In situ catalytic upgrading of biomass derived fast pyrolysis vapours in a fixed bed reactor using mesoporous materials

Slow pyrolysis (SP) and fast pyrolysis (FP) of rice husks, coconut shells and their mixtures were studied in a fixed bed reactor. The objectives of this study were to compare the yields and properties of bio-oils produced using SP and FP methods within a pyrolysis temperature range of 400 °C to 600 °C. Three different biomass compositions, 100% rice husks (RH), 100% coconut shells (CS) and a mixture of 50% rice husks with 50% of coconut shells (RH50/CS50) were experimented. In SP, the maximum yield of bio-oil for RH, CS and RH50/CS50 were 45.45%, 37.01%, 38.29% at temperatures of 550 °C, 500 °C and 600 °C respectively. As for FP, the maximum bio-oil yield obtained for RH, CS and RH50/CS50 were 50.52%, 40.14% and 42.25% at temperatures of 500 °C, 600 °C and 550 °C respectively. At these optimum pyrolysis temperatures, the percentage differences in bio oil yields for SP and FP were 10.57%, 8.11% and 9.83% for RH, CS and RH50/CS50 respectively. Based on American Society for Testing and Materials (ASTM) standard procedures, the properties of bio-oil were characterised and it was found that the bio oil produced by FP at optimum temperatures were less acidic, higher density, lower water content and viscosity as compared to the bio-oil produced by SP method for all biomass compositions.

Download Full-text

CO2 Capture Using Calcium Oxide Applicable to In-Situ Separation of CO2 From H2 Production Processes

Volume 6A: Energy ◽

10.1115/imece2013-62619 ◽

2013 ◽

Author(s):

Saeed Danaei Kenarsari ◽

Yuan Zheng

Keyword(s):

Calcium Oxide ◽

Co2 Capture ◽

Fixed Bed ◽

H2 Production ◽

Fixed Bed Reactor ◽

Capture Process ◽

Conversion Rates ◽

In Situ Separation ◽

Separation Of Co2

A lab-scale CO2 capture system is designed, fabricated, and tested for performing CO2 capture via carbonation of very fine calcium oxide (CaO) with particle size in micrometers. This system includes a fixed-bed reactor made of stainless steel (12.7 mm in diameter and 76.2 mm long) packed with calcium oxide particles dispersed in sand particles; heated and maintained at a certain temperature (500–550°C) during each experiment. The pressure along the reactor can be kept constant using a back pressure regulator. The conditions of the tests are relevant to separation of CO2 from combustion/gasification flue gases and in-situ CO2 capture process. The inlet flow, 1% CO2 and 99% N2, goes through the reactor at the flow rate of 150 mL/min (at standard conditions). The CO2 percentage of the outlet gas is monitored and recorded by a portable CO2 analyzer. Using the outlet composition, the conversion of calcium oxide is figured and employed to develop the kinetics model. The results indicate that the rates of carbonation reactions considerably increase with raising the temperature from 500°C to 550°C. The conversion rates of CaO-carbonation are well fitted to a shrinking core model which combines chemical reaction controlled and diffusion controlled models.

Download Full-text

In-situ Catalytic Upgrading of Bio-oils Derived from Fast Pyrolysis of Cellulose, Hemicellulose, and Lignin over Various Zeolites

Journal of the Japan Institute of Energy ◽

10.3775/jie.98.254 ◽

2019 ◽

Vol 98 (10) ◽

pp. 254-258 ◽

Cited By ~ 1

Author(s):

Nichaboon CHAIHAD ◽

Surachai KARNJANAKOM ◽

Irwan KURNIA ◽

Akihiro YOSHIDA ◽

Abuliti ABUDULA ◽

...

Keyword(s):

Fast Pyrolysis ◽

Catalytic Upgrading

Download Full-text

Hydrogenation and Dehydrogenation of Tetralin and Naphthalene to Explore Heavy Oil Upgrading Using NiMo/Al2O3 and CoMo/Al2O3 Catalysts Heated with Steel Balls via Induction

Catalysts ◽

10.3390/catal10050497 ◽

2020 ◽

Vol 10 (5) ◽

pp. 497 ◽

Cited By ~ 3

Author(s):

Abarasi Hart ◽

Mohamed Adam ◽

John P. Robinson ◽

Sean P. Rigby ◽

Joseph Wood

Keyword(s):

Heavy Oil ◽

Coke Formation ◽

Plug Flow ◽

Fixed Bed ◽

Effect Of Temperature ◽

Catalytic Upgrading ◽

Heavy Oil Upgrading ◽

Steel Balls ◽

Surrounding Fluid

This paper reports the hydrogenation and dehydrogenation of tetralin and naphthalene as model reactions that mimic polyaromatic compounds found in heavy oil. The focus is to explore complex heavy oil upgrading using NiMo/Al2O3 and CoMo/Al2O3 catalysts heated inductively with 3 mm steel balls. The application is to augment and create uniform temperature in the vicinity of the CAtalytic upgrading PRocess In-situ (CAPRI) combined with the Toe-to-Heel Air Injection (THAI) process. The effect of temperature in the range of 210–380 °C and flowrate of 1–3 mL/min were studied at catalyst/steel balls 70% (v/v), pressure 18 bar, and gas flowrate 200 mL/min (H2 or N2). The fixed bed kinetics data were described with a first-order rate equation and an assumed plug flow model. It was found that Ni metal showed higher hydrogenation/dehydrogenation functionality than Co. As the reaction temperature increased from 210 to 300 °C, naphthalene hydrogenation increased, while further temperature increases to 380 °C caused a decrease. The apparent activation energy achieved for naphthalene hydrogenation was 16.3 kJ/mol. The rate of naphthalene hydrogenation was faster than tetralin with the rate constant in the ratio of 1:2.5 (tetralin/naphthalene). It was demonstrated that an inductively heated mixed catalytic bed had a smaller temperature gradient between the catalyst and the surrounding fluid than the conventional heated one. This favored endothermic tetralin dehydrogenation rather than exothermic naphthalene hydrogenation. It was also found that tetralin dehydrogenation produced six times more coke and caused more catalyst pore plugging than naphthalene hydrogenation. Hence, hydrogen addition enhanced the desorption of products from the catalyst surface and reduced coke formation.

Download Full-text