Auxiliary chemicals

Figure represents catalyst and auxiliary chemicals and therefore represents an upper limit for catalyst cost. 

A method to lower the release of chemicals, auxiliaries, and residual dyestuff in exhaust processes is dyeing on a standing dyebath. In such a technique the exhausted dyebath, which contains the auxiliaries, chemicals (salt), and dyestuff, is reused for the next dyeing after a replenishment of the exhausted dyestuff and lost chemicals. In fact, such techniques are not as widely in use as might be expected because a set of requirements has to be fulfilled to introduce them ... 

Industrial Hygiene Bulletin on Handling Epon Resins and Auxiliary Chemicals, SC 62-33. Shell Chem. Corp., 1962. 

The pore size distributions of Ti-MCM-41 synthesized in this work are shown in Fig. 2. All of the samples showed a sharp distribution without addition of TMB and the use of methanol solvent resulted in the expansion of pore channel size. The average pore sizes determined by N, adsorption were 4.0nm and 2.8nm when the added solvents were methanol and ethanol, respectively. In this case, the used surfactant was C22TMAC1. In addition, the expansion of BJH pore size of Ti-MCM-41 was observed by the addition of TMB. A broad pore size distribution was investigated by using TMB as an auxiliary chemical. The mean pore size was ca. 7.5nm in methanol solvent. 

Only air is needed as an auxiliary chemical. Waste streams which might cause a pollution problem or effect the commercial feasibility are excluded. 

The United States textile industry consumes over 4 billion m3 of water annually. Much of the process water is discharged together with dyes and auxiliary chemicals, plus a loss of energy in the hot effluents. Reverse osmosis... 

Use safer solvents and reaction conditions—Avoid using solvents, separation agents, or other auxiliary chemicals (if necessary, use innocuous chemicals)... 

Large quantities of unexhausted auxiliary chemicals, such as salt and base, are wasted in the process. 

For the auxiliary chemicals 1n the dye impregnation bath, carrier was considered to be totally exhausted, and thus was added at a 100 rate each cycle. 

Use safer solvents and reaction conditions Avoid using solvents, separation agents, or other auxiliary chemicals. If these chemicals are necessary, use innocuous chemicals. More and more research demonstrates reactions may not require solvents to proceed in clean and quantitative yields. When solvents are required, water, C02, ethanol, or other low-toxicity alternatives are preferred to traditional organic solvents. 

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