Capital investment, conventional system

The early 1980s saw considerable interest in a new form of silicone materials, namely the liquid silicone mbbers. These may be considered as a development from the addition-cured RTV silicone rubbers but with a better pot life and improved physical properties, including heat stability similar to that of conventional peroxide-cured elastomers. The ability to process such liquid raw materials leads to a number of economic benefits such as lower production costs, increased ouput and reduced capital investment compared with more conventional rubbers. Liquid silicone rubbers are low-viscosity materials which range from a flow consistency to a paste consistency. They are usually supplied as a two-pack system which requires simple blending before use. The materials cure rapidly above 110°C and when injection moulded at high temperatures (200-250°C) cure times as low as a few seconds are possible for small parts. Because of the rapid mould filling, scorch is rarely a problem and, furthermore, post-curing is usually unnecessary. 

MSCC [Millisecond catalytic cracking] A fluid catalytic cracking process which uses an ultra-short contact time reaction system. It is claimed that less capital investment and higher liquid yields can be achieved using this process, compared with conventional FCC units. Developed by Bar-Co and now offered by UOP it has been operating since 1994. 

Future ethylbenzene alkylation catalyst development efforts will also undoubtedly focus on systems that convert less conventional feedstocks including ethane and ethanol. The two-step Dow ethane based process for ethylbenzene production is believed to be uneconomical because of its high capital investment requirement (26). However, it is a very attractive concept, and could be implemented if more efficient catalysts or improved process designs could be developed. 

A summary of levelized H2 pump prices, system capital investments, and levelized PV electricity prices are presented in Figs. 8-11 A summary of results for first gen eration (Year 1 Year 30) H2 production are as follows. The levelized H2 pump price, which does not include fuel use taxes, ranges from 6.48- 5.53/kg for 10% and 14% efficient PV modules respectively. With fuel tax, the H2 pump price is 7.47 6.52/kg, which is comparable to high-end 2005-2006 U.S. gasoline prices when the H2 is for FCVs with a fuel economy 2.2-times greater than conventional ICE ve hides. 

Economics The MTO process competes favorably with conventional liquid crackers due to lower capital investment. It is also an ideal vehicle to debottleneck existing ethylene plants and, unlike conventional steam crackers, the MTO process is a continuous reactor system with no fired heaters. 

Likewise, the capital investment for the spray dryer MgO process is approximately 7 percent lower than that for the conventional MgO scrubbing process ( 279/kW vs. 299/kW). The conventional MgO scrubbing process has more equipment, and hence larger investment costs, particularly in the areas of chloride purge, slurry drying, and slurry processing equipment which are not needed in the spray dryer-based system. 

Where "on-line" cleaning is considered to be necessary (see Chapter 15) either at installation or at a later date when the extent of a particular fouling problem has been established, the heat exchanger will of course, need to be designed with this in mind. Although the capital investment in such a system will be higher than the conventional method of changing velocity, its use could make a substantial reduction in operational and maintenance costs. 

The major difference between a conventional economic analysis and an economic analysis conducted as part of a thermoeconomic analysis is that the latter is done at the plant component level. The annual carrying charges (superscript C7 = capital investment) and operating and maintenance costs (superscript OM) of the total plant can be apportioned among the system components according to the contribution of the fcth component to the purchased-equipment cost PEC,ot = J2k PECk for the overall system ... 

RIM is a relatively new process. It can be used for processing of unfilled resin as well as fibre-reinforced composites. The process was discussed in Chapter 1. The process is similar to RTM (discussed previously) with some variation in mould release and reinforcement sizing to optimise resin chemistry with the process. The low viscosity reactant systems facilitate composite materials production, so-called structural RIM composites [19, 20] in which continuous fibre reinforcement mats are placed in mould cavities before injection. Capital investment and operational cost in RIM are therefore much less than those for conventional injection moulding. Polymerisation of a monomer is usually initiated by heat. However, in RIM, the polymerisation is initiated by impingement mixing (not by heat). Hence it is possible to activate polymerisation at relatively low temperature. Unlike RTM, in RIM the mould-fill times are very low ( 1 s) and a cycle time of <60 s is typical. The process is used for the rapid and automated production of large, thin and complex-shaped parts. 

Many of the polymers such as caprolactam, silicone, urethane, and polyester are multicomponent reactive liquids that may be molded by the reaction injection process which is particularly suitable for large area pieces such as auto body parts, furniture, and housing sections, because of the fast cycle and low mold clamp pressure requirement. This system greatly diminishes the capital investment requirement for such large parts. A 5000-ton conventional injection press is presently the largest and it costs 1,000,000. An automobile fender would need a 12,000 ton press costing 2,000,000 by the conventional injection process with reaction injection equipment cost might be one tenth of the machine cost for the older process. 

The SUPERFLEX FCC system is similar to that of a conventional FCC unit and consists of riser reactor, regenerator vessel and units for air compression, catalyst handling, flue gas handling and feed and effluent heat recovery. The SUPERFLEX system should be integrated into an ethylene plant in order to minimize capital investment, with the feedstock obtained directly from the steam cracker and shared common product recovery. The cooled reactor effluent can be processed in a nearby existing ethylene plant recovery unit. Alternatively, the effluent can be processed in a partial recovery unit to recover recycle streams and olefin-rich streams concentrated for further processing in a nearby ethylene plant. 

The principal advantages of the Catacarb process are production of higher purity product gas than the uncatalyzed hot potassium carbonate process, consumption of less steam than either the potassium carbonate or monoethanolamine systems, and use of smaller equipment (resulting in 20 to 30% savings in capital investment) than the conventional monoethanolamine process (Morse, 1968). 

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