- 學位論文
生質廢棄物之熱處理資源化研究
Resource Utilization of Biomass Waste via Thermal Treatment
摘要
植物性的生質能源是一種乾淨、且對環境友善的能源，具有零碳排放的特性，但一般轉換植物性生質能源的過程，所產生的廢棄物其實仍有利用價值，若就此丟棄，不啻一種浪費，亦造成污染。葵花之生育期短，含油率高，是廣受歡迎的生質柴油來源，每年因此產出的廢棄葵花籽渣之量亦頗大。本研究選用向日葵籽，經過機械榨油所得的葵花籽渣作為研究標的，設計並改良葵花籽渣的熱處理程序，以載流氣體種類、載流氣體流量、氣體環境中之相對濕度、昇溫速率、目標溫度、目標溫度停留時間、以及樣品粒徑為控制變因，探討葵花籽渣熱處理資源化程序。主要儀器為熱重分析儀(thermogravimetric analyzer)。 本研究發現，葵花籽渣之質量削減速率最大值，發生在溫度點375 ℃附近，於低溫定溫停留有助於節省高溫爐的耗能，並令反應物保持在最大反應速率之環境中。 在昇溫程序為：自室溫以20 ℃/min的速率昇至105 ℃，停留2 h；再以相同速率昇至800 ℃，並於此溫度停留10 min的組別中，於300 ℃之後，產物中才明顯的有可燃氣體生成，以甲烷為主，莫耳含率達95.8%。隨溫度昇高，短鏈分子所佔比例愈來愈少，長鏈分子則漸增。在不計入載流氣體及不可燃物的情況下，以火焰離子偵測器(Flam Ionization Detector, FID)串聯光離子偵測器(PhotoIonization Detector, PID)之氣相層析儀(Gas Chromatography, GC)定性定量葵花籽渣的熱裂解氣體產物，其熱值達53.9 kJ/g，接近天然氣的60.8 kJ/g，顯示應用上的潛力！ 氣體產量隨系統中的相對濕度(relative humidity, RH)增加而提高。氣體產率最高可達55.86%，在昇溫程序為：自室溫以20 ℃/min的速率昇至105 ℃，停留2 h；再以50 ℃/min昇至380 ℃，並於此溫度停留120 min。
並列摘要
Bioenergy is a renewable energy which is friendly towards the earth. In general energy conversion process of vegetal biomass, huge amount of waste was produced though still had reusable worth. In this study, application of thermal process for the utilization of sunflower seed residue was investigate. Multi-stage temperature program was employed. Effects of controlling parameters such as heating rate, goal temperature, holding time, sample size, relative humidity of the system, carrier gas, and flow rate were examined. The instantaneous decomposition rate of sunflower residue reaches its maximum at about 375 ℃. Compared with those high-temperature reaction, to hold the furnace stay at lower temperature such as 375 ℃ will not only consume less energy but also keep the reactants in a state with maximum reaction rate. Combustible species in the products of pyrolysis of sunflower residue arise apparently after 300 ℃. The major product is methane, its content reaches up to 95.8% at 340 ℃when the multi-stage temperature program was as follows: first, sunflower residue was heated from 25 to 105 ℃ and hold at 105 ℃ for 2 h; then the temperature was raised to 800 ℃ with heating rate of 20 ℃/min. The carrier gas was helium, with flow rate of 50 mL/min. As thermal process goes on, the proportion of combustible long chain species in gaseous product increase. The high heating value of gaseous hydrocarbon products of 53.9 kJ/g close to 60.8 kJ/g of natural gas and the total yield of methane reaches 10.94 wt.% (relative to the initial input sample). The total gas yield was elevated when the relative humidity (RH) of the system is increased, it attained to 55.86% when RH = 84.9%.