Asphalt processing costs

At a brownfield site in Illinois, the biopile process was used with air sparging to treat soils contaminated with petroleum hydrocarbons and by-products of asphalt production. Treatment at the 13- to 15-acre site occurred for one year, and site closure was achieved as a result of the process. The project cost was approximately 100,000, which was significantly less than the estimated cost of landfilling the contaminated soil (D21948R, pp. 3, 5). 

United Retek Corporation s asphalt emulsion stabilization process was used at an active paper company in Pawtucket, Rhode Island. The company wanted to expand its facility at the site however, lead contamination was discovered in the proposed 43,000-fU expansion area. Soil lead concentrations were in excess of 100 ppm at some locations within the area. Asphalt emulsion stabilization was used over 5 days to treat 2000 yd of soil. Total treatment costs were 80,000, or 2000 yd of soil treated at 40/yd. It was estimated that excavation and removal costs at the site would have been 200 to 250/yd of soil (D21950L, pp. 2, 3). 

Solvent-Refined Coal Process. In the 1920s the anthracene oil fraction recovered from pyrolysis, or coking, of coal was utilized to extract 35—40% of bituminous coals at low pressures for the purpose of manufacturing low cost newspaper inks (113). Tetralin was found to have higher solvent power for coals, and the I. G. Farben Pott-Broche process (114) was developed, wherein a mixture of cresol and tetralin was used to dissolve ca 75% of brown coals at 13.8 MPa (2000 psi) and 427°C. The extract was filtered, and the filtrate vacuum distilled. The overhead was distilled a second time at atmospheric pressure to separate solvent, which was recycled to extraction, and a heavier liquid, which was sent to hydrogenation. The bottoms product from vacuum distillation, or solvent-extracted coal, was carbonized to produce electrode carbon. Filter cake from the filters was coked in rotary kilns for tar and oil recovery. A variety of liquid products were obtained from the solvent extraction-hydrogenation system (113). A similar process was employed in Japan during Wodd War II to produce electrode coke, asphalt (qv), and carbonized fuel briquettes (115). 

Some state government officials have expressed concern that, because the two most proven forms of rubberized asphalt are patented, prices for this material may be higher than they would be if the material were not patented. It is estimated that the royalty adds 35 percent to the cost of asphalt-rubber and 27 percent to Plus Ride The patent for asphalt-rubber expires in 1991. After that time ARPG expects more companies to become involved. The TAK process is not patented, but also has not been tested as long as the patented types of rubberized asphalt. 

Dikes may be made of earth, steel, crushed stone, or concrete, and they may be lined with a layer of clay or asphalt, or plastic film. There are several constraints on dike material it must be chemically compatible with the process material, be durable under normal weathering conditions, have structural characteristics suitable to support loads from maintenance vehicles, and be cost effective. Ideally, to prevent ground contamination, the ground between a vessel and a dike wall should be nonporous. 

Styrene-containing block copolymers are commercially very important materials. Over a billion pounds of these resins are produced annually. They have found many uses, including reinforcement of plastics and asphalt, adhesives, and compatibilizers for polymer blends, and they are directly fabricated into articles. Most styrene-containing block copolymers are manufactured using anionic polymerization chemistry. However, anionic polymerization is one of the more costly polymerization chemistries because of the stringent requirements for monomer and solvent purity. It would be preferred, from an economic cost perspective, to have the capability to utilize free radical chemistry to make block polymers because it is the lowest cost mode of polymerization. The main reasons for the low cost of FR chemistry are that minimal monomer purification is required and it can be carried out in continuous bulk polymerization processes. 

The residue from crude distillation in North America is usually processed to an asphalt product as much as possible, since as a component of residual fuel oils it generally fetches a lower price than as asphalt itself. The residual fuel oil market is quite competitive since ships and tankers can choose to load at centers, which offer the lowest cost fuels. Also the price of the heavier grades of bunker fuel used to supply power stations has to be comparable to coal to be competitive. 

The high sulfur cost in comparison to bitumen during that period, the blending and storage problems encountered and the health/safety concerns had affected the use of sulfur in asphalt works. The development of solid flour pellets, added directly to the asphalt mixing process, and changes in sulfur/bitumen cost eliminated the abovementioned problems. 

Utilization of scrap tire rubber in asphalt has advantages in the performance of roads and their longevity. These include enhanced ductility, crack resistance, skid resistance, and noise reduction. Disadvantages of the rubber-modified asphalt are its cost and a possibility of toxic emissions into the air. Tests indicated that rubber-modified asphalt increases the cost of road construction by about 50% in comparison with conventional asphalt [192]. The requirement for an additional step of hot mixing during processing of the rubber-asphalt mix may possibly cause toxic emissions into the air. 

Carbon fibres are obtained from different organic fibres (precursors) by pyrolysis, which consists of decomposition into smaller molecules at high temperature. The process of fabrication of carbon fibres from special PAN fibres includes two steps oxidative stabilization at low temperature and carbonization at high temperature in an inert atmosphere. Due to the high cost of raw materials (e.g. PAN fibres) and of this production process, carbon fibres are still expensive. Carbon fibres may be also produced from crude oil deposits like pitches or asphalts. Three main groups of carbon fibres are considered as possible composite materials reinforcement ... 

As the inner seal for an externally flushed pump, such as a black oil (i.e., asphalt, resid), pump will continue to have the same loss of seal flush material to the process stream through the throat bushing with the conventional double mechanical seal as when the external seal is an seal, there is no real process incentive for use of the more costly seal. 

Over the years, multilayers of tar-based waterproofers replaced the hot asphalt used in roofing. In early 1900, asphalt became available from petroleum refining, and it was followed by oxidized bitumen interlaid with roofing felt and then alternated with a mineral base sheet, l" Asphalt-based materials are used extensively as binders, sealants, and waterproof coatings in diverse applications because of their low cost, inherent cohesive nature, weather-resistant properties, and ease of processing in the molten state. 

Many other polymeric additives are used in butyl and PIB adhesives and sealants. Most worthy of mention are factice, which can lower cost, improve processing, and reduce stringing amorphous polypropylene, which can reduce cost and improve processing as well as impart thermoplastic character various waxes, which function in much the same manner as amorphous polypropylene and asphalt, again for lower cost. 

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