Experimental and kinetic study on co2 catalytic gasification of biomass char using conventional and microwave heatin
| dc.contributor.author | Pooya Lahijani Amiri | |
| dc.date.accessioned | 2021-04-13T02:51:55Z | |
| dc.date.available | 2021-04-13T02:51:55Z | |
| dc.date.issued | 2014-06-01 | |
| dc.description.abstract | Investigations on the fundamental aspects of gasification process have shown that the char gasification rate, as the rate limiting step during the gasification of carbonaceous materials, plays an important role in overall gasification performance. The current project looks for routes to facilitate CO2 gasification of char and improve the char reactivity during the gasification reaction. In this work, oil palm shell (OPS) and pistachio nut shell (PNS) were used to prepare char for CO2 gasification. The preliminary CO2 gasification experiments were carried out under isothermal condition in a Thermogravimetric analyzer (TGA). The influence of metal catalysts on the CO2 gasification reactivity of chars was examined. The implemented catalysts were (a) iron species (FeCl3, Fe (NO3)3 and Fe2(SO4)3) loaded on OPS char, (b) metal nitrates (KNO3, NaNO3, Ca(NO3)2, Mg(NO3)2) and Fe (NO3)3) loaded on PNS char and (c) ash of palm empty fruit bunch (EFB-ash), as a natural catalyst rich in potassium, loaded on OPS char. The results of catalytic gasification studies revealed that the highest catalytic activities were devoted to 5 wt% Fe(NO3)3-OPS, 5 wt% NaNO3-PNS and 10 wt% EFB-ash loaded OPS char. Several kinetic models including shrinking core model (SCM), normal distribution function model (NDM), random pore model (RPM) and modified random pore model (MRPM) were used to describe the gasification reaction rate and the activation energy and other kinetic parameters were determined. From the Arrhenius curve fitting results, the activation energies of un-catalyzed OPS and PNS chars were obtained as 269 and 206 kJ/mol, respectively. The activation energies of Fe(NO3)3-OPS, NaNO3-PNS and EFBxxvii ash loaded OPS char were respectively 216, 152 and 160 kJ/mol, signifying the impact of the used catalysts on enhancing the char reactivity. Based on the outcomes of the gasification experiments in TGA and kinetic studies, CO2 gasification of OPS and PNS chars were investigated under microwave irradiation. A microwave heating system was developed and the influence of various parameters including the char particle size, gasification temperature and gas flow rate as well as catalyst loading on CO2 conversion and CO evolution was considered. To prove the salient features of microwave heating system, similar experiments at selected conditions were performed under conventional electric furnace heating and the results were compared. The calculated activation energies for microwave gasification reactions were impressively lower than conventional heating. The activation energies of 36, 47, 74 and 248 kJ/mol were obtained for microwave gasification of Fe(NO3)3-OPS, EFB-ash loaded OPS, pristine OPS char and thermal gasification of OPS char, respectively. The activation energies for microwave gasification of NaNO3-PNS and pristine PNS char were obtained as 27 and 47 kJ/mol respectively, while this value was 184 kJ/mol for thermal gasification of PNS char. It was also attempted to improve the quality of mix gases resembling the producer gas from air and steam gasification using catalyzed PNS char. As a result, the HHV of the gas simulating air gasification improved from an average of 6.4 to 8.0 MJ/m3 and from 7.6 to 10.4 MJ/m3 in the gas simulating steam gasification. | en_US |
| dc.identifier.uri | http://hdl.handle.net/123456789/12767 | |
| dc.language.iso | en | en_US |
| dc.title | Experimental and kinetic study on co2 catalytic gasification of biomass char using conventional and microwave heatin | en_US |
| dc.type | Thesis | en_US |
Files
License bundle
1 - 1 of 1
Loading...
- Name:
- license.txt
- Size:
- 1.71 KB
- Format:
- Item-specific license agreed upon to submission
- Description: