You are here:
INCORPORATING ENVIRONMENTAL AND ECONOMIC CONSIDERATIONS INTO PROCESS DESIGN: THE WASTE REDUCTION (WAR) ALGORITHM
Citation:
Young*, D AND H C. Cabezas*. INCORPORATING ENVIRONMENTAL AND ECONOMIC CONSIDERATIONS INTO PROCESS DESIGN: THE WASTE REDUCTION (WAR) ALGORITHM. Presented at AICHE National Meeting, Dallas, TX, 10/31-11/5/1999.
Description:
A general theory known as the WAste Reduction (WASR) algorithm has been developed to describe the flow and the generation of potential environmental impact through a chemical process. This theory integrates environmental impact assessment into chemical process design Potential environmental impact in this methodology is defined as the unrealized effect or impact that the emission of material and/or energy into the environment would have on average. The potential environmental impact of a chemical is assessed by evaluating that chemical's affect on eight different impact catgeories that span both toxicologically affects and atmospheric affects: human toxicty potential by ingestion (HTPI), human toxicity by exposure (HTPE), aquatic toxicity potential (ATP), terrestrial toxicity potential (TTP), global warming potential (GWP), ozone depletion potential (ODP), photochemical oxidation potential (PCOP), and acid rain potential (ARP). An extensive database has been compiled using these categories which contains values for approximately 1600 chemicals. The WAR methodology incorporates these potential environmental impact values of the chemicals into potential environmental impact indexes which characterize the output from and the generation within a chemical manufacturing process. The impact indexes are calculated by measured process data such as mass flow rates and stream composition, as well as the specific potential encironmental impact of the chemicals present in the process. These indexes are then used to evaluate the environmental friendliness of the process. Indexes froma design are compared to the indexes of an alternative design for the same process. In this comparative fashion, the potential environmental impact of a process can be minimized during the design stage. The theory of WAR has been extended to include the potential environmental impact of the energy consumed in a process. Energy has been included into the analysis by re-drawing the system boundaries to include the power generating facility which supplies the energy being consumed by the process. The environmental impacts of the power plant are then included into impact indexes. The effect of this addition on the original potential impact indexes will be discussed. An extensive economic evaluation will be included in the analysis of the process designs. Note, the energy consumed appears in both the economic evaluation and the environmental analysis.