Mathematical modelling and experimental study of straw co-firing with gas
Abstract
The main goal of the present study is to promote a more effective use of agriculture residues (straw) as an alternative renewable fuel for cleaner energy production with reduced greenhouse gas emissions. With the aim to improve the main combustion characteristics at thermo-chemical conversion of wheat straw, complex experimental study and mathematical modelling of the processes developing when co-firing wheat straw pellets with a gaseous fuel were carried out. The effect of co-firing on the main gasification and combustion characteristics was studied experimentally by varying the propane supply and additional heat input into the pilot device, along with the estimation of the effect of co-firing on the thermal decomposition of wheat straw pellets, on the formation, ignition and combustion of volatiles 
.
A mathematical model has been developed using the environment of the Matlab (2D modelling) and MATLAB package ”pdepe”(1D modelling) considering the variations in supplying heat energy and combustible volatiles 
into the bottom of the combustor. Dominant exothermal chemical reactions were used to evaluate the effect of co-firing on the main combustion characteristics and composition of the products
and
. The results prove that the additional heat from the propane flame makes it possible to control the thermal decomposition of straw pellets, the formation, ignition and combustion of volatiles and the development of combustion dynamics, thus completing the combustion of biomass and leading to cleaner heat energy production.
Keyword : reaction-diffusion equations, axisymmetric swirling flow, PDE system, Arrhenius kinetics
This work is licensed under a Creative Commons Attribution 4.0 International License.
References
I. Barmina, A. Kolmickovs, R. Valdmanis, M. Zake, H. Kalis and U. Strautins. Electric field effect on the thermal decomposition and co-combustion of straw pellets with peat. Chemical Engineering Transactions, 70:1267–1272, 2018.
I. Barmina, A. Lickrastina, M. Zake, A. Arshanitsa, A. Solodovnik and G. Telysheva. Experimental study of thermal decomposition and combustion of lignocellulosic biomass pellets. Latvian Journal of Physics and Technical Sciences, 50(3):35–48, 2013. https://doi.org/10.2478/lpts-2013-0018
I. Barmina, R. Valdmanis and M. Zake. Control of the development of the swirling airflow dynamics and its impact on the biomass combustion characteristics. Latvian Journal of Physics and Technical Sciences, 54(3):30–39, 2017. https://doi.org//10.1515/lpts-2017-0018
I. Barmina, R. Valdmanis, M. Zake, H. Kalis, M. Marinaki and U. Strautins. Magnetic field control of combustion dynamics. Latvian Journal of Physics and Technical Sciences, 53(4):36–47, 2016. https://doi.org/10.1515/lpts-2016-0027
I. Barmina, R. Valdmanis, M. Zake, L. Ozola and U. Strautins. Development of gasification/combustion characteristics at thermochemical conversion of biomass mixtures. In J. Palabinskis Latvia University of Agriculture(Ed.), Proc. of the 16th Int. Conf. on Engineering for Rural Development(ERDev17), Jelgava, Latvia, May 24–26, 2017, Engineering for Rural Development, pp. 54–59, 2017.
M. Brown and R.W. Judd. Emission reduction through biomass and gas co-firing the bagit project. 23th World Gas Conference, Amsterdam, p. 13, 2006.
T. Cebeci and P. Gradshaw. Physical and computational aspects of convective heat transfer. Spriger-Verlag, 1984.
J.J. Choi, Z. Rusak and A.K. Kapila. Numerical simulation of promixed chemical reactions with swirl. Combustion Theory and Modelling, 6(11):863–887, 2007. https://doi.org/10.1080/13647830701256085
J. Douglas and R. Rachford. On the numerical solution of heat conduction problems in two and three space variables. Trans. Amer. Math. Soc., 82(2):421– 439, 1956. https://doi.org/10.2307/1993056
EU. 2020 climate and energy package. Climate strategies and targets, 2012.
N.J. Glithero, P. Wilson and S. Ramsden. Straw use and availability for second generation biofuels in england. Biomass and Bioenergy, 55:311–321, 2013. https://doi.org/10.1016/j.biombioe.2013.02.033
A.K. Gupta, D.G. Lilley and N. Syred. Swirl Flows. Abacus Press, 1984.
H. Kalis, I. Barmina, M. Zake and A. Koliskins. Mathematical modelling and experimental study of electrodynamic control of swirling flame flows. In J. Palabinskis Latvia University of Agriculture(Ed.), Proc. of the 15-th Int. Conf. on Engineering for Rural Development(ERDev16), Jelgava, Latvia, May 25–27, 2016, Engineering for Rural Development, pp. 134–141, 2016.
H. Kalis, A. Kolmickovs, M. Marinaki and L. Ozola. Development of combustion dynamics at co-combustion of straw with wood. In J. Palabinskis Latvia University of Agriculture(Ed.), Proc. of the 17-th Int. Conf. on Engineering for Rural Development(ERDev18), Jelgava, Latvia, May 23–25, 2018, Engineering for Rural Development, pp. 1322–1328, 2018.
H. Kalis, M. Marinaki, L. Ozola, U. Strautins, I. Barmina and M. Zake. Mathematical modelling on electromagnetic field control of the combustion process. Magnetohydrodynamics, 53(4):687–698, 2017. https://doi.org/10.22364/mmp2017.36
H. Kalis, M. Marinaki, U. Strautins and I. Barmina. Influence of electric field on thermo-chemical conversion of mixtures of straw pellets with coal. In J. Palabinskis Latvia University of Agriculture(Ed.), Proc. of the 17-th Int. Conf. on Engineering for Rural Development(ERDev18), Jelgava, Latvia, May 23–25, 2018, Engineering for Rural Development, pp. 1746–1753, 2018.
H. Kalis, M. Marinaki, U. Strautins and O. Lietuvietis. On the numerical simulation of the combustion process with simple chemical reaction. In Dmitri Meshumayev and Bength Sunden(Eds.), Proc. of the 7-th Baltic Heat Transfer Conference , Tallinn, Estonia, Aug. 24–26, 2015, Baltic Heat Transfer Conference BHTC, pp. 175–180, 2015.
H. Kalis, M. Marinaki, U. Strautins and O. Lietuvietis. On the numerical simulation of the vortex breakdown in the combustion process with simple chemical reaction and axial magnetic field. Int. Jour. of Differential Equations and Applications, 14(3):235–250, 2015.
H. Kalis, M. Marinaki, U. Strautins and M. Zake. On numerical simulation of electromagnetic field effects in the combustion process. Mathematical Modelling and Analysis, 23(2):324–343, 2018. https://doi.org/10.3846/mma.2018.020
V.M. Kovenya and N.N. Yanenko. The method of decomposition in gas dynamical problems. Nauka Press Novosibirtsk in Russian, 1981.
C.K. Law. Combustion Physics. Cambridge, 2006.
D.G. Lilley. Swirl flows in combustion, a review. AIAA Journal, 15(8):1763– 1778, 1977.
I. Martinez. Combustion kinetics, set of lectures. http://webserver.dmt.upm.es/˜isidoro/bk3/c15/Combustion.pdf, p. 47, 2014.
D. Nordgren, H. Hedman, N. Padban, D. Bostromm and M. Ohman. Ash transformation in pulverised fuel co-combustion of straw and woody biomass. Fuel Processing Technology, 105:52–58, 2013. https://doi.org/10.1016/j.fuproc.2011.05.027
J.M. Powers. Lectures notes of Fundamentals of Combustion. Notre Dame, Indiana, USA, 2012.
Sandia National Laboratories Report SAND87-8215B. Chemkin Collection release 3.6, The Chemkin Thermodynamic Database. Reaction Design, Inc., San Diego, CA, 2000.
H. Schlichting. Grenzschicht Theorie, 5-te Auflage. Verlag G. Braun, Karlsruhe; Nauka,Moscow 1969 – in Russian, 1965.
M.D. Smooke, A.A. Turnbull, R.E. Mitchella and D.E. Keyes. Solution of twodomensional axysymmetric laminar diffusion flames by adaptive boundary value methods. NATO ASI Series E: Applied Sciences, 140:261–300, 1987.
N. Syred and J.M. Beer. Combustion on swirling flows, a review. Combustion and Flame, 23:143–201, 1974. https://doi.org/10.1016/0010-2180(74)90057-1
National Energy Technology Laboratory (NETL) U.S. Department of Energy. Biomass cofiring program. Program Facts, 2000.
S.V. Vassilev, D. Baxter, L.K. Andersen and Ch.G. Vassileva. An overview of the chemical composition of biomass. Fuel, 89:913–933, 2010. https://doi.org/10.1016/j.fuel.2009.10.022
F. Westley. Table of Recommended Rate Constants for Chemical Reactions Occurring in Combustion. National Bureau of Standards, Washington, 1980.
M. Zake, I. Barmina and M. Lubane. Swirling flame. Part 1. Experimental study of the effect of stage combustion on soot formation and carbon sequestration from the nonpremixed swirling flame. Magnetohydrodynamics, 40(2):161–181, 2004.