Materials refineries

The adsorbents have been prepared fi-om the halloysite (H) - mineral fi-om kaolinite group with an admixture of carbonaceous materials refinery waste deposits (RSI), sediment communal sewage (CSew) and cellulose (Ce), and the fiaction of these mixtures were within 30 - 70 wt.%. The mbcture of raw material was thermally (carbonaceous materials carbonization, 973 K) and hydrothermally (crystallization of the amorphous metahalloysite in alkaline solution to zeolitic structure of NaA type, 373 K) pretreated in order to cilitate their specific structure [1,2]. 

This category comprises conventional LPG (commercial propane and butane), home-heating oil and heavy fuels. All these materials are used to produce thermal energy in equipment whose size varies widely from small heaters or gas stoves to refinery furnaces. Without describing the requirements in detail for each combustion system, we will give the main specifications for each of the different petroleum fuels. 

Approximately 50—55% of the product from a coal-tar refinery is pitch and another 30% is creosote. The remaining 15—20% is the chemical oil, about half of which is naphthalene. Creosote is used as a feedstock for production of carbon black and as a wood preservative. Because of modifications to modem coking processes, tar acids such as phenol and cresyUc acids are contained in coal tar in lower quantity than in the past. To achieve economies of scale, these tar acids are removed from cmde coal tar with a caustic wash and sent to a central processing plant where materials from a number of refiners are combined for recovery. 

Used oil disposal trends include waste minimisation such as by reclaiming used fluid on site, as well as recycling of mineral oil lubricants instead of disposing by incineration. The recycling effort involves a system where spent mineral oils are collected then shipped to specialty refineries where the materials are distilled, hydrofinished, and re-refined into fresh base stocks. These re-refined materials are virtually identical to virgin feedstocks. 

LPG recovered from natural gas is essentially free of unsaturated hydrocarbons, such as propylene and butylenes (qv). Varying quantities of these olefins may be found in refinery production, and the concentrations are a function of the refinery s process design and operation. Much of the propylene and butylene are removed in the refinery to provide raw materials for plastic and mbber production and to produce high octane gasoline components. 

Naphthenic acid corrosion has been a problem ia petroleum-refining operations siace the early 1900s. Naphthenic acid corrosion data have been reported for various materials of constmction (16), and correlations have been found relating corrosion rates to temperature and total acid number (17). Refineries processing highly naphthenic cmdes must use steel alloys 316 stainless steel [11107-04-3] is the material of choice. Conversely, naphthenic acid derivatives find use as corrosion inhibitors ia oil-weU and petroleum refinery appHcations. 

Fig. 8. Combustion turbines with process heat recovery (a) represents direct use of exhaust gas for process heating where industrial process includes refinery, chemicals, food processing, and ethanol production and (b) exhaust-to-water heat exchanger where industrial process includes material drying,...

The indirect hydration, also called the sulfuric acid process, practiced by the three U.S. domestic producers, was the only process used worldwide until ICI started up the first commercial direct hydration process in 1951. Both processes use propylene and water as raw materials. Early problems of high corrosion, high energy costs, and air pollution using the indirect process led to the development of the direct hydration process in Europe. However, a high purity propylene feedstock is required. In the indirect hydration process, C -feedstock streams from refinery off-gases containing only 40—60 wt % propylene are often used in the United States. 

Miscellaneous. Where a copper refinery is adjacent to a lead (qv) plant it is feasible to recover the selenium in slimes by smelting them in conjunction with lead-bearing materials. Utilizing the lower temperatures needed to melt lead, the selenium is volatilized from a lead bath or cupel blown with air. The selenium is recovered from flue dust and fume by scmbbing. This is the process used by Union Miniere at its Hoboken plant in Belgium. 

Other components in the feed gas may react with and degrade the amine solution. Many of these latter reactions can be reversed by appHcation of heat, as in a reclaimer. Some reaction products cannot be reclaimed, however. Thus to keep the concentration of these materials at an acceptable level, the solution must be purged and fresh amine added periodically. The principal sources of degradation products are the reactions with carbon dioxide, carbonyl sulfide, and carbon disulfide. In refineries, sour gas streams from vacuum distillation or from fluidized catalytic cracking (FCC) units can contain oxygen or sulfur dioxide which form heat-stable salts with the amine solution (see Fluidization Petroleum). 

Many of the reserves of bitumen in tar sand formations are available only with some difficulty, and optional refinery methods are necessary for future conversion of these materials to Hquid products, because of the substantial differences in character between conventional petroleum (qv) and bitumen (Table 1). 

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