Minimizing energy requirements

Minimal Energy Requirements. The relative effect of the cost of the energy on the cost of the freshwater produced depends on local conditions, and is up to one-half of the total. In attempting to reduce this cost, it is of interest to determine the minimal energy amount thermodynamically needed for separating the water from the saline solution. The physical background to this will be introduced in a simple example. Because of the negligible... 

The combination of a less-constrained ASU for oxygen production and a carbon capture process using membranes instead of amine solvents can conduce to a minimal energy requirement associated with an oxygen purity ranging between 0.5 and 0.6 molar fraction. 

Considerable effort has been made to minimize energy requirements in the nitrations plants too. 

Design processes with minimal energy requirements. 

Chlorination or chlorine dioxide treatment is almost always followed by a caustic extraction. Alkaline extraction neutralizes the pulp and removes the lignin rendered more soluble by chlorine treatment. Removal of this modified lignin opens up the cell wall and allows for milder delignification to be used in later bleaching steps. Caustic extraction is generally performed with most chlorinated chemical pulps at 50-60° with 0.5-5% NaOH for 1 to 2 hr. Consistencies are usually quite high (12 to 16%) to reduce the amount of water and minimize energy requirements. 

Glycerol is a non-insulin-dependent source of carbohydrate that can be used to avoid stress-related hyperglycemia in critically iU patients. A major disadvantage of the available glycerol solution is the dilute concentration of carbohydrate and amino acids (3% of each). Most patients require 3 to 4 L/day of glycerol solution and supplemental IVFE to meet minimal energy requirements. 

An air-stripping system designed to minimize energy requirements (8) was installed to remove volahle organic compounds at levels between 200 and 250 pg/L from drinking water supplied by a municipal well field. The system was capable of treahng 2.16 MGD (8,176 m /d) at effluent levels not exceeding 10 pg/L total VOCs. Total installed cost was approx 200,000, and operational costs were less than 20,000/yr. 

Dispersion is carried out at the lowest acceptable temperature to minimize energy requirements, and is designed to complement the preliminary dispersion action in the pulper. Thickened stock is progressively dewatered to around 40% concentration in preparation for the kneader disperser stage, which breaks down the ink/fiber bonding of more difficult printed materials (123). 

Choice of reaction path (minimize energy requirements by use of selective catalysts). 

The tendency for liquid phase collisions to occur in groups or sets does not have a very large effect for ordinary reactions that involve a significant activation energy, because no individual collision within the set is more likely to lead to reaction than any other. On the other hand, some reactions have zero or minimal energy requirements (e.g., free-radical recombination reactions). Such reactions will occur at virtually every collision. For... 

Then the equation for the minimal energy required for full switching, Emirif is obtained as follows ... 

The minimum ignition energy, denoted, and expressed in J is the minimal energy required to initiate the combustion of a fuel by any means (e.g., thermal, electrical, mechanical). Usually ignition energy of most fuels are in the order of a millijoule (mj). 

As the example in Fig. 3.18 shows, apart from achieving selectivity, biocatalysis also renders steps such as protection, deprotection, or activation redundant, thereby increasing atom-efficiency, reducing waste, and minimizing energy requirements. 

GC Principle Minimize energy requirements Lower temperatures and pressures are typically required in electrochemical operations compared to those of equivalent non-electrochemical counterparts (e.g., incineration, supercritical oxidation). In addition, the... 

The minimal energy required for the first step can be estimated from the heats of formations known for all the species involved. It is 42.1 kcal mor and thus the energy of near-UV light is sufficient to initiate the process. Other alkylthiyl radicals were also suggested to isomerize into a-thioalkyl radicals through a dissociation-addition sequence within the solvent cage [27] ... 

The anodic process is restricted to a 2e" change in order to minimize energy requirements, and the cell operates continuously at ambient temperature (in contrast to the rival chemical processes which generally involve an effective 4e change in a high temperature, batch process at c. 3I5 "C). 

The energy expended by the body when (1) the subject is awake, but there is complete physical and mental rest and (2) from 14 to 18 hours have elapsed after the last meal. Also, the environmental temperature must be in the comfort zone (usually 70° to 80°E [21° to 27°C]) so that no extra work is being done by the body either to heat or to cool itself. The energy expenditure which is measured under these conditions is taken to represent the minimal energy required to sustain the life of a healthy person. The extra energy expended over and above that used for basal metabolism is call the activity increment. 

---