Investigation of an Intensified Thermo-Chemical Experimental Set-Up for Hydrogen Production from Biomass: Gasification Process Performance—Part I (original) (raw)

AN EXPERIMENTAL INVESTIGATION OF HYDROGEN PRODUCTION FROM BIOMASS GASIFICATION

An experimental study of hydrogen production from biomass was conducted using a benchscale fluidized bed gasifier. Parametric experiments were performed to determine the effects of reactor temperature, equivalence ratio, and steam to biomass ratio. Experimental measurements of gas composition and yield were used to calculate the hydrogen yield potential, the capacity of the gas stream for hydrogen production by shifting carbon monoxide and steam reforming higher hydrocarbons. Over the ranges of experimental conditions examined, hydrogen yield potential proved to be most sensitive to equivalence ratio, varying from 62 g H, kg-' of dry, ash-free biomass at an equivalence ratio of 0.37, to 128 g Hz kg-' of dry, ash-free biomass at an equivalence ratio of 0.0. Of the conditions tested, the highest hydrogen yieId potential, 128 g H2 kg-' of dry, ash-free biomass, was achieved at a reactor temperature of 85o " C, equivalence ratio of 0.0, and a steam to biomass ratio of 1.7. This is 78% of the theoretical maximum yield of 165 g H, kg-' of dry, ash-free biomass for this feedstock. c 1998 International Association for

Clean Hydrogen Production via Novel Steam-Air Gasification of Biomass

cder.dz

Gasification converts biomass into H2 and CO rich product gas by using air, oxygen and/or steam as reaction agent. An experimental and modelling study of hydrogen production was conducted using a laboratory scale counter-current fixed bed gasifier with preheated air and steam ...

Hydrogen production from biomass via gasification process: The results of the eu UnifHY project

2017

This paper quotes an overview of the UNIfHY project results regarding pure hydrogen production from biomass gasification. Tests with different gasification agents (steam/air/oxygen) and at different temperatures showed syngas yield from 1.1 to 1.7 Nm3dry/kg of dry biomass, hydrogen content from 20 to 40%-v dry, tars, particulate in the range of 10-20 g/Nm3dry, sulphur and chlorine compounds in the range of 50-90 ppmv, ammonia up to 1600 ppmv. Candle filters showed particulate removal efficiency higher than 99%-wt. A portable purification system (PPS) consisting in a ZnO guard bed reactor, a water gas shift reactor (WGS), compressor and gas upgrading unit (PSA) was designed and realized. The system was proven to be operable stably and continuously in experimental runs lasting more than 12 h. Hydrogen production at concentration of 99.99%-v was achieved with an H2 yield from PSA of 66.4%. Based on the data collected, UNIfHY can reach an economic production cost of 3-10 €/kg H2 (in the range 4.00-0.04 t H2/day, respectively) with low environmental impact (0.5-2.4 kg CO2/kg H2) but targets have to be different for decentralised (40% efficiency, 10 years lifetime, <10 €/kg cost, production of electricity and heat) and centralised (70%, 20 years, <5 €/kg no electricity neither heat) production and higher performance and reliability can be achieved by means of the implementation of better configurations.

Hydrogen production via biomass gasification—A life cycle assessment approach

Chemical Engineering and Processing: Process Intensification, 2008

This study develops a new simulation model by ASPEN Plus for gasification integrated with water-gas shift reactors and product recovery unit for hydrogen production. Timber and wood waste (T&WW) as a lignocellulosic biomass was also considered as the input feedstock to the system. Then, the model is applied to investigate the effect of two agents of air and a mixture of air-steam under different operating conditions of temperature and steam to biomass ratio (SBR). The results reveal that the produced hydrogen through the air-steam gasification is at the highest points for all studied temperatures and it would be maximum (44.37 Kmol/hr per 1 ton T&WWs) at 700 ˚C. The hydrogen production efficiency (HPE) can be also raised, stemming from the growth of H2. It values 39.2% at SBR = 0.1 that grows to 70% at SBR = 0.9. The optimum SBR lies between 0.7-0.8 that specific mass flow rate of hydrogen would be higher than 0.1 kghydrogen/kgT&WW.

Influence of the main gasifier parameters on a real system for hydrogen production from biomass

International Journal of Hydrogen Energy, 2016

The production of hydrogen from waste biomass could play an important role in the world energy scenario if efficient and reliable processes will be developed. Via kinetic and thermodynamic simulation and experimental data system, realized during the European project UNIfHY, to produce pure hydrogen from biomass is analysed. The plant is mainly composed of bubbling fluidized bed gasifier with catalytic filter candles, Water Gas Shift and Pressure Swing Adsorption (PSA). Focussing on the hydrogen production, a sensitivity study was carried out varying parameters as the steam to biomass ratio and the gasifier operating temperature. The results show that the hydrogen yield increases at increasing temperature and steam to biomass ratio, even if the required energy input increases as well. The global efficiency depends substantially on the PSA unit: the off gas of this unit is composed of residual CO, CH 4 and H 2 , that can be burned in the combustor of the dual fluidized bed gasifier to supply the extra-heat to the gasification process avoiding the input of auxiliary fuel.

Thermodynamic optimization of biomass gasifier for hydrogen production

International Journal of Hydrogen Energy, 2007

A thermodynamic equilibrium model was used to predict the chemical composition of the products of biomass gasification. The effects of temperature, pressure, steam biomass ratio (SBR) and equivalence ratio (ER) on the equilibrium hydrogen yield were studied. Gibbs energy minimization approach was used to determine the product gas composition. Wood (designated by CH 1.5 O 0.7) was used as the model biomass compound and Stanjan (v 3.93L) software was used. Gasifier, the most critical component of any biomass gasification system, was modeled as an equilibrium reactor and the energy consumption and thermodynamic efficiency were determined. A first law analysis of the gasifier showed that the optimum conditions for hydrogen production occurred at a gasification temperature of 1000 K, SBR of 3, ER of 0.1. Finally, equilibrium calculations were compared with experimental data from literature which showed that for high gas residence times and high gasification temperatures there is a close match of equilibrium results with experimental ones.

Simulation of hydrogen production from biomass via pressurized gasification using iCON

Proceedings of International …, 2010

Renewable energy in the form of biomass has been used to produce heat, electricity, steam and petrochemicals due to the zero net carbon emission. With regards to the environmental concerns related to fossil fuel usage, hydrogen has the potential as an alternative clean energy. Currently, production of hydrogen from biomass using a pressurized system is not widely being analyzed and developed yet. Thus, process and flowsheet development of pressurized gasification process of biomass coupled with carbon dioxide adsorption for hydrogen production were investigated using a PETRONAS iCON simulation model. The effect of parameters such as pressure, temperature and steam-to-biomass ratio on the hydrogen yield was investigated. Hydrogen yield is predicted to be increasing with pressure, temperature, and steam-to-biomass ratio in this high pressure gasification system.