Safety problems

Absorption. If possible, a component which already exists in the flowsheet should be used as a solvent. Introducing an extraneous component into the flowsheet introduces additional complexity and the possibility of increased environmental and safety problems later in the design. 

Operation at extremes of pressure and temperature brings a number of safety problems ... 

It should be noted finally that adding gasoline to diesel fuel which was sometimes recommended in the past to improve cold behavior conflicts with the flash point specifications and presents a serious safety problem owing to the presence of a flammable mixture in the fuel tank airspace. Adding a kerosene that begins to boil at 150°C does not have the Scune disadvantage from this point of view. 

Reppe s work also resulted in the high pressure route which was estabUshed by BASF at Ludwigshafen in 1956. In this process, acetylene, carbon monoxide, water, and a nickel catalyst react at about 200°C and 13.9 MPa (2016 psi) to give acryUc acid. Safety problems caused by handling of acetylene are alleviated by the use of tetrahydrofuran as an inert solvent. In this process, the catalyst is a mixture of nickel bromide with a cupric bromide promotor. The hquid reactor effluent is degassed and extracted. The acryUc acid is obtained by distillation of the extract and subsequendy esterified to the desked acryhc ester. The BASF process gives acryhc acid, whereas the Rohm and Haas process provides the esters dkecdy. 

Potential health and safety problems of acryflc polymers occur in their manufacture (159). During manufacture, considerable care is exercised to reduce the potential for violent polymerizations and to reduce exposure to flammable and potentially toxic monomers and solvents. Recent environmental legislation governing air quality has resulted in completely closed ketde processes for most acryflc polymerizations. Acryflc solution polymers are treated as flammable mixtures. Dispersion polymers are nonflammable. 

Corrosion occurs when the metallic iron in DRI is wetted with fresh or salt water and reacts with oxygen from air to form mst, Ee(OH)2- The corrosion reactions continue as long as water is present. Because water evaporates at approximately 100°C, corrosion reactions have a low temperature limit even though the reactions are exothermic. Small amounts of hydrogen may be generated when DRI reacts with water. However, this poses no safety problem as long as proper ventilation is provided. 

R. H. Hunt, Optical demote Sensing and Applications to Environmental and Industrial Safety Problems, Apr. 6—8, 1992, Ain and Waste Management Association, Pittsburgh, Pa., 1992, p. 446. 

Most general-purpose release agents have been developed for this market in part because of their low toxicity and chemical inertness and do not usually present health and safety problems. Some of the solvent dispersions require appropriate care in handling volatile solvents, and many supphers are offering water-based alternatives. Some of the sohds, particularly finely divided hydrophobic sohds, can also present inhalation problems. Some of the metallic soaps are toxic, although there is a trend away from the heavier, more toxic metals such as lead. The reactive type of release coating with monomers, prepolymers, and catalysts often presents specific handling difficulties. The potential user with health and safety questions is advised to consult the manufacturer directly. 

The most important hazard ia the manufacturiag of xanthates is the use of carbon disulfide (qv) because of its low flash poiat, ignition temperature, and its toxicity. A report on the manufacture of sodium ethyl xanthate at Keimecott Nevada Mines Division discusses the various safety problems and the design of a faciUty (81). A plant layout and a description of the reagent preparations are also given. 

The low autoignition temperature of benzaldehyde (192°C) presents safety problems since benzaldehyde can be ignited by exposure to low pressure steam piping, for example. Benzaldehyde may also spontaneously ignite when soaked into rags or clothing or adsorbed onto activated carbon (13). 

Metal Finishing and Corrosion Control. The exceptional corrosion protection provided by electroplated chromium and the protective film created by applying chromium surface conversion techniques to many active metals, has made chromium compounds valuable to the metal finishing industry. Cr(VI) compounds have dominated the formulas employed for electroplating (qv) and surface conversion, but the use of Cr(III) compounds is growing in both areas because of the health and safety problems associated with hexavalent chromium and the low toxicity of trivalent chromium (see... 

Although many environmental and safety problems can be avoided using UCG, there is some concern about groundwater contamination as a result of the process (see Groundwatermonitoring). 

In contrast to other cryogenic fluids, liquid oxygen is slightly magnetic. It is also chemically reactive, particularly with hydrocarbon materials. Oxygen thus presents a safety problem and requires extra precautions in handling. 

Facilities Reviews There are many lands of facilities reviews that are useful in detec ting and preventing process safety problems. They include pre-start-up reviews (before the plant operates), new-plant reviews (the plant has started, but is stiU new), reviews of existing plants (safety, technology, and operations audits and reviews), management reviews, critical instrument reviews, and hazardous materials transportation reviews. 

Institute for Safety Problems ofNPP NASU, Chernobyl ... 

Elimination of lube oil and auxiliary systems, thereby eliminating certain potential safety problems and maintenance costs. 

Measures to minimize safety problems must be initiated at the start of the life cycle of any product, but too often determinations of criticality are left to production or quality control personnel who may have an incomplete knowledge of which items are safety critical (Hammer, 1980). Any potential non-conformity that occurs with a severity sufficient to cause a product or service not to satisfy intended normal or reasonably foreseeable usage requirements is termed a defect (Kutz, 1986). The optimum defect level will vary according to the application, where the more severe the consequences of failure the higher the quality of conformance needs to be. 

Safety problem - degradation of function with possible severe injury... 

Working with a Process Hazards Analysis (PHA) team was particularly rewarding. The plant operators on the team pointed out items that they had considered safety problems for years, but that hadn t been fully addressed until the PHA team was formed. We used the What if analysis method. Many methods are available for PHA. 

In the lithium-ion approach, the metallic lithium anode is replaced by a lithium intercalation material. Then, tw O intercalation compound hosts, with high reversibility, are used as electrodes. The structures of the two electrode hosts are not significantly altered as the cell is cycled. Therefore the surface area of both elecftodes can be kept small and constant. In a practical cell, the surface area of the powders used to make up the elecftodes is nomrally in the 1 m /g range and does not increase with cycle number [4]. This means the safety problems of AA and larger size cells can be solved. 

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