Study type	Type of gasifier	Operating conditions	Particle size	Main findings	Reference
Experimental investigation and modelling study of long stick wood gasiﬁcation in a top lit updraft ﬁxed bed gasiﬁer	TLUG	MC: 25%, 180 W of blower power air supply, T: 432˚C - 936˚C ER: 0.26 - 0.43 H: nd D: nd	sticks with length ∼68 cm and diameter ∼6 cm	・ measurement of the ER is a simple way of analyzing the behavior of the gasifier ・ TLUG gasified 90 kg of wood for 10 h in two batches per day	[23]
Low temperature gasification of olive kernels in a 5-kW fluidized bed reactor for H₂-rich producer gas	5-kW fluidized bed reactor	MC: 10%wt - 12%wt T: 750˚C - 850˚C and ER: 0.2 - 0.4 H: 1400 mm	Bulk density (kg/m³): 573 size fraction of olivine (500 - 425 μm)	・ increase in ER deteriorated producer gas quality, decreased H₂ content and favored CO₂, thus lowering producer gas heating value	[75]
An experimental study on biomass air-steam gasification in a fluidized bed	a fluidized bed reactor of atmospheric pressure	T: 700˚C - 900˚C in 50˚C increments Biomass feed rate: 0.445 kg/h; air: 0.5 m³/h; steam rate: 1.2 kg/h ER: 0.22; S/B: 2.7	size: 0.3 - 0.45 mm, silica sand (particle size 0.2 - 0.3 mm) as bed material	・ the LHV of fuel gas decreased with ER ・ the introduction of steam improved gas quality compared to biomass air gasification but excessive steam would lower gasification temperature and so degrade fuel gas quality ・ smaller particle more favorable for higher gas LHV and yield	[76]
Experimental investigation of a downdraft biomass gasifier	a blow-type downdraft gasifier	H: 2.5 m ID: 600 mm ER: 0.268 - 0.43	size of the biomass material (wood chips and furniture wood + charcoal) used was equivalent to 50 mm cube	・ calorific value of the producer gas increases with ER initially, attains a peak and then decreases with the increase in ER ・ the gas flow rate per unit weight of the fuel increases linearly with ER ・ complete conversion of carbon to gaseous fuel did not occur even for the optimum ER ・ optimum ER (0.38) for the best performance of the downdraft biomass gasifier	[77]
Scale-up of downdraft moving bed gasifiers (25 - 300 kg/h)-design, experimental aspects and results	downdraft moving bed gasifiers	H₁: 1050 mm and H₂: 1800 mm ・ Feed: 5 - 6 kg unchanging air flow: 100 N∙m³/hr, FCR: 50 kg/h and SGR: 0.283 kg/s∙m²	Particle size: 84% between 0.5 and 16 mm	・ air flow is an influential variable and it determines the biomass consumption and the gas and solid production ・ mass conversion efficiency (MCE) and cold gas efficiency (CGE) values increase with ER	[78]
Effect of pyrolysis temperature and heating rate on biochar obtained from pyrolysis of safflower seed press cake	fixed-bed reactor	H: 104 mm ID: 70 mm feed: 20 g ・ inert gas (nitrogen) ・ T = 400˚C, 450˚C, 500˚C, 550˚C and 600˚C heating rates: 10˚C, 30˚C and 50˚C∙min⁻¹	average particle size: 1.8 mm	・ biochar yield and quality depend principally on the applied temperature where pyrolysis at 600˚C leaves a biochar with higher fixed carbon (80.7%) and relative carbon content (73.8%), and higher heating value (30.3 MJ∙kg⁻¹) in comparison with the original feedstock (SPC) and low VM content (9.80%) ・ the biochars had low surface areas (1.89 - 4.23 m²/g) and contained predominantly aromatic compounds	[55]
Simplifying pyrolysis: Using gasification to produce corn stover and wheat straw biochar for sorptive and horticultural media	top-lit updraft cookstove	・ average temperatures CS: 520 ± 150 WS: 550 ± 25 WS + GT: 595 ± 80 ・ gasification time: 30 min H: nd ID: nd ER: nd	pellets size: 6 mm diameter by 8 - 10 mm long	・ biochar from the gasification process had carbon content > 70% and an ash content of 25% which was equal or better than the same biochar produced using the retort oven ・ the same biochar showed successful use as a peat moss replacement in horticultural applications ・ gasification is a simpler, more cost-effective means to produce biochars and should be considered for horticultural and other similar applications	[18]