A heuristic design advisor for incorporating pollution prevention concepts in chemical process design

 The application of pollution prevention concepts to chemical process design is often hampered by lack of sufficient information about potential design alternatives. The high cost of collecting this information can thus present act as a constraint on the thoroughness of the final design optimization. One approach to dealing with such data constraints is the application of design heuristics. Particularly when coupled with the use of robust optimization methods, heuristic approaches can provide useful insight and direction at all stages of the design effort. Pacific Northwest National Laboratory has been developing a heuristic-based tool for use in chemical process design. Known as the Process Heuristic Review of Environmental Design (PHRED) this design tool uses conventional backwards chaining expert systems techniques to identify and prioritize applicable design heuristics based on a minimal set of process data. The development philosophy and current status of the PHRED tool are discussed in this paper. Received: 8 September 1998 / Accepted: 6 May 1999     

Recent advances in ion exchange materials and processes for pollution prevention

 Even though ion exchange technology is mature and widely employed in industry, new applications, approaches, and materials are emerging at a rapid pace. This article summarizes recent advances in ion exchange technology abstracted from presentations made at the Trends in Metal Adsorption Workshop held on May 5–6, 1998 in Cincinnati, OH co-sponsored by the United States Environmental Protection Agency (U.S. EPA), the American Institute of Chemical Engineers (AIChE), the Council for Chemical Research, and the United States Department of Energy (U.S. DOE). Additional information was obtained from reviews of U.S. EPA sponsored pollution prevention projects, panel discussions and workshops, user surveys, and the authors' discussions with practitioners in industry. The objectives of this article in the context of ion exchange applications were: (1) to review advances and applications of ion exchange; (2) to present an overview of commercially available ion exchange technology; and (3) to highlight areas for further research. Many of the advances discussed achieve improvement in ion exchange performance through the use of alternate support matrices or through the combination of technologies such as membranes or electric fields with ion exchange. Received: 8 October 1998 / Accepted: 15 Januar 1999     

Computer-aided tools for pollution prevention: solvent-based processes

 This paper provides an analysis of pollution prevention, treatment and cure with respect to solvent-based processes. It is postulated that, in new processes, considering environmental constraints in the early stages of process design can prevent pollution due to inefficient recovery of solvents or inefficient separation by solvents. Pollution in existing processes can also be prevented through early treatment that includes assessment of causes and effects of future changes in process conditions and/or environmental regulations. Pollution cure is more difficult, since the process is already violating some environmental constraints and any solution also needs to satisfy social and economic constraints. A technique for pollution prevention, treatment and cure that is based on the use of computer-aided tools is presented. Application of the technique is illustrated through a case study that highlights the important steps of the solution approach and serves as a proof of concept. Received: 13 July 1999 / Accepted: 3 November 1999     

Sustainable development of process facilities: state-of-the-art review of pollution prevention frameworks

Pollution prevention (P2) strategy is receiving significant attention in industries all over the world, over end-of-pipe pollution control and management strategy. This paper is a review of the existing pollution prevention frameworks. The reviewed frameworks contributed significantly to bring the P2 approach into practice and gradually improved it towards a sustainable solution; nevertheless, some objectives are yet to be achieved. In this context, the paper has proposed a P2 framework 'IP2M' addressing the limitations for systematic implementation of the P2 program in industries at design as well as retrofit stages. The main features of the proposed framework are that, firstly, it has integrated cradle-to-gate life cycle assessment (LCA) tool with other adequate P2 opportunity analysis tools in P2 opportunity analysis phase and secondly, it has re-used the risk-based cradle-to-gate LCA during the environmental evaluation of different P2 options. Furthermore, in multi-objective optimization phase, it simultaneously considers the P2 options with available end-of-pipe control options in order to select the sustainable environmental management option.     

Design and topology/shape structural optimisation for additively manufactured cold sprayed components

Integrating advanced structural optimisation, such as topology optimisation (TO), with additive manufacturing (AM) allows design and fabrication of extremely efficient and effective components. Such integration is challenging because characteristics can vary from process to process. In this paper, designing and optimising a part for the cold spray AM process is demonstrated. Cold spray process characteristics and constraints are enforced throughout. The analysis shows a tradeoff between stress and mass, but the combined process delivers a structure at much lower stress (up to 3X reduction in peak stress in a case study) with the capability to be much lighter than the original part (case study: 20% reduction in weight). The general approach to specifying design guidelines, interpreting TO results, and applying other structural optimisation methods is directly applicable to many AM processes – and especially other spray deposition techniques – in addition to cold spray.     

A source reduction approach: Integrated bio-based tanning methods and the role of enzymes in dehairing and fibre opening

Due to increased legislation geared towards environmental protection and preservation of water quality, tanneries are under constant pressure to implement source reduction technologies that reduce their organic and inorganic wastewater loading. The processing of hides or skins to leathers involves five important stages: raw skins/hides preservation, pre-tanning, tanning, post tanning, and finishing, of which, pre-tanning and tanning processes are known to contribute more than 90% of the total pollution load from leather processing. These include soaking, liming, reliming, deliming, bating, pickling, chrome tanning and basification. Wide variation in pH (2.8–12.0) is also encountered during the entire leather making process. These different operations and the pH variations result in the emission of large pollution loads as biochemical oxygen demand (BOD), chemical oxygen demand (COD), total solids (TS), chlorides, sulphates, chromium and sludge. This article describes an integrated three-step bio-based process, which limits the pH range in leather processing to 4.0–8.0. A sequence of operations namely, dehairing, fibre opening and pickle-basification-free chrome tanning (chrome tanning that does not require pickling or basification), has been designed primarily with the use of enzymes. Application of this source reduction process leads to a substantial decrease in chemical consumption from 380 to 50 kg for tanning one ton of raw skins. Leathers processed using this process sequence matched the performance of conventionally processed leathers. Further, the integration of enzyme technology with a specially designed chrome tanning process presents substantial environmental benefits as observed in the reduction of COD, total solids and chromium by 61, 78 and 92%, respectively. Cost data are presented to demonstrate that the process is economically viable.     

Analysis of stamping performances of dual phase steels: A multi-objective approach to reduce springback and thinning failure

The industrial interest on light weight components has contributed in the last years to a significant research effort on new materials able to guarantee high mechanical properties, good formability and reasonable costs together with reduced weights when compared to traditional mild steels. Among such materials advanced high strength steels (AHSS) such as transformations induced plasticity (TRIP) and dual phase (DP), and light weight alloys proved their usefulness in stamping of automotive components. As AHSS are concerned, one of the main drawbacks is related to springback occurrence. Many aspects have to be taken into account when springback reduction is investigated: material behavior issues, process conditions, numerical simulations parameters calibration, geometrical aspects and so on. Moreover, springback minimization problems are typically multi-objective ones because springback reduction may conflict with other goals in stamping design such as thinning reduction. In this paper, such problem was investigated through integration between numerical simulations, Response Surface Methodology and Pareto optimal solutions search techniques. The design of a U-channel stamping operation was investigated utilizing two different dual phase steel grades: DP 1000 and DP 600. An explicit/forming-implicit/springback approach was utilized for the numerical simulations. Friction conditions and blank holder force were optimized as design variables in order to accomplish two different objectives: reduce excessive thinning and avoid excessive geometrical distortions due to springback occurrence.     

Hazardous waste reduction from mixed acid titanium etching

This paper presents the findings of a technical study performed by the New York State Pollution Prevention Institute at Rochester Institute of Technology to evaluate process modifications that would reduce hazardous waste generated from the manufacture of titanium alloy turbine blades. This study focused on the acid etch process step in which titanium alloy turbine blades are immersed in a mixed nitric and hydrofluoric acid solution to chemically mill the blades; which is one of a sequence of finishing steps. The spent acid is a hazardous waste that is sent off-site for disposal. A pollution prevention approach identified several process and operational improvements that would significantly reduce the amount of hazardous acid waste generated. Implementation of process improvements identified in this study resulted in reducing the quantity of hazardous waste generated from 502 tons/year in the Baseline year to less than 210 tons/year in Year 2, thereby resulting in a cost savings of nearly 43% per year. Full implementation of the study recommendations are expected to reduce the hazardous waste quantity to 71 tons/year, thereby achieving a cost savings of nearly 70% due to an 86% reduction in waste generation and a 66% reduction of total acid purchase and disposal costs.     

热害矿井空气能系统降温与废热提级利用系统设计

针对目前热害矿井在开采过程中存在的危害,各国针对存在热害的矿井采取了不同的防治措施,并且取得了一定效果,但是其系统的投资与运行费用较高。提出一种利用空气能系统对矿井进行降温的新模式,结合平顶山大庄矿矿井基本情况,对机电硐室进行空气能制冷降温与废热提级利用系统设计,并对主要设备进行了选型。最后与传统冷水机组制冷降温系统进行比较,空气能系统具有显著的经济效益。研究成果为企业节能减排方案的选择提供了参考和依据。     

Novel Approach of Semiconductor Manufacturing Process on Copper Dual Damascene Processes Integration

Abstract:  The performance of the manufacturing process in each of these areas determines the overall manufacturability of the process. As device geometries are reduced, understanding and minimising the sources of process-induced defects is critical to achieving and maintaining high device yields. This paper presents a comprehensive investigation of a novel metrology on semiconductor process module integration and technology on optimal integrated lithography processes and solution to the problem of defects reduction on semiconductor wafer in sub-micron processes integration. As dual damascene integration copper process is complicated and critical in semiconductor processes. It has been common knowledge that pattern collapse and missing of this process and numerous defects could be prevented by optimal the process module tuning. To investigate novel semiconductor process integration on deep pattern aspect ratio effects of sub-micron semiconductor wafer BEOL (Back-End-Of-Line) structure were included in this study. Moreover, the electrical device investigations of device checking were also included.     

论我国农村噪声污染现状与治理方向

对自2005年至今的国内大量公路建设项目环评、竣工环保验收和道路交通噪声研究过程中积累的噪声监测数据进行统计分析。形成对中国农村噪声污染现状的基本判断,识别出主要的噪声污染源为交通噪声。以问卷调查的形式了解农村居民对噪声问题的关注度,从环境监测机制,现行降噪措施效果和特点、实施情况等几个方面分析目前农村声环境污染防治存在的主要问题,并提出几点改进农村噪声污染治理的建议。     

Clean production with membrane technology

 Membrane processes, because of unique, specialized, and cost-effective applications, have the potential of playing a significant role in preventing pollution from occurring in manufacturing plants. Opportunities are seen in resource recovery, species purification, and energy savings. Emerging technologies of membrane reactors that combine separation with reaction in one physical unit are important developments also. In this paper we discuss the scope of membrane technologies in industrial applications as well as hurdles that must be overcome. Received: 15 April 1998 / Accepted: 9 August 1998     

Environmental and risk screening for prioritizing pollution prevention opportunities in the U.S. printed wiring board manufacturing industry

Modern manufacturing of printed wiring boards (PWBs) involves extensive use of various hazardous chemicals in different manufacturing steps such as board preparation, circuit design transfer, etching and plating processes. Two complementary environmental screening methods developed by the U.S. EPA, namely: (i) the Tool for the Reduction and Assessment of Chemical and Other Environmental Impacts (TRACI) and (ii) Risk-Screening Environmental Indicators (RSEI), are used to quantify geographic and chemical environmental impacts in the U.S. PWB manufacturing industry based on Toxics Release Inventory (TRI) data. Although the release weight percentages of industrial chemicals such as methanol, glycol ethers and dimethylformamide comprise the larger fraction of reported air and water emissions, results indicate that lead, copper and their compounds' releases correspond to the highest environmental impact from toxicity potentials and risk-screening scores. Combining these results with further knowledge of PWB manufacturing, select alternative chemical processes and materials for pollution prevention are discussed. Examples of effective pollution prevention options in the PWB industry include spent etchant recovery technologies, and process and material substitutions. In addition, geographic assessment of environmental burden highlights states where promotion of pollution prevention strategies and emissions regulations can have the greatest effect to curb the PWB industry's toxic release impacts.     

Integration of new processes and geothermal heat into a wood processing cluster

In this study, process integration methods have been used to investigate the heat integration of new processes with a model wood processing cluster. Due to anticipated future demand for bio-derived fuels and chemicals, it is important to identify which emerging conversion processes would benefit from integration with existing facilities. Identifying specific integration schemes help quantify economic and environmental benefits and can assist the commercialisation and adoption of these new processes. The synergies gained through integration are examples of industrial symbiosis, which is the sharing of resources between co-located facilities. A background/foreground analysis of the grand composite curves was used to determine any heat recovery potential between the cluster and the new entrant and the effect on the utility system. The model cluster consisted of a thermo-mechanical pulp and paper mill, kraft pulp and paper mill and saw mill. Some of the processes had little or no integration potential due to having similar pinch temperatures as the cluster. Processes based on biomass gasification had large potential due to the pinch temperatures being very different and the shape of grand composite curve being complimentary. The integration of geothermal energy for process heat was also investigated and if available has a distinct advantage of allowing surplus black liquor to be used as a feedstock to some of the new processes. Results show that high pinch temperature processes show the greatest integration potential and can provide significant fuel reduction potential.     

Chemical process design using heuristics in the context of pollution prevention

 Compiled in sufficient quantities, the effectiveness of design heuristics (rules-of-thumb) to help identify pollution prevention alternatives has been demonstrated. In this paper, a core structure of associated heuristics and procedures developed using chemical engineering principles are presented for use during conceptual as well as retrofit design. The approach is applicable for continuous bulk processes and has been encoded in the software P2TCP (Pollution Prevention Tool for Continuous Processes), a prototype expert system, to help develop inherently cleaner processes. Unlike hierarchical or step-wise design techniques, heuristics (knowledge based rules) are presented that help identify potential unit operations and analyze their interactions independently within the reaction and separation systems of a chemical process. Interactions between the reaction and separation systems are then taken into account to further reduce the number of overall flow diagrams requiring subsequent evaluation. Future extensions to the knowledge base and combination with complimentary tools like process simulation packages are envisioned. Received: 16 April 1999 / Accepted: 27 April 1999     

Many-objective harmony search for integrated order planning in steelmaking-continuous casting-hot rolling production of multi-plants

This paper investigates a challenging problem of integrated order planning (IOP) in steelmaking-continuous casting-hot rolling production of multiple plants with consideration of four conflicting objectives. The objective functions refer to the earliness/tardiness ratio, the non-hot charge ratio and the imbalance ratio of production capacity utilisation corresponding to SCC plants and HR Plants. The IOP guided by the integration strategy, which includes the vertical integration of production stages and the horizontal integration of steel plants, is regarded as a large-scale many-objective optimisation problem. To deal with the difficulty of large-scale decision variables, we introduce a new concept named ‘order-set’ for modelling. In addition, a novel knee point-driven many-objective global-best harmony search (KGHS) algorithm, mainly integrating a KGHS process and a new knee point-driven Pareto optimisation, is developed to tackle this many-objective problem. The proposed model and algorithm were tested with benchmarks and real production data. Experiments demonstrate that the proposed approach generates effective solutions superior to those generated by the other popular many-objective optimisation methods.     

多学科集成下的老年智能产品设计研究

目的 基于多学科集成理论,分析老年智能产品设计现状,在了解老年用户群体对产品需求的基础上,进行设计实践创新方法研究。方法 通过阐明多学科集成方法中系统化、框架化、协同化、优化算法等理论,针对使用者、设计者双方进行分析,寻找出产品设计过程中存在的问题,在服务设计原则和多学科集成的理论支持下,进而推导出设计思路和方法。 结论 提出老年智能产品设计的基础是用户的操作体验和特定需求,设计过程涉及多学科、多目标;以“多目标实现”“多学科综合系统模型”“新技术融合”等应用实例,解释了如何解决产品设计过程中,由于用户需求复杂所产生的计算复杂性和选择复杂性等问题,优化了设计框架,归纳了设计信息,提升了设计过程的合理性、高效性和准确性。     

Use of vacuum for counter-gravity casting of metals

 The use of vacuum to fill molds to form investment castings in a countergravity casting fashion was started in the early 1970s. This paper describes how the processes work and the reasons for their advantages in cost, quality, and process control. Countergravity casting is being done in sand, permanent, and investment (lost wax) ceramic molds and alloys are cast in air and inert atmospheres. The process started with common steels, was extended to heat resistant superalloys, and recently even titanium alloys are being cast routinely using ceramic crucibles. The use of a unique mold design enables a great reduction in metal cast to yield a given part, thereby greatly reducing the energy use in making such castings. Computerized control of the rate of vacuum application enables complete control of filling rates, permitting casting of very high quality castings in very viscuous metals, such as metal matrix composites of aluminum. These processes are used to produce more than $200  million worth of castings annually and this will greatly increase in the next few years due to the production of automotive exhaust manifolds in stainless steel. Received: 21 July 1998 / Accepted: 10 September 1998     

国外生成式产品设计研究综述

目的 设计是一项复杂的求解过程,合适的方法对开发新产品起着至关重要的作用.设计计算的进步可能促使机器从传统的辅助角色转变为设计内容的生成器.通过回顾国外1998年至今的生成式产品设计方法,指出未来发展趋势与挑战,为产品设计师及相关的技术与应用研究者提供相应的参考.方法 从生成式设计的定义出发,给出生成式设计的定义;整理归纳生成式产品设计的主要步骤及优势;通过综述的形式,将典型的生成式产品设计方法和相关研究进行整理分类;从技术因素和设计因素两个角度总结,对比分析生成式产品设计方法.结论 数据驱动的生成式产品设计将会更好地为设计师带来全新的视角.生成式产品设计的革命性影响能否实现,将取决于设计界和业界思维方式的重大变化.生成式产品设计未来研究的影响,将取决于学术发展和行业研究之间的融合.