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Selection and utilization of criteria for process development in green production of organic chemicals

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2008
Haydaroğlu, Şencan
Sustainability and green engineering are two main concepts considered throughout this study. Sustainability deals with the utilization of renewable and replaceable sugar-based twelve most promising building blocks included in the report prepared by U.S. Department of Energy and green engineering concept is related with the incorporation of environmental performance criteria to chemical process design. Process performance criteria at the conceptual design stage are selected as persistence, bioaccumulation and aquatic toxicity, economical potential of the processes, atom & mass efficiency of the processes and the relationship between Gibbs free energy of reaction values and economical potential. It is observed that bioaccumulation potentials of both the raw materials and products are low. Petrochemical raw materials are more persistent in air than the bio-based ones. The aquatic toxicity of bio-based raw materials is low; whereas some of the petrochemicals are moderately toxic and allyl alcohol and acrylonitrile among the petrochemicals are classified as highly toxic. Bio -based routes are not economically feasible with 2002 market prices. Atom and mass efficiencies of petrochemical reactions for a group of chemicals are higher than bio-based ones due to mostly addition or substitution reactions. Among high number of products, 1,3 propanediol production from glycerol with two microorganisms is analyzed at preliminary design stage. Process performance criteria are selected as material and energy consumption, cooling water requirement, CO, CO2, SO2 and NOX emissions to the atmosphere per unit of 1,3 propanediol production. Klebsiella pneumoniae process requires less cooling water, but it is less energy efficient and causes higher emissions.