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Tar yield and collection from the pyrolysis of relatively larg eparticles of biomass are investigated using the model of Miller and Bellan (199b). A variety of feedstocks are considered by varying the ratios of cellulose, hemicellulose and lignin within the biomass. Effects of secondary tar reactions, quenching, temperature, particle size and carrier gas are assessed.
The previously tested State-of-the-Art (SOA) air revitalization architecture onboard the International Space Station recovers approximately 50% of the oxygen (O 2 ) from metabolic carbon dioxide (CO 2 ) via the Sabatier process. Maximum O 2 recovery is required to reduce resupply mass for long-duration manned missions. O 2 recovery is constrained by the limited availability of reactant hydrogen (H 2 ) from water (H 2 O) electrolysis, and Sabatier-produced methane (CH 4 ) is vented as a waste product resulting in a continuous loss of reactant H 2 . The Plasma Pyrolysis Assembly (PPA) has the potential to substantially increase O 2 recovery by post-processing the Sabatier-produced methane to recover H 2 . The PPA decomposes CH 4 into predominately H 2 and acetylene (C 2 H 2 ). A separation system is needed to purify the H 2 from the PPA stream before it is recycled back to the Sabatier reactor. Two sub-scale electrochemical H 2 separation systems, developed by Skyre, Incorporated, were delivered to NASA for evaluation. Complimentary of the previous submittal, ICES-2023-260, this paper reports a summation of Phase I and Phase II testing and evaluation of the C 2 H 2 removal systems as well as lessons learned.
Mass spectrometer pyrolysis of ammonium perchlorate at low pressure
Rapid linear pyrolysis of thermoplastic solid fuels by intense heat flux levels to simulate combustion
Intermediacy of azomethine nitrene generated from 3 benzyl 4 phenyl 1,2,4 oxadiazolone 5 by either pyrolysis or photolysis
Capillary gas chromatography mass spectrometry combined by molecular separators applied to methane pyrolysis product analysis
Xanthate and ester pyrolysis reactions in epimeric cis- and trans-2-methylcyclohexyl-S-methyl xanthates and acetates
Effect of chemical properties of pyrolysis gases on heat shield mass required for lifting reentry vehicle in typical reentry trajectory
Thermochemical data from simulated pyrolysis gas flow through ablating char layer
Oxygen depletion effect in chemical reactions between pyrolysis gases and air stream on surface recession of charring ablators
Bioorganic comparative analysis of desert soils, Precambrian shales and meteorites by automated pyrolysis-gas chromatography-mass spectrometry system for future Mars soil analysis
Determining composition of pyrolysis products from degradation of ablative materials
Thermal cracking of phenolic-nylon pyrolysis products analyzed on passing through heated char
Rapid linear pyrolysis of polymethyl methacrylate
Charring ablative composites pyrolysis products composition determination, comparing chemical analysis techniques
Hydrocarbons pyrolysis in Knudsen cells at low pressures, using mass spectrometry to study reactions and products
The carbon contents of various lunar soil particle types and sieve fractions of Apollo 15 and 16 samples have been determined by the pyrolysis method. The mineral, glass, and high-grade breccia fragments in the soils examined contain relatively low amounts of carbon (approximately 8, 25, and 25 microg C/g sample respectively in 149-250 micron grains). Most low-grade breccias and all agglutinates examined have high carbon contents (approximately 52 and 80 microg C/g sample respectively), and agglutinate abundance is indicative of the carbon content and maturity of a soil. The distribution of carbon with respect to particle size in mature soils generally reveals a minimum in carbon content at about 100 micron particle diameter. At smaller particle diameters, carbon content is directly proportional to particle surface area and therefore increases with the ratio (surface area)/(particle mass). A model relating the cycle of comminution and aggregation of soil particles to the redistribution of surface implanted carbon is developed.
Pyrolysis of several structurally different amino acids in a column at 500 C showed differences in the mechanisms and final products. The aliphatic protein amino acids decompose mainly by simple decarboxylation and condensation reactions, while the beta amino acids undergo deamination to unsaturated acids. Alpha amino acids with alpha alkyl substituents undergo an unusual intramolecular SN1 reaction with the formation of an intermediate alpha lactone which decomposes to yield a ketone. The alpha alkyl substituents appear to stabilize the developing negative charge formed by partial heterolytic cleavage of the alpha carbon - NH3 bond. The gamma and delta amino acids give 2-pyrrolidinone and 2-piperidone respectively, while the epsilon acids yield mixed products.