The University of California in collaboration with West Biofuels, LCC, has developed an advanced thermochemical gasification system (5 ton/day) for the conversion of waste stream biomass for the production of bio-fuels and bio-energy. The “Pyrox” gasifier design is based on a dual-fluidized bed system operating at atmospheric pressure with air. Simulation of this gasifier was conducted with a n...

In the entrained-flow gasifiers used in integrated gasification combined cycle (IGCC) plants, the majority of mineral matter transforms to liquid slag on the wall of the gasifier and flows out the bottom. However, a small fraction of the mineral matter is entrained (as fly ash) with the raw syngas out of the gasifier to downstream processing. This molten/sticky fly ash could cause fouling of th...

Kinetics-free equilibrium models can predict the exit gas composition, given the solid composition and the equilibrium temperature, but they cannot be used for reactor design Hence, there is a need to develop a combined transport and kinetic model which takes into account of the kinetics of homogeneous and heterogeneous chemical reactions, transport of volatiles produced, heat and mass transfer...

A study was conducted to quantify tar formation in a stratified downdraft gasifier using wood pellets. The effect of biomass flow rate on tar concentration was also analyzed, and more than thirty compounds in tar were quantified. Among the different compounds in tar, tertiary condensed products such as toluene, o/p-xylene, naphthalene, phenol, styrene, and indene were observed in significant am...

High-sodium lignite from the Freedom mine in North Dakota was tested in a Transport Gasifier at the Power Systems Development Facility (PSDF). The tests occurred in October 2003 and August 2004 for a total of 445 hours of operation. Due to its high sodium content, the Freedom mine lignite presented unusual challenges to gasifier operations. This paper discusses high-sodium lignite gasification ...

The Power Systems Development Facility (PSDF) is an engineering scale demonstration of advanced coal-fired power systems and high-temperature, high-pressure gas filtration systems. The PSDF was designed at sufficient scale so that advanced power system components and the Department of Energy’s Clean Coal Roadmap program elements could be tested in an integrated fashion to provide data for comme...

Three-dimensional computational fluid dynamics (CFD) modeling of the gasification performance in a one-stage, entrained-bed coal gasifier (Shell Coal Gasification Process (SCGP) gasifier) was performed, for the first time. The parametric study used various O2/coal and steam/coal ratios, and the modeling used a commercial code, ANSYS FLUENT. CFD modeling was conducted by solving the steady-state...

This paper presents a comparison of commercial fluidized bed gasifiers and combustors used to recover energy from municipal solid wastes and biomass. The work reported here is excerpted from four case studies prepared for the International Energy Agency’s Bioenergy Agreement, under Task 23 (Energy from Thermal Conversion of MSW and RDF, 1998-2000) and Task 36 (Energy from Integrated Solid Waste...

The molar flow rate of carbon has been selected as the processing parameter for comparison for several reasons. The heterogeneous feedstock (air/oxygen and solid material such as biomass) of most gasifiers permits a wide range of total mass feed rate depending on parameters such as the C/O ratio of the solid, the S/C ratio of the gasifier feed, and equivalence ratio of the gasifier. However, th...

The Burlington, Vermont gasifier is the first commercial scale demonstration of Future Energy Resources SilvaGas biomass gasification process. The gasification plant is the largest operation of its type in the United States. The Burlington plant is coupled to the McNeil station of the Burlington Electric Department and is being used to evaluate and demonstrate the gasification technology both a...