Claus method

Notwithstanding the uncontestable advantages of the general clause method, it has a major disadvantage there is considerable lack of regulation and the final decision is passed on to the courts. 

The idea of a single comprehensive law on technology may have to be waived. It would either be devoid of practical substance or, if it did include substantive regulations, would be obsolete before final promulgation. However, the principles should be adhered to. Legislative procedures, for example, which follow the general clause method will be determining factors in the future as well. 

Sulfur recovery catalysts. Sulfur reclaim is to transform the acidic gas containing H2S produced during processes into sulfate, and then sulfate is recycled. The sulfur recovery has many methods, such as iron oxide process, ADA process, G-V process, hypermanganate process, dichromate process, catalytic combustion process and Claus method etc. Herein, the Claus method will be introduced briefly. 

The Claus method is based on reaction that H2S is combusted into SO2 with a mole ratio (H2S/SO2) of 2 1 in the presence of limited amount of air. The resulted gas mixture is then transformed into elemental sulfur on AI2O3 catalyst. Meanwhile, the organic sulfur compounds are hydrolyzed on the Claus catalyst. The basic reactions are as follows ... 

Current methods for removing sulfur from the hydrogen sulfide gas streams are typically a combination of two processes the Claus Process followed by the Beaven Process, SCOT Process, or the Wellman-Land Process. 

In addition to the methods developed to meet the product safety requirements of clause 4.1.7.1 you will need to provide the following to ensure compliance with applicable regulations ... 

The standard requires documented procedures to be prepared consistent with the requirements of this international standard, but what does this mean Preparing procedures consistent with the requirements of the standard means preparing those procedures where the standard requires them. Outside ISO 9001, ISO/TS 16949 does not use the same wording to require procedures. In some clauses it requires a process and in others it requires methods or a methodology or a system. Although systems are not procedures, procedures are not processes and methods are not necessarily procedures, systems, or processes. Some methods, however, will inevitable need one or more procedures. By including systems, methods, and processes, the standard now requires 43 documented procedures directly. 

Prior to conducting process studies a statement of objectives, the methods to be used, and the form in which the results are to be recorded should be defined. This might be called a Process Study Plan and be an output of process development (see clause 4.2.4.9). During process studies the results should be recorded in terms of measure-... 

The standard doesn t require a procedure covering inspection and test status however, as clause 4.2 requires a documented quality system, you will need to document the methods employed to denote inspection and test status. If you use stamps you will need a register to allocate stamps to particular individuals and to indicate which stamps have been withdrawn. When a person hands in a stamp it is good practice to avoid using the same number for 12 months or so to prevent mistaken identity in any subsequent investigations. 

Hydrogen sulfide, a coproduct, is used to recover sulfur by the Claus reaction. A CS2 yield of 85-90% based on methane is anticipated. An alternative route for CS2 is by the reaction of liquid sulfur with charcoal. However, this method is not used very much. 

Make sure that the drawings, specifications and bid documents are clear and unambiguous. Do not rely on exclusion clauses in the specification or bid document. Have designs checked and use methods and equipment that comply with British Standards and Codes of Practice. 

The regulation states The report must be reviewed with all affected personnel whose job tasks are relevant to the incident findings, including contract employees where applicable. The aim of this clause is to ensure that all affected employees understand why the incident occurred and what actions could prevent a recurrence. While the regulation does not specifically define the methods to comply with this requirement, it is imperative that the review is prompt and complete. In almost all cases, the review requires personal meetings, either individually or in small groups, to thoroughly review the incident and recommend corrective actions. 

Sulfur is widely distributed as sulfide ores, which include galena, PbS cinnabar, HgS iron pyrite, FeS, and sphalerite, ZnS (Fig. 15.11). Because these ores are so common, sulfur is a by-product of the extraction of a number of metals, especially copper. Sulfur is also found as deposits of the native element (called brimstone), which are formed by bacterial action on H,S. The low melting point of sulfur (115°C) is utilized in the Frasch process, in which superheated water is used to melt solid sulfur underground and compressed air pushes the resulting slurry to the surface. Sulfur is also commonly found in petroleum, and extracting it chemically has been made inexpensive and safe by the use of heterogeneous catalysts, particularly zeolites (see Section 13.14). One method used to remove sulfur in the form of H2S from petroleum and natural gas is the Claus process, in which some of the H2S is first oxidized to sulfur dioxide ... 

The method that Shavlik developed to carry out the structure generalization is complex, and requires the introduction of an extension to the horn clause deduction scheme to allow the repetitive application of a... 

Clausing P, Brunekreef B, van Wijen JH. 1987. A method for estimating soil ingestion by children. Int Arch Occup Environ Health 59 73-82. 

The simplest method of using intrinsically safe electrical circuits is not to design and certify them yourself, but rather to take advantage of a clause contained in NFPA 493 which states ... 

In its NEP, OSHA points out that for workplaces not covered by 1910.272, but where combustible dust hazards exist within dust control systems or other containers, citations under section 5(a)(1) of the OSH Act (the General Duty Clause) may generally be issued for deflagration (fire) or explosion hazards. National Fire Protection Association (NFPA) standards should be consulted to obtain evidence of hazard recognition and feasible abatement methods. Other standards are applicable to the combustible dust hazard. For example, if the workplace has a Class II location, then citations under 29 CFR 1910.307 may be issued to those employers having electrical equipment not meeting the standard s requirements. 

Companies should note that the Medicines and Healthcare products Regulatory Agency is entitled to request particulars of an advertisement, including particulars as to the content and form of the advertisement, the method of dissemination and the date of first dissemination, and such a request is not subject to any time limit. This does not apply to the certificates themselves in respect of which the three year limit in Clause 14.5 is applicable. 

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