Rapid High Temperature Solar Thermal Biomass Gasification in a Prototype Cavity Reactor

2010 ◽  
Vol 132 (1) ◽  
Author(s):  
Paul Lichty ◽  
Christopher Perkins ◽  
Bryan Woodruff ◽  
Carl Bingham ◽  
Alan Weimer

High temperature biomass gasification has been performed in a prototype concentrated solar reactor. Gasification of biomass at high temperatures has many advantages compared with historical methods of producing fuels. Enhancements in overall conversion, product composition ratios, and tar reduction are achievable at temperatures greater than 1000°C. Furthermore, the utilization of concentrated solar energy to drive these reactions eliminates the need to consume a portion of the product stream for heating and some of the solar energy is stored as chemical energy in the product stream. Experiments to determine the effects of temperature, gas flow rate, and feed type were conducted at the high flux solar furnace at the National Renewable Energy Laboratory, Golden, CO. These experiments were conducted in a reflective cavity multitube prototype reactor. Biomass type was found to be the only significant factor within a 95% confidence interval. Biomass conversion as high as 68% was achieved on sun. Construction and design considerations of the prototype reactor are discussed as well as initial performance results.

Author(s):  
Paul Lichty ◽  
Christopher Perkins ◽  
Bryan Woodruff ◽  
Carl Bingham ◽  
Alan Weimer

High temperature biomass gasification has been performed in a prototype concentrated solar reactor. Gasification of biomass at high temperatures has many advantages compared to historical methods of producing fuels. Enhancements in overall conversion, product composition ratios, and tar reduction are achievable at temperatures greater than 1000°C. Furthermore, the utilization of concentrated solar energy to drive these reactions eliminates the need to consume a portion of the product stream for heating and some of the solar energy is stored as chemical energy in the product stream. Experiments to determine the effects of temperature, gas flow rate, and feed type were conducted at the High Flux Solar Furnace (HFSF) at the National Renewable Energy Laboratory (NREL). These experiments were conducted in a reflective cavity multi-tube prototype reactor. Biomass type was found to be the only significant factor within a 95% confidence interval. Biomass conversion as high as 68% was achieved on sun. Construction and design considerations of the prototype reactor are discussed as well as initial performance results.


Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 462
Author(s):  
Houssame Boujjat ◽  
Sylvain Rodat ◽  
Stéphane Abanades

Solar biomass gasification is an attractive pathway to promote biomass valorization while chemically storing intermittent solar energy into solar fuels. The economic feasibility of a solar gasification process at a large scale for centralized H2 production was assessed, based on the discounted cash-flow rate of return method to calculate the minimum H2 production cost. H2 production costs from solar-only, hybrid and conventional autothermal biomass gasification were evaluated under various economic scenarios. Considering a biomass reference cost of 0.1 €/kg, and a land cost of 12.9 €/m2, H2 minimum price was estimated at 2.99 €/kgH2 and 2.48 €/kgH2 for the allothermal and hybrid processes, respectively, against 2.25 €/kgH2 in the conventional process. A sensitivity study showed that a 50% reduction in the heliostats and solar tower costs, combined with a lower land cost of below 0.5 €/m2, allowed reaching an area of competitiveness where the three processes meet. Furthermore, an increase in the biomass feedstock cost by a factor of 2 to 3 significantly undermined the profitability of the autothermal process, in favor of solar hybrid and solar-only gasification. A comparative study involving other solar and non-solar processes led to conclude on the profitability of fossil-based processes. However, reduced CO2 emissions from the solar process and the application of carbon credits are definitely in favor of solar gasification economics, which could become more competitive. The massive deployment of concentrated solar energy across the world in the coming years can significantly reduce the cost of the solar materials and components (heliostats), and thus further alleviate the financial cost of solar gasification.


1999 ◽  
Vol 121 (1) ◽  
pp. 36-39 ◽  
Author(s):  
A. Ferriere ◽  
C. Faillat ◽  
S. Galasso ◽  
L. Barrallier ◽  
J-E. Masse

A recent French contribution in the field of surface hardening of steel using concentrated solar energy is presented. Single spot and continuous scanning processes have been investigated in a small-scale solar furnace. Hardened regions of 0.5–1.5 mm in thickness have been obtained on specimens of carbon steel, resulting from the transformation hardening process. Compressive stresses are induced in the thermally affected layer, without tensile peak in the bulk.


2019 ◽  
Vol 56 (1) ◽  
pp. 261-270
Author(s):  
Maria Stoicanescu ◽  
Aurel Crisan ◽  
Ioan Milosan ◽  
Mihai Alin Pop ◽  
Jose Rodriguez Garcia ◽  
...  

This paper presents and discusses research conducted with the purpose of developing the use of solar energy in the heat treatment of steels. For this, a vertical axis solar furnace called at Plataforma Solar de Almeria was adapted such as to allow control of the heating and cooling processes of samples made from 1.1730 steel. Thus temperature variation in pre-set points of the heated samples could be monitored in correlation with the working parameters: the level of solar radiation and implicitly the energy used the conditions of sample exposed to solar radiation, and the various protections and cooling mediums.The recorded data allowed establishing the types of treatments applied for certain working conditions. The distribution of hardness, as the representative feature resulting from heat treatment, was analysed on all sides of the treated samples. In correlation with the time-temperature-transformation diagram of 1.1730 steel, the measured values confirmed the possibility of using solar energy in all types of heat treatment applied to this steel. In parallel the efficiency of using solar energy was analysed in comparison to the energy obtained by burning methane gas for the heat treatment for the same set of samples. The analysis considered energy consumption, productivity and the impact on the environment. Thanks to various data obtained through developed experiences, which cover a wide range of thermic treatments applied steels 1.1730 model, we can certainly state that this can be a solid base in using solar energy in applications of thermic treatment at a high industrial level.


Proceedings ◽  
2018 ◽  
Vol 2 (23) ◽  
pp. 1450
Author(s):  
Daniel Fernández-González ◽  
Juan Piñuela-Noval ◽  
Luis Felipe Verdeja

Solar energy when properly concentrated offers a great potential in high temperature applications as those required in metallurgical processes. Even when concentrated solar energy cannot compete with conventional metallurgical processes, it could find application in the treatment of wastes from these processes. These by-products are characterized by their high metallic contents, which make them interesting as they could be a raw material available in the own factory. Slags are one of these by-products. Slags are most of them disposed in controlled landfill with environmental impact, but also with economic impact associated to the storing costs and the metallic losses. Here we propose the treatment of ferromanganese and silicomanganese slags with concentrated solar energy with the purpose of evaluating the recovery of manganese from these slags.


2012 ◽  
Vol 512-515 ◽  
pp. 1418-1421 ◽  
Author(s):  
Qiu Hui Yan ◽  
Bei Bei Wang

Based on the integration of different systems and the comprehensive step utilization of energy, the system of hydrogen production by biomass gasification in supercritical water using concentrated solar energy has been coupled by using the combination of solar and biomass as an energy source. As a model compound of biomass, glucose was gasified in supercritical water at 25MPa and 873K, whether there is pre-heater water in the hydrogen production system was compared by the way of thermodynamic analysis. The results show that energy and exergy efficiency is high in the hydrogen production system with pre-heat water.


2016 ◽  
Vol 139 (2) ◽  
Author(s):  
W. Villasmil ◽  
T. Cooper ◽  
E. Koepf ◽  
A. Meier ◽  
A. Steinfeld

This work reports a numerical investigation of the transient operation of a 100-kWth solar reactor for performing the high-temperature step of the Zn/ZnO thermochemical cycle. This two-step redox cycle comprises (1) the endothermal dissociation of ZnO to Zn and O2 above 2000 K using concentrated solar energy, and (2) the subsequent oxidation of Zn with H2O/CO2 to produce H2/CO. The performance of the 100-kWth solar reactor is investigated using a dynamic numerical model consisting of two coupled submodels. The first is a Monte Carlo (MC) ray-tracing model applied to compute the spatial distribution maps of incident solar flux absorbed on the reactor surfaces when subjected to concentrated solar irradiation delivered by the PROMES-CNRS MegaWatt Solar Furnace (MWSF). The second is a heat transfer and thermochemical model that uses the computed maps of absorbed solar flux as radiation boundary condition to simulate the coupled processes of chemical reaction and heat transfer by radiation, convection, and conduction. Experimental validation of the solar reactor model is accomplished by comparing solar radiative power input, temperatures, and ZnO dissociation rates with measured data acquired with the 100-kWth solar reactor at the MWSF. Experimentally obtained solar-to-chemical energy conversion efficiencies are reported and the various energy flows are quantified. The model shows the prominent influence of reaction kinetics on the attainable energy conversion efficiencies, revealing the potential of achieving ηsolar-to-chemical = 16% provided the mass transport limitations on the ZnO reaction interface were overcome.


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