Year: 2015
Type: dissertation
Abstract: The GoBiGas (Gothenburg Biomass Gasification) project was initiated by Göteborg Energi to\nenable biogas/bio-SNG production through gasification of biomass from forest residuals. The\npurpose of GoBiGas is to gain knowledge, at a pre-commercial scale, within gasification of\nforest residues as well as methanation for the purpose of producing biomethane of sufficient\nquality to be distributed in the conventional gas grid. The performance goal of GoBiGas is\nthat the cold gas efficiency should be at least 65 % and the overall thermal efficiency should\nbe at least 90 %. The aim of this thesis is to establish methods to verify process data and\nquantify the performance of the gasification process of GoBiGas. Losses in different parts of\nthe process and potential improvements are discussed and proposed.\nThe process data was verified through energy and carbon balances over the gasification\nprocess and section. To include variations in the measurements, the process data was\nrandomized with a normal distribution. Using normally distributed data implies that the results\nfrom the calculations, such as the efficiencies of the process, were normally distributed with a\nmean and standard deviation.\nThe method of comparing the normal distributions from the energy and carbon balances did\nnot show any large errors in the measurements of the process data. The cold gas efficiency\nof the gasification process was within 73 – 80 % and reaching a cold gas efficiency of 65 %\nover the entire process is possible if less product gas is combusted in the combustion\nchamber. The overall thermal efficiency of the gasification process was within 80 – 86 %, and\nto reach an overall thermal efficiency of 90 % over the entire process, the heat losses need\nto be decreased. The losses in the gasification process could be decreased by; increasing\nthe isolation of the gasification section, decreasing the temperatures in the gasification\nsection, increasing the preheating of steam and air, and combusting less product gas.
Author: Malin Karlbrink
Language: English
Subfield: Fuel Technology
Field: Energy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W1233720148