Pyrolysis of Napier Grass in a Fixed Bed Reactor: Effect of Operating Conditions on Product Yields and Characteristics

Abstract

This study presents a report on pyrolysis of Napier grass stem in a fixed bed reactor. The effects of nitrogen flow (20 to 60 mL/min), and reaction temperature (450 to 650 °C) were investigated. Increasing the nitrogen flow from 20 to 30 mL/min increased the bio-oil yield and decreased both bio-char and non-condensable gas. 30 mL/min nitrogen flow resulted in optimum bio-oil yield and was used in the subsequent experiments. Reaction temperatures between 450 and 600 °C increased the bio-oil yield, with maximum yield of 32.26 wt% at 600 o C and a decrease in the corresponding bio-char and non-condensable gas. At 650 °C, reductions in the bio-oil and bio-char yields were recorded while the non-condensable gas increased. Water content of the bio-oil decreased with increasing reaction temperature, while density and viscosity increased. The observed pH and higher heating values were between 2.43 to 2.97, and 25.25 to 28.88 MJ/kg, respectively. GC-MS analysis revealed that the oil was made up of highly oxygenated compounds and requires upgrading. The bio-char and non-condensable gas were characterized, and the effect of reaction temperature on the properties was evaluated. Napier grass represents a good source of renewable energy when all pyrolysis products are efficiently utilized..

Co-pyrolysis of Rice Husk with Underutilized Biomass Species: A Sustainable Route for Production of Precursors for Fuels and Valuable Chemicals

“…This process continues to be attractive as it comprises fewer steps, relatively less complex and virtually all kinds of biomass material can be processed. High biooil yield up to 75 % can be obtained under a careful control of process parameters [10][11][12]. Studies on pyrolysis of RH to bio-oil have been carried out by many researchers [13][14][15][16][17][18][19][20][21][22][23][24].…”

Catalytic fast pyrolysis of Pearl Millet and Sida cordifolia L. to investigate products distribution and bio-oil quality

“…Several fast pyrolysis studies have been conducted by using different biomasses and catalysts to investigate the effects of different operating conditions on the products distribution and bio-oil quality [7,[17][18][19][20][21][22][23][24]. The feasibility, byproducts, and comprehensive characterization of pearl millet (PM) and napier grass hybrid [25] and the physicochemical, nutritive, and spectral properties of biochar prepared from India's four important agricultural residues including PM [26] have been studied.…”

In-situ Upgrading of Napier Grass Pyrolysis Vapour Over Microporous and Hierarchical Mesoporous Zeolites

“…Production of alternative fuels from renewable sources continue to gain attention in recent times due to the fear of energy insecurity in the near future and environmental impact associated with the use of petroleum-based fuels together with socio-political issues [1][2][3][4]. Lignocellulosic biomass (non-food materials) is being considered as an alternative feedstock for the production of renewable biofuel due to the presence of carbon in their building blocks, which can be processed into liquid fuel.…”

“…Lignocellulosic biomass (non-food materials) is being considered as an alternative feedstock for the production of renewable biofuel due to the presence of carbon in their building blocks, which can be processed into liquid fuel. Pyrolysis remains an attractive route for the thermochemical conversion of biomass as it comprises fewer steps and capable of high liquid yield (known as pyrolysis oil or bio-oil) through a careful control of process variables such pyrolysis temperature, heating rate, vapour residence time in the reactor, and rapid cooling of the volatile in the condenser [4,5]. Pyrolysis oil from biomass is a complex mixture consisting predominantly of oxygenated organic compounds, phenolics, light hydrocarbons and traces of nitrogenous and sulphur containing compounds depending on nature of the source biomass.…”

“…Pyrolysis oil from biomass is a complex mixture consisting predominantly of oxygenated organic compounds, phenolics, light hydrocarbons and traces of nitrogenous and sulphur containing compounds depending on nature of the source biomass. The high level of the oxygenated compound in the oil is responsible for the poor physicochemical characteristics such as low pH, low chemical stability, low energy content [4][5][6] and therefore rendered the oil unsuitable for direct application as fuel or refinery-ready feedstock for quality fuel production and other consumer products.…”