A multi-criteria approach to screening alternatives for converting sewage sludge to biodiesel

The search for cheaper feedstock for use in the production of biofuels such as biodiesel has turned attention to various forms of waste products including animal fats, waste oils and now lipids in sludge. With the potential of obtaining sludge at a reduced cost, free, or possibly with incentives, sewage sludge is being investigated as a potential feedstock for biofuel production. For the extraction of oils from the sewage sludge and the subsequent processing, there are various alternatives that should be designed, analyzed, and screened. In developing and screening these alternatives, it is necessary to have a consistent basis for comparing alternatives based on key criteria. While most of the design studies focus on techno-economic criteria, it is also important to include safety metrics in the multi-criteria analysis. In this work, a detailed economic analysis and a safety evaluation are performed on a process involving extraction of triglycerides and fatty acids, pre-treatment of fatty acids (direct conversion to biodiesel), and transesterification of triglycerides to biodiesel. Four solvents, toluene, hexane, methanol and ethanol, are individually used in the extraction process. The resulting triglycerides and fatty acids from each extraction are modeled in the pre-treatment process. ASPEN Plus software is used to simulate the detailed process. Economic analysis is performed using ASPEN ICARUS, and scale-up of a previously analyzed process is used to estimate the cost of the biodiesel portion of the process. A new safety metric (referred to as the Safety Index “SI”) is introduced to enable comparison of the various solvent extraction processes. The SI is based on solvent criteria as well as process conditions. A case study is presented to demonstrate the insights and usefulness of the developed approach. The results of the techno-economic analysis reveal that of the four solvents used for the initial extraction, hexane and toluene were least costly (2.89 and 2.79 $/gal, respectively). Conversely, the safety analysis utilizing the SI reveals that methanol and ethanol are the safer solvent options. The issue of cost/safety tradeoffs is also discussed.     

水的生态治理机制对林业劳动安全生产影响分析

随着我国可持续发展战略的实施,自然环境综合治理机制越来越受到社会关注,水资源保护成为自然生态保护的重要内容,水资源保护过程中需要建立完善的生态治理机制,保证水资源能够合理循环,实现经济社会的可持续发展。林业劳动安全生产对水具有高度依赖性,因此水资源生态治理机制建设可以推动林业劳动安全生产管理工作得以顺利开展,全面实现林业生产效益,保障林业劳动生产的安全性。     

城市小康社会安全指标体系设计

城市安全是我国小康社会安全的关键和重要组成部分 ,科学地设计城市小康社会的安全指标体系 ,对于定量地分析和认识城市安全的状况 ,科学地评价安全的社会价值有着现实的意义。笔者首先提出了安全小康社会的概念及其发展目标的体系和原则 ;然后结合我国的政府管理部门需要 ,定义了城市安全的 12大领域 ,并设计了指标体系 ,包括社会稳定、社会治安、公共场所安全、公共卫生、交通安全、生产安全、食品安全、减灾防灾、人口安全、环境安全、能源安全及宏观综合。每个具体指标都是在研究该安全领域具体现状的基础上 ,经过分析影响其安全状况的重要因素设计而成的。城市小康社会安全指标体系能够应用于评价城市的总体安全状况。     

Safety assessment of potential supercritical solvents for Fischer–Tropsch Synthesis

Fischer–Tropsch Synthesis (FTS) is a primary pathway for gas-to-liquid (GTL) technology. In order to overcome commercial problems associated with reaction and transport phenomena, the use of supercritical solvents has been proposed to enhance conversion, catalyst stability and improve temperature control in fixed-bed reactors. One of the major challenges in designing the supercritical FTS reactor unit is selecting appropriate solvents of critical properties within the required reaction operating conditions. Numerous alternatives exist and should be screened based on relevant criteria. The main aim of this paper is to develop a screening methodology to identify an optimum supercritical solvent or a mixture of solvents that meet the aforementioned criteria while minimizing the cost and more importantly satisfying the safety constraints. A safety metric system was developed in order to compare the risk issues associated with using different solvents. In addition, an economic analysis of using the different solvents was performed. Finally, a case study was solved to illustrate the use of the proposed metrics and the selection of solvents based on safety and techno-economic criteria.     

Competency requirements for process hazard analysis (PHA) teams

Process hazard analysis (PHA) is a cornerstone of process safety management programs. The quality of the PHA performed directly affects the level of risk tolerated for a process. The lower the quality of a PHA, the more likely higher risk will be tolerated. There are few requirements for PHA team members in the U.S. Occupational Safety and Health Administration's process safety management regulations. More detailed requirements for participation in a PHA are desirable.A competency management program should be used to ensure PHA practitioners and teams are appropriately qualified. Criteria for selecting PHA team leaders, or facilitators, and other team members are key to such a program and are described in this paper. The criteria cover both technical and personal attributes. Application of the criteria is described and team performance metrics, which can be used to correlate performance with the assessment of competency to validate the criteria and methods used, are discussed.Owing to the importance of the role played by team leaders, certification of their competency is desirable. Criteria for certification are described and their application is discussed.     

“三线一单”促进四川省高质量发展

过去40年来我国经济建设取得了举世瞩目的成绩,但是也留下了很多生态环境问题。目前我国经济已经由高速增长阶段转向高质量发展阶段,但高质量发展缺乏指标体系和具体路径。“三线一单”是一套生态环境分区管控体系,其主要目的是统筹地方社会经济与环境保护的矛盾,促进经济结构转型。四川省在“三线一单”编制过程中,通过建立指标体系从生态环境保护的角度为地区高质量发展提供了量化标准,通过差异化管控要求为地区高质量发展提供了具体路径,从生态环境角度助力高质量发展。     

Prioritizing highway safety improvement projects: A multi-criteria model and case study with SafetyAnalyst

This paper presents a multi-criteria model for prioritizing highway safety improvement projects, in which a set of criteria related to the project’s technical, economic, and social impacts are properly weighted in consideration. The proposed model features an Analytical Hierarchy Process (AHP) framework to tackle the multi-criteria decision making problem. Different from the conventional AHP, this paper adds a fuzzy scale level between the criteria level and the alternative level, which offers the advantage of preventing the vagueness and uncertainty on judgments of the decision-maker(s). Such a unique modeling feature is further embedded with a non-linear optimization formulation to maximize the consistency in pair-wise comparison and weight estimation for each criterion. Case study results reveal that the proposed model is efficient not only for selecting the most suitable project for a specific site, but also for determining the priorities for implementing those suitable projects among multiple sites given the budget constraint. Comparative study between the proposed model and the existing ranking methods has also indicated its capability to capture the comprehensive impacts of all contributory factors which have been neglected by most existing single multi-criteria approaches during the safety project selection process. The clarity of model inputs, ease of synthesizing the final score of each candidate project, and the interpretation of results with respect to different selection criteria offer its best potential to be used as an effective tool for highway safety managers to assess and refine the safety improvement investments.     

Migrating an incident reporting system to a CCPS process safety metrics model

A major chemical company established a formal incident investigation and reporting system several years ago. The original system focused heavily on worker-related injuries, illnesses, and near-misses and was used primarily to track statistics reportable to the Occupational Safety and Health Administration (OSHA). This Occupational Injury and Illness (OII) approach has been recognized to be an ineffective tool for measuring, predicting, and preventing process safety incidents. The Center for Chemical Process Safety (CCPS) recently published guidelines on how to establish safety metrics for the measurement and reduction of process safety incidents. The process safety metrics approach relies upon leading and lagging metrics to improve organization process safety. This paper is a case study of the analysis of one organization’s incident database, which represents approximately five years of data from over a dozen facilities. The aim of this investigation was to extract useful process safety metrics from the incident investigation and reporting system, which would be pertinent to the types of process units and process functions at these facilities. This paper will discuss the approach taken to extract process incident information from an OII-based database and present the difficulties of performing an analysis on such a database. This paper provides guidance on how to migrate an existing OII-based reporting system to a program that includes process safety metrics in accordance with industry best practices.     

Organizational Climate Metrics as Safety,Health and Environment Performance Indicators and an Aid to Relative Risk Ranking within Industry

The chemical, pharmaceutical and other related process industries are characterized by inherently hazardous processes and activities. To ensure that considered risk management decisions are made it is essential that organizations have the ability to rank the risk profiles of their assets and operations. Current industry risk ranking techniques are biased toward the assessment of the risk potential of the asset or operation. Methodologies used to assess these risks tend to be engineering-based and include, for example, hazard identification and event rate estimation techniques. Recent research has associated lagging safety performance indicators with metrics of organizational safety climate. Despite the evidence suggesting their potential usefulness, organizational climate metrics have not yet been exploited as a proactive safety, health and environmental performance indicator or as an aid to relative risk ranking. This paper summarizes research that successfully produced a statistical model of organizational climate and its relationship to site significant injury frequency rates, allowing the relative risk ranking of sites based upon organizational climate metrics. The responses to an industrial organizational survey are examined for a pharmaceutical company's sites in the United Kingdom, Sweden and the United States. Projection to Latent Structures Analysis is performed on the survey responses. The resultant models are shown to be able to accurately model the site significant injury frequency rates. The organizational climate metrics that discriminate between the safety performance levels of different sites are identified.     

A method for assessing health and safety management systems from the resilience engineering perspective

This article introduces a method for assessing health and safety management systems (MAHS) that has two innovative characteristics: (a) it brings together the three main auditing approaches to health and safety (HS) – the structural approach (which assesses the system prescribed), the operational approach (which assesses what is really happening on the shop-floor) and the performance approach (which assesses the results of performance indicators); (b) it emphasizes the resilience engineering perspective on HS, which takes into consideration four major principles (flexibility, learning, awareness, and top management commitment). Such principles underlie seven major assessment criteria, which in turn are divided into items (e.g. hazard identification from a resilience perspective is an item that belongs to the criteria of production processes). The items are sub-divided into statements, which are the requirements that should be assessed based on interviews, analysis of documents and direct observations. Within the 112 requirements proposed, 38 of them have clear links with at least one out of the four resilience engineering principles adopted. The remaining requirements are based on traditional assumptions underlying the so-called best practices of HS management. The results of the assessment for each item are expressed by a score on a scale of compliance with the established requirements, ranging from 0% to 100%. The specific score within that scale is obtained from tables used to assess applications for the Brazilian national quality award. The MAHS was tested in a case study that was carried out in a factory that manufactures automobile exhaust systems, located in Brazil.     

锅炉烟尘监测过程质量控制及现场采样应注意的问题

以生态文明全面取代工业文明,是实现人类生存进步及经济可持续发展的唯一途径。以我国为例,在经历40年社会改革开放、经济高速增长之后,工业化、城市化、现代化所取得巨大成就的背后,是生态环境的严重破坏,尤其近年来"雾霾"成为生态环境治理中最为顽固的诟病。锅炉烟尘是造成雾霾现象的"主要元凶",从环境监测角度出发,加强锅炉烟尘监测过程及现场采样质量控制,精准地获取相关数据,能够为环境治理方案提供科学依据。但同时,锅炉烟尘监测及采样是十分复杂且具有系统性的工作,在整个过程中需要加强质量控制。本文列举相关注意问题,以供技术人员在操作中参考借鉴。     

中国职业安全卫生一体化发展模式探索

一体化管理是现代企业安全管理发展的必然趋势,中国职业安全卫生在不断的发展和完善过程中正从狭隘的劳动保护朝着一体化可持续的方式发展。针对当前影响安全生产的主体要素,探讨了从安全观念、统一立法、管理体系、人才培养、社会保障5个层面构建中国职业安全卫生一体化发展模式的可能性和必要性,并指出了OSH一体化发展模式的要害与对策。     

水资源管理模式发展趋势探析

随着工业进步和社会发展,水污染亦日趋严重,已对人类的生存安全构成重大威胁,成为人类健康、经济和社会可持续发展的重大障碍。水安全与水资源管理是全球战略问题,如何进行水资源管理和研究也是当今社会面临的难题。本文就水资源管理模式发展趋势进行阐述。     

一体化动态安全管理

管理(质量、安全、健康、环境)一体化是现代企业发展的目标之一,随其不断的完善和发展,安全管理正朝着一体化可持续的方向发展。安全管理的一体化不仅能解决安全管理中出现的各种具体问题,提高安全管理工作的效能,而且能深化企业管理的一体化,一体化动态安全管理是安全管理发展的必然趋势。笔者构建了一体化动态安全管理体系,一体化安全管理体系是一个“以人为本,以法律、制度以及规范为基础的可持续发展的全面控制动态体系”。在安全管理一体化的过程中,不仅实现了微观一体化———对象一体化和过程一体化,还实现了宏观一体化;阐述了一体化安全管理的几个基本原则;分析了一体化安全管理体系的特点。一体化动态安全管理的实施将从真正意义上实现以人为本,实现安全管理的可持续发展。     

Methodological application of system dynamics for evaluating traffic safety policy

System dynamics (SDs) is a methodology that can be used to understand the behavior and dynamics of complex systems over time. SD utilizes a range of tools and techniques such as influence and causal loop diagrams, computer simulation and optimization. SD has been used to facilitate the analysis of complex physical and social systems, e.g. water resources, climate change and industrial accidents. One of the key reasons for its growing popularity is that it allows policy experimentation and facilitates the discussion of ‘what-if’ scenarios. Within the realm of road traffic research, SD has been primarily used to examine micro level issues such as the interactions between the driver, infrastructure and the vehicle. Even though such micro level analysis are important, macro traffic safety policies can create more sustainable systems that pre-empt safety issues and reduce likelihood of traffic accidents. This paper develops two models to demonstrate how the methodology of SD can facilitate and encourage macro and meso level analysis of traffic safety policy. The first model is used to assess policy options so as to encourage the purchase of cars with higher safety ratings. The second model, is used to evaluate the impact of public transport policies on travel time and traffic safety considerations. The strength and weaknesses of the SD methodology in road transport/safety analysis are also examined. It is suggested that SD is most appropriate for formulating macro level policy as it can account for the dynamic complexity associated with the road transport system.     

浅述市场经济下的安全生产

在建立社会主义市场经济过程中 ,难免出现经济秩序混乱、恶性竞争、忽视安全生产、规章制度不健全、事故多发等现象。如何有效遏制事故多发 ,促使安全生产长治久安 ,切实保障人民群众生命财产安全是社会各界关注的话题。通过对西昌市凉山州安全生产现状的分析 ,笔者认为 ,理顺体制、健全法治、依法严治、提高人民安全意识是市场经济条件下安全生产切实可行的长效监管机制     

On the use of criteria based on the SMART acronym to assess quality of performance indicators for safety management in process industries

Management of safety, and barriers in particular, includes using information expressing performance, i.e. use of safety performance indicators. For this information to be useful, the indicators should demonstrate adequate quality. In other words, they should satisfy some predefined set of quality criteria. Without showing adequate quality, the indicators are generally unable to provide sufficient support for barrier management, which could result in poor decisions. In this article, the use of the SMART criteria is considered to assess the quality of safety performance indicators in process industries. SMART being an acronym for ‘specificity’, ‘measurability’ or ‘manageability’, ‘achievability’, ‘relevancy’ and ‘time-based’, covering five key aspects and criteria for assessing the quality of an indicator. A discussion on whether the indicators are able to demonstrate adequate quality by satisfying these criteria has been conducted. The finding is that all of the SMART criteria should be satisfied for a safety performance indicator to demonstrate acceptable quality and to be regarded as useful to support barrier management decision-making. However, it has also been observed that including the ‘M’ criterion in the assessment of quality is not needed. When all the other criteria are satisfied there is no way the conclusions could be misleading as a result of measurability or manageability aspects. Hence, for safety performance indicator quality, only four of the criteria are assessed and suggested for such situations to shorten the acronym to ‘STAR’. A key safety indicator used in downstream process facilities, i.e. ‘dangerous fluid overfilling events’, motivated from the 2005 Texas City refinery accident, is used to illustrate the situation. The indicator is also applied to another incident, the Buncefield oil storage depot's accident in 2005, to provide a broader context for using it. The findings in this article could also be applied beyond the context studied. This means that, despite focusing on safety indicators in the process industries, the findings are considered as relevant and applicable to other types of performance indicators and to other energy industries.     

石油化工催化剂生产过程中的职业病防治及应急处理

石化企业使用了大量的催化剂,催化剂开发、生产过程复杂,有许多原料和生产工艺,存在许多潜在的安全隐患和职业病危害因素。为预防催化剂生产过程中的事故,通过分析催化剂生产过程中的职业病危害分析,提出了相应的职业病防范及应急处置措施,加强催化剂生产过程中的职业病防治和应急处置能力,创造良好的经济、生态和社会效益,有效防止催化剂生产过程中发生安全事故和职业病。     

从社会变革看我国事故频发的管理根源——价值缺陷导致的管理失灵分析

如何认识和解决我国事故高发问题始于20世纪90年代,至今仍未得到很好地解决,已成为社会广泛关注的焦点。笔者以探索事故高发的管理根源为目的,对我国目前事故高发问题即“安全管理的困惑”从不同方面、不同层次上的具体表现进行了分析,将其寓于我国社会经济变革的大背景进行认识,从安全管理的哲学层次和我国社会经济变革的发展中研讨“事故高发、频发”的管理根源,分别从安全科学理论、世界社会经济发展的历史以及安全管理层次及其相互联系的角度,对我国事故高发问题进行了全面论述,提出了哲学文化层次带来的问题是产生“管理困惑”的源头。从整体上来看,我国事故高发、频发的管理根源在于:社会经济变革条件下产生的,由价值缺陷导致的“管理失灵”。“管理失灵”是问题的表现形式和结果,社会经济变革产生的“价值缺陷”是问题的核心。     

安全科学与社会可持续发展

笔者介绍了安全科学的兴起和内涵 ;认为安全科学的定义应是保护人类安全健康的、促进社会可持续发展的、跨门类综合性的交叉科学 ;论述了安全生产是我国的一项基本国策及全国安全生产现状 ,说明了伤亡事故的严重性和重大损失对我国社会发展的负面影响。还对安全科学促进社会可持续发展提出了 1 0项建议 ,其中包括 2 1世纪初期 2 0年内的重大科技问题的攻关内容的建议 ,可供国家有关部门战略决策的参考。