Solar steam reforming of natural gas for hydrogen production using molten salt heat carriers

Abstract

in Wiley InterScience (www.interscience.wiley.com).The utilization of concentrated solar energy as external heat source for methane steam reforming has been investigated. Molten salts at temperatures up to 5508C can be used as solar heat carrier and storage system, and hydrogen selective membranes can be used to drive reforming reaction at lower temperatures than conventional (\5508C), with hydrogen purification achieved thereby. The combination of new technologies such as membranes and membrane reactors, concentrating solar power (CSP) systems, and molten salt heat carriers, allows a partial decarbonation of the fossil fuel together with the possibility to carry solar energy in the current natural gas grid. Different plant configurations and operating conditions have been analyzed using a mathematical model and AspenPlus simulator.

Catalyst development for steam reforming of methane and model biogas at low temperature

“…The utilization of molten salts up to 550 • C with a heat storage system can ensure constant-rate solar heat supply even for an energy demanding industrial chemical process like the steam reforming of methane [11]. Moreover, in order to use hydrogen as an energy carrier, a transition period comprising both renewable and fossil sources will exist.…”

A review of solar methane reforming systems

“…The maximum conversion achieved in these studies ranged between 15 and 21% [76,78]. Simulations concluded that increasing the residence time, steam to fuel ratio, and inlet temperature increases the methane conversion, while increasing the operating pressure decreases the methane conversion [77].…”

“…Simulations concluded that increasing the residence time, steam to fuel ratio, and inlet temperature increases the methane conversion, while increasing the operating pressure decreases the methane conversion [77]. Moreover, conversion was increased to between 54 and 69% when multiple reactor stages with hydrogen permeable membranes between each reactor stage was utilized [78].…”

“…Numerical studies for similar reforming systems have been done except with molten salt as the heat transfer fluid [76,77,78]. The reformer temperatures for these studies were much lower than the ASTERIX project (450-530…”

“…While designs for traditional membrane-based reformers (i.e., no solar) have been proposed and experimentally studied [87,88,89], there has not been much experimental work on the subject of solar membrane-based reformers. Numerical studies have been done on pairing membrane-based reformers with molten salt streams heated by solar energy [78,86]. The reformer design is similar to previously discussed tubular heat exchanger reformer concepts.…”