Advanced Concepts in Modular Coal and Biomass Gasifiers

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
John P. Dooher ◽  
Marco J. Castaldi ◽  
Dean P. Modroukas
Keyword(s):  
Hydrothermal Treatment ◽  
Flow Reactor ◽  
Small Scale ◽  
Test Results ◽  
Gasification Process ◽  
Cold Gas Efficiency ◽  
Wide Range ◽  
Entrained Flow Reactor ◽  
End Use ◽  
Gas Efficiency

The program involves the application of a novel gasification concept, termed a modular allothermal gasifier (MAG) to produce syngas from coal, biomass, and waste slurries. The MAG employs a steam-driven gasification process using a pressurized entrained flow reactor wherein the external wall surfaces are catalytically heated to 1000 °C via heterogeneous combustion of a portion of the produced syngas. The MAG can be fed by a hydrothermal treatment reactor for biomass and waste feedstocks, which employs well-developed hydrothermal processing technology using the addition of heat and water to provide a uniform slurry product. The hydrothermal treatment reactor requires no preprocessing and a clean syngas is produced at high cold gas efficiency (80%). Importantly, the MAG can operate over a wide range of positive pressures up to 3 MPa (30 bar) which provides process control to vary the output to match end-use needs or feedstock rate. The system produces minimal emissions and operates at significantly higher efficiency and lower energy requirements than pyrolysis, plasma gasification, and carbonization systems. The system is compact and modular, making it easily transportable, for example, to a variety of sites, including those where remoteness, inaccessibility, and space limitations would preclude competing systems. The system can be applied to small gasification systems without the increase in heat losses that plague conventional small scale gasifiers. Test results and model simulations are presented on a single tube system and analyses of a variety of configurations presented.

scholarly journals Modelling and experimental analysis of a small-scale olive pomace gasifier for cogeneration applications: A techno-economic assessment

2019 ◽  
Vol 25 (4) ◽  
pp. 329-339
Author(s):  
João Cardoso ◽  
Valter Silva ◽  
Daniela Eusébio ◽  
Tiago Carvalho ◽  
Paulo Brito
Keyword(s):  
Economic Assessment ◽  
Gas Production ◽  
Waste To Energy ◽  
Small Scale ◽  
Producer Gas ◽  
Olive Pomace ◽  
Gasification Process ◽  
Cold Gas Efficiency ◽  
Gas Efficiency ◽  
Cold Gas

A 2-D numerical simulation approach was implemented to describe the gasification process of olive pomace in a bubbling fluidized bed reactor. The numerical model was validated under experimental gasification runs performed in a 250 kWth quasi-industrial biomass gasifier. The producer gas composition, H2/CO ratio, CH4/H2 ratio, cold gas efficiency and tar content were evaluated. The most suitable applications for the potential use of olive pomace as an energy source in Portugal were assessed based on the results. A techno-economic study and a Monte Carlo sensitivity analysis were performed to assess the feasibility and foresee the main investment risks in conducting olive pomace gasification in small facilities. Results indicated that olive pomace gasification is more suitable for domestic purposes. The low cold gas efficiency of the process (around 20%) turns the process more appropriate for producer gas production in small cogeneration facilities. Olive pomace gasification solutions showed viable economic performance in small cogeneration solutions for agriculture waste-to-energy recovery in olive oil agriculture cooperatives. However, the slender profitability may turn the project unattractive for most investors from a financial standpoint.

Effect of Swirl on Gasification Characteristics in an Entrained-flow Coal Gasifier

2020 ◽  
Vol 18 (3) ◽  
Author(s):  
Rongbin Li ◽  
Mingzhuang Xie ◽  
Hui Jin ◽  
Liejin Guo ◽  
Fengqin Liu
Keyword(s):  
Coal Gasification ◽  
Three Dimensional ◽  
Reaction Model ◽  
Gas Temperature ◽  
Swirl Number ◽  
Entrained Flow ◽  
Gasification Process ◽  
Cold Gas Efficiency ◽  
Product Composition ◽  
Gas Efficiency

AbstractThe three-dimensional (3-D) comprehensive mathematical model was developed to simulate the coal gasification process in an entrained flow gasifier with a swirl burner. The models employed or developed includes the coal devolatilization model, the char combustion and gasification model, the gas homogeneous reaction model, the random-trajectory model, gas turbulence model, and the P-1 radiation model. The solution of models was executed based on the computational fluid dynamics (CFD). By qualitatively comparing the results at different swirl number, the significant influences of swirl on characteristics of coal gasification such as flow distributions, gas temperature and product composition including hydrogen (H2), carbon monoxide (CO), etc., and on the performance of coal gasification such as averaged exit product composition, carbon conversion rate and cold gas efficiency, were in detail discussed. Especially, a proper swirl number (S ≤ 0.65) in favor of gasification was found for the investigated gasifier in this paper.

The Effect of Biomass Contents with Heavy Metal on Gasification Efficiency during Fluidized Bed Gasification Process

2012 ◽  
Vol 512-515 ◽  
pp. 575-578
Author(s):  
Hsien Chen ◽  
Chiou Liang Lin ◽  
Wun Yue Zeng ◽  
Zi Bin Xu
Keyword(s):  
H2 Production ◽  
Heating Value ◽  
Gasification Process ◽  
Cold Gas Efficiency ◽  
Zn Concentration ◽  
Lower Heating Value ◽  
Gasification Efficiency ◽  
Waste Gasification ◽  
Gas Efficiency ◽  
Cu And Zn

Catalysis was used to increase the H2 production, syngas heating value, enhanced carbon conversion efficiency and cold gas efficiency during gasification. Due to Cu and Zn were abundant in waste according to previous researches, this research discussed the effect of Cu and Zn on artificial waste gasification. The syngas composition and total lower heating value (LHV) were determined in this study. The results showed that the existence of Cu and Zn increased production of H2 and CO. However, the production of CH4 and CO2 decreased. At same time, total LHV was also increased. Additionally, the different Cu concentration affected gas composition and LHV, but the effect of Zn concentration was not significant.

scholarly journals Effect of Gasification Temperature on Synthesis Gas Production and Gasification Performance for Raw and Torrefied Palm Mesocarp Fibre

2020 ◽  
Vol 19 (2) ◽  
pp. 138
Author(s):  
Najwa Hayati Abdul Halim ◽  
Suriyati Saleh ◽  
Noor Asma Fazli Abdul Samad
Keyword(s):  
Synthesis Gas ◽  
Gas Production ◽  
Energy Applications ◽  
Gasification Process ◽  
Cold Gas Efficiency ◽  
Bubbling Fluidized Bed ◽  
Pre Treatment ◽  
Gas Efficiency ◽  
Solid Biomass ◽  
Gasification Temperature

Biomass gasification is widely used for converting solid biomass into synthesis gas for energy applications. Raw biomass is commonly used as feedstock for the gasification process but it usually contains high moisture content and low energy value which lowering synthesis gas production. Thus, torrefaction as a pre-treatment process is necessary in order to upgrade the properties of feedstock for producing more synthesis gas production and improving gasification performance. The objective of this work is to study the effect of gasification temperature on the synthesis gas production and gasification performance using raw and torrefied palm mesocarp fibre (PMF). The gasification process is conducted using bubbling fluidized bed using steam as gasifying agent. Based on experimental work, by increasing gasification temperature from 650 – 900 °C, the compositions of hydrogen and carbon monoxide gases were enhanced greatly while carbon dioxide and methane gases were decreased for both raw and torrefied PMF. In terms of gasification performance, synthesis gas yield for raw and torrefied PMF is increased from 0.91 to 1.23 Nm3/kg and 1.10 to 1.35 Nm3/kg respectively. Besides, lower heating value (LHV) of torrefied PMF is 0.04 MJ/Nm3 higher than raw PMF at 900 °C. The result showed that the percentage of cold gas efficiency (CGE) reached maximum of 67% for raw PMF while carbon conversion (CC) at 85.6% for torrefied PMF at a gasification temperature of 900 °C. The higher CC obtained by torrefied PMF is because of the increment of carbon content from 45.2% to 53.7% as a result of torrefaction. Gasification temperature of 800 °C showed the best performance of the PMF gasification since the maximum performances of LHV is achieved and started to decrease once the gasification temperature is operated beyond 800 °C.

A Novel Coal Gasification System Through Thermochemical Regenerative Process of Syngas Sensible Heat to Enhance Cold Gas Efficiency

2017 ◽  
Author(s):  
Dandan Wang ◽  
Sheng Li ◽  
Lin Gao
Keyword(s):  
Energy Level ◽  
Coal Gasification ◽  
The Novel ◽  
Sensible Heat ◽  
Exergy Destruction ◽  
Gasification Process ◽  
Cold Gas Efficiency ◽  
Gas Efficiency ◽  
Gasification Technology ◽  
Cold Gas

In this paper, a novel coal gasification technology used for Integrated Gasification Combined Cycle (IGCC) power plants is proposed, in which a regenerative unit is applied to recover syngas sensible heat to generate steam and then the high temperature steam is used to gasify coke from pyrolyzer. Through such a thermochemical regenerative unit, the sensible heat with lower energy level is upgraded into syngas chemical energy with higher energy level, and therefore a higher cold gas efficiency (CGE) is expected. The Aspen Plus Software is selected to simulate the novel coal gasification system. Then the exergy and Energy-Utilization Diagram (EUD) analyses are applied to disclose the plant performance enhancement mechanism. It reveals that 83.2% of syngas sensible heat can be recovered into steam agent and so the CGE is upgraded to 90%. And with the enhancement of CGE, the efficiency of an IGCC plant based on the novel gasification system can be as high as 51.82%, showing a significant improvement compared to 45.2% in a Texaco coal gasification based plant. At the same time, the exergy destruction of gasification process is reduced from 132.5MW to 98.4MW through thermochemical reactions. Lift of accepted energy level (Aea), and decrease of released energy level (Aed) and heat absorption (ΔH) contribute to the exergy destruction reduction in the gasification process. Additionally, since oxygen agent is no longer used in the IGCC, 34.5MW exergy loss in the air separation unit is avoided. Thereby the novel coal gasification technology proposed in this paper has a good thermodynamic performance and may provide a quite promising way for high efficient and clean coal utilization.

scholarly journals Pulverized coal gasification with steam and flue gas

2018 ◽  
Vol 240 ◽  
pp. 05036
Author(s):  
Robert Zarzycki
Keyword(s):  
Coal Gasification ◽  
Flow Reactor ◽  
Coal Dust ◽  
Pulverized Coal ◽  
Numerical Calculations ◽  
Fuel Oil ◽  
Eddy Motion ◽  
Entrained Flow ◽  
Gasification Process ◽  
Entrained Flow Reactor

The study presents the concept and numerical calculations of the coal dust gasification in the entrained flow reactor with power of 16 MWt. The gasification process in the reactor can be performed in the atmosphere of O2, CO2 and H2O. The combustible gases obtained during gasification are composed mainly of CO and H2 and can be used to feed pulverized coal-fired boilers. Integration of the reactor (reactors) for coal dust gasification with the pulverized coal-fired boiler allows for improved flexibility, especially in the range of low loads if stabilization of coal dust combustion in pulverized-fuel burners or support for their work with ignition burners fed with gas or light fuel oil is necessary. The concept of the gasification reactor assumes strong eddy motion of the coal dust, which substantially allows for elongation of the time of fuel remaining in the reactor and obtaining a high reaction level. The concept of the entrained flow reactor presented in this study and the results of numerical calculations can be helpful for development of the devices with greater powers which in the nearest future should be integrated in the systems of pulverized coal-fired boilers in order to reduce their minimum load without using the ignition burners.

scholarly journals Sensitivity Analysis of Different Parameters on the Performance of a CHP Internal Combustion Engine System Fed by a Biomass Waste Gasifier

Energies ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 688 ◽  
Author(s):  
Mauro Villarini ◽  
Vera Marcantonio ◽  
Andrea Colantoni ◽  
Enrico Bocci
Keyword(s):  
Internal Combustion Engine ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Operating Conditions ◽  
Waste To Energy ◽  
Biomass Waste ◽  
Gasification Process ◽  
Cold Gas Efficiency ◽  
Gas Efficiency ◽  
Cold Gas

The present paper presents a study of biomass waste to energy conversion using gasification and internal combustion engine for power generation. The biomass waste analyzed is the most produced on Italian soil, chosen for suitable properties in the gasification process. Good quality syngas with up to 16.1% CO–4.3% CH4–23.1% H2 can be produced. The syngas lower heating value may vary from 1.86 MJ/ Nm3 to 4.5 MJ/Nm3 in the gasification with air and from 5.2 MJ/ Nm3 to 7.5 MJ/Nm3 in the gasification with steam. The cold gas efficiency may vary from 16% to 41% in the gasification with air and from 37% to 60% in the gasification with steam, depending on the different biomass waste utilized in the process and the different operating conditions. Based on the sensitivity studies carried out in the paper and paying attention to the cold gas efficiency and to the LHV, we have selected the best configuration process for the best syngas composition to feed the internal combustion engine. The influence of syngas fuel properties on the engine is studied through the electrical efficiency and the cogeneration efficiency.

scholarly journals Catalytic Coal Gasification Process Simulation with Alkaline Organic Wastewater in a Fluidized Bed Reactor Using Aspen Plus

Energies ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1367 ◽  
Author(s):  
Xiao ◽  
Wang ◽  
Zheng ◽  
Qin ◽  
Zhou
Keyword(s):  
Process Simulation ◽  
Equivalence Ratio ◽  
Coal Gasification ◽  
Aspen Plus ◽  
Operating Conditions ◽  
Catalytic Gasification ◽  
Gasification Process ◽  
Cold Gas Efficiency ◽  
Gas Efficiency ◽  
Organic Wastewater

A co-gasification process was proposed both for treating alkaline organic wastewater and to promote coal gasification by the alkaline substances in situ. A catalytic gasification model was developed by introducing a catalytic correction factor to describe the catalytic effects quantitatively. An integrated process simulation was carried out using Aspen Plus equipped with FORTRAN subroutines. The model was verified using the root mean square error between the simulation results and experimental data from the literature. Syngas composition, cold gas efficiency, and carbon conversion efficiency were analyzed with respect to different operating conditions (reaction temperature, steam/coal ratio, and equivalence ratio). The optimal conditions are summarized based on a self-sufficient system by using sensitivity analysis: Gasification temperature of 700 °C, steam/coal ratio = 1.0, and equivalence ratio = 0.4.

A parametric study on coal gasification for the production of syngas

2012 ◽  
Vol 66 (7) ◽  
Author(s):  
Afsin Gungor ◽  
Murat Ozbayoglu ◽  
Cosku Kasnakoglu ◽  
Atilla Biyikoglu ◽  
Bekir Uysal
Keyword(s):  
Parametric Study ◽  
Coal Gasification ◽  
Steam Gasification ◽  
Heating Value ◽  
Fuel Ratio ◽  
Gasification Process ◽  
Cold Gas Efficiency ◽  
Reactor Temperature ◽  
Gas Efficiency ◽  
Optimum Working

AbstractIn this parametric study, the effects of coal and oxidiser type, air-to-fuel ratio, steam-to-fuel ratio, reactor temperature, and pressure on H2 and CO amounts at the gasifier output, H2/CO, and higher heating value of the syngas produced have been calculated using a coal gasification model. Model simulations have been performed to identify the optimum values which are assumed to be 100 % for both cold gas efficiency and carbon conversion efficiency in the gasification process. From this study, it may be observed that the moisture content of the coal type is of crucial importance for the air gasification process; the O2 content of similar coals (taking into consideration the moisture and H2 content) is of significant importance for the air gasification process. When compared with air gasification, air-steam gasification becomes a more effective coal gasification method. The optimum working condition for air-steam gasification is to carry out the process at one atmosphere. High gasifier temperatures are not needed for the air-steam gasification of coal.

scholarly journals How water vapor and carbon dioxide additives affect oxygen gasification of pulverized coal fuel

2021 ◽  
Vol 21 (1) ◽  
pp. 21-28
Keyword(s):  
Carbon Dioxide ◽  
Water Vapor ◽  
Pulverized Coal ◽  
Gas Content ◽  
Thermochemical Conversion ◽  
Gasification Process ◽  
Cold Gas Efficiency ◽  
Coal Fuel ◽  
Pulverized Coal Fuel ◽  
Gas Efficiency

The paper analyzes entrained-flow high-oxygen gasification of pulverized coal (a Shell type process)is considered. Water vapor is commonly added to increase the yield of combustible components. This research uses a mathematical model in a one-dimensional stationary approximation to see how adding carbon dioxide and a mixture of carbon dioxide and water vapor to the oxygen flow will affect the process. The paper presents estimates of thermochemical conversion rate (cold gas efficiency), combustible gas content, and completeness of fuel carbon conversion for all the tested configurations. Calculations show that adding carbon dioxide can reduce the specific oxygen consumption of the gasification process whilst ensuring more complete fuel conversion. Adjustments in the water vapor to carbon dioxide ratio help control the gas composition (albeit in a rather narrow range) and the temperature of the raw produced gas at the reaction zone outlet.

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