Minimal waste production

The TS-1 catalysed hydroxylation of phenol to a 1 1 mixture of catechol and hydroquinone (Fig. 2.16) was commercialized by Enichem (Romano et ai, 1990). This process offers definite advantages, such as higher selectivities at higher phenol conversions, compared to other catalytic systems. It also illustrates another interesting development the use of solid, recyclable catalysts for liquid phase (oxidation) processes to minimize waste production even further. 

Preservation of a habitable planet demands that we minimize waste production and responsibly dispose of waste that is generated (Box 2-1). Recycling of chemicals is practiced in industry for economic as well as ethical reasons it should be an important component of pollution control in your lab. 

A.K. Hilaly, S.K. Sikdar, Pollution balance a new methodology for minimizing waste production in manufacturing process, J. Air Waste Manage. Assoc. 44 (1994) 1303-1308. 

Ionic liquids (ILs) tend to have good thermal stability, they exhibit liquid ranges of up to 300° C, and because they have negligible vapor pressure, they do not evaporate—all of which explains their use as replacements for volatile organic compounds. This also makes them very easy to contain and transfer, and allows their use under high vacuum conditions. Another quite important aspect is that ILs can be recycled (often with associated catalysts dissolved in them) this considerably minimizes waste production in accordance with green chemistry, and it lessens expenditure in view of the high cost of many ILs compared with that of conventional solvents. 

Richards, A.K Anhydrous Conversion of Methane and Other Alkanes into Methanol and Other Derivatives Using Radical Pathways and Chain Reactions with Minimal Waste Products. World Patent Application 2004/041399A2, May 21, 2004. 

There is still active development of alternatives to throwaway slurry scrubbing. Advanced throwaway processes such as dual alkali and dry scrubbing offer improved economics, efficiency, and/or reliability. Re-generable processes such as MgO scrubbing and absorption/stripping produce marketable products and thereby minimize waste production. However, each of these new processes includes many of the same physical and chemical processes as in a throwaway slurry scrubbing. In addition,... 

Careful inventory management can help to minimize waste production from unused products. Obsolete stocks may cause process or application inefficiency resulting in loss of quality or need for disposal. Losses can also result from packaging damage, deterioration and from H oduct damage caused by temperature variations cn atmospheric... 

What makes a separation process green, or environmentally friendly. The first characteristics that come to mind are low energy requirements and minimal waste production. Imagine a separation process that relies on a force generated naturally from the materials involved in the separation itself and that is so selective for a particular target molecule that it requires only small amounts of adsorbent materials, which are relatively simple to recover and reuse. The potential to realize such green ideals is found in functionalized magnetic particles. 

The plastic industry, like other sectors, also seeks to minimize waste production. For this, rationalization systems have been developed (hot channels removing carrots and channels supplying materials for injection, software preventing the wrong parts being made especially at startup, etc.) or systems for immediate recovery and immediate recychng after grinding in front of the press. 

The plant minimizes waste production and personnel doses. 

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