Process stream disposal

Federal regulations (40 CFR 261) classify acrylonitrile as a hazardous waste and it is Hsted as Hazardous Waste Number U009. Disposal must be in accordance with federal (40 CFR 262, 263, 264), state, and local regulations only at properly permitted faciUties. It is Hsted as a toxic pollutant (40 CFR 122.21) and introduction into process streams, storm water, or waste water systems is in violation of federal law. Strict guidelines exist for clean-up and notification of leaks and spills. Federal notification regulations require that spills or leaks in excess of 100 lb (45.5 kg) be reported to the National Response Center. Substantial criminal and civil penalties can result from failure to report such discharges into the environment. 

Factors which may affect the cost of coal upgrading are environmental considerations such as toxicity, hazardous waste disposal, and carcinogenic properties (131). These and other environmental problems from process streams, untreated wastewaters, and raw products would figure significantly into the cost of commercialization. 

In spite of these efforts, significant quantities of metal-bearing wastes, ha2ardous or not, continue to be earmarked for disposal rather than reclamation. There are several reasons. Often the wastes are mixed from several process streams, contain relatively low concentrations of many recoverable metals, and may contain high concentrations of water, silicates, and secondary metals, such as calcium and iron. 

An important by-product of most energy technologies is heat. Few energy conversion processes are carried out without heat being rejected at some point in the process stream. Historically, it has been more convenient as weU as less cosdy to reject waste heat to the environment rather than to attempt significant recovery. The low temperatures of waste heat in relation to process requirements often make reuse impractical and disposal the only attractive alternative (see Process energy conservation). 

Chemical MF is used in several apphcations to recover caustic values from cleaning or processing streams. An example is the caustic solution used to clean dairy evaporators, which may be cleaned for reuse by passing it through a microfilter. Significant savings in caustic purchase and disposal costs provide the incentive. Acids are also recovered and reused. Ceramic microfilters are most commonly used in these apphcations. 

Most refinery process units and equipment are manifolded into a collection unit, called the blowdown system. Blowdown systems provide for the safe handling and disposal of liquids and gases that are either automatically vented from the process units through pressure relief valves, or that are manually drawn from units. Recirculated process streams and cooling water streams are often manually purged to prevent the continued buildup of contaminants in the stream. Part or all of the contents of equipment can also be purged to the blowdown system prior to shutdown before normal or emergency shutdowns. 

The term manufacture also includes coincidental production of a toxic chemical (e.g., as a byproduct or impurity) as a result of the manufacture, processing, use, or treatment of other chemical substances. In the case of coincidental production of an impurity (i.e., a chemical that remains in the product that is distributed in commerce), the de minimis limitation, discussed on page 11, applies. The de minimis limitation does not apply to byproducts (e.g., a chemical that is separated from a process stream and further processed or disposed). Certain listed toxic chemicals may be manufactured as a result of wastewater treatment or other treatment processes. For example, neutralization of acid wastewater can result in the coincidental manufacture of ammonium nitrate (solution). 

This chapter covers the design of facilities to handle equipment drainage and contaminated aqueous effluents that are sent for appropriate disposal blowdown drum systems to receive closed safety valve discharges, emergency vapor blowdowns, etc. and facilities for process stream diversion and slop storage. Also covered are criteria for selecting the appropriate method of disposal. Design of flares is covered in a subsequent chapter. 

Safety valve releases are routed to blowdown drums when the presence of liquid, toxic properties or other factors would make discharge to the atmosphere hazardous. Product and intermediate process streams may need to be diverted to alternative disposal if they are off-specification (e.g., during startup) or in the event of emergency shutdown of downstream equipment. 

Tube failure in a water-cooled or steam-heated exchanger used in hydrocarbon service can result in the contamination of the effluent cooling water or the condensate by the process stream, especially if the latter is at a higher pressure. Such effluents must be disposed of in such a maimer that the hydrocarbon contaminations can be safely contained. The following are some safe design practices ... 

The labor intensive replacement of membranes in plate and frame systems has been facilitated in the "leaf-module" design of Dorr Oliver (Figure 16). Here a number of plates are assembled in a disposable cartridge where the process stream flows over the plates and the permeate is ducted to a common header. 

Researchers claim that lonsiv TIE-96 can remove 99.9% of the plutonium, strontium, and cesium from waste solutions, allowing for wastes to be divided into separate low-level and high-level radioactive waste streams, where they can be safely and efficiently processed for disposal. 

Measuring potential agent contamination in certain solid process streams (e.g., sludges and dried salts) and in spent activated carbon presents challenges unique to the alternative technology sites. For baseline sites, these materials can be thermally treated in one of the incinerators (e.g., the metal parts furnace) to achieve the 5X decontamination level prior to disposal of the ashes. Because this is not an option for the alternative technology bulk sites, measurement techniques must be developed and demonstrated to certify that these materials have no detectable agent prior to off-site shipment for disposal. 

The sampling system consists of all the equipment required to present a process analyzer with a clean representative sample of a process stream and to dispose of that sample. When the analyzer is part of an automatic control loop, the reliability of the sampling system is as important as the reliability of the analyzer or the control equipment. 

Prior to geo-sequestration, the carbon dioxide has to be available in a concentrated form so that it can be compressed and liquefied prior to disposal. From the standpoint of the petrochemical industry, there are two types of emissions which we need to consider. The first type is when carbon dioxide is extracted from a process stream by typically dissolving the carbon dioxide in a solvent. Here the carbon dioxide is available as a... 

Sulfonation of LAB. The sulfonation of alkylbenzenes leads to sulfonic acid tyre product, which is then neutralized with a base such as sodium hydroxide to produce sodium alkylbenzene sulfonate. The sulfonation reaction is highly exothermic and instantaneous. An efficient reactor heat removal system is used to prevent the decomposition of the resultant sulfonic acid. The sulfonation reaction takes place by using oleum (SO3H2SO4) or sulfur trioxide (SO3). Although, the oleum sulfonation requires relatively inexpensive equipment, the oleum process has major disadvantages compared to sulfur trioxide. The need for spent acid stream disposal and the potential corrosion owing to sulfuric acid generation increased the problems related to oleum process [1]. 

Reactive process streams should be neutralized in a timely manner to permit conscientious disposal and to avoid safety problems. All streams that have not been effectively neutralized should be considered potentially hazardous, and the hazard should be assessed, perhaps in a safety laboratory, before storage. 

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