Ammonia Formation and NO_x, Emissions, with Various Biomass and Waste Fuels at the Vämamo 18 MW_thIGCC Plant

Thermochemical Biomass Gasification: A Review of the Current Status of the Technology

“…Unlike coal gasification, conversion to hydrogen cyanide is very low in biomass gasification [49]. If not removed, combustion of part of ammonia (occurring at temperatures above 1,000 °C, typical of combustion) results mostly in NO x formation.…”

Partitioning of fuel bound nitrogen in biomass gasification

“…Gasification can accommodate biomass and waste feedstocks with a broad range of physical properties. A few examples reported in literature include wood products of various qualities [5][6][7], tree bark [5], railroad ties [8], cacao shells [8], olive pomace [9,10], dried distiller's grains with solubles (DDGS) [11], sewage sludge [12,13], and polyethylene [10]. Gasification is distinguished from many other biomass processing technologies by its high temperatures, as feedstocks are typically heated to at least 600°C [14].…”

“…Raw syngas as it emerges from a biomass gasifier typically contains char and ash particulate, tar vapors, sulfur compounds, chlorides, and nitrogen species [18]. These contaminants lead to a variety of problems in downstream syngas applications including corrosion, catalyst poisoning and coking, pipeline fouling, and air pollution [5,19,20].…”

“…hydrogen cyanide (HCN). Both are precursors to NOX formation when syngas is combusted for heat and power applications [5]. They also poison catalysts used to upgrade syngas into fuels and chemicals [16,21].…”

“…Sample line setup for measurement of char, heavy tar, light tar, water, and permanent gas composition of the syngas: (1) 53 mm inner-diameter (ID) raw syngas pipeline, (2) isokinetic sampling probe located at sampling port A, (3) 8 mm ID stainless steel tubing heat traced to 450°C, (4) quartz thimble filter inside tube furnace at 450°C, (5) 8 mm ID tubing at 450°C, (6) tar collection pressure cooker at 100-115°C, (7) stainless steel needle valve and 8 mm ID tubing heated to 120°C, (8) tubing tee and septum for SPME sampling of light tars, (9) two 500 mL glass impingers in a water-ice bath for water collection and wet chemical measurements of ammonia and hydrogen cyanide, (10) desiccant canister for final water aerosol removal, (11) diaphragm vacuum pump, (12) rotameter with integral control valve, (13) Varian CP-4900 micro gas chromatograph, (14) drum-type total flow gas meter, and (15) . Gasification reactor consisting of: (1) Volumetric feed system calibrated for 100 g/h switchgrass feed rate, (2) thermocouple probe and temperature controlled plenum packed with steel spheres, (3) 100 g of silica sand fixed bed, (4) three thermocouple probes, the middle one for reactor temperature control, the upper and lower for temperature monitoring, (5) Watlow ceramic heaters encasing the reactor to maintain temperature, (6) . The concentration of nitrogen in the char changed very little as temperature was increased from 650°C to 850°C.…”