Life cycle inventory for base metal ingots production in Japan including mining and mineral processing processes by cost estimating system database

CO2 emission levels of copper and zinc mines from which Japanese smelters import ore concentrates into Japan, were estimated by using a database called MLED. Eleven copper mines selected from data availability of mine site covered 84% of the total imported concentrates. Adding inventories of sea transportation and smelting processes to mine development process, total CO2 emission level for copper and zinc ingots produced in Japan were calculated. The results show that the emission share of mining and mineral processing processes for each mine is indicated around 30%-70% of total emission for ingots, which implies the importance of including the mining activities to the inventory of upper stream products.     

LCI (Life cycle inventory) analysis of fuels and electricity generation in Singapore

This article offers a unique three-stage approach in LCI analysis for generating the environmental profile of electricity generation in Singapore. The first stage focuses on fuels delivered to Singapore, next on electricity generated from various types of power production plants. The third stage integrates the entire life cycle study. The final gate-to-gate results show that the total CO₂ emissions from the national grid are 455.6 kg CO₂ per MWh without any loss in transmission and 467.0 kg CO₂ per MWh with 2.5% losses. The results for the entire cradle-to-gate energy production are: 586.3 kg CO₂ per MWh without considering any losses and 601.0 kg CO₂ per MWh with 2.5% transmission loss. For the rest of the LCI, the cradle-to-gate results (per MWh) are kg 0.19 CO (carbon monoxide), 0.06 kg N₂O (nitrous oxide), 1.94–1.99 kg NO_x (nitrogen oxides), 2.94–3.01 kg SO_x (sulphur oxides), 0.064–0.066 kg VOC (volatile organic compounds) and 0.078–0.080 kg PM (particulate matters). From gate-to-gate, the results are 0.12 kg CO, 0.0016 kg N₂O, 1.42–1.46 kg NO_x, 2.56–2.62 kg SO_x, 0.033–0.034 kg VOC and 0.067–0.069 kg PM. Emissions of CO₂ from energy generation, climate change mitigation and policies for energy security are also discussed.     

A newly developed life cycle inventory (LCI) database for commonly used structural steel components

The use of steel within the construction sector has enabled the delivery of larger-volume and more complex-shaped structures, while life cycle assessment (LCA) has been introduced as a pro-active design tool to ensure their sustainability. As LCA efficiency greatly depends on the life cycle inventory (LCI) data used, it is the purpose of the current research to present detailed structural steel LCI data and thus increase environmental benefits deriving from the effective use of LCA within construction. Hot-rolled structural steel members were chosen as the research starting point and the necessary information was provided by the leading structural steel manufacturer in Greece. Results include a list of environmental inputs and outputs, which can be used within relevant LCA studies and environmental impact assessment. Critical issues hindering the use of LCA were identified, along with the most environmentally damaging production stages and environmental categories mainly burdened. A new methodology for assessment results comparison was also applied.     

桥梁生命周期环境影响评价研究

为了量化评价桥梁的综合环境影响,提出了桥梁生命周期环境影响评价方法。分析了在桥梁的设计、原材料的生产加工、现场的施工、桥梁的运营和维护、桥梁的废弃这5个阶段带来的综合环境影响。应用该方法对武汉市南太子湖大桥生命周期环境影响进行分析评价。结果表明,固体废弃物在建筑材料生产过程和桥梁施工过程中的环境影响最大,车辆排放CO2而导致的全球变暖在桥梁运营维护过程中环境影响显著。该结果可作为桥梁生命周期环境影响评价的基础数据,用于桥梁工程环境影响综合评价。     

基于光纤传感的边坡工程监测技术

传统的边坡监测技术存在着精度低、耐久性差、难以实现集成等缺陷。针对边坡工程特点,探讨了光纤光栅、布里渊光时域分析和低相干干涉等光纤传感技术在现场监测的应用。根据不同的工程需要,结合这三种技术建立边坡监测系统,可用于对边坡位移和边坡支护结构的应力、应变进行自动化监测。在详细论述了光纤传感技术的基本原理、适用场合和系统架构的基础上,以香港一个公路边坡加固工程为例,简述了光纤传感技术现场应用时的仪器安装、数据采集与分析等工作。     

基于PM方法的材料绿色度LCI评价

总结国内外材料绿色度评价的方法中存在的3个突出问题,即全生命周期边界、评价数据完备性和适用性、评价的不确定性问题,提出专家群议(PanelMethod,PM)的概念和初步的适合国内情况的生命周期列表(LCI)模型,由此构成实用绿色度评价LCI方法,讨论其实现及应用模式。     

高压变频调速技术在高炉鼓风机拖动系统中的应用

结合唐钢中厚板厂GE22MW高炉风机拖动系统和唐钢铁厂南区3200m^3高炉SIEMENS46MW风机拖动系统的安装调试运行情况,介绍了LCI型电流源变频器的系统组成和工作原理,重点分析了高压变频调速技术在风机负载控制系统中的应用,展望了同步电动机在高炉鼓风机拖动系统中的应用前景。     

LCI驱动同步电机调速系统中转矩脉动的工程计算方法研究

LCI(Load Commutated Inverter)驱动的同步电机调速系统在大容量的调速场合仍有着广泛的应用,而谐波电流引起的脉动转矩是这类系统中不可忽视的一个问题.在计算脉动转矩时,传统的时域方法存在着计算速度慢,收敛困难,不易得到转矩的频谱分布等缺点.本文提出一种计算LCI驱动同步电机调速系统脉动转矩的工程方法,从频域的角度出发,应用开关函数调制理论建立了晶闸管三相桥及整个六脉渡LCI驱动同步电机调速系统的数学模型.基于该模型可以求得系统中各次电流谐波的精确值,进而可以求出电磁转矩及其频谱分布.针对一般的调速系统,对上述模型进行了简化,保证了系统精度,并提高了运算速度.计算结果证明该方法与传统时域方法相比,具有很高的精度,并可以大大提高计算速度.     

Energy in chemical manufacturing processes: gate‐to‐gate information for life cycle assessment

Gate‐to‐gate process energy for 86 chemical manufacturing processes is presented. The estimation of the process energy follows design‐based methodology. Results show that the gate‐to‐gate process energy for half of organic chemicals ranges from 0 to 4 MJ per kg, and for half of inorganic chemicals ranges from ?1 to 3 MJ per kg. The main energy source in both organic and inorganic processes is steam energy followed by potential recovered energy. In organic chemicals, the fractions of heating oil and electricity use are relatively low, but these fractions are higher in the inorganic chemicals than in the organic chemicals. Furthermore, about 50% of the energy consumed in chemical processes is used for purifying the product, byproduct or recycled stream, which indicates that there are large opportunities for improving the process energy in chemical processes. The information presented in this study is very important for those in the life cycle assessment community in order for them to identify inaccurate information or information not based on actual process design. However, the range for the entire range of chemicals is very substantial and thus reflects the need of the life cycle inventory to separately evaluate the chemistry and degree of purity for chemical products. Copyright © 2003 Society of Chemical Industry