Performance waste minimisation

Initial investment in abatement technology is certainly one of the deciding factors for some companies. Often these firms cannot, or do not identify with the real savings associated with improved environmental performance. Waste minimisation, company image and brand association are all difficult to evaluate. 

So how should a company go about improving its environmental performance Depending on the nature of the proposed actions, the routes companies can take are often labelled as Waste Minimisation approaches or Clean Technology approaches. Commonly used descriptions of these are ... 

Esterification processes, particularly trans-esterification, provide good examples of such modifications leading to enhanced process performance and waste minimisation. The following generalised process flow diagrams will illustrate the point adequately. 

To characterise waste streams by material balance can require considerable effort. However, by doing so, a more complete picture of the waste situation can be established. This helps to establish the focus of the waste minimisation activities and provides a baseline for measuring performance. 

The chemical industry has a strong tendency to think from factory gate to factory gate. Their historic focus on environmental issues has been in minimising waste and emissions from their own operations. Many chemical companies are weak at looking at what is going on upstream of their factory or downstream. Thinking about the entire life cycle of a product allows many new opportunities for improved performance to be identified. 

Note that because fixed costs are proportionally more important for small-scale operations the influence of research and development work on reducing the imit process costs on smaller scale processes will often be significantly difierent than when applied to larger scale operations. Also equipment will not necessarily be used imder conditions which maximise its performance, but rather under conditions that minimise cost, thus for instance a fermenter will not be operated at maximum agitation rates as the power required will be too expensive. Other savings can be made by finding uses for wastes, such as the spent biomass from fermentations, and also for any out-of-specification product that is made. 

In the Ektachem 700 the electrolytes (sodium, potassium, chloride, carbon-dioxide) are measured potentiometrically. The slides to be measured are transported by the instrument via the slide rotor to the preparatory position from where the slides are immediately pushed into the incubator. In the incubator the temperature of the slides is maintained at 25.0 0.5°C. The evaporation is minimised since each slide is covered up. A total of 17 slides can be accommodated in the incubator. The total incubation time is 3 minutes. After incubation has been completed, the slide is transported to the measurement position in the electrometer and potentiometric measurement can now be performed. The result is transmitted to the computer and the measured slide can be ejected to waste. 

Better environmental performance. Modem process design should aim to zero-effluent plants by minimisation of gaseous emissions and of process waste, including wastewater. 

Incineration using modem waste-to-energy incinerators to capture the energy value of waste, while greatly reducing its volume. Incineration is the more usual method of disposal and often there are incinerators on the hospital site. However, the incinerators need to meet the EC requirements for performance and to have the appropriate after-burners and gas cleaning facilities to minimise air emissions. 

Tandem reactions refer to sequential transformations of a substrate via two or more mechanistically distinct processes that take place in a single ves-sel. Because they generate less waste and minimise handling and work-up actions in multistep syntheses, while significantly increasing molecular complexity, tandem protocols are often considered superior to stepwise procedures. Therefore, catalyst precursors that can be triggered to perform several... 

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