Selection Criteria for Coal-to-Methanol Process Designs
Publication Date: 2012-Jul-18
The IP.com Prior Art Database
Page 01 of 1
The M. W. Kellogg Company
The conceptual process flowsheet for coal to methanol processes is described in terms of the overall process chemistry requirements. Downstream of the proprietary coal gasification step, the processes employed to produce a clean make-up gas for methanol synthesis are essentially the same. Excess carbon is removed as C02, produced by shifting. Effluent handling facilities to treat gases and liquids in a manner acceptable to both the main process and the environment complete the process definition.
A detailed example of a 2500 MTD methanol from coal process is given. Texaco gasification of Illinois #6 coal is used for generation of the raw gas. A physical absorption system is employed for the acid gas/CO2 removal step.
The particular system chosen was a Selexol unit preceded by a shift and
COS hydrolysis reactor sequence. The clean syngas is converted to methanol via the ICI low-pressure process. Conventional distillation is used to purify the crude product.
The effect of the process design strategy on the total energy requirement is illustrated by the overall steam balance. Alternate process options to reduce the size of the steam system are briefly explored. In addition to the standard feed and fuel sumary, a first law analysis is made to determine where energy is lost from the process. Finally, the total capital cost estimate is broken down by major process sections.
Selection criteria~@or comparing gasification technologies are general...