The Investigation And Exploitation Of The Sulfur Capture Adsorbent Of Briquette

The letting SO₂ after coal burning results in the air pollution, which becomes a serious problem. To research the sulfur capture of coal and to control the pollution of SO₂ letting is very necessary. Calcium agent has been widely applied in the sulfur capture technique, which would be of importance in the evaluation and optimization.In this text, we discussed the burning process and the law of the sulfur separating out for the coal. During the burning process of the coal, the sulfur containing in the coal may become to the sulfur dioxide in the gaseity, and the organic sulfur and iron pyrites sulfur will be oxidized to sulfur dioxide promptly at 400-600℃. Through anglicizing the reaction of sulfur capture, we calculated the thermodynamic of the sulfur capture adsorbents CaCO₃, CaO and Ca(OH)₂) and got the results that the three kinds of sulfur capture adsorbents have larger impetus in the chemistry thermodynamics. For the high temperature product calcium sulphate, we established the function relationship of free energy and temperature with the sulfur capture process at the high temperature condition, and according to the function we can conclude the balance pressure between sulfur dioxide and sulfur capture adsorbent, and dissociation pressure of the calcium sulphate at different temperatures.Ratio of the calcium and the sulfur is a very important factor. For different kinds of coal, there will be a best ratio of the calcium and the sulfur existing. Combining the case with the law sulfur coal, the ratio of the calcium and the sulfur would be confirmed at about 2.3. Furthermore, we tested the effect of granularity, and the results indicated that the smaller the granularity size is and the larger the surface area is, the higher effective the sulfur capture is. Also we selected several metal compound additives and researched the promoting effect on the limestone sulfur capture at various accession ratios. The results show that metal compounds have the promoting effect on the limestone sulfur capture to some extent. In addition, the metal compounds is not only have the effect on calcium utilize ratio of the limestone but also exist a best accession ratio.(i.e. the best accession ratios of Na₂CO₃, Al₂O₃ and Fe₂O₃ are 2.0%, 3.0% and 3.0%, respectively.) At the end, we screened out the preferred calcium agent complex sulfur capture scheme adapting to the coal sample Fuyou Street Office provided in Beijing City, which is one kind of low cost, rich resource and convenient sulfur capture adsorbent based on limestone ore with a few minerals and industry scrap. The evaluation results indicate that this kind of sulfur capture adsorbent has the best effect on the low sulfur coal. At the definite temperature and the coal containing 1% sulfur, the total sulfur capture ratio arrives at～32%.Then we screened out the organic small molecule denoted the sulfur state in the coal, and designed the model to calculate. After calculating we got the total energy , entropy and Gibbs free energy data, including the bond grade, electric charge density, spin density and other molecular properties. By analyzing the data, we can understand the SO₂ liberative degree for the various state sulfurs interacting with oxygen. CH₃CH₂SH is easier to combine with the oxygen molecule to take place the elimination reaction, which opens out the essence of sulfur containing in coal and oxygen and provides the reference for the sulfur capture mechanism and the removing sulfur mechanism.