extraction from the raw sample. The highest biohydrogen and biomethane production were obtained as 33 mL H₂/g VS and 83 mL CH₄/g VS, respectively. Concomitantly, the maximum power peaks in PEM fuel cell studies were observed as 0.45 W/cm² and 0.23 W/cm² with current densities of 1.086 A/cm² and 0.522 A/cm² when the fuel cell was fed with pure H₂ and biogas, respectively. This suggested that acid pretreatment is more suitable for cotton straw management in sustainable and renewable ways and the results demonstrated that PEM fuel cell is a promising clean technology for energy generation from cotton straw.     

Effects of climate change on biomass production and substitution in north-central Sweden

In this study we estimate the effects of climate change on forest production in north-central Sweden, as well as the potential climate change mitigation feedback effects of the resulting increased carbon stock and forest product use. Our results show that an average regional temperature rise of 4 °C over the next 100 years may increase annual forest production by 33% and potential annual harvest by 32%, compared to a reference case without climate change. This increased biomass production, if used to substitute fossil fuels and energy-intensive materials, can result in a significant net carbon emission reduction. We find that carbon stock in forest biomass, forest soils, and wood products also increase, but this effect is less significant than biomass substitution. A total net reduction in carbon emissions of up to 104 Tg of carbon can occur over 100 years, depending on harvest level and reference fossil fuel.     

Impact of inter-fuel substitution on energy intensity in Ghana

Energy intensity and elasticity, together with inter-fuel substitution are key issues in the current development stage of Ghana. Translog production and ridge regression are applied for studying these issues with a data range of 2000–2015. The current energy dynamics reveal the expected inverse relationship: higher energy intensity and lower elasticity with economic growth. There are evidences of energy-economic challenges: high energy cost, inefficiency and backfire rebound effect. The implications are higher energy losses in the system, more consumption of lower-quality energy together with low energy technology innovation. Energy is wasted and directly not productive with economic activities. It is observed further that the higher energy intensity invariably increases CO₂ emission because approximately 95% of total energy is derived from hydrocarbons and biomass. An inter-fuel substitution future scenario design was further conducted and the results were positive with growth, lower energy intensity, and improved energy efficiency. Therefore, government and energy policymakers should improve energy efficiency, cost, and productiveness. That is, they should change energy compositions and augment energy technology innovation, thus, increasing renewable share to 15% by 2026, reducing wood and charcoal by about 69%, and increasing natural gas to about 776%. Energy policymakers should enhance the installation of smart energy, cloud energy solution, tokenization of energy system and storage.     

通用型耗能设备节能监测与分析

南京市80家重点用能单位334台通用型耗能设备(变压器、风机、水泵)节能监测数据显示,变压器、风机、水泵的监测合格率分别为73.94%、41.18%、62.22%;变压器主要监测指标(负载系数、用电体系功率因数、日负荷率)平均值分别为0.42、0.93、82.97%;风机主要监测指标(电动机负载率、风机机组电能利用率)平均值分别为68.45%、60.35%;水泵主要监测指标(电动机负载率、泵类及效率、泵类及液体输送系统效率)平均值分别为84.25%、66.70%、59.94%。通过监测样本分析,发现企业在耗能设备的使用和管理上普遍存在设备选型偏大,与生产需求不匹配;计量器具配备率不达标;生产负荷配置不合理;对二级变压器重视不够;存在国家明令淘汰的设备等问题。建议企业尽快淘汰落后设备,使用高效设备;及早实施节能技改,降低能源消耗;进一步完善计量器具配备,提高管理水平。     

Energy consumption pattern of wheat production in India

Wheat covers approximately 25% of the total global area devoted to by cereal crops. Wheat production needs to be augmented to meet the growing demand. The amount of wheat produced is a direct function of energy inputs. Wheat is produced using energy sources ranging from human and animal power to power of heavy machinery. The basic purpose of the present study is to optimize energy use patterns of different wheat growing regions (Western Rajasthan, Punjab, Uttar Pradesh (UP) and Madhya Pradesh (MP)) of the Country in order to maximize yield. Villages and farmers were randomly selected for collecting data on energy requirement of wheat in Western Rajasthan and data for other regions were taken from reports. Wheat consumed maximum energy input in Western Rajasthan because light textured soil required frequent irrigation. Punjab and UP recorded maximum output–input energy ratio, 5.2 and 4.2, respectively. Punjab recorded minimum specific energy of 4.6 MJ/kg followed by UP (6.0 MJ/kg). Further, Punjab occupied the first place among all the States with 3334.8 kg/ha average yield, which is about 31% higher than the average productivity (2550.5 kg/ha) of the regions considered under the study. However, use of commercial energy was found maximum in Punjab (91.7%). Therefore, by ensuring optimal energy inputs in different regions wheat production in the Country could be increased.     

能量因数与节能潜力评估

介绍了能量因数的概念以及应用单位能量因数能耗如何评价一个炼油厂的用能水平和不同炼油厂之间的能耗的对比.     

Energetic and exergetic aspects of cotton stalk production in establishing energy policies

Exergy analysis is important for energy resource utilization, because exergy, which is a way to a sustainable future, is a part of the energy analysis. Exergy analysis starts to play a role in several countries in developing energy policy. This paper deals with the exergetic assessment of the cotton stalk (CS) production. In this regard, Turkey, which is one of the eight countries producing 85% of the world's cotton, is given as an application country first. Energy and exergy relations used in the analysis are then presented. Finally, the Turkish CS production in 2003 is evaluated using energy and exergy analyses method, while the results obtained are discussed. The values for the net energy and exergy gained are obtained to be about 49,146 and 59,395 MJ/ha, respectively. Turkey's total energy and exergy are estimated to be 75.45 and 81.87 PJ. It may be concluded that this amount of energy is equal to 7.77% and 2.38% of Turkey's primary energy production and consumption in the same year, respectively. The overall mean energy and exergy efficiencies of the cotton production in the year studied are found to be 33.06% and 33.12%, respectively. It is also expected that the results of this study will be helpful in developing highly applicable and productive planning for energy policies.     

Energy production trend in Iran and its effect on sustainable development

The purpose of this study is to review the energy production trend from different energy resources in recent decades and its effect on sustainable energy production as one of the basic axis of sustainable development in Iran.Ninety nine percent of energy production in Iran comes from oil & gas and only 1% from renewable energy resources. Since Iran has very rich fossil energy resources, little attention has been paid to explore alternative ways of energy production. Majority of country's income is from oil & gas which put extra pressure on its natural resources. Continuing with the existing trend may lead to a path away from the goals of sustainable development, set for the country. Therefore, the sustainability study should be of interest to decision-makers.     

美国克恩河油田用能结构调整对中国油田自用油替代的启发

油田自用原油替代是降低石油开采成本,缓解我国石油短缺现状的主要方法之一。本文介绍了克恩河油田用能调整的过程及所起的作用,并分析了我国油田生产过程中利用天然气、煤、石油焦、可再生能源进行自用油替代所具有的优势。     

我国建筑能耗数据现状和能耗统计问题分析

"十二五"节能工作的重点将进一步转向建筑领域,而深化建筑节能工作需要建筑能耗数据的有力支撑。通过调研我国建筑能耗数据现状,发现尚未有权威的能够满足建筑节能分析需要的能耗数据,现有的能源消费统计方法也制约了建筑能耗统计数据的科学获得。本文回顾了当前建筑能耗数据的主要获得方法,分析了建筑能耗统计中存在的主要问题,提出了完善建筑能耗统计的初步建议。     

An economic analysis of the production of hydrogen from wind-generated electricity for use in transport applications

Wind-generated electricity is often considered a particularly promising option for producing hydrogen from renewable energy sources. However, the economic performances of such systems generally remain unclear because of unspecified or favorable assumptions and operating conditions. The aim of this paper is to clarify these conditions by examining how the hydrogen produced is used. The analysis that has been conducted in the framework of the HyFrance 3 project concerns hydrogen for transport applications. Different technical systems are considered such as motorway hydrogen filling stations, Hythane®-fueled buses or second-generation biofuels production, which present contrasted hydrogen use characteristics. This analysis reveals considerable variations in hydrogen production costs depending on the demand profiles concerned, with the most favorable configurations being those in which storage systems are kept to a minimum.     

Effects of Fe0 and Ni0 nanoparticles on hydrogen production from cotton stalk hydrolysate using Klebsiella sp. WL1316: Evaluation of size and concentration of the nanoparticles

Fe⁰ and Ni⁰ nanoparticles (NPs) of certain size were synthesized and added to the hydrogen production system from cotton stalk hydrolysate using Klebsiella sp. WL1316. Fe⁰ and Ni⁰ NPs with a size of 50 nm at all concentrations effectively improve hydrogen production during mid to late fermentation stages; particularly, the highest daily hydrogen production obtained following treatment with 50 nm Fe⁰ NPs at 30 mg/L fermented for 96 h significantly increased by 61% comparing to the control treatment. The reducing sugar consumption in cotton stalk hydrolysate and ΔOD₆₀₀ could be improved to some extent by Fe⁰ and Ni⁰ NPs supplementation. Addition of Fe⁰ or Ni⁰ NPs of 50 nm at a concentration of 30 mg/L resulted in enhanced cumulative hydrogen production with improvement of hydrogen yield reached higher than 20%, and the values of Y(H₂/S) were all higher than 90 mL/g _substrate, reflecting good hydrogen production and substrate consumption. The analysis of the main soluble metabolites profile revealed that supplementation with Fe⁰ and Ni⁰ NPs of suitable size and concentration may decrease the metabolic flux in the competitive branch of hydrogen production and increase the metabolic flux of the key node that leads to hydrogen generation, thus promoting biohydrogen synthesis.     

Energy Planning in Small Municipalities Based on Monitoring Results and Demand Side Management

Recent estimates state that the European Union is on course to achieve only half of the 20% energy consumption reduction target by 2020. As the first governmental stakeholders involved in the implementation of energy saving initiatives, municipalities play a strategic role in the energy planning process. This paper focuses on establishment of an energy planning methodology for small municipalities with numbers of inhabitants in range of 1,000-10,000 which often face common problems associated with low efficient district heat supply systems and decreasing energy consumption in buildings. Particular attention is paid to DSM （demand side management） activities. DSM scheme includes legislative and financial flows with small investments from municipality side. Based on increased information and motivation it promotes reduction of energy consumption in all kinds of buildings. Practical experience has shown that application of DSM measures allows achieving 20% energy savings in municipal buildings during the first year.     

耐火材料节能化研究

针对耐火材料行业存在的高能耗问题,介绍了在节能降耗方面所做的一些工作.节能不仅要从耐火材料组织结构入手,通过降低材料热导率减少散热损失,还要考虑工业用窑炉的技术改进和废气余热利用、材料制备过程中工艺条件的选择与新工艺新技术的开发应用、废旧耐火材料的再资源化等方面,同时利用系统统筹方法,通过优化管理和参数匹配,并辅以微机管理技术对耐火材料生产过程实行最佳配置,以达到最大程度节约能量,保护环境的目的.     

Energy crop production costs in the EU

The objective of this study was to calculate indicative ranges of production costs and assess the main sources of cost for a number of energy crops, both annual and perennial, on a regional level in Europe. The production costs were calculated in terms of the economic compensation required by the farmer in order to grow the crop, and therefore include not only the cost of cultivation, but also the costs of land and risk, which are often omitted in production cost calculations. The cost of land was calculated as the opportunity cost based on the production of cereals. Thus, higher food prices lead to higher land costs, which in turn lead to higher energy crop production costs. The analysis was performed for three cases with different assumptions concerning yields and production cost reductions resulting from scale (total cultivation area in the region), and learning effects. The calculated energy crop production costs were found to be consistently lowest for short-rotation coppice (SRC) crops and highest for annual straw crops. The production costs of SRC crops were calculated to be about 4–5 € GJ⁻¹ under present conditions and 3–4 € GJ⁻¹ under improved future conditions. The production costs for perennial grasses were calculated to be about 6–7 € GJ⁻¹ and 5–6 € GJ⁻¹ under present and improved future conditions, respectively. The production costs for annual straw crops were estimated to be 6–8 € GJ⁻¹ under present conditions with small potential for cost reductions in the future.     

Energy production from biogas in the Italian countryside: Policies and organizational models

In recent years, Italy has witnessed a proliferation of agricultural biogas plants. This article argues that institutional factors have played an important role in their diffusion. It describes the state and evolution of agricultural biogas in Italy, and then investigates the extent to which institutional pressures have been influential in shaping organizational models of biogas production. It finds that the dominance of one particular organizational model is the result of an isomorphic process in which a monopolistic market, legal structures, and subsidies play a role. The prevalence of this organizational model, however, does not lead to the effective use of biogas production, and furthermore it results in low environmental efficiency. For a more sustainable development of bioenergy, Italian policy-makers should reform the existing institutional framework by reorganizing subsidies, liberalizing the management of gas grids, and involving farmers in local projects.     

Energy and exergy analyses of sugar production stages

This paper presents the energy and exergy analyses of sugar production stages by using the operational data from Bor Sugar Plant, Turkey. For these purposes, all stages of sugar production, considered as a steady-state open thermodynamic system, were analysed by employing the first and second law of thermodynamics. In this regard, the first and second law efficiencies, the magnitude and place of exergy losses in these production stages were estimated and discussed in detail. It was concluded that the exergy loses took place mostly during the sherbet production process (η_I,sp=96.8% η_II,sp=49.3%) because of the irreversibility in the sub-operation stages, which are vapour production, circulation sherbet mixing and bagasse compression. Therefore, it is generally suggested that the irreversibility, mostly stem from the finite temperature differences at the production stages, should be reduced to conduct more productively the sugar production process. Copyright © 2003 John Wiley & Sons, Ltd.