Approaches for preventing and mitigating accidental gaseous chemical releases

This paper presents a review of approaches to prevent and mitigate accidental releases of toxic and flammable gases. The prevention options are related to: choosing safer processes and materials, preventing initiating events, preventing or minimizing releases, and preventing human exposures. the mitigation options include: secondary confinement, de-inventory, vapor barriers, and water sprays/monitors. Guidelines for the design and operation of effective post-release mitigation systems are also presented

Mitigation of unconfined releases of hazardous gases via liquid spraying

The capability of water sprays in mitigating clouds of hydrofluoric acid (HF) has been demonstrated in the large-scale field experiments of Goldfish and Hawk, which took place at the DOE Nevada Test Site. The effectiveness of water sprays and fire water monitors to remove HF from vapor plume, has also been studied theoretically using the model HGSPRAY5 with the near-field and far-field dispersion described by the HGSYSTEM models. This paper presents options to select and evaluate liquid spraying systems, based on the industry experience and mathematical modeling

Mitigation options for accidental releases of hazardous gases

The objective of this paper is to review and compare technologies available for mitigation of unconfined releases of toxic and flammable gases. These technologies include: secondary confinement, deinventory, vapor barriers, foam spraying, and water sprays/monitors. Guidelines for the design and/or operation of effective post-release mitigation systems and case studies involving actual industrial mitigation systems are also presented

The OSHA and EPA programs on preventing chemical accidents and potential applications in the photovoltaic industry

OSHA issued in 1992, the Process Safety Management (PSM) of Highly Hazardous Substances. This rule requires owners/operators of facilities that handle hazardous chemicals in quantities greater than the listed thresholds to establish all the elements of a PSM. EPA has issued in June 1996, the rules for a Risk Management Program which also refers to specific substances and threshold quantities. These rules are applicable to all the facilities that use or store any of 139 regulated substances at quantities ranging from 100 lb to 10,000 lb. The RMP rule covers off-site hazards, while the OSHA Process Safety Management (PSM) rule covers worker safety issues within the plant boundary. Some of the listed substances may be found in photovoltaic manufacturing facilities. This brief report presents the basic elements of these two rules and discusses their potential applicability in the photovoltaic industry

Penilaian kitaran hayat sel suria terpeka pewarna di Malaysia

Tenaga suria adalah sumber alam yang paling banyak di bumi yang mudah dieksploitasi, bersih, tahan lama dan stabil yang menjadikannya sesuai untuk menghasilkan tenaga elektrik berbanding dengan sumber tenaga yang lain. Walau bagaimanapun, teknologi konvensional suria fotovolta (PV) seperti silikon dan sel suria filem nipis boleh memberikan kesan alam sekitar ke atas kitaran hayat mereka yang disebabkan oleh proses pengeluaran yang rumit. Ini menyebabkan ramai saintis mengkaji sel-sel suria yang baru termasuklah sel suria terpeka pewarna (DSSC). Oleh itu, objektif penyelidikan ini adalah untuk mengkaji penilaian impak alam sekitar secara komprehensif mengenai teknologi ini di Malaysia melalui penilaian kitaran hidup (LCA) bermula dari buaian hingga pagar (cradle-to-gate). Dua petunjuk alam sekitar telah digunakan dalam kajian ini iaitu kumulatif keperluan tenaga (CED) yang memberi kesan kepada masa bayaran balik tenaga (EPBT), dan pelepasan gas rumah hijau (GHG). Hasilnya menunjukkan bahawa DSSC mempunyai EPBT iaitu 3.49 tahun, CED yang berjumlah 1190.29 MJ/m2 dan GHG sebanyak 262.38 gCO2eq/kWh yang lebih tinggi berbanding penyelidik yang lain. Penggunaan tenaga yang tinggi semasa proses fabrikasi modul dan pemasangan panel, kecekapan penukaran (ŋ) yang rendah, dan purata penyinaran suria (IR) yang rendah serta penggunaan substrat kaca FTO adalah beberapa faktor yang telah dikenal pasti sebagai penyumbang utama kepada keputusan ini

LIFE CYCLE INVENTORY ANALYSIS IN THE PRODUCTION OF METALS USED IN PHOTOVOLTAICS.

Material flows and emissions in all the stages of production of zinc, copper, aluminum, cadmium, indium, germanium, gallium, selenium, tellurium, and molybdenum were investigated. These metals are used selectively in the manufacture of solar cells, and emission and energy factors in their production are used in the Life Cycle Analysis (LCA) of photovoltaics. Significant changes have occurred in the production and associated emissions for these metals over the last 10 years, which are not described in the LCA databases. Furthermore, emission and energy factors for several of the by-products of the base metal production were lacking. This report aims in updating the life-cycle inventories associated with the production of the base metals (Zn, Cu, Al, Mo) and in defining the emission and energy allocations for the minor metals (Cd, In, Ge, Se, Te and Ga) used in photovoltaics

Model institutional infrastructures for recycling of photovoltaic modules

This paper describes model approaches to designing an institutional infrastructure for the recycling of decommissioned photovoltaic modules; more detailed discussion of the information presented in this paper is contained in Reaven et al., (1996)[1]. The alternative approaches are based on experiences in other industries, with other products and materials. In the aluminum, scrap iron, and container glass industries, where recycling is a long-standing, even venerable practice, predominantly private, fully articulated institutional infrastructures exist. Nevertheless, even in these industries, arrangements are constantly evolving in response to regulatory changes, competition, and new technological developments. Institutional infrastructures are less settled for younger large- scale recycling industries that target components of the municipal solid waste (MSW) stream, such as cardboard and newspaper, polyethylene terephthalate (PET) and high-density polyethylene (HDPE) plastics, and textiles. In these industries the economics, markets, and technologies are rapidly changing. Finally, many other industries are developing projects to ensure that their products are recycled (and recyclable) e.g., computers, non-automotive batteries, communications equipment, motor and lubrication oil and oil filters, fluorescent lighting fixtures, automotive plastics and shredder residues, and bulk industrial chemical wastes. The lack of an an adequate recycling infrastructure, attractive end-markets, and clear the economic incentives, can be formidable impediments to a self- sustaining recycling system

Real energy payback time and carbon footprint of a GCPVS

Grid connected PV systems, or GCPVS, produce clean and renewable energy through the photovoltaic e ect in the operation stage of the power plant. However, this is the penultimate stage of the facilities before its dismantlement. Before starting generating electricity with zero CO2 emissions, a negative energy balance exists mainly because of the embodied energy costs of the PV components manufacturing, transport and late dismantlement. First, a review of existing studies about energy life cycle assessment (LCA) and Carbon Footprint of PV systems has been carried out in this paper. Then, a new method to evaluate the Real Energy Payback Time (REPBT), which includes power looses due to PV panels degradation is proposed and di erences with traditional Energy Payback Time are analysed. Finally, a typical PV grid connected plant (100 kW nominal power) located in Northern Spain is studied in these sustainability terms. This facility has been firstly completely modelled, including PV modules, inverters, structures and wiring. It has been also considerated the energy involved in the replacement of those components with shorter lifespan. The PV panels degradation has been analysed through the comparison of normalised flash test reports on a significant sample of the installed modules before and 5 years after installation. Results show that real PV degradation a ect significantly to the Energy Payback Time of the installation increasing slightly a 4:2% more the EPBT value for the case study. However, along a lifespan of 30 years, the GCPVS under analysis will return only 5:6 times the inverted energy on components manufacturing, transport and installation, rather than the expected 9:1 times with the classical estimation

Life cycle assessment of ground mounted photovoltaic panels

Abstract. Nowadays, the problem of carbon emission attracts a lot of attention from people in the world. To solve this problem, many solutions are proposed to get the target of Greenhouse Gas emission reduction. Among of all, the increase of the share of renewable energy is known as a feasible and promising approach for achieving this goal. Solar power and wind power is considered as two dominant renewable sources having a significant contribution to the power generation as well as reducing CO₂ emissions. In this study, ground mounted photovoltaic plant is taken as a approach for achieving this target. The objective of the study was to answer three research questions: (1) What are the life-cycle environmental impacts of ground-mounted photovoltaic (GMPV) systems; (2) What are the missing data to perform life cycle assessment (LCA) of GMPV? and (3)What are the future development projections for GMPV and how would they impact on their LCA? Furthermore, the state of the art of GMPV technology is also reviewed. The thesis is based on the data of Ecoinvent v3.3, available in open LCA, associating with six cases studies on GMPV, will give an evaluation about the state of the art of technology, the data gap of GMPV in Ecoinvent v3.3. The LCA method is known as a quantitative approach which is utilized to make an evaluation of whole process of a product. The four steps of LCA are goal and scope definition, inventory analysis, impact assessment and interpretation. Based on the six case studies from literature, the data gaps were recognized regarding the power output, number of modules, performance module and degradation rate, and the materials in the mounting system. These data gaps are very important because they have the significant impacts on the implementation of LCA approach. If these data gaps were filled, operators would be likely to have a more precise evaluation of GMPV systems. It was concluded that multicrystalline silicon module is the commercially available material with highest efficiency but, because of their high cost, the development is shifted towards CdTe thin film materials. CdTe thin film is gradually proving its position in the photovoltaic (PV) commercial market because of growing efficiency and reasonable cost, which are very important when applying in the large scale of GMPV systems. Finally, it was suggested that the third generation technology, which is the combination between Generation 1 technology and Generation II technology with the feature of high efficiency and reasonable cost, has the highest potential for applying in GMPV

Las células fotovoltaicas como alternativa energética

Las células fotovoltaicas como alternativa energética