Shift setup for pulverized coal gasification
Thread Content
The CO content in the syngas produced by the gasification of shell powder is as high as around 65%, making methanation reactions highly likely to occur in the shift reactor. It is therefore very important to control the depth of the transformation reaction. All forum members are welcome to share information regarding the settings of their conversion devices, the models of catalysts used, the amount of catalyst loaded, as well as any problems that arise during operation, so that everyone can learn from it. * This post was last edited by ft2489244 on 2008-3-7 at 16:37.]
Our company uses four-nozzle water-coal slurry gasification, rather than Shell powder coal gasification; the CO content is around 42%. The shift reaction is carried out using medium-pressure sulfur-resistant shift catalysts, with an operating pressure of about 5.9 MPa. The catalyst used is of the QCS-01 type developed by the Qilu Petrochemical Research Institute.
This is a great topic, but I would like to ask everyone whether a very small methanol plant (10 wt/y) can achieve gas production from coal dust
Generally not, because powder coal gasification requires large investments, and a scale of 100,000 tons is too small. The time required to recover the investment is long, resulting in no economic benefits. However, 200,000 tons of methanol are produced using powder gasification. The 200,000-ton methanol gasifiers in Linquan, Anhui, and Puyang, Henan, use space-based furnaces.
Our plant uses Shell pressurized coal gasification for gasification; the CO content in the gas at the shift inlet is 65% and the pressure is 3.8 MPa. K8-11 catalysts are used for the first and second shifts, while QDB-04 catalysts are used for the third shift
May I ask which factory is upstairs? I’d like to learn about how you use shells
To address the issues in China related to the high CO content in the gas produced by powder coal gasification, the tendency for methanation side reactions during the shift process, and the difficulties in controlling the reaction depth and bed temperature peaks, a new low-water/gas sulfur-resistant shift process for powder coal gasification has been developed through research on the factors affecting methanation side reactions, as well as on the control of reaction depth in multi-stage and single-stage reactors. This process takes advantage of the low water content in the syngas produced by pulverized coal gasification. The QDB-04 catalyst is used throughout, and the depth of the shift reaction in the first reactor as well as the hotspot temperature in the bed are controlled by regulating the water/gas ratio in the process gas. To achieve partial conversion of high-concentration CO without the occurrence of methanation side reactions. In the first stage of this process, the water/gas ratio shall not exceed 0. 3. The maximum value for water/gas in all other sections shall not exceed 0. 5. The maximum peak temperature does not exceed 400, the operating conditions are mild, the conversion unit runs smoothly without any methane side reactions, which allows for a significant reduction in steam consumption and savings in equipment investment.
The low moisture ratio process you mentioned is used only by Liuhua; it involves 5 conversion furnaces, and its operation and control are complicated. However, it enables a significant reduction in steam consumption and saves on equipment investment. ”It’s hard to know where to start when talking about the savings in equipment investment.
In China, powder gasification units are generally designed with a five-ring configuration. The sulfur-resistant conversion process in this design works as follows: a small amount of catalyst is used in one furnace, some gas is fed in, and auxiliary systems are used for temperature control to maintain a high space velocity; this results in an uneven temperature distribution across the catalyst bed. The converted gas mixes with the unconverted gas, giving a CO concentration of around 45%, which then enters the second and third conversion stages. For methanol synthesis gas, a third stream of gas is separated out, which is used to adjust the final CO concentration without going through conversion. Generally, K8-11/H is used in the first furnace, while catalysts from the QSC or QDB series are used in the second and third furnaces.