The Evaluation on Three Types of Malaysian Dolomites as a Primary Catalyst in Gasification Reaction of EFB and Tar Cracking Efficiency

Abstract

The conversion of biomass into hydrogen-rich syngas has been getting attention recently, as it has potential sustainability benefits of agricultural residues. In this study, gasification of empty fruit bunch (EFB) was performed using various calcined Malaysian dolomite catalysts, which were denoted as P1, P2, and P3. The physicochemical properties of the catalysts were examined using X-ray fluorescence (XRF), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), and scanning electron microscopy (SEM). The effect of various catalyst to biomass (C/B) ratios (varied in the range of 0.05-0.3 in an increment of 0.05) of P1, P2, and P3 catalyst in EFB gasification was evaluated at a gasifier temperature of 850 • C. The gas produced was analyzed by gas chromatography (GC). The effect of various C/B ratios on tar conversion was also examined. The result showed that, with lower impurities in calcined dolomites and high content of active sites (CaO-MgO), improved characteristics of P1 and P2 in crystalline structure contributes to a significant reduction in tar cracking (∼78 and 75%, respectively) and higher H 2 yield (32.25 mg H 2 /g EFB).

H2-Rich and Tar-Free Downstream Gasification Reaction of EFB by Using the Malaysian Dolomite as a Secondary Catalyst

“…The effect of the secondary catalyst was investigated at different cracking temperature varied from 700 up to 900 • C while the gasifier temperature was kept at 850 • C. The catalytic system inserted between the fluidized-bed gasifier and cooling system as illustrated in Figure 2. The results obtained were compared with previously reported work [25].…”

“…In this paper, the tar referred to major GC detectable aromatic and phenolic compounds. Detailed methodology for both products (gaseous product and tar) can be referred to the earlier published work [25].…”

“…Tar is a complex mixture of condensable hydrocarbon (HCs) with 1-5-ring aromatic compounds, other oxygen-containing HCs and complex polyaromatic HCs (PAH) [24]. Tar can be eliminated by non-catalytic (collection and disposal method), catalytic (catalytic tar conversion), or by biomass-coal co-gasification [25]. Employing a catalyst has been found to enhance the gasification process by augmenting the amount of hydrogen, reducing the gasification temperature, and converting liquid tar into gases [5].…”

“…From their observation, dolomites were significantly active above 800 • C and able to retain a small amount of H 2 S and HCl that enhance tar cracking reaction. Our previous work [25] reported on Malaysian dolomite studied from three different sources as a primary catalyst in the gasification reaction of EFB. The results showed an approximately 78% and 75% significant tar reduction for P1 and P2 which has high content of CaO and MgO, respectively.…”