Cellulose separation

Table 7 shows typical values for different qualities of cellulosic separators from various producers. 

Surprisingly the water consumption of a starter battery, provided it contains anti-monial alloys, is affected by the separator. Some cellulosic separators as well as specially developed polyethylene separators (e.g., DARAMIC V [76]) are able to decrease the water consumption significantly. The electrochemical processes involved are rather complex and a detailed description is beyond the scope of this chapter. Briefly, the basic principle behind the reduction of water loss by separators is their continuous release of specific organic molecules, e.g., aromatic aldehydes, which... 

Topping, D. Illman, R.J. Trimble, R.P. (1985). Volatile fatty acid concentrations in rats fed diets containing gum Arabic and cellulose separately and a mixture. Nutrition Reports International, Vol. 32, (nd) pp. 809-814, ISSN 0029-6635. 

Nonwoven materials such as cellulosic fibers have never been successfully used in lithium batteries. This lack of interest is related to the hygroscopic nature of cellulosic papers and films, their tendency to degrade in contact with lithium metal, and their susceptibility to pinhole formation at thickness of less than 100 fjim. For future applications, such as electric vehicles and load leveling systems at electric power plants, cellulosic separators may find a place because of their stability at higher temperatures when compared to polyolefins. They may be laminated with polyolefin separators to provide high-temperature melt integrity. 

Early separators used in NiCd cells for space applications consisted of materials as ordinary as Whatman filter paper and eventually nonwoven nylon felt (Pellon 2505). Pellon 2505 was more stable than cellulosic separators, but it too had stability limitations. In the late 1960s and early 1970s, nonwoven polypropylene saw limited use in NiCd cells. The PP separators were quite useful where sterilization (heating the cell to 135 °C) was required.The major difficulty with nonwoven polypropylene was that it was only marginally wet-table. and the amount of electrolyte that can be placed in the cell was limited. 

Danko, T. Properties of cellulose separators for alkaline secondary batteries. Proceedings of the 10th Annual Battery Conference on Applications 8z Advances, IEEE New York, 1995 p 261. 

Electrolyte. The electrolyte in silver-zinc cells is 30-45% KOH. The lower concentrations in tliis range have higher conductivities and are preferred for high rate cells. Higher concentrations have a less deleterious effect on cellulosic separators and are preferable for extended life characteristics. 

The results presented in this paper were only a very preliminary study of pretreatment of maize silage. Trials should be made at lower temperatures to examine if more energy could be saved in the process. It would also be interesting to determine the content of starch and cellulose separately by enzymatic hydrolysis, instead of total glucan as is the case in this study. Also, enzymatic hydrolysis and SSF using low enzyme loadings (of both cellulases and amylases) should be made to fully see the potential of this promising raw material for bioethanol production. 

On the basis of these different Tj values, we were able to record the spectra of the crystalline and noncrystalline components of native cellulose separately by appropriate pulse techniques. 

However, concerns about the toxicity of cadmium have accelerated the replacement of these batteries by nickel-metal hydride batteries, described in Section 9.3.5. In nickel-cadmium (nicad) batteries, the anode is cadmium and the cathode is an unstable nickel oxyhydroxide, formed in the unusual conditions found in the cell, and written variously as Ni(OH)3 or NiO(OH). It is generally formed together with stable nickel hydroxide, Ni(OH)2. The electrolyte is NaOH or KOH. The anode and cathode are assembled in a roll separated by a cellulose separator containing the electrolyte. The cathode/separator/anode roll is contained in a nickel-plated stainless steel can (Figure 9.10). The cell voltage is 1.3 V but the working voltage is usually nearer to 1.2 V. The schematic cell reactions are as follows. 

Wood Paper Cellulosic separators are made from cotton linters or craft pulp and generally coated with phenolic resin for acid resistance and strength Comparatively large pore size and relatively high electrical resistance... 

Polyethylene pocket separators Sintered PVC separators Cellulosic separators Cellulosic/ glass mix separators Glass fiber leaf separators... 

Figure 3 47 Separation of (1-4)-linked o-giucans after partial acetolyse of cellulose. Separator column CarboPac PA1 eluent (A) 0.15 mol/L NaOH, (B) 0.15 mol/L NaOH + 0.5 mol/L NaOAc gradient linear, 20% B to 50%...

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