Conceptual design of hydrogen production process from bioethanol reforming

摘要

Hydrogen is considered to be one clean energy carrier for the future. The main advantage of using hydrogen as energy carrier represents the negligible greenhouse gas emissions. One of the most encouraging hydrogen production methods is based on bioethanol. This paper is devoted to the conceptual design of hydrogen production process using bioethanol reforming at an industrial scale (100000 Nm~3/h hydrogen equivalent to 300 MW thermal). The syngas will be then converted into hydrogen by water gas shift reaction. Two distinct designs were investigated, one without carbon capture and one with carbon capture. In the design with carbon capture and storage (CCS), the shifted syngas is treated for removing CO_2 by gas-liquid absorption process. Considering that bioethanol has a low or negligible fossil carbon footprint, the case with CCS has a negative CO_2 emissions contributing to decreasing atmospheric CO_2. The conceptual designs of bioethanol reforming were modeled and simulated to produce mass and energy balances for quantification of key plant performance indicators (e.g. bioethanol consumption, plant energy efficiency, ancillary energy consumption, specific CO_2 emissions etc.). A particular accent is put on assessment of reforming unit operation conditions, process integration issues of reforming unit and syngas conditioning line with carbon capture unit, modeling and simulation of whole plant, thermal and power integration of various plant sub-systems by pinch analysis. Benchmark cases based on fossil fuels partial oxidation were also presented.