In general, the raw product gas of biomass gasification contains a range of minor species and contaminants, including particles, tar, alkali metals, chlorine, nitrogen compounds and sulphur compounds. This study reviews the recent developments in product gas cleaning technologies for these species and summarizes the findings of the research project 'Mop fan and electrofilter: an innovative approach for cleaning product gases from biomass gasification' which was recently carried out by the authors. The results of the project showed that combination of mop fan and electrofilter (ESP) has great potential in removing fine particles, tars and chemical contaminants in the product gas.

Hazardous waste products along with the syngas produced from biomass gasification are one of the major problems of today world. Tar and other solid contaminants removal from syngas are necessary as it is widely used for the production of energy in thermal and power sectors. The raw syngas can be clean up by directly controlling the operating parameters and applying cleaning units. This study aimed to analyze bubbling fluidized bed gasifier and focuses on investigating the novel tar reducing techniques. Different cleaning units; char bed, woodchip bed and mop fan were used to arrest tar directly from producer gas. For the first time, a novel strategical technique of mop fan based on water spray was evaluated. Results showed that tar arrest with bio-char is unsuccessful due to the burning of bed while the average concentration of tar captured by woodchips and mop fan with or without water spray was 0.459 mg/L, 0.987 mg/L and 0.617 mg/L respectively. Furthermore, the concentration of naphthalene and phenanthrene reduced

The current study investigates the short rotation coppice (SRC) gasification in a bubbling fluidized bed gasifier (BFBG) with air as gasifying medium. The thermochemical processes during combustion were studied to get better control over the air gasification and to improve its effectiveness. The combustion process of SRC was studied by different thermo-analytical techniques. The thermogravimetric analysis (TGA), derivative thermogravimetry (DTG), and differential scanning calorimetry (DSC) were performed to examine the thermal degradation and heat flow rates. The product gas composition (CO, CO2, CH4 and H2) produced during gasification was analyzed systematically by using an online gas analyzer and an offline GC analyzer. The influence of different equivalence ratios on product gas composition and temperature profile was investigated during SRC gasification. TG/DTG results showed degradation occur in four stages; drying, devolatilization, char combustion and ash formation. Maximum mass loss~70% was observed in devolatilization stage and two sharp peaks at 315-500°C in TG/DSC curves indicate the exothermic reactions. The temperature of gasifier was increased in the range of 650-850 o C along with the height of the reactor with increasing equivalent ratio (ER) from

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