Nickel-catalysed pyrolysis/gasification of biomass components

Abstract

Hydrogen and syngas production have been investigated from the pyrolysis /gasification of biomass components (cellulose, xylan and lignin) in the presence of Ni-based catalysts by using a two-stage fixed-bed reaction system. Biomass samples were pyrolysed at the first stage and the derived products were gasified at the second stage. The Ni-Mg-Al and Ni-Ca-Al catalysts, prepared by co-precipitation, were applied in the gasification process.The lignin sample pyrolysed with more difficulty (56.0 wt.% of residue fraction) compared with cellulose and xylan at 500 °C, and therefore resulted in the lowest gas yield (42.7 wt.%) for the pyrolysis/gasification of lignin. However, the highest H 2 concentration from the three types of feedstock (55.1 vol.%) was collected for the lignin sample in the presence of steam and catalyst. Carbon deposition was barely observed from the TPO and SEM analysis of the reacted Ni-Mg-Al catalyst. The investigation of reaction conditions showed that water injection rate (0.02 and 0.05 g min -1 ) had little influence on the gas production from the pyrolysis/gasification of lignin in the presence of the Ni-Ca-Al catalyst; however, the increase of gasification temperature from 700 to 900 ˚C resulted in a higher gas and hydrogen production due to the promotion of secondary reactions during the gasification process.Furthermore, coking was highest for the reacted Ni-Ca-Al catalyst at the gasification temperature of 800 °C (7.27 wt.%), when the temperature was increased from 700 to 900 °C.This work shows that the components of biomass have a significant influence on the catalytic gasification process related to hydrogen and syngas production.

Novel Ni–Mg–Al–Ca catalyst for enhanced hydrogen production for the pyrolysis–gasification of a biomass/plastic mixture

“…The weight loss observed at around 100 °C for all the catalysts was due to the release of moisture in the catalysts [26,33]. The weight increase at ~300 °C corresponded to the oxidation of Ni which was produced from the reduction of NiO by the reduction agents such as H 2 and CO produced during the pyrolysis-gasification [24,31,34]. A lower Ni oxidation for the catalysts produced at the higher calcination temperature was observed, indicating the stronger interaction between Ni and the catalyst support.…”

“…After the gasification, filamentous carbon was deposited on the 750-Ca0 catalyst surface ( Figure 7 (b)). Wu et al [24] reported that negligible amount of filamentous carbon was depositted on the Ni-Mg-Al surface during the pyrolysis-gasification of wood biomass [24]. On the other hand, filamentous carbon was observed when polypropylene was gasified using Ni-Mg-Al catalyst [31], hence, the deposited filamentous carbon might be mainly derived from the polypropylene fraction in the feed material.…”

“…Wu et al [22] investigated polypropylene gasification using Ni-Al and Ni-Mg-Al catalysts synthesized by a co-precipitation method [23], which showed that the introduction of Mg into the Ni-Al catalyst significantly decreased the coke formation on the catalyst surface without hydrogen yield loss. The Ni-Mg-Al catalyst was also applied to the gasification of biomass components such as cellulose, xylan, and lignin, resulting in the highest gas yield of 73.0 wt% from cellulose at 800 ºC [24]. Furthermore, a Ni-Mg-Al-CaO catalyst synthesized by the calcination of a mixture of Ni-Mg-Al catalyst and calcium oxide (CaO) was used as a catalyst for gasification and in situ CO 2 absorption [25,26].…”

Hydrogen Production from Steam Reforming of Acetic Acid over Ni-Fe/Palygorskite Modified with Cerium

“…They found that hydrogen content was increased from 30.1 to 50.6 vol.% ( the volume fraction in total gas composition) with the increase of Ni loading from 5 to 40 wt.% during the wood sawdust pyrolysis-gasification (Wu et al 2011). They also revealed the compositions of biomass, gasification temperature, and the addition of steam had significant influence on hydrogen production (Wu et al 2013). Additionally, the 2D dynamic model of biomass pyrolysis or steam reforming in two-stage fixed-bed reactors had been posed by Olaleye et al (2014), and it agreed well with the experimental data in predicting the product and hydrogen yields from pyrolysis/steam reforming of different biomass feedstock at different reaction conditions.…”

Effect of alkali and alkaline earth metals addition on Ni/ZrO2 catalyst activity in cellulose conversion

“…On the other hand, the literature data show that due to their catalytic properties and relatively low price, nickelbased systems become the most popular catalysts in the thermo-chemical conversion of biomass [11,12] (for example-the cost of synthesis of supported nickel catalyst using nitrate precursor is from a few to tens times lower than the price of the platinum-containing material, even taking into account introduction of lower percentage of precious metal) [13]. However, it is known that the catalytic activity and deactivation rate of Ni catalysts in the pyrolysis or gasification of lignocelluloses strongly depend on the presence and type of the applied support [12].…”