以礦物碳酸化法封存CO2

Abstract

CO2封存技術中，有礦物封存、生物封存、海洋封存、油槽及天然氣槽封存，因礦物封存具有1.產物不會造成二次污染2.礦物蘊藏量豐富3.反應過程為放熱反應。本研究目的為了解礦物鑑定分析資料及最佳碳酸化反應途徑並探討中鋼爐石為替代吸收劑之可行性。 本研究將CO2與天然矽酸鹽礦石及中鋼爐石之漿液進行碳酸化作用形成安定之碳酸鹽產物以達到CO2封存。其機制為CO2溶於水中形成HCO3後解離成H+及HCO3-，再與實驗試樣本體溶出Ca2+/Mg2+反應形成CaCO3或MgCO3沉澱，經TGA分析，500oC~850oC之重量損失可計算CO2轉換率。 本實驗針對反應之溫度、壓力、時間、試樣粒徑大小、液固比、攪拌速率、漿液組成成分作一系列之探討研究。由實驗結果顯示，反應溫度150oC、反應壓力1250psig、反應時間6小時、粒徑顆粒大小<44μm、L/S=10g/g、以去離子水為作為試樣漿液，鈣矽石及中鋼爐石之轉換率皆可達99%以上。 此外，粒徑縮減可增加反應之比表面積，有效增加CO2轉換率，相同反應條件下，鈣矽石<44μm之轉換率較88~125μm約增加25%。中鋼爐石<44μm之轉換率較53~62μm約增加2%。攪拌速率及液固比對轉換率無明顯影響，且使用1M NaHCO3為試樣漿液組成並不會增加CO2轉換率,反而造成轉換率下降。

CO2 is sealed up for safekeeping in technology, it is sealed up for safekeeping that there is mineral, the living beings seal up for safekeeping, seal up for safekeeping in the ocean, the oil groove and natural gas trough are sealed up for safekeeping, because the mineral is sealed up for safekeeping have 1. The secondary pollution that the result will not cause is 2. The reserves of mineral are abundant 3. The response course is the exothermic reaction. This research purpose, in order to understand mineral determine that analyses materials and the best carbonic acid reflect the steel stove stone in way and discussion in order to substitute the feasibility of the absorbent. Research this hit CO2 and natural silicate ore steel size, stove of stone carry on carbonic acid function form stable carbonate result with reach CO2 seal. Solve before becoming H+ and HCO3- after its mechanism dissolves and forms HCO3 in water for CO2, it is with experiment sample noumenonn dissolve been and then let's appear Ca2+ /Mg2+ the response form because there aren't CaCO3 or MgCO3, analyse by TGA 500℃ again can calculate CO2 conversion ratio of loss of weight of 850℃. This temperature, the pressure, time, sample grains of foot-path size when there is to reacting experiment, it is the firm for liquid than, mix there aren't speed, size. Shown by the experimental result, response temperature 150℃, response pressure 1250psig, 6 hours such as time such as response, a grain of foot-path particle size <44&brvbar;&Igrave; m, L/S=10g/g, regard deionized water as as sample size, wollastonite and hit steel conversion ratio, stove of stone can more than 99% all. In addition grain is it can is it react than the surface area to increase to reduce directly, increase CO2 conversion ratio effectively, under the same response condition, the wollastonite the conversion ratio of 44μm nearly increases by 25% than 88~125μm. the conversion ratio of 44μm nearly increases by 2% than 53~62μm on the steel stove stone in China. It doesn't obviously influence than the conversion ratio to mix the speed and liquid firmly, and use 1M NaHCO3 to make up and will not increase CO2 conversion ratio for the sample size, cause the conversion ratio to drop instead.