Catalytic Gasification of Coal Using Eutectic Salts: Recovery,Regeneration, and Recycle of Spent Eutectic Catalysts

Abstract

Catalyst recovery studies were conducted for gasified chars produced from steam gasification of Illinois #6 coal catalyzed with two different catalyst systems. A ternary (43.5 mol% Li₂ CO₃ –31.5 mol% Na₂ CO₃ –25 mol% K₂ CO₃ ) and a binary (29 mol% Na₂ CO₃ –71 mol% K₂ CO₃ ) eutectic catalyst system were used for gasifying coal. Various extraction schemes, such as water extraction, H₂ SO₄ extraction, and acetic acid extraction, were evaluated with respect to their extraction efficiencies. Effects of major process variables, such as solvent-to-char ratio, mixing time, temperature, and concentration, on the extraction efficiency were evaluated. A process schematic for the entire catalyst recovery, regeneration, and recycle scheme was developed and the preliminary process economics were determined based on these extraction schemes. H₂ SO₄ extraction was found to be the most desirable. It also turned out to be more attractive than a once-through throwaway system.     

绿色建筑的雨水收集和中水回用

文中介绍了绿色建筑中雨水收集的方案和流程,区域建筑中中水处理和回用以及目前存在的问题和雨水、中水的利用及前景。     

Reuse of hydroponic waste solution

Attaining sustainable agriculture is a key goal in many parts of the world. The increased environmental awareness and the ongoing attempts to execute agricultural practices that are economically feasible and environmentally safe promote the use of hydroponic cultivation. Hydroponics is a technology for growing plants in nutrient solutions with or without the use of artificial medium to provide mechanical support. Major problems for hydroponic cultivation are higher operational cost and the causing of pollution due to discharge of waste nutrient solution. The nutrient effluent released into the environment can have negative impacts on the surrounding ecosystems as well as the potential to contaminate the groundwater utilized by humans for drinking purposes. The reuse of non-recycled, nutrient-rich hydroponic waste solution for growing plants in greenhouses is the possible way to control environmental pollution. Many researchers have successfully grown several plant species in hydroponic waste solution with high yield. Hence, this review addresses the problems associated with the release of hydroponic waste solution into the environment and possible reuse of hydroponic waste solution as an alternative resource for agriculture development and to control environmental pollution.     

化工固体废物的综合利用

对我国化工固废的产生、治理、利用和重点化工行业氯碱工业等化工固体废弃物的处理和综合利用技术进行了分析、综述，并指出了该领域的发展趋势。     

推广中水回用及措施

介绍了国内中水回用的推广情况及推广中水回用的主要措施。     

印染废水出水回用与实践

采用过滤-碳纤维吸附工艺对印染废水一级出水进行深度处理,废水COD可由80 mg/L降至30～40mg/L,出水水质完全满足生产工艺回用水要求.该技术具有工艺简单、投资少、运行费用低、操作简单等优点,特别适用于水资源短缺的中小印染企业.     

绿色大学污水资源化初探

绿色大学是一个全新的概念,如何在高校新校区建设之初就立足于建成适合时代发展要求的绿色大学,因此,从其污水资源化的角度进行了探讨,指出并分析了建立中水回用系统结合小型生活污水处理站的可行性.     

城市污水资源化回用探析

通过分析我国污水回用的潜力、回用的途径、以及经济和环境效益，介绍了污水回用的一些新技术。根据我国目前污水回用的实际情况，阐述了实现污水回用存在和需要解决的问题。     

UASB-好氧曝气-深度处理工艺处理聚酯废水和回用

介绍了气提-厌氧-好氧曝气-深度处理工艺在聚酯废水处理及回用技术中的实际应用,分析并总结了工程设计及运行的经验。实践表明,运用气提塔先对高浓度聚酯废水进行预处理,可以去除废水中大部分有机物,保证后续生化处理的稳定运行。经气提-厌氧-好氧曝气-深度处理后可以回用于生产过程中。该工艺具有运行稳定和处理效率高等优点,为企业带来了良好的经济效益和社会效益。     

The Impact of Increased Recycle Rates on Markets in Florida

The State of Florida passed The Florida Solid Waste Management Act of 1988 mandating that county recycling programs be initiated by July 1, 1989. The legislation further expressed the goal that, at a minimum, recycling efforts reduce the amount of solid waste requiring final disposal or resource recovery by 30 percent by the end of 1994. This study was performed to determine the impact on recycle markets when the amounts of materials recycled from the municipal solid waste stream are increased by 30 percent in Florida.

The composition of the municipal waste stream was quantified in terms of the amounts of paper, plastic, metals, glass, and rubber. The effect of a 30 percent increase in the recycle rate of each class of material was calculated and compared to existing recycle rates in the State of Florida. It was determined that there are few capacity constraints on the increase in recycle rates for aluminum, steel (i.e., tin cans), and color separated glass. There are, however, serious constraints on increasing recycle rates for paper, plastics and rubber tires.     

冷轧废水污泥铬回收后残渣的脱硫研究

为了最大限度地对污泥进行回收利用,将钢厂冷轧废水处理后污泥铬回收后的残渣制备成脱硫剂,并研究其脱硫特性.结果表明,加入碳酸钠在高温下有氧焙烧,冷轧废水处理后污泥铬回收后的残渣中Fe2O3约为45%(质量分数),Fe2ZnO4约为6%(质量分数);将该残渣与粘结剂、制孔剂和结构剂按一定配比混合制备脱硫剂,在空速为400～500 h-1和不持续补充水分的实验条件下,与含3 500 mg/m3左右H2S的模拟气接触时,一次脱硫实验表明其穿透硫容在5%以上.     

废印刷电路板回收利用探讨

通过对废印刷电路板的结构和物质组成的分析,并对可能的各种回收利用的方法及其原理进行了分析和对比,从而得出二次污染小且成本低的回收利用的方法和原则流程,为废印刷电路板的回收利用提出了一个方向性的建议.     

发展循环经济 推行“绿色打印”

伴随着打印机使用的日益普及，与之相配套的耗材——墨盒、硒鼓等正以每年30％的速度递增。而这些不可降解的耗材，被当作垃圾丢弃，既造成资源浪费，又日益威胁着人们的生存环境。用持续发展的观点审视之，当务之急是要树立科学的发展观，发展循环经济，推行“绿色打印”，减少环境污染。     

Dairy Manure Treatment,Digestion and Nutrient Recovery as a Phosphate Fertilizer

A combined approach of biological treatment, solids digestion and nutrient recovery was tested on dairy manure. A sequencing batch reactor (SBR) was operated in three modes, in order to optimize nutrient (nitrogen and phosphorus) removals. The highest average removal efficiencies of 91% for NH₄-N, 59% for PO₄-P and 80% for total chemical oxygen demand (COD) were achieved. Staining experiments suggested the coexistence of glycogen and phosphorus accumulating organisms. Anaerobic digestion of wasted bio-solids was able to produce a PO₄-P concentration of 70 mgL^?1 in the supernatant. A pilot-scale experiment, designed to recover phosphorus in the supernatant as struvite (magnesium ammonium phosphate), was able to remove 82% of soluble PO₄-P.     

Improved Spray Dry Scrubbing through Grinding of FGD Recycle Material

A laboratory size spray dry scrubbing unit consisting of a spray dryer and a pulse Jet baghouse was used to study the effect of grinding recycle waste on SO₂ removal across the spray dryer and on sorbent utilization. The equipment treats simulated flue gas with a dry flow rate of 1.5 m³ h^?1 (stp) and utilizes an ultrasonic nozzle for atomization. The apparatus was initially tested over a broad range of operating conditions; a close agreement in SO₂ removal was found with data from much larger units. The effect of grinding the FGD recycle material on the SO₂ removal across the spray dryer was found to be great. Grinding the recycle material can enhance the SO₂ removal efficiency to a level comparable to operation with a large excess of fresh lime.     

马钢中板厂含油污水回用系统改进工艺研究

马钢中板厂原有的含油污水二级沉淀工艺处理效率低，不能满足污水回用要求。实验室中对该含油污水的处理进行了改进工艺的研究。结果表明：用混凝气浮工艺处理该含油污水能达到罗高的悬浮物及油的去除率，可满足污水回用要求；同时，混凝气浮工艺可以利用原有工艺设施无需新的土建。因此是一条可行的改进路线。     

生化-Fenton氧化联合工艺处理石化净化水的回用

净化水是经过一定预处理的石化废水,具有很高的回用价值,为此采用生化-Fenton联合工艺对净化水进行了处理,研究了初始pH、反应温度、H2O2与Fe2+的摩尔投加比、投加量和反应时间等因素对废水COD去除率的影响。结果表明,Fenton氧化反应可有效去除生化处理出水中的COD,在H2O2(30%)投加量为6.34 m L/L,H2O2与Fe2+的摩尔投加比为5∶1,pH值为4,温度30℃,反应时间2h条件下,废水COD的去除率可达79.7%。GC-MS分析结果表明,Fenton氧化反应对难降解有机污染物具有较好的去除效果,同时可有效提高废水的可生化性,B/C比最大可提升至0.58,氧化出水经生化处理后的剩余COD可降至77.9 mg/L,达到工业回用水标准。     

Recovery of Soil Water,Groundwater, and Streamwater From Acidification at the Swedish Integrated Monitoring Catchments

Recovery from anthropogenic acidification in streams and lakes is well documented across the northern hemisphere. In this study, we use 1996–2009 data from the four Swedish Integrated Monitoring catchments to evaluate how the declining sulfur deposition has affected sulfate, pH, acid neutralizing capacity, ionic strength, aluminum, and dissolved organic carbon in soil water, groundwater and runoff. Differences in recovery rates between catchments, between recharge and discharge areas and between soil water and groundwater are assessed. At the IM sites, atmospheric deposition is the main human impact. The chemical trends were weakly correlated to the sulfur deposition decline. Other factors, such as marine influence and catchment features, seem to be as important. Except for pH and DOC, soil water and groundwater showed similar trends. Discharge areas acted as buffers, dampening the trends in streamwater. Further monitoring and modeling of these hydraulically active sites should be encouraged.     

宝应县有机农业循环产业链模式的研究

循环型农业是一种新的农业经济发展模式,宝应县是全国唯一的国家有机食品基地示范县。文中介绍了循环型农业的内涵和特征,概述了宝应县有机农业循环经济的现状,通过对已实施的三种有机农业循环产业链模式的研究,结果表明,宝应县有机农业循环产业链模式能使农业废弃物资源化,并能有效地控制宝应县的农业面源污染,实现经济与环境持续发展。