• 한국연소학회지
• /
• 제16권1호
• /
• pp.8-14
• /
• 2011

Biomass gasification is a promising technology in terms of clean energy and flexible options for end use such as heat, steam, electricity, gaseous or liquid fuels. In a gasification process, reduction of tar is very important because it can cause any mechanical problems and small tar implies high energy efficiency. However, generation and conversion mechanisms of tar have not been fully understood due to its complex nature. In this study, characteristics of tar generated from different gasification stages were investigated. Korean pine woodchip was used as feedstock and tar was sampled in a separate way during devolatilization and char gasification stage, investigated. As a result. more various kinds of hydro carbon compounds were identified in the devolatilization stage than char gasification stage because primary tar compounds are released mostly from pyrolysis of cellulose and hemicellulose. When the reaction temperature increased up to $900^{\circ}C$, tar composition becomes simplified into about 10 aromatic compounds mostly with 1-4 rings without substitution up to phenanthrene. The sampled tar in the char gasification stage mostly contains 5-7 simple aromatic compounds.

• 한국가스학회지
• /
• 제27권1호
• /
• pp.1-12
• /
• 2023

석탄가스화는 석탄을 불완전 연소하여 수소와 일산화탄소로 이루어진 합성가스를 생성하는 공정이다. 기 존 석탄 연소와 달리 질소 산화물이나 황 산화물이 배출되지 않고 미세먼지 발생량이 적어 석탄을 청정하게 이용할 수 있으며 합성가스를 통해 부가적인 화학물질을 생산할 수 있다. 석탄가스화는 합성가스 생산방식에 따라 석탄가스화복합화력발전(Integrated Gasification Combined Cycle, IGCC), 플라즈마 석탄가스화, 지하석탄 가스화(Underground Coal Gasification, UCG)로 분류된다. 최근에는 합성가스의 수소를 활용하기 위하여 일산화탄소를 수소로 전환하는 수성가스전환(Water Gas Shift, WGS) 반응기와 이산화탄소를 포집하는 설비를 결합하는 사례가 늘고 있다. 본 연구에서는 석탄가스화와 합성가스를 이용한 수소 생산 방법에 대하여 정리하였으며 현재 진행되고 있는 석탄가스화를 이용한 수소 생산 프로젝트를 조사하였다.

• 한국연소학회:학술대회논문집
• /
• 한국연소학회 2014년도 제49회 KOSCO SYMPOSIUM 초록집
• /
• pp.255-257
• /
• 2014

The installation of light oil facilities or delayed cokers seems to be inevitable in the oil refinery industry due to the heavy crude oil reserves and the increased use of light fuels as petroleum products. Petroleum coke is a byproduct of oil refineries and it has higher fixed carbon content, higher calorific value, and lower ash content than coal. However, its sulfur content and heavy metal content are higher than coal. In spite of disadvantages, petroleum coke might be one of promising resources due to gasification processes. The gasification of petroleum coke can improve economic value of oil refinery industries by handling cheap, toxic wastes in an environment-friendly way. In this study, $CO_2$ gasification reaction kinetics of petroleum coke, various coals and mixing coal with petroleum coke have investigated and been compared by using TGA. The kinetics of $CO_2$ gasification has been performed with petroleum coke, 3 kinds of bituminous coal [BENGALLA, White Haven, TALDINSKY], and 3 kinds of sub-bituminous coal [KPU, LG, MSJ] at various temperature[$1100-1400^{\circ}C$].

• 한국환경과학회지
• /
• 제15권6호
• /
• pp.601-606
• /
• 2006

The coal gasification fuel is important to replace petroleum fuel. Also they have many benefits for reducing the air pollution. Measurements on the combustion characteristics of synthetic gas from coal gasification have been conducted as compared with LPG in constant volume combustion chamber. The fuel is low caloric synthetic gas containing carbon monoxide 30%, hydrogen 20%, carbon dioxide 5%, and nitrogen 45%. To elucidate the combustion characteristics of the coal gasification fuel, the combustion pressures, combustion durations, and pollutants(NOx, $CO_2$, CO) are measured with equivalence ratios($\phi$), and initial pressures of fuel-air mixture in constant volume chamber. In the case of the coal gasification fuel, maximum combustion pressure and NOx concentration are lower rather than LPG fuel. However CO and $CO_2$ emission concentration are similar to that of LPG fuel.

• 한국연소학회:학술대회논문집
• /
• 한국연소학회 2005년도 제31회 KOSCO SYMPOSIUM 논문집
• /
• pp.43-49
• /
• 2005

Social interest and request about low pollution waste treatment process are growing and gasification melting method, as a new technology concept, is risen. The necessity of engineering analysis to determine design standards and operation condition is required. In this study, the objective and function of components and operation process of various gasification melting furnaces such as shaft type, fluidized bed and Rotary Kiln type gasification melting furnace are reviewed and the design standard and operation range of gasification melting furnace are determined by inspecting the change of output and operation condition with input condition change.

• Korean Chemical Engineering Research
• /
• 제50권1호
• /
• pp.76-82
• /
• 2012

볏짚 톱밥과 같은 바이오매스는 석탄과 함께 사용할 수 있는 잠재력이 큰 에너지원으로 이들을 가스화공정에 적용하면 수송용 연료같은 bio-oil을 생산할 수 있다. 본 연구에서는 상압의 열천칭 반응기(thermobalance)에서 톱밥, 볏짚, 갈탄, 역청탄, 무연탄의 수증기 가스화 반응특성을 수행하였으며, 가스화 온도 $600{\sim}850^{\circ}C$, 수증기 분압 30~90 kPa의 범위에서 조업변수들이 가스화반응속도에 미치는 영향을 조사하였다. 세 가지의 기체-고체 화학반응모델이 가스화반응의 거동을 예측하는 능력을 비교하였으며, modified volumetric reaction model을 사용하여 공정설계에 필수적인 kinetic 정보를 도출하였다. 두 가지 바이오매스와 세 가지 석탄 촤의 가스화반응성을 비교하였다. Arrhenius plot으로부터 얻어진 바이오매스와 석탄의 활성화에너지는 모두 문헌상의 범위에 속하였다. 각 연료에 대하여 수증기분압에 대한 반응차수를 결정하였으며, 가스화공정 설계의 기초데이타로서 겉보기 반응속도식을 제시하였다.

• 한국연소학회지
• /
• 제13권2호
• /
• pp.23-32
• /
• 2008

Gasification characteristics in the fluidized bed reactor are essential for the design of a gasification furnace to optimize the operation condition. Moisture content of the solid fuel is one of the important factors to influence directly the gasification characteristics. So it is necessary to investigate the effect of moisture content of solid fuel in partial oxidation condition. Gasification characteristics are investigated with results from thermogravimetric analyzer and lab-scale fluidized bed reactor for wood and RDF samples along with changing moisture contents. Additionally lab-scale fluidized bed reactor was run continuously and gas concentrations at the exit were measured. It is observed that the rate of reaction in partial oxidation condition is between the results from the combustion environment and from the inert condition. Moisture content in a particle slows down the heating rate of a particle. So, reaction is delayed by the moisture content. However, RDF samples those are easy to break-up don't show the effect of moisture content. The result of continuous operation condition shows that proper moisture content promotes gasification because steam from the particles helps gasification of the solid fuel. A simulation to predict the syn-gas composition was conducted by the Aspen Plus process simulator. The cold gas efficiency of the experiment was compared with results from the simulation.

• 한국농공학회논문집
• /
• 제48권3호
• /
• pp.63-71
• /
• 2006

A downdraft gasifier was made of stainless steel for biomass gasification. Internal reactor had a 300 mm diameter and 8 air intakes. Three thermocouples were installed to measure the temperature inside the reactor. Three different biomass fuels were provided in the experiments to find out the effects of fuel conditions on gasification processes; charcoals, woodchips, and mixture of woodchip and charcoals. Two different experiments were conducted fer charcoal experiments, small and larger sizes of charcoal fuels. It took about 10 minutes after ignition to generate combustible producer gas when charcoal was f9d, but 20 or more minutes for woodchips. When the gasification was stabilized, the highest temperature was observed just below the combustion zone. The air flow rate for woodchip experiment was provided at 25% of a stoichiometric requirement of combustion, which was within the range of typical air flow rate fer woody biomass gasification. Carbon monoxide concentrations were also within the values reported in the previous studies, ranging 20 to 30% depending on fuel types. It could be seen that fuel size and heating value were very important parameters in biomass gasification. These parameters should be taken into account in operating and designing biomass gasifiers.

• 한국연소학회:학술대회논문집
• /
• 한국연소학회 2007년도 제34회 KOSCO SYMPOSIUM 논문집
• /
• pp.161-167
• /
• 2007

Gasification characteristics in the fluidized bed reactor are essential for the design of a gasification furnace to optimize the operation condition. Moisture content of the solid fuel is one of the important factors to influence directly the gasification characteristics. So it is necessary to investigate the effect of moisture content of solid fuel in gasification process. Gasification characteristics are investigated with results from thermogravimetric analyser and lab-scale fluidized bed reactor for wood and RDF samples along with changing moisture contents. Additionally lab-scale fluidized bed reactor was run continuously and gas concentrations at the exit were measured. It is observed that the rate of reaction in partial oxidation condition is in between the results from the combustion environment and from the inert condition. Moisture content in a particle slows down the heating rate of a particle. So, reaction time is delayed by the moisture content. However, RDF samples that are easy to break-up doesn't show the effect of moisture content. The results of continuous operation condition shows that proper moisture content promotes gasification because steam from the particles helps gasifcation of the sold fuel.

• 한국기계가공학회지
• /
• 제20권11호
• /
• pp.80-85
• /
• 2021

The gasification of coffee leaves, which are a type of biomass waste, was conducted on a pilot of a downdraft fixed gasification system to investigate the gasification characteristics. The experiment was performed using a coffee leaf pellet size and a batch-type gasification system consisting of a gasifier, cooling cyclone, scrubber, and bag filter. It was found that the air-to-fuel ratio was 2.32 Nm³/kg·h and the reaction temperature was 700 ℃-900 ℃. However, the air flow rate changed to 0.45 Nm³/min, which was lower than the initial starting value depending on the temperature change during the gasification process. It was concluded that coffee leaves can be converted from biomass waste into useful synthetic gas as an alternative energy source.