Pyrolysis was performed between 250-610 ☌ with a vapor residence time between 0.2-0.3 s. A laboratory-scale fluidized-bed flash pyrolysis reactor that allowed rapid heat transfer to the biomass along with short vapor residence time, was designed and constructed. In this study, flash pyrolysis was performed using milled soybean as a model substrate to assess the production of liquid fuels from oleaginous biomass feedstocks. In conclusion, self-compaction has proven to have a significant effect on airflow resistance, therefore it should be considered in the analysis and modeling of cooling, aeration and low-temperature drying of in-store grain bulks. The relative importance of modeling parameters was evaluated by a sensitivity analysis. The variation of pore volume ε was modeled and facilitated the development of a generalized model for predicting the relationship between ΔP and va. A disproportional increase of the pressure drop ΔP with bulk depth Hb and storage time t was observed, which was ascribed to the irreversible spatio-temporal behavior of self-compaction. Results revealed a reduction of in-situ pore volume ε from 0.413 to 0.391 at bulk depths Hb of 1.0 to 3.4 m after 1 h storage time t and from 0.391 to 0.370 after 236 h storage time t, respectively. A tailored product factor k was employed for the specific grain bulk conditions. For the semi-empirical characterization of the relationship between ΔP and va, the model of Matthies and Petersen was used, which was proficient in describing the experimental data with decent accuracy (R2 = 0.990, RMSE = 68.67 Pa, MAPE = 12.50%). Pressure drop ΔP was measured at bulk depths Hb of 1.0, 2.0, 3.0 and 3.4 m and storage times t of 1, 65, 164 and 236 h.

kg−1 d.b.) accommodated in a laboratory-scale bin (Vb = 0.62 m3) at a coherent set of airflow velocities va.

Thus, this study focused on investigating the effect of self-compaction on the pressure drop ΔP of wheat bulk (Triticum aestivum L., cv.

However, during storage, grain bulk experiences self-compaction due to its dead weight, which alters the bulk properties and impedes the uniform flow of air during aeration. Solve the grain mass aeration model proposed by Thorpe.Īeration is a key post-harvest grain processing operation that forces air through the pore volume of the grain bulk to establish favorable conditions to maintain grain quality and improve its storability. In light of the above, the Leith method is recommended to numerically The proposed methods were considerably smaller than the error obtained by the UDS -Įxplicit method. It was also verified that the errors obtained by Widely used in literature, the UDS - Explicit. The difference in the CPU time using the methods CDS -Ĭrank-Nicolson, Roberts and Weiss, and Leith, was very small compared to the method Were compared to the analytical solution and the CPU (central processing unit) times atĭifferent levels of refinement. In addition, the results obtained numerically The effective order of theĭiscretisation error achieved with the refinement of the mesh was verified by performingĪn error analysis for all approximations used. Scheme (CDS) and UDS with deferred correction (UDS-C), combined with the explicit, implicitĪnd Crank-Nicolson temporal formulations was applied.

Methods of Roberts and Weiss, Leith, upwind difference scheme (UDS), central difference The finite difference method (FDM), employing the spatial approximations given by the Literature, several numerical approximations to solve the mathematical model were used. Of the grain mass aeration process, proposed by Thorpe. Manufactured solutions (MMS), for the mathematical model that describes the behaviour The goal of this paper is to present an analytical solution, by means of the method of Representative property values for common grains and oilseeds are summarized from the published literature.

In this chapter, only the methods that are currently in use or widely accepted methods are described. There are many methods of measuring these properties. The properties of interest are: bulk and particle densities, porosity, roundness, sphericity, friction coefcients of grains against commonly used bin wall materials, emptying and lling angles of repose, equilibrium moisture content (EMC), specic heat, thermal conductivity, dielectric constant, electrical conductivity, reflectance, terminal velocity, and drag coefcient. To design handling, inspection, and storage systems for grains and oilseeds, data on many properties of individual seeds and seeds in bulk are needed. Often the storage period may be longer than 3 years, for example, when the grain is stored for potential famine relief. The world produces annually about 2 billion tonnes (Gt) of grains and oilseeds that are handled and stored on-and off-farm for periods of up to 3 years.

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