Fuel
Carbon-supported one-component (Fe, Ru, Pt) and two-component (FeRu and FePt) catalysts were used for hydrodenitrogenation of pyridine (HDN) at 3.0 MPa and 573 K. The Fe catalyst was less active for pyridine conversion and less selective for the formation of n-pentane than the noble metal catalysts were. For the two-component catalysts, activity was closely related to that of the noble metal component,...
The combustion characteristics of six middle distillate oil blends were examined using the controlled combustion testing facilities at the Energy Research Laboratories of the Canada Centre for Minerals and Energy Technologies (CANMET). Test fuels were specifically prepared for a research project to study the impact of changes in commercial heating fuel composition on the combustion performance of...
N-methyl-2-pyrrolidinone (NMP) is widely used for coal extractions. It is well known that extraction solvents are retained in the coal extracts even after extensive drying procedures. The amount of NMP retained will affect the accuracy of the extraction yield and the character of the extracts. Thermal extraction gas chromatography-mass spectrometry (g.c.-m.s.) has been applied to quantify the amount...
The influence of heating rate upon pyrolysis of coal tar pitch (CTP) and mixtures of coal tar pitch plus first-stage FeCl 3 -graphite intercalated compounds (CTP-GIC) has been studied. In the two cases, the smaller the heating rate (from 20 to 0.5°C min - 1 ), the higher the green coke yield. The presence of FeCl 3 in GIC, present in the CTP, also provokes an increase...
Experiments were conducted to measure the dynamic surface tension of coal-water slurry (CWS) mixtures containing various types of surfactants and with different coal loadings. A maximum air bubble pressure technique measured the dynamic surface tension. The coal used for the CWS had 55 μm volume mean diameter (VMD) and was mined from the Upper Elkhorn seam, Virginia. Five surfactants were selected...
Simultaneous SO 2 and NO x reduction in flue gas by the dry furnace sorbent injection process was simulated with an entrained-flow reactor. Several ammonium salts as well as urea were tested. Urea was found to give the highest NO x removal efficiency. By using urea-limestone sorbent, >90% SO 2 removal and >80% NO x removal were obtained at CaS and NNO...
To estimate the influence of mineral matter in coal on coal combustion, fluidized bed combustion (FBC) and pulverized coal combustion (PCC) were simulated by simple models. The theoretical calorific values of some hypothetical coals of different rank and mineral matter content were calculated. The calculated calorific values of coals tend to decrease with increasing mineral matter content. This...
The mechanisms of the rehydrogenation of 1,2-dihydronaphthalene and naphthalene, formed during the tetralin H-transfer process for stabilizing free radicals stemming from thermal decomposition of model radical precursors such as benzyl phenyl ether (BPE), were studied using natural catalysts (pyrite, pyrrhotite) or catalysts originating from in situ sulfidation of iron oxide. These catalysts had...
The desulfurization of selectively oxidized coals and unoxidized control coals was investigated using mild pyrolysis and various base treatments. Both an Illinois No. 6 and an Indiana No. 5 coal were selectively oxidized with peroxyacetic acid in the pretreatment step and then treated with various hydroxide and carbonate bases, using either water, methanol or ethanol as the solvent. Reaction variables...
The floatability of oxidized coal was investigated by means of electrokinetic studies, contact angle measurements and flotation tests. Electrokinetic measurements showed that the zeta potential of unoxidized and oxidized coal samples depends on pH. Hydroxonium and hydroxyl ions are potentially significant ions, both for oxidized and unoxidized coal. Increasing oxidation times decreased the measured...
The trace elements (As, B, Ba, Be, Bi, Cd, Co, Cr, Cs, Cu, Ga, Ge, Hg, Li, Mn, Mo, Ni, Pb, Rb, Sb, Se, Sn, Sr, Ta, Th, Tl, U, V, W, Y, Zn, Zr and REE) in a subbituminous coal and their behaviour during combustion in a large power station were characterized by their content and distribution in the fuel (organic and/or inorganic affinities) and in the combustion wastes (partition and volatility). Samples...
Experiments with a test rig on the formation of NO x and N 2 O and their reduction in pressurized fluidized-bed combustion of bituminous coal are reported. The emission of NO x is controlled by two NO reduction methods--ammonia injection and staging of combustion air--and the emission of N 2 O by increasing the combustion temperature. Both ammonia injection and staging...
The sulfur capture capacities of 11 limestones and six dolomites were determined by means of a pressurized thermogravimetric analyser. The determinations were made under conditions relevant to pressurized fluidized bed combustion. The actual experiments were performed at two different temperatures (850 and 950°C) and at a pressure of 1.5 MPa. Additionally, some experiments were performed at atmospheric...
Experimental studies on surface area and pore structure development during pyrolysis of digested sewage sludge were carried out. Surface area and pore structure characterization of the resultant chars was evaluated using an accelerated surface area and porosimetry system (ASAP 2000). The effects of process parameters, temperature and hold time were found to be significant. Generally, the surface...
The effects of process variables on the activity of a Co/HZSM-5 zeolite bifunctional catalyst for the conversion of syngas to hydrocarbons were studied. The catalyst was prepared by incipient-wetness impregnation from aqueous solutions of cobalt and thorium nitrate, the latter used as promoter. The reactions were carried out in a fixed-bed integral reactor. A simple two-level factorial design was...
The hydrocarbon type analysis of light naphthas, alkylates and reformates was carried out by multidimensional gas chromatography (MD-g.c.) using a mode which provided the amounts and carbon number distributions of paraffins, olefins, naphthenes and aromatics (PONA) in each sample. The MD-g.c. results were compared with the total saturates, olefins and aromatics obtained by the ASTM method D 1319,...
The pyrolysis of the mined and crushed ore from the Whiterocks oil sand deposit was studied in a fluidized bed reactor. The reactor was designed to operate by pulling the fluidizing gas through the reactor rather than by pushing the gas through the bed. This was accomplished by reducing the pressure above the bed with a gas pump operating in the suction mode. This mode of operation resulted in...
The reduction of NO by CO was studied in a tubular reactor filled with small pieces of quartz glass tubing. The influence of residence time, concentration of CO and temperature on the reaction was investigated. The reaction rate is first-order with respect to both NO and CO. The rate constant, determined over the temperature range 973-1123 K and for a total surface-to-volume ratio of the filled...
Demineralization of Blue Creek coal by selective agglomeration using diesel oil involves high-shear mixing to disperse the diesel in a slurry of fine coal and separation of the resulting agglomerates from the tailings. A total of 54 agglomeration trials were made with thickener underflow from the Jim Walters Resources Inc. No. 4 mine preparation plant. Two additional particle size distributions...
The changes in radical concentrations and species brought about by vacuum and gas flow drying of New Vale lignite and Stockton bituminous coal samples were studied. Vacuum drying produces a sudden increase in concentration, flow drying a more gradual but ultimately greater one. For both coals the changes depend on a balance between decarboxylation, which produces new radical sites, and removal of...