Attractive solute

Processing heavy oils and bitumens represents a challenge for the current refinery processes, because heavy oils and bitumens poison the metal catalysts used m the refineries. In our research at the Loker Institute, we found the use of superacid catalysts, which are less sensitive to heavy oils, an attractive solution to their processing, particularly hydrocracking. 

The basic premise of Kamlet and Taft is that attractive solute—solvent interactions can be represented as a linear combination of a nonspecific dipolarity/polarizability effect and a specific H-bond formation effect, this latter being divisible into solute H-bond donor (HBD)-solvent H-bond acceptor (HB A) interactions and the converse possibility. To establish the dipolarity/polarizability scale, a solvent set was chosen with neither HBD nor HBA properties, and the spectral shifts of numerous solvatochromic dyes in these solvents were measured. These shifts, Av, were related to a dipolarity/polarizability parameter ir by Av = stt. The quantity ir was... 

There are several different situations in which petroleum hydrocarbons pose a threat that has attracted solution by bioremediation. These include (1) oil-refinery waste and contamination of the surrounding soil, (2) leakage from oil pipelines and underground storage tanks or basins, and (3) spillage of crude oil in the marine enviromnent after accidents at sea. 

By perforating the casing with millimeter holes a small over-pressure will force the water to flow out, as shown in Figure 65. With this solution overpressure can never occur. This very attractive solution might not be all that legal (for now). 

Biphasic systems, in which the catalyst is designed to be dissolved in a liquid phase which is immiscible with the product (either with or without a separate solvent) potentially provide some of the most attractive solutions to the problem of product... 

The key to attractive solutions to high-throughput compatible GC-analytical technologies will require the development of fast separations. There are again several ways to shorten the analysis time required for a GC separation. The choice of the GC column is essential but will not be discussed in this context as this would go far beyond the framework of this chapter. 

Also in remote areas, such as low-populated islands, without any access to the electricity grid and for using large renewable resources, which are far away from any user centres (so-called stranded resources), hydrogen could be an attractive solution (see also the discussion in Chapter 17). 

At the system level, requirements are for a reliable, cost-effective and attractive solution to energy supply needs.. This means pursuing solutions that can reduce costs at the component and/or system level, increase the overall performance of the system and improve the functionality of and the services provided by the system. 

The main alternative to grants is for sponsors to award best entry prizes to whichever researcher(s) achieve the most important results in a prede-hned period. Like patents, prizes are a powerful method for eliciting new ideas. Since researchers cannot claim a prize without concrete results, best entry prizes also provide substantial protection against lazy or inefficient researchers. Best entry prizes are already widely used to solve chemical engineering problems. The best-known prizes are managed by a company called Innocentive. It specializes in problems that companies have been unable to solve in-house, attracting solutions from around the world (Maurer 2005). 

The need for enhanced detection sensitivity and automation has steadily increased for the separation and analysis of peptides from natural sources or proteolytic digestion of low abundance proteins this is also partly a consequence of the greater usage of combinatorial solid-phase synthetic approaches. Narrow bore (1-2 mm i.d.), microbore (0.5-1.0 mm i.d.), and capillary (100-500 pm i.d.) columns have provided attractive solutions to these problems. 1221 An important attribute of very small particle diameter micropellicular, porous, or nonporous RPC sorbents is that they are ideally suited to such microbore or capillary... 

Introducing a solute into a solvent initiates a toumciment of forces. Attractive forces between solute and solvent compete with attractive solute-solute and solvent-solvent forces. A solution forms only to the extent that solute-solvent forces dominate over the others. The process in which solvent molecules compete and win in the tournament of forces is called solvation or, in the specific case where water is the solvent, hydration. Solvated solutes are surrounded by solvent molecules. When solute ions or molecules become separated from one another and surrounded in this way, we say they re dissolved. 

NOx direct decomposition seems the most attractive solution in emission control, because the reaction does not require any reductants added and potentially could lead to the formation of only N2 and 02. Cu zeolite is one of the best catalysts for NOx direct decomposition, but the activity is very poor and needed to be improved several orders of magnitude high (Iwamoto et al., 1981). 

Catalysis in liquid-liquid biphasic systems has developed recently into a subject of great practical interest because it provides an attractive solution to the problems of separation of catalysts from products and of catalyst recycle in homogeneous transition metal complex catalysis. Two-phase systems consist of two immiscible solvents, e.g., an aqueous phase or another polar phase containing the catalyst and an organic phase containing the products. The reaction is homogeneous, and the recovery of the catalyst is facilitated by simple phase separation. 

Fig. 5. VET rate constants of benzene in scC02 as a function of reduced density (filled circles). The solid line represents calculations of the local density at the position of the first maximum of the radial distribution function around an attractive solute in a Lennard-Jones fluid (see Fig. 7 and text for details). Experimental conditions pred = 2.1 (500bar, 318K), prei = 1.6 (150 bar, 318K), pred= 1.2 (lOObar, 318K), pred= 0.7 (lOObar, 328K).

These aspects do not form an unmixed blessing, however. If the metal must be reduced by electrolysis, the process may become energy intensive. Thus attractive solutions to this problem are reduction of more valuable gold by less expensive zinc and of more valuable copper by scrap iron. Finally, in view of the large amounts of waste water formed as by-product, one may be trading an air pollution problem for a water pollution problem. A comparison of the two types of processes is given in Table 10.6. 

Utilizing solar energy and extracting energy from the carbon fixed by photosynthesis in plants offers a potentially attractive solution to establish clean and sustainable resources for both energy demands and raw material needs. It has been estimated that 10u-1012 tons of carbon is fixed annually around the world by photosynthesis of higher plants. Potentially, this renewable resource can provide approx 10 times our current energy demand from all sources (1). 

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