Young Nam Chun

EFFECT OF TWO-STAGE COMBUSTION ON NOX EMISSIONS IN PULVERIZED COAL COMBUSTION

Abstract The effects of NO reduction by two-stage combustion in a pilot scale combustor have been investigated using propane gas flames loaded by pulverized coal particles with a nitrogen content of 1.3%. The secondary air is radially injected into the combustion chamber through four injection points. The combustion air is divided into primary and secondary stages. In the primary stage partial combustion is carried out with a much lower air ratio than that of normal combustion. Afterwards secondary air is supplied to complete the combustion. Experiments have been carried out using the primary to secondary air ratio, the total air ratio, the secondary air injection points and the coal size (and size distribution). The reduction of NO emission is barely influenced by the total air ratio. When the secondary air is injected where there is a reducing atmosphere, NO emission is reduced effectively. The results of NO reduction in fine coal combustion using a staged combustion are better than those from coarse coal combustion.

The Study of Model Biogas Catalyst Reforming Using 3D IR Matrix Burner

Global climate changes caused by CO2 emissions are currently debated around the world; green sources of energy are being sought as alternatives to replace fossil fuels. The sustainable use of biogas for energy production does not contribute to CO2 emission and has therefore a high potential to reduce them. Catalytic steam reforming of a model biogas (CH4 : CO2 = 60% : 40%) is investigated to produce H2-rich synthesis gas. The biogas utilized 3D-IR matrix burner in which the surface combustion is applied. The ruthenium catalyst was used inside a reformer. Parametric screening studies were achieved as Steam/Carbon ratio, biogas component ratio, Space velocity and Reformer temperature. When the condition of Steam/Carbon ratio, CH4/CO2 ratio, Space velocity and Refomer temperature were 3.25, 60% : 40%, 14.7 L/g・hr and 550°C respectively, the hydrogen concentration and methane conversion rate were showed maximum values. Under the condition mentioned above, H2 yield, H2/CO ratio, CO selectivity and energy efficiency were 0.65, 2.14, 0.59, 51.29%.

Production of Biofuel Energy by High Temperature Pyrolysis of Sewage Sludge Using Microwave Heating

The recent gradual increase in the energy demand is mostly met by fossil fuel, but the research on and development of new alternative energy sources is drawing much attention due to the limited fossil fuel supply and the greenhouse gas problem. This paper assesses the feasibility of producing fuel energy from a dewatered sewage sludge by microwave-induced pyrolysis with sludge char and graphite receptor. Both receptors produced gas, char, and tar in order from product amount. The gas produced for the sludge char receptor contained mainly hydrogen and methane with a small amount of light hydrocarbons. The graphite receptor generated higher gravimetric tar and generated higher light tar. Through the results, the product gas from the microwave processes of wet sewage sludge might be possible as a fuel energy. But the product gas has to be removed the condensable PAH tars.

Characteristics of Gasification for a Refused Plastic Fuel

Waste energy conversion to SRF (Solid Refuse Fuel) has the effects not alternative fossil fuel usage but also the reduction of greenhouse gas. But the direct burning of the SRF including a plastic waste generates air pollution problem like soot, dioxin, etc. so that an application of pyrolysis and gasification treatment should be needed. The purpose of this study is to supply a basic thermal data of the pyrolysis gasification characteristics in the plastic-rich SRF which are needed for developing the novel pyrolyser or gasifier. To do so, a bench-scale test rig was newly engineered, and then experiments were achieved for the production characteristics of gas, tar, and char. While SRF sample, gasification air ratio, holding time changed as 2 g, 0.691, 32 min respectively, the H2 1.36%, CH4 2.18%, CO 1.88%, Cl2 15.9 ppm, HCl 6.4 ppm were composed. Also light tar benzene 4.03 g/m, naphthalene 0.39 g/m, anthracene 0.11 g/m, pyrene 0.06 g/m, gravimetric tar 18 g/m, and char 0.29 g was formed.

Characteristics of a Plasma-Dump Combustor for VOC Destruction

VOCs (Volatile Organic Compounds) are generally generated in the painting process, or at the company and laundry where use organic solvents. The VOCs consist of various hydrocarbons and has low calorific value due to its dilution with atmospheric air. Therefore, the VOCs are difficult to burn by a conventional fuel combustor. In this study, a novel plasma dump combustor was proposed for the treatment of low calorific VOC gases. This combustor was designed a combination of the characteristics in a plasma burner, a dump combustor and a 3D matrix burner. The combustor has good structure for maintaining enough residence time and reaction temperature for stable flame formation and VOC destruction. For investigating the performance characteristics of the plasma dump combustor, an experiment was achieved for VOC feed rate, VOC injector position, etc. Toluene was used as a surrogate of VOC. The novel combustor gave better performance than a conventional combustor, showing that VOC destruction rate and energy efficiency were 89.64% and 12.27 kg/kWh respectively, at feeding rate of 450 L/min of VOC of 3,000 ppm of toluene concentration.

Hydrogen Gas Production from Methane Reforming Using Oxygen Enriched Compression Ignition Engine

The purpose of this paper is to investigate the reforming characteristics and maximum operating condition for the hydrogen production by methane reforming using the compression ignition engine induced partial oxidation. An dedicated compression engine used for methane reforming was decided operating range. The partial oxidation reforming was investigated with oxygen enrichment which can improve hydrogen production, compared to general reforming. Parametric screening studies were achieved as ratio, total flow rate, and intake temperature. When the variations of ratio, total flow rate, and intake temperature were 1.24, 208.4 L/min, and , respectively, the maximum operating conditions were produced hydrogen and carbon monoxide. Under the condition mentioned above, synthetic gas were .