Economical alternative

Addition of surfactant to the injection water (14,15) can displace the oil remaining near the well. The lower oil saturation results in an increase in the water relative permeabihty (5). Therefore, a greater water injection rate may be maintained at a given injection pressure. Whereas ultimate oil recovery may not be increased, the higher water injection rate can increase oil production rates improving oil recovery economics. Alternatively, a lower injection pressure can be used. Thus smaller and cheaper injection pumps may be used to maintain a given injection rate. The concentration of surfactant in the injection... 

Sulfuric acid is an economical alternative source of acid and many commercial generators substitute concentrated sulfuric acid for HCl. Furthermore, the requited chloride ion needed as the reductant is already present or added as NaCl in the chlorate solution or crystal obtained from the chlorate manufacturer. This process, popular in the 1960s and 1970s, produces substantial amounts of Hquid effluent containing 20—35% sulfuric acid, 20—25% sodium sulfate, and minor amounts of sodium chloride and unreacted chlorate that must be neutralized with alkaH. 

Further, because of the nature of sohds-gas contacting, which is usually by parallel flow and rarely by through circulation, heat transfer and mass transfer are comparatively inefficient. For this reason, use of tray and compartment equipment is restricted primarily to ordinaiy drying and heat-treating operations. Despite these harsh hmitations, when the listed situations do exist, economical alternatives are difficult to develop. 

Although the continuous-countercurrent type of operation has found limited application in the removal of gaseous pollutants from process streams (Tor example, the removal of carbon dioxide and sulfur compounds such as hydrogen sulfide and carbonyl sulfide), by far the most common type of operation presently in use is the fixed-bed adsorber. The relatively high cost of continuously transporting solid particles as required in steady-state operations makes fixed-bed adsorption an attractive, economical alternative. If intermittent or batch operation is practical, a simple one-bed system, cycling alternately between the adsorption and regeneration phases, 1 suffice. 

A more economical alternative is found in a submersible pump where the pump, directly coupled with the prime mover, is slid into the tubewell through narrow pipes. Narrow pipes are easy to sink into rocky terrain or very deep water levels. They are less expensive and are easy to install due to the elimination of the need for a pump house. Once the unit is slid into the well it requires little maintenance. (See Figures 7.5-7.7.) Such pumps have a standard centrifugal multistage arrangement, and the motors are required to work under water or any other liquid. These motors have an exclusive application for submersible pumps. 

The size and therefore the cost of a conventionally wound voltage transformer will be almost proportional to the system voltage for which it is wound. As a cost consideration, therefore, a more economical alternative is found in a Capacitor Voltage Transformer (CVT) (Figure 15.6(a)). 

Segregation may also be necessary in the packaging of products not only to prevent visible damage but electrical damage, as with electrostatic-sensitive devices. Segregation may be the only way of providing adequate product identity, as is the case with fasteners. While a well-equipped laboratory can determine the difference between products and materials the consumer needs a simple practical method of identification and labeled packets are often a reliable and economic alternative. 

Membranes are a relatively new technology. They are an attractive economic alternative for treating CO2 from small streams (up to 10 MMscfd). With time they may become common on even larger streams... 

Gas chromatography (GC) has also been used for preparative purposes, but is restricted to relatively volatile racemates such as anesthetics, pheromones or monoterpenes and, therefore, very few applications are reported. Nevertheless, in the cases to which GC may be applied, it could be considered as an economical alternative to HPLC. Most of the resolutions of enantiomers were performed on cyclodex-trin-derived CSPs [109, 144-153], and only on very few occasions were other chiral selectors used [153]. 

The removal of such impurities is relatively simple at a waterworks, but a typical plant cannot provide the chemical expertise needed to keep the process in good working order. Treatment should therefore be avoided if there is any reasonable economical alternative. 

There is a need to seek an environmentally benign, technically feasible and economical alternative fuel because of the limited crude oil reserves and serious pollution all over the world. Recently, dimethyl ether (DME) is proved to be used as an alternative clean fuel in transportation, power generation and household use for its excellent behavior in compression ignition for combustion, cetane number of over 55 and zero sulfur content, and is praised as a super-clean fuel in the 21 century. It has a promising foreground of application. Therefore, the efficient synthesis of DME from syngas derived from natural gas, coal or biomass has drawn much attention. 

If A has significant economic value then it should be separated from the reactor effluent stream and recycled for subsequent use. Since the conversion level is higher in the plug flow reactor, the recycle rate will be much smaller and the demands on the separation equipment for reclaiming species A will also be somewhat smaller. Even when species A is of relatively little economic value, there may be circumstances when the costs associated with meeting the pollution control requirements for the process effluent will dictate separation and recycle of this reactant as the most economic alternative. 

There are commercial processes for the direct upgrading of residues under high severe hydroconversion conditions. Other alternatives consider the previous hydrotreatment of the residue, so that the hydrocracking stage does not need to be so harsh. Otherwise, residue conversion could also proceed via carbon rejection methods, these processes fall out the scope of the present book and will not be considered here. However, it is important to mention than VR coking is seen as a more economical alternative than HDP, especially for the more heavy crudes, for which concentrations of metals and nitrogen would require the toughest conditions. 

Hydride Compressors using reversible metal hydride alloys offer an economical alternative to traditional mechanical compressors for GH2. The simplicity and passive operation of the hydride compression process offers many advantages over mechanical compressors. Hydride compressors are compact, silent, do not have dynamic seals, require very little maintenance, and can operate unattended for long periods. However, they are a very new and may be difficult to be built at the scale required for GH2 transmission pipeline service. 

Focusing on a clean, economical alternative to nonrenewable energy, this volume provides the latest information on the hydrogen fuel economy. 

The first proteins from transgenic plants to reach commercial status were avidin and P-glucuronidase (GUS) both of which are used as diagnostic agents in molecular biology. An important principle demonstrated by these case studies is that molecular farming in cereals can be an economical alternative even when the natural source of a protein is abundant (i.e. egg whites for avidin, and Escherichia coli for GUS) and where a market is already established. 

To maintain the acidity of the brine at pH5, more hydrochloric acid is required during hypochlorite recycling to the feed brine. This extra acid demand is the cause of the largest increase of variable production costs - approximately 100 000 Dutch guilders per year. Alternative solutions showed variable costs up to one million Dutch guilders per year. The investment for this project proved to be the best economical alternative to solve the chlorate and bromate emissions problem. 

The trailer transport of compressed hydrogen is - because of the low energy density of gaseous hydrogen - only an economic alternative for the distribution of small quantities and short distances (such as during the early phase of hydrogen penetration) and can, therefore, be excluded as an option for the area-wide implementation of a supply infrastructure in a later phase. 

Selection of the best alternative depends on the quantity of water produced, type of product, degree of contamination, air quality consideration, site-specific considerations, and local regulations. For sites that will be operational for only a short period of time, and producing a small quantity of water, hauling can sometimes be an economical alternative. The costs associated with initial cost of equipment, acquisition of permits, and continued operation must be compared with a per-unit cost of employing a commercial disposal firm. 

In conclusion, copper-manganese-catalyzed organomagnesium reagents and copper-catalyzed organomanganese reagents are a simple, efficient, and economic alternative to copper-catalyzed organomagnesium reagents and especially to... 

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