Options for utilizing low-pressure steam in coal-to-methanol plants
Thread Content
Currently, many large-scale coal-to-methanol projects are in operation, and there is an excess of low-pressure steam within these plants; how to make effective use of this steam has become a problem. I have two ideas; I’d like everyone to discuss their feasibility or suggest new ways to apply them. My thoughts: 1. Fuel coal used in dry fluidized bed boilers ； 2. Lithium bromide refrigeration units are used to generate low-temperature water, which serves to supplement the cooling capacity required by air separation and low-temperature methanol washing processes.
The suggestion is great; I just wonder if there are any manufacturers that have implemented your second suggestion, so we can learn from them! !
The cooling requirements for low-temperature methanol washing are -40°C and 0°C. Wouldn’t it be a waste to use chilled water? (Water may not freeze at 0°C, but what state is it at -40°C?) ? ? ). This portion of steam still condenses directly into acid. Last edited by purpleghj on 2008-1-14 17:06.]
Used in turbine-driven centrifugal circulators or pumps to replace the original motor drive.
1. So far, there is no news of industrialization having been achieved; I plan to discuss this with the design team after determining its feasibility through everyone’s input. 2. This portion of cooling capacity is used as a supplement, rather than completely replacing ammonia cooling. My original intention was to connect it with ammonia cooling in order to save energy.
I think lithium bromide units should be feasible, but I wonder if they will be very large.
The steam generated by our company’s medium-pressure and high-pressure methanol units has a pressure of 0.3~0.4 MPa, and it is used in the gas generation process (in steam drums), where it performs well. This post was last edited by liuyz79 on 2008-1-16 23:06.]
Reply: 1. By considering its utilization in conjunction with the steam used by the thermal power plant, low-pressure steam can be used as steam for the boiler feedwater deaerator. 2. It is a good choice as a heat source for lithium bromide absorption chillers, and it is widely used in small and medium-sized enterprises that produce methanol as a by-product of nitrogen fertilizer production. 3. It is impossible to use a drive turbine; medium-pressure superheated steam is generally required. 4. The general principle is to take into account the overall steam balance of the entire plant in order to make the most efficient use of steam. However, the fundamental solution lies in improving the process flow and equipment configuration, thereby minimizing the generation of low-quality steam; with less such steam generated, its utilization becomes less of an issue, for example by increasing the pressure level of the waste boilers.
In addition to being used as steam for boiler feedwater, excess low-pressure steam can be employed for power generation using low-temperature media, simultaneously recovering low-temperature heat energy from chimneys and similar sources, resulting in good energy-saving effects.