Gasification continued systems

The test rig is equipped with a feedstock hopper suitable to low-bulk-density biofuels and the biomass is fed continuously into the sand bed of the reactor via an injector screw which can feed fuel either into the bottom of the bed or to about 1 meter above the air distributor. The maximum fuel mass flow rate is 90 kg/h. The feeding system consists of two screw feeders in series separated by a rotary valve. The second screw has a higher feeding rate thus it will remain almost empty and therefore is not likely to be blocked by pyrolysis products. Steam can be added to the primary air as a gasification agent. 

The gas cleaning system has been developed and continually improved during the past year. Future work will look at building on the previous four years experience with a self-cleaning gas filtration system and use of a series 1 Jenbacher engine [146 kWe] for an onsite gasification system for Shawton Engineering Ltd.. 

Our tests on the Sanya biomass gasification-power generation plant so far have yielded positive results. The CFB technology is suitable for gasification of powdered wood material, and proves reliable in continuous operation under different load conditions. After passing the gas cleaning system, the producer gas can be used in the... 

This paper presents the empirical approach we used to understand this complex system. The main question of operability and feasibility of gasification had to be answered. To accomplish this, a metal reactor was designed which would take an initial charge of fuel and allow us to determine the rate at which the carbon gasified in a large excess of steam. This was a batch-decay type of rate study. Continuous operation must be studied in larger equipment. 

The COt Acceptor Gasification Process is discussed in light of the required properties of the CaO acceptor. Equilibrium data for reactions involving the CO% and sulfur acceptance and for sulfur rejection jit the process requirements. The kinetics of the reactions are also sufficiently rapid. Phase equilibrium data in the binary systems CaO-Ca(OH)t and Ca(OH)jr-CaCOs show the presence of low melting eutectics, which establish operability limits for the process. Data were obtained in a continuous unit which duplicates process conditions which show adequate acceptor life. Physical strength of many acceptors is adequate, and life is limited by chemical deactivation. Contrary to earlier findings both limestones and dolomites are equally usable in the process. Melts in the Ca(OH)2-CaC03 system are used to reactivate spent acceptors. 

The basic conversion scheme is depicted in Figure I and the processing equipment is shown in Figure II. The system is operated continuously and is a simulator of commerical scale processing for the most part. Thus equipment and procedure development has accompanied factor and optimization studies. The system is conveniently divided into two sections (1) gasification, and (2) liquid fuels synthesis. 

A mathematical development of the gasification system is in progress. Also an environmental assessment of the configuration continues. The primary stream of concern is the pyrolysis reactor scrubber liquid discharge. The thrust here is to characterize the stream and hopefully minimize formation of any contaminates in the pyrolysis step. Alternatively, a water cleanup steam would have to be incorporated. 

The catalytic wood gasification experiments were carried out in a 2.8-inch I.D. pressurized continuous reactor system. The experimental system is shown schematically in Figure I and consists of the following sections. 

Li, Y., Guo, L., Zhang, X., Jin, H., Lu, Y. (2010). Hydrogen production from coal gasification in supercritical water with a continuous flowing system. International Journal of Hydrogen Energy, 35, 3036—3045. 

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