Toxic by-products from the combustion of Kraft lignin.
Lignin samples, sub-product in the Kraft process of cellulose from eucalyptus wood, were burnt in a laboratory scale furnace at different residence temperatures and with distinct fuel-rich atmospheres. The yields of CO, CO(2), eight light hydrocarbons (methane, ethylene, ethane, propylene, acetylene, butane, etc.) and 60 semi-volatile+volatile compounds (benzene, toluene, ethylbenzene, styrene, indene, naphthalene, dibenzofuran, phenanthrene, chrysene, etc.) were determined, with nominal reactor temperatures between 800 and 1100 degrees C and residence times of the volatiles evolved and formed between 4 and 7 s. The collection of the gases and volatiles evolved was carried out with a Tedlar bag and by XAD-4 resin respectively, comparing the data obtained in both cases. The emission factor (mg/kg) of the CO was between 2500 and 90000, and under the poor-oxygen atmosphere, the emission factors of many by-toxic products were greater than 100 mg/kg. A pyrolysis run was also performed, obtaining emission factors between 30 and 3000 mg/kg, facilitating its identification. The behaviour of different compounds in the combustion runs was discussed considering three groups in accordance with their stability vs. oxygen, and two groups vs. temperature.
Font
Rafael
R
Departamento de Ingeniería Química, Universidad de Alicante, Apartado, PO Box 99, 03080, Alicante, Spain. rafael.font@ua.es
Esperanza
Mar
M
García
Angela Nuria
AN
D000393:Air Pollutants / Q000032:analysis* / Q000737:chemistry / Q000633:toxicity; D002245:Carbon Dioxide / Q000032:analysis* / Q000633:toxicity; D002248:Carbon Monoxide / Q000032:analysis* / Q000633:toxicity; D006838:Hydrocarbons / Q000032:analysis* / Q000633:toxicity; D017745:Incineration / Q000295:instrumentation / Q000379:methods; D008031:Lignin / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry; D013696:Temperature; D014835:Volatilization
D000393:Air Pollutants; D006838:Hydrocarbons; D002245:Carbon Dioxide; D002248:Carbon Monoxide; D008031:Lignin; D010100:Oxygen