On the reactivity of various biomass species with CO 2 using a standardised methodology for fixed-bed gasification

Abstract

CO 2 gasification of char from seven European and Indian biomass species. Samples compared under methodology replicating fixed-bed gasification. Results exhibit thermolysis as predicted by random pore model. Coconut coir and jute highest reactivity. Sugar Bagasse similar kinetics to woody European species. a b s t r a c t A standardised method for studying the kinetics of CO 2 gasification was applied to seven different biomass species from Europe and Asia. The aim was to gain a truer understanding of variations in feedstock behaviour inside fixed bed biomass gasifiers. Slow heating rates and fixed variable in-situ pyrolysis was followed by gasification at isothermal temperatures from 800 1C to 950 1C. There was closer similarity in reactivity between all species in the region of 900r1C r950 suggesting that these temperatures could be optimal for the design of generic gasifier settings. Values of activation energy were in the range of 159 rkJ mol À 1 r216 for European arboreal species plus Sugar Bagasse. Coconut Coir and Jute had CO 2 gasification characteristics that were distinct from the other species (lower activation energy and higher reactivity), particularly at lower temperatures of 800r 1C r 875. CO 2 gasification thermolysis was found to develop as predicted by the theoretical random pore model; and a unique episode of ultra-low temperature devolatisation was observed during pyrolysis of Sugar Bagasse samples.

Experiments on torrefied wood pellet: study by gasification and characterization for waste biomass to energy applications

“…This reveals, and enables quantification of, the extent and rate of volatile release. The fixed to volatile carbon ratios seen here are in accordance with previous studies [ 51 ]. The mass loss at approximately 88 min occurs from the switch to 100% CO 2 and therefore indicates the ( 2.1 ) reaction from which kinetic values were calculated.…”

“…The amount of air is sufficient only to provide heat for development of drying, pyrolysis and reduction zones and to create autothermal operation. For an explanation of downdraft gasifier thermochemistry and mechanics, see [ 6 , 16 , 51 , 52 ]. Thermocouples are placed at the base of the combustion zone and bottom of the reduction zone (upper and lower ‘T/C’ in figure 2 ), and there are two pressure sensors: one located at the combustion zone and the other after the reduction zone, to provide real-time readouts of temperature and pressure across the reactor.…”

“…Using the TA Q500 instrument set up as previously (§2.4.1), a standardized methodology for downdraft gasification kinetics was used to determine parameters associated with reaction ( 2.1 ) [ 51 ]: …”

Karakteristik Gas Buang Dual Fuel Gasifier Downdraft Serbuk Kayu Dan Diesel Engine Generator Set 3 Kw

“…Gas-gas yang dihasilkan dari proses gasifikasi umumnya berbentuk CO, CO 2 , H 2 dan CH 4 yang kemudian gas-gas ini disebut Syngas atau Synthetic Gas. Nilai kalori dari gas hasil ini berkisar antara 1000 -1200 kcal.N/m 3 [7]. Pada proses gasifikasi downdraft Bahan bakar padat yang dimaksud adalah berupa biomass, batubara atau arang seperti pada gambar 1.…”

Optimization of a Biomass Micro-Gasification Process for the Production of Synthesis Gas From Palm Shell

“…The fig.2 shows a simplified schematic of a downdraft gasifier. [14] The syngas calorific value is influenced by the air/biomass ratio, reaction temperature and the geometry of the reactor; however, in the present work, the biomass granulometry is evaluated, as well as the gasifying agent velocity and the reactor disposition. The variables of interest were reaction temperature and the air/biomass ratio.…”