以超重力反應沉澱技術製備碳酸鹽微粒

Preparation of Fine Carbonate Salts Using a Higee System

戴嘉德(Chia-Te Tai)

指導教授 ： 戴怡德

國立臺灣大學/工學院/化學工程學研究所/博士(2007年)

https://doi.org/10.6342/NTU.2007.00685

摘要

本研究目的在建立一超重力技術平台，以探討其製備微細粒子之可行性。所採用之超重力結晶設備有旋轉填料床反應器（簡稱RPBR）及旋轉盤反應器（簡稱SDR）兩種。採用上述兩種裝置，透過氣-液碳化法及液-液混合兩種反應沈澱的方式，進行碳酸鈣、碳酸鋇的製備。選擇碳酸鈣為物系，是因為經微粒化之碳酸鈣於高分子聚合物、造紙及封裝材料上具有機能性之應用；此外，微粒化之桿狀碳酸鋇則可應用於光電產業上。
研究內容包括：首先建立一套良好且固定之粒子分散方式以取得具再現性的粒徑量測結果。然後透過氣-液碳化反應，系統性地分析超重力系統中，轉速、漿液流量、進料濃度、二氧化碳通氣量等變因對產品粒徑之影響，並且比較RPBR與SDR兩反應器之微粒化效果。對於碳酸鈣系統，我們透過循環碳化的方式，以RPBR製備出平均粒徑0.39 μm，方解石晶相之碳酸鈣，產率約在85∼90 %。而在碳酸鋇系統方面，則透過連續碳化方式，以RPBR及SDR製備出平均粒徑分別為0.39μm、0.34μm，具斜方晶相之桿狀碳酸鋇。產率約在75∼80 ％。此外，亦比較超重力裝置與一般常重力裝置之微粒化效果。結果發現將超重力裝置應用於快速的反應沈澱製程中，可展現出較常重力裝置更為優異之微細化、均勻化的效果。
綜觀研究結果，超重力裝置因設備小不佔空間，且可連續操作。此外因超重力下之快速吸收及混合的效果而可獲得粒徑小且分佈窄之產品，相當符合綠色程序之製程強化範疇。

關鍵字

超重力 ； 微細粒子 ； 旋轉填料床反應器 ； 旋轉盤反應器 ； 碳酸鈣 ； 碳酸鋇 ； 碳化法 ； 反應沈澱 ； 製程強化

並列摘要

The purpose of this study was to build a platform to apply the high-gravity (higee) technique in crystallization for producing fine particles. We used two types of higee equipment, rotating packed bed reactor (RPBR) and spinning disk reactor (SDR), to produce CaCO3 and BaCO3 particles via a gas-liquid-carbonation or a liquid-liquid-mixing reactive precipitation route. Fine CaCO3 particles can be used in polymers, paper industry etc., to enhance the performance of material. Small rod-like BaCO3 particles can also be used in optical and electronic industry.
First of all, an adequate particle-dispersing technique was developed and subsequently was used for PSD measurement. Through comparison of the results obtained from the PSD measurement, the effects of operation variables in a higee system on PSD of products, including rotating speed, flow rate, and solid-content of feed slurry, were investigated via a carbonation route; meanwhile comparison of the performance between RPBR and SDR was also included. As the CaCO3 system was concerned, RPBR was used to produce CaCO3 particles with volumetric mean size 0.39μm and calcite-polymorphism in a circulate carbonation process. The yield for this process was 85∼90 %. For the other system, we used types of reactors, i.e., RPBR and SDR, to produce BaCO3 particles in a continuous carbonation process. The volumetric mean size of BaCO3 was 0.39μm and 0.34μm for RPBR and SDR separately, and the prepared particles were rod-like and had a orthorhombic crystal morphology. The yield for the continuous carbonation process was about 75∼80 ％. Finally, we compared the products produced by a high-gravity reactor and a normal-gravity reactor.
Viewed in this light, the higee system fits the category of process intensification in the development of green processes, concerning the less space required, suitable for continuous operation, and much more improved efficiency in absorption and mixing to be able to produce fine particles with narrow distribution.

並列關鍵字

high-gravity (higee) ； fine particles ； rotating packed bed reactor (RPBR) ； spinning disk reactor (SDR) ； CaCO3 ； BaCO3 ； carbonation ； reactive precipitation ； process intensification.

參考文獻

陳昱劭，“旋轉填充床中黏度對質傳影響之研究”，台灣大學化學工程研究所博士學位論文. (2004)

Burns, J. R. and C. Ramshaw, “Process Intensification: Visual Study of Liquid Maldistribution in Rotating Packed Beds”, Chem. Eng. Sci., 51, 1347. (1996)

Cafiero, L. M., G. Baffi, A. Chianese, and R. J. J. Jachuck, “Process Intensification: Precipitation of Barium Sulfate Using a Spinning Disk Reactor”, Ind. Eng. Chem. Res., 41, 5240. (2002)

Chakraborty, D., V. K. Agarwal, S. K. Bhatia, and J. Bellare,“Steady-state Transitions and Polymorph Transformations in Continuous Precipitation of Calcium Carbonate ”, Ind. Eng. Chem. Res., 33, 2187. (1994)

Chen, J. F., Y. H. Wang, F. Guo, X. M. Wang, and C. Zheng, “Synthesis of Nanoparticles with Novel Technology: High-gravity Reactive Precipitation”, Ind. Eng. Chem. Res., 39, 948. (2000)