Summary of C-MU's environmental technical support studies at the CO/sub 2/-acceptor coal gasification pilot plant

• Main Authors: Fillo, J.P., Pochan, M.J., Nakles, D.V.
• Language: unknown
• Published: 2020
• Subjects: 01 COAL; LIGNITE; AND PEAT; CARBON DIOXIDE ACCEPTOR PROCESS; ENVIRONMENTAL EFFECTS; PILOT PLANTS; FUEL GAS; IMPURITIES; QUENCHING; AMMONIA; COAL GASIFICATION; COAL TAR; CONDENSATES; CYANIDES; HYDROCYANIC ACID; OILS; PHENOLS; SAMPLING; THIOCYANATES; AROMATICS; CARBONIC ACID DERIVATIVES; FLUIDS; FUELS; FUNCTIONAL MODELS; GAS FUELS; GASES; GASIFICATION; HYDRIDES; HYDROGEN COMPOUNDS; HYDROXY COMPOUNDS; INORGANIC ACIDS; NITROGEN COMPOUNDS; NITROGEN HYDRIDES; ORGANIC COMPOUNDS; ORGANIC SULFUR COMPOUNDS; OTHER ORGANIC COMPOUNDS; SNG PROCESSES; TAR; THERMOCHEMICAL PROCESSES; Carbonic acid
• Online Access: http://www.osti.gov/servlets/purl/5452305; https://www.osti.gov/biblio/5452305; https://doi.org/10.2172/5452305

Significant degradation of effluent species in aqueous condensate samples can occur if samples are not properly preserved. Specifically, cyanide and thiocyanate required precipitation of soluble sulfide immediately upon sample collection. Significant variability in effluent concentratin with time occurs as a result of variations in process operating parameters. This variability can be partially attributed to fluctuations in coal feed rate. Ultimately, the residual variability will be correlated with process parameters to define the necessary relationships for extrapolation of the pilot plant data base. Results of raw product gas characterization before and after the quench tower indicated: (1) Ammonia production accounted for nearly 100% of the coal feed nitrogen, corresponding well with aqueous condensate characterization. (2) Removal of impurities from raw product gas by the quench tower varies significantly, ranging from approx. 50% for HCN to effectively 100% for ammonia. (3) Limited data indicate sulfur production in the overhead gas of approx. 45% of the feed coal sulfur. Significant evidence was collected regarding the formation/decomposition phenomena governing effluent production: (1) Devolatilization of hydrocarbon species from incoming fresh coal is restricted exclusively to a small region in the vicinity of fresh gasifier coal feed. (2) Characteristics of phenolic compound production from the CO/sub 2/-Acceptor gasifier is a combination of formation during coal devolatilization and subsequent decomposition in the gasifier char bed, whereas ammonia and hydrogen cyanide production appear independent of residence time/decomposition effects. (3) Formation of hydrocarbon tars and oil appears to be inhibited during coal devolatilization in the presence of fluidized coal/char.