Fast Pyrolysis of Sisal Residue in a Pilot Fluidized Bed Reactor

Abstract

The objective of this research was to study the fast pyrolysis of sisal residue, performed in a pilot unit with a fluidized bed reactor. The tests were carried out by varying the flows of nitrogen (8−14 N m 3 /h), biomass (10.33−25.95 g/ min), and temperature (450−550°C). The experimental planning technique was used to identify the number of tests and the influence of operational variables on the bio-oil yield. One of the highest H 2 /CO (2.16) ratios was found from the eighth test on, which was an appropriate value for the production of methanol and liquid biofuels. All bio-oil samples produced were characterized, and the results showed that the sisal residue bio-oil is different from other bio-oils reported in the literature. It has high viscosity at room temperature, with a pour point of 55°C and average molecular weight of 414.2 g/mol. In addition, phenolic species completely prevail in relation to the other monomeric components. The biochar obtained is an amorphous, fine powder. Despite the porosity, its specific surface area is lower than of commercial activated carbon.

Development of process-product relations for the pyrolysis of sisal residue

“…Fast pyrolysis reactions were carried out in a pilot-scale fluidized-bed pyrolysis unit, and details of the setup are given in previous papers [39,41]. Before starting the experiments, the silica sand (2.2 kg and di=0.4 mm) was inserted into the reactor (10 L); then, it was preheated by electrical resistances and fluidizing gas up to the reaction temperature defined in the overview of experiments (vide infra).…”

“…The tests were carried out based on the manipulated variables shown in Table 1. Our group selected the nitrogen gas flow, biomass flow rate, and reaction temperature from an earlier study [39], while the pressure was included as a new investigative element. In another earlier research [41], the pressure was identified as a factor that affects the sisal residue bio-oil viscosity, which may imply a variation in the composition of the bio-oil to a certain extent.…”

“…After drying, the sisal residue exhibited particle sizes between 0.15 and 5.66 mm, with 90 % of the material size range 0.60-4.83 mm. The main properties of sisal residue have been reported in detail elsewhere [39,40].…”

“…The bio-oil from sisal residue differs from others found in the literature by its remarkable characteristics. Our previous research [39] evaluated the influence of operational variables on the bio-oil yield, and the bio-oil with the highest yield was characterized. The results indicated: a viscous aspect at room temperature, meaning a high viscosity (100 -400 mPa⋅s at 40 • C); low O/C ratio (0.16); low average Mw (414 g/mol); low water content (5.18 %) and the predominance of phenolics in its composition.…”

Study of The Biomass, Sand, and Biochar Fluidization in A Typical Bed of Fast Pyrolysis

“…The sisal residue was obtained after processing to obtain sisal fibers and is therefore considered a primary by-product of the sisal fiber production process. This biomass and its biochar were obtained in a fast pyrolysis pilot plant for bio-oil production, with a bubbling fluidized bed reactor [13].…”