GC: n

CT: Biomass is relatively cleaner than coal and is the only renewable carbon resource that can be directly converted into fuel. Biomass can significantly contribute to the world’s energy needs if harnessed sustainably. However, there are also problems associated with the thermal conversion of biomass. This paper investigates and discusses issues associated with the thermal conversion of coal and biomass as a blend. Most notable topics reviewed are slagging and fouling caused by the relatively reactive alkali and alkaline earth compounds (K2O, Na2O and CaO) found in biomass ash. The alkali and alkaline earth metals (AAEM) present and dispersed in biomass fuels induce catalytic activity during co-conversion with coal. The catalytic activity is most noticeable when blended with high rank coals. The synergy during co-conversion is still controversial although it has been theorized that biomass acts like a hydrogen donor in liquefaction. Published literature also shows that coal and biomass exhibit different mechanisms, depending on the operating conditions, for the formation of nitrogen (N) and sulfur species. Utilization aspects of fly ash from blending coal and biomass are discussed. Recommendations are made on pretreatment options to increase the energy density of biomass fuels through pelletization, torrefaction and flash pyrolysis to reduce transportation costs.

S: www.mdpi.com/1996-1073/7/3/1098/pdf (last access: 23 February 2015)

N: 1. From co- (in Latin, the form of com- in compounds with stems beginning in vowels and h- and gn-; taken in English from 17c. as a living prefix meaning “together, mutually, in common,” and used promiscuously with native words and Latin-derived words not beginning with vowels, sometimes even with words already having it) and conversion (mid-14c., originally of religion, from French conversion, from Latin conversionem (nominative conversatio), noun of action from past participle stem of convertere; General sense of “transformation” is early 15c; Of buildings, from 1921).
2. The burning of biomass blended with fossil fuel such as pelleted or briquetted sawdust with coal, which may have advantages of burning with a hotter flame, diluting of pollutants (sulphur) in coal, and providing a more complete combustion of biomass.

S: 1. OED – http://www.etymonline.com/index.php?allowed_in_frame=0&search=co&searchmode=none; http://www.etymonline.com/index.php?allowed_in_frame=0&search=conversion&searchmode=none (last access: 23 February 2015). 2. TERMIUMPLUS.

SYN: co-combustion

S: TERMIUMPLUS; http://digital.csic.es/handle/10261/77992 (last access: 23 February 2015).

CR: biomass, biomass energy.