Performance evaluation of 10 kWe pilot scale downdraft gasifier with different feedstock

• Published in: Journal of the Energy Institute 2019-08, Vol.92 (4), p.913-922
• Main Authors: Upadhyay, Darshit S., Makwana, Haresh V., Patel, Rajesh N.
• Format: Article
• Language: English
• Subjects: Cold gas efficiency; Gasification; Particulate matter; Tar
• ISSN: 1743-9671
• DOI: 10.1016/j.joei.2018.07.013

Gasification is a thermochemical conversion of carbonaceous biomass into the producer gas. Gasification of lignite, wood, sawdust briquette and their mixtures are investigated on a 10 kWe laboratory scale downdraft gasifier at atmospheric pressure. The air is used as a gasifying medium. The gasifier was operated on different particle sizes of lignite and lignite-wood ratio; 22–25 mm lignite particle size and lignite – wood ratio (70:30, w/w) were found to be optimum to overcome clinker formation and higher Cold Gas Efficiency (CGE). To avoid unwanted maintenance, it is essential to diminish the producer gas pollutants such as tar and particulate matter (PM) before injecting the producer gas into a turbine or a gas engine. A setup was developed to measure tar and PM from the producer gas. The gasifier performance was evaluated on various parameters such as tar, PM, fuel consumption, gas yield, gas composition, gas calorific value and CGE for all selected feedstock. The tar in the producer gas was found in the range of 201.30 mg Nm−3 to 617.80 mg Nm−3 whereas PM was found in the range of 36.76 mg Nm−3 to 68.35 mg Nm−3. CGE and gas calorific value were observed in the range between 64.99% and 71.62% and 4.64 MJ Nm−3 to 5.29 MJ Nm−3, respectively. Specific fuel consumption (SFC) was obtained in the range of 1.52 kg kWh−1 to 1.84 kg kWh−1. CGE with lignite – wood or sawdust briquette ratio (70:30, w/w) is found maximum whereas tar and PM are found minimum with wood and sawdust briquette feedstock in the present study. •Experiments on a 10 kWe downdraft gasifier with different feedstock were carried out to investigate tar and PM.•Maximum cold gas efficiency was found with lignite–wood (70:30, w/w) and lignite–briquette (70:30, w/w).•85–90% tar in the producer gas was captured in cleaning systems at downstream of gasifier.•Tar and particulates were found minimum with wood and briquette feedstock.