Process Optimization of Hydrogen Production from CoalGasification

Hydrogen is a high quality energy carrier, contains no carbon and generates little or no polluting emissions at the point of use. A hydrogen-based energy system is an advantageous option for delivering efficient, clean and safe energy in a wide range of applications [1]. At present, significant cost and performance improvements in production, storage, transportation and technologies are required. Research, development and commercial efforts should be combined to achieve these goals. Hydrogen is a secondary form of energy, produced using other primary energy sources. Most of the hydrogen is made by steam reforming of natural gas (which is mainly methane). However, the use of coal as source is desirable, being a low-cost fuel and guaranteeing a longterm availability. Coal gasification is an efficient, clean and versatile process, which can be adapted for producing hydrogen [2]. The comparison of different technologies as well as the assessment of advanced options (e.g. introduction of a combined cycle, use of pure oxygen, CO2 sequestration) are necessary to maximize the conversion, the process efficiency and the environmental benefits [3]. Even, the integration of the gasification process with a centralized power plant (thus sharing steam, heat, emissions and residue char) may be competitive, reducing significantly the cost for hydrogen production. This work aims to assess the efficiency of the coal gasification process, the opportunity of different options and the effect of the operating conditions on hydrogen production, net energy production. Preliminary experimental applications and process modeling on the coal pyrolysis Enel plant of Bastardo (Perugia – Italy) gave promising results [4]. These are the bases to develop a process optimization method, which uses thermodynamic databases, parametric models (for the pyrolysis and gasification steps) and a steady state simulation software. The results reported in this work are a first example of the potential of combining these tools and will be deepened in the frame of the FISR project “Integrated Systems for Hydrogen Production and Use in Distributed Generation”, which will optimize the integration with a centralized power plant [5].