Dry Methane Reforming Without a Metal Catalyst in a Directly Irradiated Solar Particle Reactor

Abstract

Dry methane reforming with carbon dioxide in a directly irradiated particle receiver seeded with carbon black is presented in this study. Carbon particles were entrained in the reacting gases and acted as heat transfer and reaction surface. The reactions were not catalyzed by a metal catalyst. The molar ratio between the entrained carbon particles and the working gases (Ar, CO2, and CH4) was 4–7 mmol carbon/mol gas. The temperature of the reforming experiments varied from 750°C to 1450°C with CO2/CH4 ratios varying from 1:1 to 1:6. Experimental results show that methane reacts at lower temperatures than expected for its thermal decomposition; this indicates that the decomposing reaction is enhanced by the presence of the carbon black particles. At 1170°C 90% of the methane reacted in the receiver during a residence time of 0.3 s. The reaction between carbon dioxide and carbon black is faster than is documented in the literature, but the reaction rate does not seem to change if only carbon dioxide and carbon black are present in the receiver, compared with experiments where methane is also part of the gas mixture. The experimental results indicate that a high solar flux, i.e., about 2500 kW/m2 or higher, significantly accelerates the reaction rate of methane decomposition. Total or partial blockage of the solar radiation reduced the yield by about 50%, compared with tests when the receiver was exposed to the full solar radiation flux, at the same operating temperature.

Solar Thermochemical Fuel Generation

“…In order to achieve the high-efficient progress of the solar methane reforming reaction, research on solar methane reforming reactors has also continued. Klein et al [33] proposed a schematic diagram of a fluidized bed reactor. This experiment is a methane dry reforming experiment, where gas reactants and carbon particles are mixed and passed into the reactor together.…”

A generalized approach for selecting solar energy system configurations for a wide range of applications

“…Some examples are methane reforming, water splitting, CO 2 dissociation, coal gasification, and reduction of various metal-oxides. [87][88][89][90][91] A significant number of these studies have included the development of innovative solar reactors, where the endothermic reaction is performed. 87,89,91 Examination of the overall systems required for performing these processes at a commercial level reveals the following:…”

Dry Reforming in a Milli-Scale Reactor Driven by Simulated Sunlight

“…Solar energy is a desirable energy input because it is clean and sustainable compared to other energy sources. In recent years, solar energy has been applied to methane reforming reactions [14,[17][18][19][20][21][22]; however, dry reforming has not been performed in a miniaturized solar reactor (or a reactor driven by simulated solar energy).One of the first reports of solar-driven dry reforming is reported in the work of Diver et al [22]. This work details the use of a heat pipe system integrated with a solar furnace to run the dry reforming reaction.…”

“…In this scheme, the CO 2 and CH 4 flow on different sides of the membrane. One advantage of this concept is the inherent separation of products; however, the rate of syngas production is limited by the mass loading of perovskite in the reactor, which makes heat distribution using solar energy difficult.A solar-driven reactor for non-catalytic reformation is implemented by Klein et al [19]. Carbon black particles entrained in the reactor feed gas at a C:CO 2 ratio of 0.5:100 improve heat transfer and provide a surface for the reaction to proceed.…”

“…A solar-driven reactor for non-catalytic reformation is implemented by Klein et al [19]. Carbon black particles entrained in the reactor feed gas at a C:CO 2 ratio of 0.5:100 improve heat transfer and provide a surface for the reaction to proceed.…”