Mechanically processed biofuels

It is useful to consider two major forms of biomass fuel mechanically processed and chemically processed. For mechanically processed biofuel in which the material is used essentially in its natural form (as harvested) direct combustion usually supplies heat for cooking, space heating or electricity production, although there are also small- and large-scale industrial applications for steam raising and other processes requiring low-to-medium temperature process heat. 

Appendix B consists of a systematic classification and review of conceptual models (physical models) in the context of PBC technology and the three-step model. The overall aim is to present a systematic overview of the complex and the interdisciplinary physical models in the field of PBC. A second objective is to point out the practicability of developing an all-round bed model or CFSD (computational fluid-solid dynamics) code that can simulate thermochemical conversion process of an arbitrary conversion system. The idea of a CFSD code is analogue to the user-friendly CFD (computational fluid dynamics) codes on the market, which are very all-round and successful in simulating different kinds of fluid mechanic processes. A third objective of this appendix is to present interesting research topics in the field of packed-bed combustion in general and thermochemical conversion of biofuels in particular. 

This demonstration plant has been installed at the Zeltweg power plant operated by DRAUKRAFT (15). The BIOCOMB process is designed for preparation of biofuels for co-combustion by partial gasification and attrition due to mechanical and thermal stress in a circulating fluidized bed reactor (CFB) (Fig. 2). 

One of the chemical treatments of triglycerides of different vegetable and algae oils and animal fats produces the biofuel known as biodiesel. This development was based on the knowledge of the catalytic processes as well as on the evolution of instrumental techniques, which permitted the elucidation of the esterification mechanisms and consequently, the study of transesterification. Homogeneous and heterogeneous processes were studied focusing on basic, acid, and enzymatic catalysis [13, 15, 16, 22-36], Usually,... 

Funke, A., Ziegler, F., 2010. Hydrothermal carbonization of biomass a summary and discussion of chemical mechanisms for process engineering. Biofuels, Bioproducts and Bioreiining 4 (2), 160-177. 

Mechanisms related to cellulose-derived biofuels focus on the chemistry offuran derivatives. Beyond the unimolecular decompositions and oxidative reactions discussed previously in this section, furan derivatives can undergo a wide variety of other reactions. They are transformed by pyrolytic, hydrolytic, and other chemical processes to longer chain ethers (R1OR2) and aldols (hydroxyaldehydes and hydroxyketones, Ri(0H)R2C(0)R3). These oxygenated species are then converted through hydrogenation and deoxygenation processes to liquid HC fuels (alkanes). 

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