Environmental consequence analysis for resource depletion

Resource depletion is of concern to both present and future generations in terms of access to resources. It is a prominent impact category within life cycle assessment (LCA) and sustainability assessment. This paper examines existing resource depletion approaches and indicators in the context of natural gas depletion, and their limitations in modelling the wider environmental consequences of resource consumption. Some existing models assume substitution of scarce fossil fuels with an alternative fossil fuel or mix, but do not consider all of the subsequent change in impacts. An additional methodology is proposed to measure the impact changes when fossil fuel substitution occurs as a result of scarcity. The methodology will demonstrate the effect of resource scarcity for individual processes but also multiple processes which operate at different levels of resource consumption with varying degrees of impacts. The methodology is applied to a scarcity situation of natural gas in Australia, where black coal is substituted for gas. It is first applied to natural gas consumed for electricity generation only. In the second case, the methodology is applied to the substitution of natural gas for both electricity generation and hydrogen production. The varying impacts on emissions to air and water, together with solid waste generation and water depletion, as a result of the substitution are used to reflect the consequences of fossil fuel depletion. The indicators also provide information on the impacts of substitution in each product, thus enabling users to prioritise products based on the impacts produced during natural gas allocation.     

Thermodynamic investigation and hydrate inhibition of real gas flow through orifice during depressurization

A thermodynamic procedure has been proposed which can be used to predict the gas pressure, temperature and flow rate through orifice upon chock flow condition, using equation of state (EOS). The procedure applied for emergency depressurization operation incorporating the Peng-Robinson EOS and validated by comparing flow rates of a multi-component hydrocarbon gas mixture for thirteen experimental cases. The average absolute deviations of the predicted flow rates for orifice discharge coefficients of 0.85 and 0.9, are 7.36% and 2.03%, respectively. The corresponding error for API 520 (American Petroleum Institute Recommendation Practice 520) method is 6.91%. In this work, the hydrate formation temperature and hydrate inhibitor type and its required weight fraction for preventing the hydrate formation upon orifice and its upstream conditions are evaluated by the EZ-Thermo software using the Moshfeghian–Maddox method. The results qualitatively show that the hydrate prevention is essential for the safety of the operation due to low temperature condition.     

Simulation-based fault propagation analysis—Application on hydrogen production plant

Recently production of hydrogen from water through the Cu–Cl thermochemical cycle is developed as a new technology. The main advantages of this technology over existing ones are higher efficiency, lower costs, lower environmental impact and reduced greenhouse gas emissions. Considering these advantages, the usage of this technology in new industries such as nuclear and oil is increasingly developed. Due to hazards involved in hydrogen production, design and implementation of hydrogen plants require provisions for safety, reliability and risk assessment. However, very little research is done from safety point of view. This paper introduces fault semantic network (FSN) as a novel method for fault diagnosis and fault propagation analysis by using evolutionary techniques like genetic programming (GP) and neural networks (NN), to uncover process variables’ interactions. The effectiveness, feasibility and robustness of the proposed method are demonstrated on simulated data obtained from the simulation of hydrogen production process in Aspen HYSYS^®. The proposed method has successfully achieved reasonable detection and prediction of non-linear interaction patterns among process variables.     

半刚性路面基层环境影响评价研究

采用输人输出模型,通过清单分析和归一化处理对我国典型的路面基层材料水泥稳定粒料与石灰稳定粒料以及几种工业固体废弃物路面基层材料的环境影响进行了研究并和水泥混凝土进行了对比.结果表明,工业固体废弃物路面基层对资源能源消耗量少,生产过程中固体废弃物、温室气体、酸雨气体的排放量小.和我国目前广泛使用的水泥稳定粒料相比,其环境影响较小,而且可以被再循环用作水泥生产的混合材,是一类典型的生态建筑材料.     

Y形通风采空区自燃与有害气体排放的数值模拟

基于非均质多孔介质漏风渗流方程、多相气体渗流-扩散方程和多孔介质渗流综合传热方程,建立了采空区瓦斯与自燃发火耦合数值模型,开发了用迎风格式有限元方法联立求解的计算机程序(简称G3).计算以图形方式给出各量的区域分布解,从理论上描绘了Y形通风采空区的漏风流态,动态描绘了瓦斯、氧和CO的体积分数以及温度分布状态及其变化过程,并证明了Y形通风形式能避免采空区瓦斯向工作面涌出.计算中采空区按冒落非均质介质处理,考虑了瓦斯涌出对自燃的耦合作用,给出了这种耦合作用关系和解决办法.Y形通风采煤的自燃,两者存在着顾此失彼的关系.     

板坯火焰清理机烟气治理技术

介绍了国产板坯火焰清理机烟气的治理系统及湿式电除尘器的结构和技术特点.结果表明,该烟气治理系统及湿式电除尘器能够满足火焰清理机工况和烟气排放的环保要求,完全可以替代同类进口设备.     

高温碱间歇式处理对互花米草厌氧发酵特性的影响

以互花米草为原料,采用中温(35±1)℃批式发酵的方式,考察了NaOH高温碱间歇式处理对互花米草厌氧消化过程的影响.结果表明,互花米草一次发酵至产气停止,单位TS产气量为263mL/g,发酵过程中出现酸化现象, pH值最低为5.17.二次发酵原料为一次发酵后的固体残余物,主要组分为可分解有机物以及一些难分解有机物,过程中未出现酸化现象, pH值经短暂下降后很快稳定在7.5左右,累积产气量在一次发酵的基础上提高了46%.互花米草单位TS产气量为383mL/g.消化液中有机酸乙酸含量最大,丙酸和丁酸含量相当.     

陶瓷纤维滤管在烟气净化一体化技术中的应用

在对国内外现有的一体化烟气处理工艺系统梳理的基础上,重点分析了基于陶瓷纤维滤管的烟气净化一体化技术,对其技术原理、应用特性、应用现状进行了分析总结,并以江苏某垃圾焚烧发电厂中试示范项目为例进行验证.结果表明,NOx、SO2、HCl、颗粒物、二噁英类去除效率分别为97.6％、84.1％、74.8％、>99.9％、99.9...     

印染污泥焚烧烟气污染控制案例分析

以广东省某两家印染厂的印染污泥焚烧项目为主要研究对象,从污泥处理技术路线、焚烧设备及烟气处理流程等各方面入手,对各厂印染污泥与煤混烧烟气中颗粒物、NOx、SO2、酸性气体(HF、HCl)和重金属等污染物的进行采样分析,并对各厂现有烟气污染物控制设施的运行效果进行调研,结果表明,布袋除尘的效果较为理想,除尘效率可达99%以上;使用印染废水作为吸收液的湿法脱硫技术对SO2及酸性气体的去除效果不理想;SNCR对NOx具有一定的去除效果,是一种较为经济、高效的脱硝技术;焚烧后,大部分重金属最终以飞灰的形式被除尘器去除,但仍有部分重金属如Hg在出口烟气中的浓度仍然很高,需要采取必要的措施控制烟气中的重金属. 此外,基于印染污泥焚烧实例分析,提出适于印染污泥与煤混烧烟气处理工艺流程.     

Measurement of watershed phosphorus: A review

Eutrophication control programs are based on phosphorus management which, in turn, requires a detailed quantification of the watershed phosphorus budget. This involves an assessment of non‐point sources of phosphorus, a key element of which is determining the fraction of soil‐P and sediment‐P available to support algal growth. This paper presents a review of the state‐of‐the‐art of estimating algal available‐P from non‐point sources, and an analysis of pertinent data. The need to employ multi‐interval algal bioassays in developing phosphorus management systems is stressed.