Systematic Evaluation and Uncertainty Analysis of the Refuse-Derived Fuel Process in Taiwan

Abstract

In the last few years, Taiwan has set a bold agenda in solid waste recycling and incineration programs. Not only were the recycling activities and incineration projects promoted by government agencies, but the related laws and regulations were continuously promulgated by the Legislative Yen. The solid waste presorting process that is to be considered prior to the existing incineration facilities has received wide attention. This paper illustrates a thorough evaluation for the first refuse-derived fuel pilot process from both quantitative and qualitative aspects. The process is to be installed and integrated with a large-scale municipal incinerator. This pilot process, developed by an engineering firm in Tainan County, consists of standard unit operations of shredding, magnetic separation, trommel screening, and air classification. A series of sampling and analyses were initialized in order to characterize its potentials in the solid waste management system. The probabilistic modeling for various types of waste properties derived in this analysis may provide a basic understanding of system reliability. IMPLICATIONSThis analysis presents a thorough performance testing and reliability analysis for the refuse-derived fuel (RDF) process that was built as the first pilot plant in Taiwan. The mass balance analysis indicates that such a presorting process for subsequent waste-to-energy facilities may achieve a 50% production rate based on the waste inflow of 30 tons/hr in several test runs. With the resultant higher heat value (30 tons/hr up to 3716 kcal/kg on average) and lower amount of non-combustibles existing in the final RDF products, the systematic implications to energy recovery, combustion efficiency, pollution control, and ash reuse potential in an integrated waste-to-energy facility are phenomenal. Reliability analysis by the identification of probability distribution to each related factor extends the insight in the feasibility study.

Compatibility Analysis of Material and Energy Recovery in a Regional Solid Waste Management System

“…3,4 Tables 1 and 2 describe those related parameter values for this analysis. Because of the installation of such a presorting system that may exhibit capability of waste reduction, the original service area assigned for the Pa-Li incinerator could be enlarged to cover more administrative districts.…”

“…(from incineration plants to ash landfills) (2) Total construction cost ϭ CC ϭ CC 1 ϩ CC 2 ϩ CC 3 ϩ CC 4 They are construction cost for landfill(s), incineration plant(s), RDF plant(s), and ash landfill(s), respectively.…”

“…The pilot study of an RDF process mentioned previously is now applicable for tuning the solid waste streams destined to the Pa-Li incinerator. [3][4][5] The planning questions of interest to the planners and decision makers are (1) What is the optimal size of the presorting process to be installed prior to the Pa-Li incinerator for assessing the optimal shipping strategy in the service area? ; (2) What is the short-term shipping pattern of solid waste streams in the designated service area given that the installation of such a presorting processes prior to the Pa-Li incinerator may come into a reality in Taipei County in the future?…”

“…For example, Chang and Wang 2 applied a goal-programming model for the evaluation of the compatibility potential between recycling and incineration with respect to several types of solid waste management alternatives. In addition, the interactions between several types of solid waste presorting processes and some wasteto-energy facilities were fully explored by Chang et al [3][4][5] from a regional aspect. The main findings of such a series of studies may be useful to facilitate the evaluation of new managerial strategies for various types of solid waste management systems in terms of cost effectiveness, environmental impacts, and material/energy recovery.…”

“…The presorting process selected in this systems analysis has been fully tested and the process functionality can be used as a given condition in this study. 4 To ease the situations of insufficient treatment and disposal capacity, residents' reluctance toward recycling activities, and the rapid increase of solid waste generation in the designated service area of an existing incinerator, it is possible to proclaim that the proper integration of a presorting process with a target incinerator could alleviate the pressure of solid waste disposal in the short term. This paper explores a new idea that a short-term operating policy should be optimally arranged with respect not only to the energy recovery targets and throughput requirements in an incineration plant but to a costeffective shipping strategy in terms of a given presorting process.…”