An oxygen enriched air blown pilot scale pressurized fluidized bed refractory lined gasifier

Abstract

The present invention discloses oxygen enriched air blown pressurized fluidized bed pilot scale refractory lined gasifier of 1.5 TPD feed capacity to gasify coal, biomass, washery rejects, and their blends in any proportion in the actual atmosphere of commercial gasifier. The system is equipped in such a way that it can be operated in air/oxygen/oxygen enriched air/steam as well as their mixture in any proportion as per process requirement. The present invention discloses gasifier having feed rate carrying capacity up to 60 kg/hour, maximum operating temperature up to 1050° C. and pressure up to 10 kg/cm2. The facility consists different sections for gaseous and solid feeding, gasification, ash withdrawal, and gas Cooling & Cleaning. Besides gasification performance analysis, present invention is also discloses the study of agglomeration characteristics, entrainment and other fluidized bed gasification related parameters.

1 - 12 . (canceled) 
     
     
         13 . An oxygen enriched air blown pilot scale pressurized fluidized bed refractory lined gasifier system comprising:
 a cylindrical vessel of two different diameters;   a gaseous reactant generation and supply system with the provision of preheating and thorough mixing before entering into the gasifier;   plurality perforation removable conical distributors;   an air plenum;   differential pressure measurement instrument across the distributor and bed;   a fuel feeding system with a feed hopper arrangement comprising of a rotary feeder and a screw feeder;   plurality of feeding nozzles;   an inclined feed lines with the provision of pneumatic conveying of feed materials;   an ash withdrawal system consisting of a rotary extractor;   a purging system;   a rupture disc/safety valve;   a cyclone separator;   a quench column;   a ventury scrubber;   a knockout drum;   a settling tank;   a gas sampling port;   a flare stack; and   a nitrogen generator,   
       wherein nitrogen flushing comprises a control panel and data acquisition section operative to store and display data including process parameters enabling a wide range of operational flexibility with respect to pressure, temperature, feedstock, feed rate, gaseous reactant, residence time, particle size and particle density. 
     
     
         14 . The gasifier system of  claim 13 , wherein the heat resistant refractory lined two-diameter cylindrical gasifier comprises a bed section, a freeboard section, and a transition section between the bed section and the freeboard section, the transition section comprising thermocouples for temperature measurement. 
     
     
         15 . The gasifier system of  claim 13 , wherein the gaseous reactant generation and supply system comprises a steam generator with an accumulator, an air compressor with a gas holder, a PSA based oxygen generator, an oxygen booster, and a reactant process header operable for heating different gaseous streams at 150° C. to 600° C., wherein, before entering into the gasifier with the aid of:
 (i) reactant pre-heater for heating air/oxygen enriched air up to 150° C.; 
 (ii) steam super-heater with the capacity of heating up to 250° C.; 
 (iii) a first reactant mixture-cum-super-heater with maximum heating capacity of 400° C.; and 
 (iv) a second reactant mixture-cum-super-heater with the capacity of heating up to 600° C. depending on the combustibility and gasification characteristics of different carbonaceous feedstock. 
 
     
     
         16 . The gasifier system of  claim 13 , wherein the removable air plenum is of multiple conical distributors. 
     
     
         17 . The gasifier system of  claim 13 , wherein the solid fuel feeding system with the feed hopper arrangement has variable RPM multi-pocket rotary feeder and screw feeder fitted with a first feed lock vessel and a second feed lock vessel for sequential pressurization and depressurization/isolation by dome valve and actuated ball valve, having two feed nozzles connected to the feeder assembly with feed line having different inclination, one being above the distributor and another being above the bed in the gasifier to handle carbonaceous feedstocks. 
     
     
         18 . The gasifier system of  claim 13 , wherein the ash withdrawal system comprises an ash cooler, a variable RPM rotary extractor, a first ash lock vessel, and a second ash lock vessel for sequential pressurization and depressurization or isolation by a dome valve and an actuated ball valve. 
     
     
         19 . The gasifier system of  claim 13 , wherein the cyclone separator is fitted with a one water jacketed cyclone ash lock, a dome valve, and a actuated ball valve for sequential pressurization and depressurization. 
     
     
         20 . The gasifier system of  claim 13 , wherein the quench column is a jacketed water quench column comprising two concentric pipes having spray nozzles at an inner shell thereof, a quench seal pot, a quench water tank, a quench water circulation pump, and a multi compartment gravity settling tank for separation of scrubbed suspended solids from a quench column water stream. 
     
     
         21 . The gasifier system of  claim 13 , wherein the ventury scrubber is integrated with a ventury alkaline solution seal pot, an alkaline solution tank, and an alkaline solution recirculation pump adapted to remove acidic components from a gas stream followed by a knockout drum for removal of moisture from the gas stream before sampling and flaring with an LPG supported flare stack. 
     
     
         22 . The gasifier system of  claim 13 , adapted for product gas analysis by an on-line gas analyzer coupled with the gasifier system in an exit line through the gas sampling port or for collecting outgoing gas from the gas sampling port. 
     
     
         23 . The gasifier system of  claim 13 , further comprising a process control and data acquisition system comprising a PLC-SCADA control station operable to control and monitor temperature and pressure of the gasifier. 
     
     
         24 . The gasifier system of  claim 13 , configured for a maximum operating temperature up to 1050° C., a pressure up to 10 kg/cm 2 , a feed rate up to 60 kg/hour, a particle size acceptability from greater than 0 mm to 6 mm, the system being capable to gasify coal; biomass; washery rejects; and blends thereof.