Jinsheng Wang

Natural Resources Canada | NRCan

This paper presents a concise overview of ash deposition in combustion or co-firing of biomass (woody biomass, agricultural residues, peat, etc.) with other fuels for power/heat generation. In this article, the following five research aspects on biomass combustion ash deposition are reviewed and discussed: influence of biomass fuel characteristics,...

Carbon capture and storage (CCS) is one of the major transformative technologies for reducing atmospheric CO2 emissions from large CO2 emitters where a large potential for geological CO2 storage exists. CO2 captured from the emitters contains various impurities, such as N2, O2, Ar, SOx, etc., and allowing these impurities to be stored together with...

A Canadian limonite iron ore was tested for the first time as a catalytic bed material for air-blown gasification of pine sawdust at various equivalence ratios (ER, 0.20–0.35) on a pilot-scale fluidized bed gasifier, in comparison to a conventional olivine bed material. Effects of bed materials (iron ore and olivine) on tar formation and gasificati...

Effects of impurities in CO2 streams on geological storage of CO2 have been investigated. A number of key issues have been addressed, and several significant findings have been made. Highlighted among the findings are: (1) non-condensable impurites such as N2, O2 and Ar greatly reduce CO2 storage capacity of geological formations, and there is a ma...

Shale gas is viewed by many as a global energy game-changer. However, serious concerns exist that shale gas generates more greenhouse gas emissions than does coal. In this work the related published data are reviewed and a reassessment is made. It is shown that the greenhouse gas effect of shale gas is less than that of coal over long term if the h...

The ash deposition behaviors of co-combustion of three-fuel blends of white pine pellet (WPP), peat pellet (PP), and crushed lignite (CL) coal were studied on a pilot-scale bubbling fluidized-bed combustor operated at 40% excess air ratio. Reference tests with individual fuel (pine, peat, or lignite) and two-fuel blends of lignite and pine or peat...

Co-firing peat with lignite for power generation was studied at pilot-scale, focusing on the issue of ash deposition, the major concern for this application. A specially designed probe was used to measure the rate of ash deposition under similar conditions of power plant boiler operation. Fraction of peat in the feed was varied up to 100%. It was o...

The objective of this study was to examine the ash deposition tendencies of biomass fuels and the biomass−coal blended fuels against the base fuel (coal) during co-firing and how the operating parameters influence the ash deposition tendencies. In this study, ash deposition behaviors during combustion and co-combustion of white pine pellets (WPP) a...

The reversible reaction between CaO and CO2 is an extremely promising method of removing CO2 from the exhaust of a power station, generating a pure stream of CO2 ready for geological sequestration. The technology has attracted a great deal of attention recently, owing to a number of its advantages: the relatively small efficiency penalty which it i...

CaO-based regenerative sorbents for CO2 capture in power generation and H2 production are receiving growing attention. A major challenge for this technology is the decay of sorbent activity with increasing number of the sorption/regeneration cycles. Evaluation of long-term sorbent activity currently requires substantial experimental work. In this s...

Using CaO-based regenerative sorbents to capture CO 2 in fossil fuel based power generation and H 2 production is a promising technology for reduction of CO 2 emission. A major challenge for this technology is the decay of sorbent activity with increasing cycles of sorption/regeneration. Evaluation of long-term sorbent activity currently requires l...

Characterizations of ash deposits from co-firing/co-combusting of a woody biomass (i.e., white pine) and lignite coal were investigated in a fluidized-bed combustor using a custom designed air-cooled probe installed in the freeboard region of the reactor. Ash deposition behaviors on a heat transfer surface were comprehensively investigated and disc...

The effect of halogen species on CO oxidation in circulating fluidised bed combustion has been studied with combustion experiments with iodine addition. As iodine concentration increased to 0.4%, CO concentration in the flue gas increased by two orders of magnitude. The markedly increased CO concentration is attributed to increased recombination of...

Combustion tests for fish oil and its blends with fuel oils were performed in a pilot tunnel furnace and two residential boilers to evaluate fish oil as an alternative fuel for conventional boilers and furnaces. Droplet evaporation tests were also conducted as a complementary study of the combustion properties. Fish oil and the blends burned readil...

Steam gasification of carbon residue in bed solids of a low-temperature black liquor gasifier was studied using a thermogravimetric system at 3bar. Complete gasification of the carbon residue, which remained unreactive at 600°C, was achieved in about 10min as the temperature increased to 800°C. The rate of gasification and its temperature dependenc...

A chemical-looping process is proposed for the clean combustion of solid fuels for electric power or heat generation. The process is based on coal gasification with CO2 to produce CO. The CO then reduces CaSO4, which is used as an oxygen carrier, in a separate reactor to give CaS and CO2. A portion of the CO2 is recycled for the gasification stage...

Simultaneous hydration and carbonation of ash from fluidized bed combustion was studied using a new sonication technology. Enhanced carbonation of the ash by CO2 was achieved at ambient temperature by use of a sonic generator with low frequency (100–500 Hz). At lower sonic intensity, the product was mainly Ca(OH)2 whereas at higher intensity the pr...

A common decay pattern has been observed in a number of very different systems under cyclic operations. The decay behavior can be described by a simple equation. The cause of the decay is considered to be compositional or structural inhomogeneities of the system. Although the decay mechanisms are divergent, a unified description of the decay can be...

Destruction of polychlorinated biphenyls (PCBs) in contaminated soils and wastes using circulating fluidized bed combustion (CFBC) technology was studied using a pilot plant and simulated waste material. The results show that the technology is effective and particularly promising for treatment of PCB-containing materials like the toxic sludge from...

High-temperature chemical reactions in mixtures of solid CaSO4 and Na2CO3 were investigated in order to explore the mechanisms of enhanced sulfur capture by limestones doped with Na2CO3 in fluidized bed combustion. Drastic weight loss of the mixtures was observed in a thermogravimetric analyzer near the melting temperature of Na2CO3, indicating che...

A simple model is proposed for sulphation of CaO-based sorbents in fluidized bed combustion. The model focuses on the sintering effect of CaSO4 product on the sorbent particles. The resultant equation is validated with experimental data and is seen to describe the time dependence of the sulphation well. It is also shown that for short sulphation ti...

CaSO4 and CaS are the only sulphur compounds found in solid residues from the sulphation process in FBC boilers. Early results indicated very high levels of CaS in ashes from small-scale FBC pilot plant combustors. However, these results were due to the presence of high levels of char carbon in standpipes and cyclones. In commercial-scale FBC boile...

Ignition tests were conducted with delayed and fluid petroleum cokes, a high volatile bituminous coal and their blends in bench- and pilot-scale fluidized bed combustors. In the bench-scale FBC tests, a visual inspection ignition criterion was developed based on the ‘CO–CO2’ profiles obtained as a function of time and bed temperature. In the pilot-...

Pilot plant studies were conducted to assess the feasibility of remediation of coal tar-contaminated soil and oil-contaminated gravel by incineration in a fluidized bed combustor and the same equipment converted to a calciner, with environmentally acceptable performance. Besides adequate decontamination and emission control, effort was devoted to t...

The efficiency of limestone sorbent utilization in fluidized bed combustors (FBCs) is low, because of incomplete sulfation of CaO. Hydration of the FBC ash can reactivate the partially sulfated sorbent, and the hydrated ash can be reinjected into the combustors as the SO2 sorbent. In this work, the rate of hydration, which is of primary importance...

Communication: Mercury is emitted into the environment by various anthropogenic and natural activities. Hg reacts with Cl-2 even at ambient temperature. While this reaction is a subject of great interest, data for this system is scarce, apparently due to experimental difficulties. In this work, the reported data for the reaction between Hg and Cl-2...

Capturing CO2 from large-scale power generation combustion systems such as fluidized bed combustors (FBCs) may become important in a CO2-constrained world. Using previous experience in capturing pollutants such as SO2 in these systems, we discuss a range of options that incorporate capture of CO2 with CaO in FBC systems. Natural limestones emerge f...

Polychlorinated dibenzodioxins/furans (PCDD/F) were formed in substantial quantities in a pilot-scale fluidized bed combustor burning salt-laden waste wood, a common fuel for Canadian coastal pulp and paper mills. Formation of PCDD/F increased with increasing chloride content in the feed, and appeared to correlate with the chlorine content in the f...

To explore the use of a CaO-based sorbent to capture CO2 from flue gases of combustors in multiple absorption/desorption cycles, formulas for the decay behavior of the absorption capacity have been examined and a new simple equation has been proposed. This equation is shown to describe the reported data better and uses only one parameter. By analog...

Petroleum coke is a challenging fuel in terms of its low volatile content, high sulfur and nitrogen content, which give rise to undesirable emission characteristics. However, the low price and increased production of petroleum coke from high-sulfur feedstocks give a powerful economic stimulus to use it for power generation. In this study two strate...

N2O formation in low-concentration NO and SO2 mixtures was examined and the promotional effects of O2 and water vapor on the formation were studied. At 25°C N2O formed in dry gas mixtures with NO and SO2 concentrations as low as 10ppm. With the addition of water vapor N2O formation rate increased significantly. The effect of water vapor was more pr...

Accurate ranking of fluid catalytic cracking (FCC) feeds will help oil producers price their commodities. The value of an FCC feed depends on its properties, which, in turn, contribute toward producing high-value products with good qualities. Feed ranking based on general analyses is the simplest way to determine the best feeds but can be misleadin...

Ten vacuum gas oil feeds were cracked in a fixed-bed microactivity test (MAT) unit and a modified ARCO riser reactor on separate occasions. Several important observations from the MAT study were reported, including the effects of gasoline precursors on the maximum gasoline yields, light cycle oil (LCO) precursors on the optimum LCO yields, and arom...

To minimize the disposal of highly reactive spent sorbent from a fluidized bed combustor, a new method for reactivation has been developed. The method consists of grinding the spent ash in a rotary mill, hydrating the ash with an excess of water, and mixing the wet ground ash with dry solids to absorb the excess water. The mixing process eliminates...

The efficiency of limestone utilisation for sulphur capture in fluidised bed combustors (FBC) is low due to incomplete sulphation of CaO. The disposal of the spent sorbent is problematic and costly. Reutilisation of the spent sorbent is highly desirable both in terms of improving overall plant economics and process efficiency. In this work, wet gri...

Mercury emission from coal-fired power plants is causing great concern. Thermodynamic equilibrium calculations are commonly used for prediction of Hg speciation in the flue-gas. According to representative calculations, at temperatures below 725 K all Hg should exist in oxidized forms. However, Hg speciation measurements for flue-gas at much lower...

Asphaltenes are problematic substances for heavy-oil upgrading processes. Recently interesting findings on thermal-cracking kinetics of an asphaltenic residue were reported, but a proposed model which considered parallel reactions for oil + gas and coke formation could not describe the behavior at higher temperatures. It was suggested that in such...

N2O was reported to form in sample containers of flue gases containing NO and SO2. This could have significant implications for the evaluation of N2O buildup in the atmosphere. Existing models are based either on liquid-phase reactions, which cannot account for N2O formation at low humidity, or on termolecular reactions, which are not likely to occ...

A simplified four-lump model for fluid catalytic cracking (FCC) as reported in the literature has been examined. The model, which relates the coke yield to other yields, is important to FCC operation but requires intensive data analyses. In this article, a new methodology that can validate the model and substantially simplify the data treatments is...

A fluid catalytic cracking (FCC) study of 10 vacuum gas oil feeds was performed using a fixed-bed microactivity test (MAT) unit. Gas, liquid, and coke yields at several conversion levels were compared with reported pilot plant data obtained from a modified ARCO riser reactor using the same feeds. The data indicated that except for coke yield, MAT r...

Photoinhibition mechanism is studied for ethylene production by a recombinant cyanobacterium. The kinetic pattern of the production is similar to that of substrate inhibition in enzyme reactions, whereas the photoinhibition is believed not to be substrate-related, but to originate from the enzyme for ethylene formation. In a proposed model, the inh...

A method for graphically analyzing the pH dependence of enzyme activity is presented. Linear plots can be made to test the applicability of the assumed models. For three simple cases, if the pH dependence curves are measured at two substrate concentrations, it is possible to evaluate ion dissociation constants from the linear plots. The method woul...

A model of substrate inhibition for enzyme catalysis was extended to describe the kinetics of photosynthetic production of ethylene by a recombinant cyanobacterium, which exhibits light-inhibition behavior similar to the substrate-inhibition behavior in enzyme reactions. To check the validity of the model against the experimental data, the model eq...

A method of visual validation of a widely used dual-mode model for sorption of gases in glassy polymers is presented. Instead of directly fitting the model equation to the sorption data to determine its three parameters, the method evaluates one of the parameters, Henry's law coefficient independently and then plot the data in a linear way. Good li...

A model of substrate inhibition for enzyme kinetics is applied to photosynthetic production of ethylene by a recombinant cyanobacterium, which exhibits light inhibition behavior. Kinetic parameters of the model were evaluated from a linear plot of the data. Parameter values obtained in this way described well the light-intensity dependence of ethyl...

Sorption, dilation, and diffusion behaviors were studied for the system of polysulfone/CO2 with regard to the effects of CO2 conditioning, i.e., exposure to high-pressure CO2. Concurrent measurements of solubility, dilation, and diffusivity were performed for polysulfone films before and after the conditioning at 25 and 50 atm. While the solubility...

Kinetic studies were carried out for ethylene production by recombinant cyano bacteria which harbor a gene for the ethylene-forming enzyme of Pseudomonas syringae. The production rate depended on light intensity and cell concentration. Experimental data obtained at low cell concentrations were used to predict the production rate at high cell concen...

Sorption of CO2 in poly(methyl methacrylate) at 35−200 °C and concurrent dilation of the polymer at 35−85 °C over a pressure range up to 50 atm were studied. Dissolution and Flory−Huggins interaction parameters for the gas in the polymer, not only in the rubbery state but also in the glassy state, were estimated by analyzing the sorption data above...

The effect of a penetrant-induced isothermal glass transition on sorption, dilation, and diffusion behavior was studied in a single experimental run for CO2 in cast polybenzylmethacrylate films. The dual-mode type sorption isotherms below the glass transition temperature of the polymer changed to linear ones above a certain concentration. Meanwhile...

Sorption and dilation isotherms and diffusion coefficients for seven hydrocarbons (n-butane, isobutane, 1-butene, cis-2-butene, trans-2-butene, isobutylene, and 1,3-butadiene) in two rubbery polymers, 1,2-polybutadiene (PB) and poly(ethylene-co-vinyl acetate) (EVAc), were measured at 25°C. Dissolution parameters (Henry's law coefficient and Flory-H...

Sorption and dilation isotherms and diffusion coefficients for the polysulfone/CO2 system were measured concurrently. The sorption parameters, the partial molar volume of sorbed CO2 and the concentration dependence of the diffusion coefficient were obtained for the temperature range 15–75°C. The sorption parameters were well related to the temperat...

Sorption equilibria and permeation rates for CO2, O2 and N2 in poly(ether imide) (PEI) membrane which has a glass-transition temeperature of 216°C and in poly(ether ether ketone) (PEEK) (a typical crystalline polymer, crystallinity=0.4) membrane, whose glass-transition temperature is 143°C, were measured at 25, 30 and 40°C and at pressures up to 3...

The processes of gas sorption and permeation in a polymer membrane at temperatures above and below the glass-transition point were examined using poly-4-methylpentene-1 (glass-transition temperature reported to be 40°C) as a membrane material. The permeabilities to O2 and N2 were independent of applied gas pressure at every temperature; the mean pe...

Both homogeneous and asymmetric polyethersulfone (PES) membranes were prepared by solvent casting. The sorption and permeation behavior of CO2, O2, and N2 using these two kinds of cast PES membranes and commercially available homogeneous PES film was investigated to extract the pressure dependence of gas permeability and the permselectivity for CO2...

Steady-state permeation rates for pure CO2, CH4, and O2 through two kinds of homogeneous dense membranes, copolymer of methyl methacrylate and n-butyl acrylate and poly(methyl methacrylate), were measured at three temperatures between 20 and 40°C and upstream pressures up to 3 MPa. The logarithms of the mean permeability coefficients for CO2 in bot...

Permeation behavior of pure CO2, O2, and N2 and separation characteristics of CO2–air mixtures were examined using hollow fiber modules of asymmetric cellulose triacetate membrane at 30°C. The ideal separation factor for CO2 relative to N2 ranged from 21 to 24. Permeation behavior for pure CO2 was interpreted in terms of the total immobilization mo...

An analytical solution has been obtained for the modified dual-mode mobility model for a single gas proposed by Zhou and Stern and extended to a binary gas mixture to describe the pressure dependence of mean permeability coefficients for CO2 and CH4 mixtures in homogeneous cellulose triacetate membranes. The permeabilities calculated from the model...

Pilot plant studies were carried out to evaluate the feasibility of remediation of coal tar- contaminated soil and oil-contaminated gravel by incineration with environmentally acceptable performance. In addition to adequate decontamination and emission control, effort was devoted to treating the special feedstocks with difficult handling properties...