Regenerative energy production using energy crops

Review of micro- and small-scale technologies to produce electricity and heat from Mediterranean forests׳ wood chips

“…There are, accordingly, fixed bed, fluidized bed and entrained flow reactors following the latter criterion [14,58,68,74,75].…”

“…Fluidized bed reactors are characterized by introducing a third agent, the fluidizing material into the equation and thus reducing the slagging of the reaction [77] and improving the uniformity and adjustability of the temperature distribution [58,75], thus increasing the biomass conversion rate up to 100% [78]. According to the velocity of the gasification agent flow, two different types exist: bubbling fluidized bed and circulating fluidized bed.…”

“…In an analogous way, there are differences between the gasification technologies: fixed bed reactors, in particular the downdraft ones due to their low tar content of the produced gas [74,76], require lower investments [75] and engine cleaning operations [14] than fluidized bed reactors. Therefore, fixed bed reactors are the most suitable alternative for small-scale gasification applications [58,101] that are constrained to have low O&M costs [64,157] while fluidized beds have been claimed to be more appropriate for mid-and large-scale applications [58,67,81,101].…”

“…In addition, fixed bed reactors produce a low-heating value gas [158], which is only a minor problem in small-scale plants. On the other hand, fluidized bed reactors are constrained to be fuelled with low-size and low-density fuels such as sawdust [58,75], especially in the case of circulating fluidized bed reactors [129].…”

Saccharum spontaneum L. ssp. aegyptiacum (Willd.) Hack. a potential perennial grass for biomass production in marginal land in semi-arid Mediterranean environment

“…Up to now, much emphasis has been placed to evaluate the potential yield of bioenergy crops, while biomass quality has not received as much attention (Osowski and Fahlenkamp, 2006;Monti et al, 2008). Biomass quality can drastically lower the net energy output, bioconversion efficiency, and lifetime of the equipment in both thermochemical and biochemical conversion of biomass to heat, energy, and biofuel due to inadequate moisture content, stem to leaf ratio, ash and mineral content, ash melting point, cellulose, hemicelluloses, lignin, and extractives, among others.…”