Waste loading

Interpreting results of the pinch diagram As can be seen from Fig. 3.12, the pinch is located at the corresponding mole fractions (y,Xi.jc ) - (0.(K)10, 0.0030, 0.0010). The excess capacity of the process MSAs is 1.4 x lO" kg mol benzene/s and cannot be used because of thermodynamic and practical-feasibility limitations. This excess can be eliminated by reducing the outlet compositions and/or flowrates of the process MSAs. Since the inlet composition of S2 corresponds to a mole fraction of 0.0015 on the y scale, the waste load immediately... 

Three additional mass-load paths S3-R2-S2, S3-R1-S1, S3-R1-S2 ) can be employed to shift removal duties from the process MSAs to the external MSA until all the waste load (0.104 kg phenol/s) is removed by the external MSA... 

Many facilities in this industry use in-plant technology to reduce or eliminate the waste load, requiring end-of-pipe treatment and thereby improve the quality of the effluent discharge and reduce treatment costs. In-plant technology involves water reuse, process material conservation, reclamation of waste enamel, process modifications, material substitutions, improved rinse techniques, and good housekeeping practices.3-615... 

The sources, amounts, and composition of injected hazardous wastes are a matter of record, because the Resource Conservation and Recovery Act (RCRA)5,14 requires hazardous waste to be manifested (i.e., a record noting the generator of the waste, its composition or characteristics, and its volume must follow the waste load from its source to its ultimate disposal site). The sources and amounts of injected hazardous waste can be determined, therefore, based on these records. Table 20.2 shows the estimated volume of deep-well-injected wastes by industrial category.3 More than 11 billion gallons of hazardous waste were injected in 1983. Organic chemicals (51%) and petroleum-refining and petrochemical products (25%) accounted for three-quarters of the volume of injected wastes that... 

Results of waste load found in verification sampling of unit product of aluminum fluoride are given in Table 22.6. 

Summary of Waste Loadings Found in Aluminum Fluoride Verification Data... 

Summary of Raw Waste Loadings Found in Verification Sampling of Unit Product of Chlor-Alkali (Mercury Cell and Diaphragm Cell Processes)... 

Summary of Raw Waste Loading Found in Screening and Verification Sampling of Nickel Sulfate... 

A typical plant production of sodium hydrosulfite is shown in the process diagram (Figure 22.15). Results of raw waste load found in verification sampling for a sodium hydrosulfite plant are given in Table 22.17. 

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