Abstract
This article deals with Life-Cycle Assessment (LCA) of electric power and Town-gas (gas through mains) system. LCA is an objective process to evaluate the environmental burdens associated with a product, process, or activity by identifying and quantifying energy and materials used and wastes released to the environment, to assess the impact of them, and to evaluate and implement opportunities to affect environmental improvements. The assessment includes the entire life cycle of the product, process, or activity, encompassing extraction and processing of raw materials, manufacturing, transportation and distribution, use/re-use/maintenance, recycling, and final disposal.
For this purpose, we first developed a novel mathematical model called Process-relational Model. Utilizing this model, we can dissolve the difficulties of LCA in retracing complicated repercussions among production systems and in allocating environmental emissions among multiple products. Then we investigated electric power and town gas system, and developed data-base of energy and material balance concerning them, and calculated primary energy consumption and CO2 emission per respective units. Applying the results, we simulated the replacement from conventional system utilizing electricity-gas to co-generation system utilizing Town-gas, and we evaluated the variation of resource requirements and emissions.
