Main Purification Operations

Syngas final usage requires a previous step of cleaning and conditioning to meet with the requirements of its final use which might range from chemicals and fuels production to power and/or heat. This chapter deals with the description and the modelling of the required syngas treatment units before electricity production or before hydrogen generation, specifically in an IGCC power plant. In the case of electricity generation application, the pursued objective is to avoid as much as possible nitrogen and sulphur oxide emissions to the atmosphere. In a first step, the gas is cleaned from solids. Secondly the gas before its combustion goes through an acid and basic species removal train of units. In the case of hydrogen generation, besides syngas cleaning from other species, the main pursued objective is to separate CO from H₂. In order to accomplish the former, CO should be converted into CO₂ and then separated from the main stream. Hydrogen can be further purified to be sold to the market, or used in a combined cycle, in an analogous way as the syngas. Modelling calibration and validation are shown, and the chapter finishes with a model utilisation to evaluate the behaviour of the already built up superstructure to produce hydrogen or syngas for electricity generation section, or hydrogen for other applications.