Sustainable optimization of waste management network over extended planning time horizon

This study proposes a multiperiod mixed integer linear programming model for the management of a single municipal solid waste (MSW) treatment plant with sustainability as the objective. Discrete and continuous variables define the capacity selections for diverse MSW technologies, and the operation of the MSW network, respectively. The economic target is considered to maximize the net present value. The environmental impact is the minimization of a normalized environmental objective function (NEOF). The social target is the maximization of jobs. An interesting feature about the research work is the requirement of biodrying technologies for MSW moisture content control. Due to the conflicted nature among the sustainability components, a multiobjective optimization (MO) is carried out to find the Pareto optimal solutions. The MO results show that the Pareto optimal solutions vary around profit range of $4.9–8.5 billion, NEOF impact range of 3.2–3.6 units, and social benefit range of 2700–4828 jobs.     

Hydrogen production with an auto-thermal MSW steam gasification and direct melting system: A process modeling

Municipal solid waste steam gasification and direct melting system is proposed in this study for H₂ production and ash melting simultaneously. Part of the H₂ generated in gasification is extracted for combustion with pure oxygen in the melting zone to provide the energy necessary for auto-thermal operation. A simulation model is developed with Aspen Plus to investigate the performance and optimum conditions of the system. For the feedstock with a lower heating value of 18.91 MJ/kg used in this study, 39.8% of the generated H₂ needs to be extracted to maintain the heat balance of the system at the gasification temperature of 900 °C, melting temperature of 1400 °C, and S/M of 1. The net H₂ yield is ～77.3 kg/t-MSW with a net cold gas efficiency of 49.1% under the same operating condition. An optimum operation condition for T (850–1000 °C) and S/M (0.6–1.0) is determined considering the balance between H₂ production ability and the auto-thermal energy balance.     

城市垃圾填埋体的动力特性及地震响应

结合某垃圾填埋场工程 ,利用表面波频谱分析法 (SASW )测试垃圾填埋体的剪切波速 ,得到了用于静动力响应分析的填埋体参数。在假定地表降水入渗为填埋场垃圾土体唯一补给来源的前提下 ,提出了确定浸润线自由面的方法 ,通过静力和动力有限元计算 ,对某填埋场边坡进行了稳定分析。对最危险滑动面的位置分析后发现 ,在地震过程中 ,滑动面的位置比较集中。在此基础上 ,对Newmark方法进行了改进 ,采用圆弧滑动面 ,得到了填埋场在地震作用下的永久位移。实例分析表明 ,垃圾在填埋过程中的初始压实 ,对埋场的地震稳定具有重要意义。     

土工合成材料在城市固体垃圾填埋场中的应用

对一系列新型化工产品———土工合成材料在城市固体垃圾填埋场中的应用 ,特别对其中土工织物 (GT)、土工膜 (GM)、土工合成材料粘土垫 (GCL)、土工网 (GN)、土工复合材料 (GC)以及土工泡沫 (GF)等在填埋场衬垫、封盖系统中的应用作了全面的总结 ,详尽地分析了各种材料的主要用途     

模糊数学方法在垃圾堆肥质量评价中的应用

通过选择堆肥质量指标，制定指标评价等级，构建模糊数学评价体系，采用垃圾堆肥试验数据，在单因素评价的基础上，综合考虑各因素的影响，对堆肥质量进行模糊综合评价。结果表明运用模糊综合评价法能客观地反映堆肥质量。该法可以作为一种简单有效的城市生活垃圾堆肥质量评价方法。     

生活垃圾焚烧灰渣代砂混凝土配合比及力学性能试验

对生活垃圾焚烧灰渣代砂作为混凝土细骨料进行了试验研究。从有毒物质浸出、筛分、压碎指标等分析了生活焚烧垃圾灰渣的骨料特性,并对5种水胶比、3种代砂率的生活垃圾焚烧灰渣细骨料混凝土进行了配合比试验及力学性能试验。试验结果表明,生活垃圾焚烧灰渣多孔、吸水率高、压碎指标低,具有一定的潜在水硬性;通过增加减水剂等合理配合比设计,可以配出工作性能满足工程要求的生活垃圾焚烧灰渣细骨料混凝土;生活垃圾焚烧灰渣细骨料混凝土强度要低于同配合比条件的普通天然砂混凝土,尤其是100%代砂率焚烧灰渣混凝土28 d抗压强度仅为普通天然砂混凝土的一半左右,50%代砂率焚烧灰渣混凝土抗压强度更接近普通天然砂混凝土。     

The 2013 reforms of the Flemish renewable electricity support: Missed opportunities

The Flemish renewable electricity support system has struggled to address a number of problematic issues in the past. These included excessive profit margins and general malfunctioning of the green certificate market, as well as a lack of qualification of various existing renewable energy technologies. The Flemish government responded to these issues by introducing major reforms in 2013, including “banding” to differentiate the support for various technologies. However, reliable methods for differentiating renewable electricity technologies and calculating support levels have not been sufficiently developed. The main objective of the 2013 reforms was to reduce support costs, but application of German feed-in tariffs on 18 reference technologies has shown that most projects in Flanders continue to receive high levels of support. The 2013 reforms did not succeed in addressing malfunctioning of the green certificate market. On the contrary, the confidence of investors in renewable electricity plants has decreased as the terms of support can be altered retroactively by adjusting remuneration levels and through political interventions. Future adaptations are likely to be made which will further decrease the overall stability and effectiveness of the system.     

Air-steam gasification of municipal solid wastes (MSWs) for hydrogen production

Gasification process can be considered as a partial thermal oxidation, which results in the production of a mixture of useful gases (CO, H₂, CH₄, and other gaseous hydrocarbons), little quantities of carbon black (char), ash, and several organic impurities (tar). In this study, we introduced an artificial neural network (ANN) model to simulate the influence of operating conditions on the concentration of products during the gasification process of municipal solid wastes (MSW). Results showed when increasing the residence time, more char is gasified, leading to an increase in the greenhouse gas emissions. It is also found that a further increase in the residence time results in a constant rate of products due to the heat and mass transfer limitations.     

柱淋滤模式下生活垃圾焚烧炉渣中Cu2+和Zn2+浸出规律

垃圾焚烧炉渣是一种活性材料，在其储存、预处理及应用等过程与雨水频繁接触时，炉渣中重金属随着水域环境发生迁移和浸出现象。本研究采用连续柱淋滤试验装置模拟自然降雨，开展了0～5mm和5～10mm焚烧炉渣的动态淋滤毒性浸出分析，重点研究了pH和降雨强度对Cu²⁺和Zn²⁺的浸出影响。结果表明，动态淋滤过程中，淋滤液pH变化对Cu²⁺和Zn²⁺的浸出水平影响显著，且在酸性较强淋滤液作用下Cu²⁺浸出水平比Zn²⁺更强，与Ⅴ类地表水环境浓度限值对比，在整个淋滤时间内Cu²⁺浸出浓度严重超标，在炉渣工程应用时需预防相关的环境风险；原生炉渣粒径大小与重金属浸出水平无直接相关性，但是0～5mm细炉渣中可浸出Zn²⁺含量更高，这与细颗粒物中Zn赋存形态和可溶出态含量较高有关；淋滤强度对重金属浸出水平影响主要反应了动态淋滤过程液固比和水分运移速率情况，当较低淋滤强度时具有低液固比，溶出液中重金属含量较高。     

半干式除酸塔喷雾系统简述

简要介绍了两种垃圾焚烧炉半干法烟气净化技术中除酸塔的喷雾系统,并对这两种喷雾方式进行了对比和分析,可为半干法工艺喷雾系统的选择提供一定的参考。认为要发展我国垃圾焚烧产业,则必须要解决喷雾系统设备的国产化问题。