【摘要】：我國資源賦存具有“富煤、貧油、少氣”的特點(diǎn),石油儲(chǔ)采比僅為11.4年,對外依存度超過60%。我國油頁巖資源豐富,其干餾產(chǎn)生的頁巖油可以代替石油。油頁巖熱解過程中,黃鐵礦中的硫會(huì)遷移到產(chǎn)物里,嚴(yán)重的污染了環(huán)境、腐蝕了設(shè)備。另一方面,黃鐵礦又會(huì)對熱解過程產(chǎn)生影響。因此,研究黃鐵礦對油頁巖熱解過程的影響意義重大。為了排除其他礦物質(zhì)對油頁巖干餾的影響,本文采取酸洗的方法制備龍口油頁巖有機(jī)質(zhì),詳細(xì)分析了酸洗前后油頁巖中礦物質(zhì)和各種官能團(tuán)的變化情況。在水平爐干餾試驗(yàn)臺(tái)上,研究了氧化鐵、單質(zhì)硫和黃鐵礦對油頁巖有機(jī)質(zhì)熱解產(chǎn)物產(chǎn)率、不凝氣釋放以及半焦官能團(tuán)的影響。通過對龍口油頁巖酸洗前后XRD和FTIR分析,發(fā)現(xiàn)采用HCl-HF-HNO3逐級酸洗的方法可以脫除98.5%的灰,制得較為純凈的有機(jī)質(zhì),但會(huì)對有機(jī)質(zhì)的結(jié)構(gòu)產(chǎn)生一定影響。酸洗會(huì)促使芳香烴結(jié)構(gòu)向苯環(huán)二取代方式轉(zhuǎn)變,同時(shí)使有機(jī)鹽轉(zhuǎn)化為有機(jī)酸,提高羧酸和酚羥基含量;對于脂肪結(jié)構(gòu),酸洗會(huì)增加不對稱CH2所占比例,造成脂肪鏈長度增大,而對于羥基來說,酸洗會(huì)在一定程度上破壞OH-O的氫鍵結(jié)構(gòu)。對酸洗前后油頁巖進(jìn)行熱重實(shí)驗(yàn),結(jié)果表明酸洗會(huì)降低熱解起始溫度和終止溫度,增大熱解速率,但基本不影響最大失重峰的溫度范圍,這說明酸洗并不會(huì)顯著改變有機(jī)質(zhì)的主體結(jié)構(gòu)。龍口油頁巖酸洗除去的礦物質(zhì)對熱解表現(xiàn)為抑制作用。通過對半焦官能團(tuán)的紅外譜圖分析,發(fā)現(xiàn)在熱解終溫500℃、停留時(shí)間40min時(shí),有機(jī)質(zhì)基本已經(jīng)分解完全。熱解會(huì)使脂肪長鏈斷裂,含氧官能團(tuán)比例下降,其中羧酸已完全反應(yīng)。對芳香烴而言,熱解會(huì)使芳香氫取代程度升高,取代方式向氫含量減少的方向進(jìn)行。氧化鐵、硫、黃鐵礦均會(huì)促進(jìn)芳香烴的取代,過量的氧化鐵和黃鐵礦會(huì)使苯環(huán)的取代方式向苯環(huán)三取代進(jìn)行,硫會(huì)使苯環(huán)的取代方式向苯環(huán)四取代進(jìn)行。3種添加劑都會(huì)抑制大分子的縮合,使半焦中CH2/CH3的值不斷升高。當(dāng)添加40%的硫時(shí),紅外譜圖中2870cm-1處對稱的CH3伸縮振動(dòng)峰的強(qiáng)度明顯增強(qiáng),表明過量的硫會(huì)促使焦炭中芳香環(huán)開裂,增加支鏈化程度。熱解過程中,氧化鐵、硫、黃鐵礦均對有機(jī)質(zhì)大分子結(jié)構(gòu)的斷裂起到促進(jìn)效果。氧化鐵和硫均降低了焦油的產(chǎn)率,促進(jìn)了不凝氣的生成;隨著黃鐵礦添加量的增大,焦油產(chǎn)率先下降后上升,氣體產(chǎn)率先上升后下降。熱解氣CO和CO_2的生成總是先于CH_4和C_2H_6。氧化鐵會(huì)提高CO_2的產(chǎn)率,降低CO、CH_4和C_2H_6的產(chǎn)率;硫會(huì)提高CO的產(chǎn)率,降低CO_2、CH_4和C_2H_6的產(chǎn)率,同時(shí),硫的加入會(huì)使這4種氣體開始生成的時(shí)間推后;黃鐵礦會(huì)提高CO_2的產(chǎn)率,而CO、CH_4和C_2H_6的產(chǎn)率先升高后下降,在添加量2%時(shí)達(dá)到最大值。
[Abstract]:The occurrence of resources in China is characterized by "rich coal, lean oil and less gas". The ratio of oil storage to production is only 11.4 years, and the degree of external dependence is more than 60%. China is rich in oil shale resources and the shale oil produced by its retorting can replace oil. During the pyrolysis of oil shale, sulfur in pyrite will migrate to the product, which will seriously pollute the environment and corrode the equipment. On the other hand, pyrite will affect the pyrolysis process. Therefore, it is of great significance to study the influence of pyrite on the pyrolysis process of oil shale. In order to eliminate the influence of other minerals on oil shale retorting, the organic matter of Longkou oil shale was prepared by acid pickling method. The changes of minerals and various functional groups in oil shale before and after pickling were analyzed in detail. The effects of iron oxide, elemental sulfur and pyrite on the yield of pyrolysis products of oil shale organic matter, the release of uncondensed gas and the functional groups of semi-coke were studied on a horizontal furnace dry distillation test rig. By analyzing the XRD and FTIR of Longkou oil shale before and after pickling, it is found that 98.5% of the ash can be removed by using the method of HCl-HF-HNO3 pickling step by step, and the pure organic matter can be prepared, but it will have a certain influence on the structure of organic matter. Acid pickling can change the structure of aromatic hydrocarbons to benzene-ring disubstituting, at the same time, the organic salts can be transformed into organic acids and increase the contents of carboxylic acids and phenolic hydroxyl groups. For fat structure, pickling will increase the proportion of asymmetric CH2 and increase the length of fat chain. For hydroxyl groups, acid pickling can destroy the hydrogen bond structure of OH-O to some extent. The thermogravimetric test of oil shale before and after pickling shows that acid pickling can decrease the starting temperature and termination temperature of pyrolysis and increase the pyrolysis rate, but it has no effect on the temperature range of the maximum weight loss peak. This shows that pickling does not significantly change the main structure of organic matter. The minerals removed by acid pickling of Longkou oil shale inhibit pyrolysis. By analyzing the infrared spectrum of the functional groups of semi-char, it is found that the organic matter has basically been completely decomposed when the final pyrolysis temperature is 500 鈩，

本文編號：2205375