Costs olefines

Acetylene is used primarily as a raw material for the synthesis of a variety of organic chemicals (see AcETYLENE-DERiVED CHEMICALS). In the United States, this accounts for about 80% of acetylene usage and most of the remainder is used for metal welding or cutting. The chemical markets for acetylene are shrinking as ways are found to substitute lower cost olefins and paraffins for the acetylene, with some products now completely derived from olefinic starting materials. Metalworking appHcations, however, have held up better than chemical uses. 

FacilitatedTransport Process for Eow-Cost Olefin—Paraffin Separation, ATv2iacedTec m.o ogyPi.ogt.2im.E o. 70NANB4H1528 National Institute of Science and Technology, 1994. 

Current cost reduction demands point toward an on-board or on-module acoustic system integrated with the original layer structure of the module. This economic drive combined with the benefits of a monolithic, multilayer design bring a market growth opportunity for low-cost olefinic TPEs to compete with incumbents on the basis of ... 

Prospective Processes. There has been much effort invested in examining routes to acetic acid by olefin oxidation or from ethylene, butenes, or j -butyl acetate. No product from these sources is known to have reached the world market the cost of the raw materials is generally prohibitive. 

Ethers, such as MTBE and methyl / fZ-amyl ether (TAME) are made by a catalytic process from methanol (qv) and the corresponding isomeric olefin. These ethers have excellent octane values and compete on an economic basis with alkylation for inclusion in gasoline. Another ether, ethyl tert-huty ether (ETBE) is made from ethanol (qv) and isobutylene (see Butylenes). The cost and economic driving forces to use ETBE vs MTBE or TAME ate a function of the raw material costs and any tax incentives that may be provided because of the ethanol that is used to produce it. 

Characterization. In many cases, ftir is a timely and cost-effective method to identify and quantify certain functionaHties in a resin molecule. Based on developed correlations, ftir is routinely used as an efficient method for the analysis of resin aromaticity, olefinic content, and other key functional properties. Near infrared spectroscopy is also quickly becoming a useful tool for on-line process and property control. 

Although synthetic lubrication oil production amounts to only about 2% of the total market, volume has been increasing rapidly (67). Growth rates of the order of 20% per year for poly( a-olefin)s, 10% for polybutenes, and 8% for esters (28) reflect increasing automotive use and these increases would accelerate if synthetics were adopted for factory fill of engines by automotive manufacturers. The estimated production of poly( a-olefin)s for lubricants appears to be approximately 100,000 m /yr, esters 75,000, poly(alkylene glycol)s 42,000, polybutenes 38,000, phosphates 20,000, and dialkyl benzene 18,000 (28,67). The higher costs reflected in Table 18 (18,28) have restricted the volume of siUcones, chlorotrifluoroethylene, perfluoroalkylpolyethers, and polyphenyl ethers. 

Polyethylene. Traditional melt spun methods have not utilized polyethylene as the base polymer because the physical properties obtained have been lower compared to those obtained with polypropylene. Advances in polyethylene technology may result in the commercialization of new spunbonded stmctures having characteristics not attainable with polypropylene. Although fiber-grade polyethylene resin was announced in late 1986 (11,12), it has seen limited acceptance because of higher costs and continuing improvements in polypropylene resin technology (see Olefin POLYMERS, POLYETHYLENE). 

Over 70% of the total volume of thermoplastics is accounted for by the commodity resins polyethylene, polypropylene, polystyrene, and poly(vinyl chloride) (PVC) (1) (see Olefin polymers Styrene plastics Vinyl polymers). They are made in a variety of grades and because of their low cost are the first choice for a variety of appHcations. Next in performance and in cost are acryhcs, ceUulosics, and acrylonitrile—butadiene—styrene (ABS) terpolymers (see... 

A polysulfone is characterized by the presence of the sulfone group as part of its repeating unit. Polysulfones may be aUphatic or aromatic. AUphatic polysulfones (R and are alkyl groups) were synthesized by radical-induced copolymerization of olefins and sulfur dioxide and characterized many years ago. However, they never demonstrated significant practical utiUty due to their relatively unattractive physical properties, not withstanding the low cost of their raw materials (1,2). The polysulfones discussed in this article are those based on an aromatic backbone stmcture. The term polysulfones is used almost exclusively to denote aromatic polysulfones. 

HP Alkylation Process. The most widely used technology today is based on the HE catalyst system. AH industrial units built in the free world since 1970 employ this process (78). During the mid-1960s, commercial processes were developed to selectively dehydrogenate linear paraffins to linear internal olefins (79—81). Although these linear internal olefins are of lower purity than are a olefins, they are more cost-effective because they cost less to produce. Furthermore, with improvement over the years in dehydrogenation catalysts and processes, such as selective hydrogenation of diolefins to monoolefins (82,83), the quaUty of linear internal olefins has improved. 

Conventional triorganophosphite ligands, such as triphenylphosphite, form highly active hydroformylation catalysts (95—99) however, they suffer from poor durabiUty because of decomposition. Diorganophosphite-modified rhodium catalysts (94,100,101), have overcome this stabiUty deficiency and provide a low pressure, rhodium catalyzed process for the hydroformylation of low reactivity olefins, thus making lower cost amyl alcohols from butenes readily accessible. The new diorganophosphite-modified rhodium catalysts increase hydroformylation rates by more than 100 times and provide selectivities not available with standard phosphine catalysts. For example, hydroformylation of 2-butene with l,l -biphenyl-2,2 -diyl... 

Light-Duty Recreational Surfaces. Artificial surfaces intended for incidental recreational use, eg, swimming pool decks, patios, and landscaping, are designed primarily to provide a practical, durable, and attractive surface. Minimum cost is a prime consideration and has driven the quaUty of some such products to a low level. Most surfaces in this category utilize polypropylene ribbon and a tufted fabric constmction (see Olefin polymers, polypropylene). ... 

The ethylene feedstock used in most plants is of high purity and contains 200—2000 ppm of ethane as the only significant impurity. Ethane is inert in the reactor and is rejected from the plant in the vent gas for use as fuel. Dilute gas streams, such as treated fluid-catalytic cracking (FCC) off-gas from refineries with ethylene concentrations as low as 10%, have also been used as the ethylene feedstock. The refinery FCC off-gas, which is otherwise used as fuel, can be an attractive source of ethylene even with the added costs of the treatments needed to remove undesirable impurities such as acetylene and higher olefins. Its use for ethylbenzene production, however, is limited by the quantity available. Only large refineries are capable of deUvering sufficient FCC off-gas to support an ethylbenzene—styrene plant of an economical scale. 

Miscellaneous Commercial Applications. Dimer acids are components of "downweU" corrosion inhibitors for oil-drilling equipment (see Petroleum Corrosion and corrosion inhibitors). This may account for 10% of current dimer acid use (71). The acids, alkyl esters, and polyoxyalkylene dimer esters are used commercially as components of metal-working lubricants (see Lubrication). Dimer esters have achieved some use in specialty lubricant appHcations such as gear oils and compressor lubricants. The dimer esters, compared to dibasic acid esters, polyol esters and poly(a-olefin)s, are higher in cost and of higher viscosity. The higher viscosity, however, is an advantage in some specialties, and the dimer esters are very stable thermally and can be made quite oxidatively stable by choice of proper additives. 

Recycles are meticulously accounted for because they load equipment and draw utilities. An olefin plant sustaining relatively low conversion per pass often builds up large amounts of unreacted feed that is recycled to the steam crackers. With utilities charged to ultimate products, these recycles would seem to the model to be free. The model would likely opt for very low conversion, which usually gives high ultimate yield and saves feedstock. Assigning the utility costs to users causes the compressor to pay for the extra recycle and the model raises conversion to the true optimum value. 

The trichlorosilane may be obtained by reacting hydrogen chloride with silicon in yields of 70% and thus is obtainable at moderate cost. As the olefins are also low-cost materials this method provides a relatively cheap route to the intermediates. It is, of course, not possible to produce chloromethylsilanes by this method. 

Hydrogenation of olefinic unsaturation using ruthenium (Ru) catalyst is well known. It has been widely used for NBR hydrogenation. Various complexes of Ru has been developed as a practical alternative of Rh complexes since the cost of Ru is one-thirtieth of Rh. However, they are slightly inferior in activity and selectivity when compared with Rh catalyst. 

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