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Research paper : A rationalization guideline for the utilization of energy and resources considering total manufacturing processes (H. Kita et al.)−206 Synthesiology - English edition Vol.1 No.3 (2009) 4 Summary4.1 Evaluation of manufactureExergy analysis was done in case where members were manufactured with ceramics and steel, used as production member for 7 years in casting line for aluminum engine, and then disposed.①Exergy input per product was 4175 MJ for ceramics and 621 MJ for steel, and significantly higher exergy was consumed for ceramics compared to steel.②Exergy fixed in ceramics was 229 MJ, or 5.5 % of exergy input, and most are emitted outside the system.③By operation, granulation and sintering consumed 80 % of total input.④As result of high exergy input, ceramics have high conservation. When it is used in molten aluminum using this characteristic and used for 7 years, exergy consumption is reduced 362 GJ compared to steel.4.2 Rationalization consideration Assuming current system, guidelines for rationalization when ceramics or steel members were used and technologies needed for rationalization of casting system as a whole were summarized.①Steel・Development of material and coating technology that is not readily corroded by molten aluminum.②CeramicsTo improve manufacturing efficiency of ceramics, rationalization of granulation and sintering operations that have significantly high consumption is mandatory.・Optimization of water content while considering effect on preliminary and following operations, such as selection of deflocculant and adjustment of granularity.・Catalyst that allows nitrification at low temperature using rough silicon particle, or combination of nitrification and sintering processes.・Hollow structure design. Reduced amount of raw material and shortened sintering time.・Technological development for exchange and repair of parts to use ceramics member manufactured with large exergy input.③Casting system・To increase efficiency of delivery system of molten metal, development of transportation container that is lightweight and has excellent insulation is the key.・System for delivering the metal as solid and melting only necessary amount to be used for product. Several issues must be solved including heating source that allows instant melting, large ceramics tube and container with high insulation and without adhesion of molten metal, engine design with higher disassembly, and diffusion of recovery system of waste engine in the society.5 Future prospectBased on above considerations, we summarized the efficacy and issues of exergy analysis.5.1 Efficacy of exergy analysis①Normally, environmental impact assessment is conducted at manufacture phase and the content is already determined in the general plan, so options as measures for impact reduction are limited. It is necessary to forecast resource consumption and environmental impact of systems across wide-ranging level such as planning, R&D, and design, and the result should be fed back to technology and manufacturing. Exergy that links matter and energy is index appropriate for preliminary evaluation due to its characteristic, and effective use is desired.②Cycling system is the outer shell of sustainability. To reduce input of resource and energy from outside needed to drive the cycling system, rationalization of system using exergy must be done swiftly.③Although case of ceramics and metal was discussed in this paper, exergy is not limited to certain field or subject. Final goal is to link manufacturing (micro factor) to global level sustainability (macro result). It is possible, in principle, to calculate consumption speed of exergy using macro input and output data at national level for emission. This may become index for shift to sustainability.5.2 Issues that must be improved①Powder particle and sinted body made from that material were evaluated using same chemical exergy. In the future, it is necessary to have index that shows difference in condition such as surface and interface energy.②Exergy is not appropriate for evaluating rarity or hazard, and it is necessary to conduct multifaceted evaluation by combining with other indices.AcknowledgementsThis paper was written with hints from some discussions that arose within the Minimal Manufacturing Working Group composed of cross-disciplinary members of AIST, and we are grateful to people in the Working Group. Terminology(52)−Exergy: Effective energy that can be converted to other energy.Term 1.

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