The University of Utah's Gasification Research Facility was originally constructed under two U.S. DOE-funded programs to investigate black liquor gasification. The Facility houses two types of gasifiers:  a pressurized fluidized bed steam reformer and a pressurized oxygen-blown entrained-flow gasifier. Both gasifiers are capable of operating at elevated pressures, and maximum fuel throughput for the system exceeds 1 ton per day. Though currently configured to process black liquor, both gasifiers were designed to handle a variety of fuels, including biomass, coal and oil.

The Gasification Research Facility includes all required feed, product gas handling and support systems, as well as analytical systems for synthesis gas characterization. The entire system is integrated into a common digital control system (DCS) shared with the building's auxiliary cooling water and flue gas systems. Operation is completely automated. The operator controls the system through a graphical computer interface.

The Gasification Research Facility comprises several sub-systems for the various feed streams, reactors, product gas streams and system control infrastructure. These sub-systems are described in the sections that follow.

Fluidized Bed Steam Reformer

The fluidized bed reactor has a maximum throughput of 30 lb/hr black liquor or 70 lb/hr biomass, and can operate at temperatures to 825°C (1515°F) and at pressures to 2.0 Mpa (300 psi). The reactor is built in five sections, and consists of a gas distributor, bed section and freeboard. The reactor is a custom-manufactured, ASME-coded pressure vessel rated at 425°C (800°F) and 2.0 MPa (300 psi) pressure. The shell is 0.75 meter (30 inches) diameter, and the total height of the reactor is approximately 5.2 meters (17 feet). The fluidized bed itself is formed from refractory inside the vessel and is 0.25 meters (10 inches) diameter, 1.4 meters (55 inches) tall. The freeboard above the bed is approximately 3 meters (10 feet) in height, and has an internal cyclone to return entrained solids to the bed.

The fuel is injected directly into the bed, where it will be converted into a hydrogen-rich synthesis gas. Upon exiting the top of the reactor, the gas will be fed to the facility's afterburner. Steam reforming is an endothermic reaction, so the reactor must be heated to maintain its temperature. Heating of the fluidized bed is accomplished with 80 cartridge heaters configured in four perpendicular banks of 20 heaters each. Total power input to the heaters is 32 kW maximum. The incoming steam is superheated before passing through the distributor plate to enhance temperature uniformity and minimize the load on the in-bed heaters.

During steam reforming of black liquor, the inorganic product remains on the particles that make up the fluidized bed, so the bed height increases over time. A pressurized lock hopper system at the bottom of the bed allows automatic removal of bed solids while the system is operating.

Entrained-Flow Gasifier

The entrained-flow gasifier is a downwards-fired, "Texaco-style" or "GE-style" refractory-lined, oxygen-blown reactor having a capacity of more than 1 ton per day. The gasifier can operate at pressures up to 32 atmospheres (450 psig) and at temperatures to 1500°C (2730°F).

The fuel is fed with oxygen into a burner at the top of the reactor, and undergoes partial oxidation to form a combustible synthesis gas containing high concentrations of hydrogen and carbon monoxide. The gas and smelt (slag) products exit the bottom of the reactor and enter a water-cooled quench system where they are separated and the temperature of the syngas is decreased so that it does not damage downstream equipment. The cooled syngas is then fed to the system's afterburner.

Analytical Systems

The synthesis gas produced by the gasifiers is analyzed by a continuous emission monitor (CEM) for hydrogen, carbon monoxide, carbon dioxide and methane. An on-line micro-GC provides more detailed analysis and measures the concentrations of the species below:

	• methane	• hexane	• hydrogen sulfide
	• ethane	• acetylene	• methyl mercaptan
	• propane	• ethylene	• carbon monoxide
	• isobutane	• propylene	• carbon dioxide
	• n-butane	• benzene	• oxygen
	• pentane	• hydrogen	• nitrogen

The Industrial Combustion and Gasification Research Facility where the gasifiers are housed has an on-site laboratory where certain fuel and condensed-phase product analyses can be carried out. Other analyses can be conducted at the University's on-campus labs or by third party laboratories.