Reactor For Co-production Research Articles

Experimental study of a high-temperature porous-medium filled solar thermochemical reactor for CO production

Solar thermochemistry via a two-step cycle has been considered as a promising technology as it is feasible to convert solar energy into fuels directly. The improvement of solar-to-fuel energy efficiency is strongly dependent on the heat recovery during the temperature swing between the reduction and oxidation steps. The present article describes the experimental results of a solar thermochemical reactor with gas-gas heat recovery. The reactor's inlet and outlet gases are exchanged through the heat exchanger, thereby improving the energy utilization efficiency, and a series of experiments are carried out to further demonstrate the feasibility of this technology. The influence of the pressure of the endothermic reduction step and the influence of the concentration of reactants in the exothermal oxidation step on the experimental results are analyzed. The experimental results show that vacuuming condition further promoted the reduction kinetics compared with Ar purging, and the yield of CO increases from 1.13 mL/gCeO2 to 1.32 mL/gCeO2 within 60 min. Therefore, the following experiments are completed under vacuuming condition for the endothermic reduction reaction. The yield of CO is favored at higher CO2 partial pressure, and the yield of CO increases from 44.65 mL to 279.42 mL as the volume flow rate of CO2 increase from 0.5 L/min to 4 L/min. This research provides useful information on the industrial implementation of the thermochemical technology.

Smart solar reactor for co-production of hydrogen and industrial grade carbon under any weather conditions

Abstract The impending shortage of fossil fuels and environmental consequences of fossil fuel consumption are two of the most imperative problems in the world. This presentation is about a novel design of a solar reactor cavity system composed of a camera-like aperture and moving-wall system to house a unique thermo-fluid-chemical process known as ‘solar cracking’. Differing from typical solar powered Rankine cycles, solar cracking uses concentrated solar energy as a heat source for direct decomposition of natural gas into gaseous H2 and particulate carbon. This process offers a CO2 emission free hydrogen production method, as the carbon is collected in a high-grade and/or nanotube form. However, solar cracking reactors have two implicit major problems: The intrinsic losses in energy conversion efficiency as a result of the high internal temperatures and corresponding re-radiation losses as well as the inherently transient nature of the solar energy. Literature on solar reactors reveals a distinct focus on optimal reactor design for steady state efficiency, but little regarding transient inefficiencies. This presentation provides an advanced perception to solar cracking reactors by presenting you the latest results of our research at Sustainable Energy Research Lab on the design of a ‘smart solar reactor’ that is sensitive to variations in solar flux, and can adjust itself accordingly to maintain quasi-equilibrium internal conditions. A unique system design is presented featuring a solar-flux intensity sensitive aperture that can enlarge the aperture diameter when the flux is low and reduce the diameter when the flux is high. Carbon particle deposition on the reactor window, walls, and at the exit. Carbon deposition. particularly at the exit, causes reactor clogging. There have been many innovative reactor designs aimed to achieve increased conversion efficiencies through novel flows developed at ETH-Zurich, CNRS-France, WIS-Israel, Colorado-USA, Florida-USA, and DLR-Germany. From vortex-flow to tornado, and from fluidized bed to rotating cavity, the designs of these reactors have moved toward the goal of seeking enhanced flow conditions that result in improved overall efficiencies, but have not solved the carbon deposition problem. Our latest research results at Sustainable Energy Research Lab shows that our ‘aero-shielded cyclone solar reactor’ concept provides a laminar flow shield covering the walls as a thin layer flow with a velocity that is strong enough to sweep carbon particles away. This presentation will show you the results of our research on this concept with a 3D animation of the reactor.