Experimental and simulation study on coal-fired power generation coupling with fluidized bed biomass gasification

Thermoeconomic evaluation of double-reheat coal-fired power units with carbon capture and storage and waste heat recovery using organic Rankine cycle

The validity of the model developed for fluidized bed gasification of biomass was tested using experimental data obtained from a 400 kWthermal, dual-distributor-type fluidized bed gasifier. The fluidized bed was operated on wheat straw at various equivalence ratios, fluidization velocities, and bed heights. Both the predicted and the experimental bed temperatures increased linearly with the increase in equivalence ratio. At higher equivalence ratios (ER > 0·25) the model predictions for gas composition and the higher heating value were in good agreement with the experimental data. However, at lower equivalence ratios (ER < 0·20) the higher heating value of gas and the mole fractions of methane were overpredicted by the model This was because of the drastic increase in tar formation at such low equivalence ratios. The model predictions were improved substantially when the tar formation was included in the model.

Experimental study and characterization of a two-compartment cylindrical internally circulating fluidized bed gasifier

This work aims to assess the effect of the operating parameters of the gasifying agent preheating temperature and equivalence ratio (ER) on the conversion of sewage sludge (SS) to syngas through gasification and combined heat and power (CHP) generation. A novel gasification model was simulated in Aspen Plus to represent a fixed-bed updraft gasifier to generate syngas from SS through an equilibrium approach restricted by temperature. The novelty of this work is that the model was developed by applying the gasifying agent preheating temperature as an operating variable instead of the gasification temperature. It was calibrated by using a set of experimental values and then validated by comparing the numerical results with the experimental outcomes related to nine different operating conditions of air preheating temperatures and ER. A good agreement between the simulation and experimental results was observed. The optimum gasification process parameters of the air preheating temperature and ER were predicted to be 150 °C and 0.2, respectively. The CHP generation potentiality of SS was assessed to be 2.54 kW/kg SS as dry solids (DS), of which 0.81 kW was electrical and the remainder was thermal power. The conversion of SS to CHP through the proposed treatment can reduce 0.59 kg CO₂/kg SS as DS emissions compared with that of natural gas combustion to generate a similar quantity of energy.

Process modelling and thermodynamic performance optimization of biomass air gasification fuelled with waste poultry litter pellet by integrating Aspen plus with RSM

Experimental study on catalytic steam gasification of natural coke in a fluidized bed

Coal-fired power plants are one of the major sources of coal consumption in China; they discharge various air pollutants and cause serious human health damage. There is an urgent need to focus on the associated health effects. Thus, this study aims to advance an integrated life cycle assessment (LCA)-based health damage model to quantify the health burden of air pollutant emissions from coal-fired power generation (CFPG) and to achieve an economic interpretation of health damage. A case study of the Zaozhuang coal-fired power project was conducted to better visualize and mitigate the impacts. The results reveal that willingness to pay (WTP) for health damage caused by the CFPG project in 1year amounted to USD 15.71 million, and the total amount of life lost was 155.81years. During the CFPG process, coal combustion caused the most health damage, respiratory disease was the type of damage with the greatest influence on health, and SO2 was the air pollutant that causes the most serious health damage. The model developed in this study can be broadly applied to assess the potential life loss due to air pollutant emissions from CFPG systems. The identified key points for health damage prevention can also be used as practical solutions for decision-making regarding the prioritization of control sources for environmental management.

Thermodynamic performance analysis of an improved coal-fired power generation system coupled with geothermal energy based on organic Rankine cycle

The experimental investigation on gasification characteristics of natural coke from Peicheng, Jiangsu with steam were conducted in a fluidized bed gasifier setup. The effects of several parameters, in terms of the catalyst type, the catalyst mixed manner and the dosage of catalyst over coke on the yield, the components, the heating value of fuel gas and the carbon conversion rate were examined. Results indicate that the fluidized bed gasification technology could overcome the shortcomings of natural coke. Ca-, Fe- and Cu-based nitrates could improve the gasification reaction effectively with a little difference, they could be listed in a descending sequence as follows: Cu-based>Fe-based>Ca-based according to their catalytic effect. The influences of Fe/Ca ratio and Cu/Ca ratio on gasification are similar, gas yield, carbon conversion rate and gas heating value per hour increase as Fe/Ca ratio or Cu/Ca ratio increases, but all of them go up first and then drop with decrease in Fe/Cu ratio. When the dosage of Ca-, Fe- and Cu-based nitrates mixed with the ratio of Ca/Fe/Cu= 10/35/55 is 3%, the best catalytic effect is achieved.

A model was developed to describe the performance of a bench scale fluidized bed gasifier and predict product composition, flowrate and temperature from a given biomass composition, steam to biomass ratio, equivalence ratio and furnace temperature profile using Aspen Plus. The gasifier was divided into zones which had different reaction temperatures. Mass balance and minimization of Gibbs free energy were applied for determining the product composition. Experiments for validation of the model were performed on a bench-scale fluidized bed gasifier using distillers grains as feed material. The results show that the predicted flowrate of hydrogen was similar but the predicted flowrate of methane was lower and the predicted total gas flowrate was higher than the experimental results. The recommendations for improvement in the model have been suggested.

Hydrogen production via gasification of meat and bone meal in two-stage fixed bed reactor system

Development of a 5kWth internally circulating fluidized bed reactor containing quartz sand for continuously-fed coal-coke gasification and a beam-down solar concentrating system

Assessment of biomass energy potential for SRC willow woodchips in a pilot scale bubbling fluidized bed gasifier

P.025 Galea-pericranium free flap for primary palatoplasty in cleft lip and palate patients

Influence of bed material on biomass gasification in fluidized beds via a TFM-DEM hybrid model