As a tobacco producer, Serbia has to deal with large amounts of leftover tobacco stalks after harvesting. One option for this type of biomass is to burn it, but burning is not encouraged in Serbia, since the levels of its combustion products have not been investigated yet. The aim of this study was therefore to determine the elemental composition, ash and nicotine content, heat values, and composition of gaseous combustion products of tobacco stalk briquettes and to see if their mixing with other types of biomass available in Serbia could improve their ecological profile. We made 11 different types of briquettes: six of pure raw materials, including burley tobacco stalks, sunflower head remains, wheat straw, corncob, soy straw, and beech sawdust and five by mixing tobacco stalks with these other raw materials in a 50:50 mass ratio. All briquettes meet the ecological criteria regarding the emission limits for nitrogen oxides (NOx), sulphur dioxide, carbon monoxide, and carbon dioxide. Nicotine content in flue gases (<10 mg/kg) is far below the maximum level allowed by the European Union. Heat values of all biomass samples are acceptable, although lower than those specified for solid biofuels (≥16.0 MJ/kg), save for corncob and beech sawdust and their mixtures with tobacco stalks. Our findings therefore encourage the use of tobacco stalks as a viable biofuel.
Kao proizvođač duhana, Srbija raspolaže velikim količinama stabljika duhana koje ostaju nakon berbe listova. Jedna je od opcija za ovu vrstu biomase njezino izgaranje, ali se ono ne promiče u Srbiji jer još uvijek nisu istraženi njezini produkti izgaranja. Stoga je cilj ovog istraživanja bio utvrditi elementarni sastav, sadržaj pepela i nikotina, ogrjevnu vrijednost i sastav plinovitih produkata pri izgaranju briketa od duhanskih stabljika i ustanoviti može li njihovo miješanje s drugim vrstama biomase, koje su dostupne u Srbiji, poboljšati njihov ekološki profil. Proizveli smo 11 različitih vrsta briketa: šest od čistih sirovina, uključujući stabljike berlej duhana, ostatke glava suncokreta, pšeničnu slamu, kukuruzni oklasak, sojinu slamu i bukovu piljevinu, a pet od mješavina stabljike duhana s ostalim navedenim sirovinama u odnosu 50:50. Utvrđeno je da svi briketi ispunjavaju ekološke kriterije u pogledu ograničenja emisije dušikova oksida (NOx), sumporova dioksida, ugljikova monoksida i ugljikova dioksida. Sadržaj nikotina u dimnim plinovima (<10 mg/kg) znatno je ispod maksimalne vrijednosti koju dopušta Europska unija. Prihvatljive su ogrjevne vrijednosti svih uzoraka biomase iako su ispod kriterija za specifikacije i klase čvrstih biogoriva (≥16,0 MJ/kg), osim za kukuruzni oklasak i bukovu piljevinu, kao i njihove mješavine sa stabljikama duhana. Naši nalazi stoga idu u prilog uporabi stabljika duhana kao održivoga biogoriva.
Keywords: combustion products; heat value; nicotine content; obnovljiva energija; produkti izgaranja; renewable energy; sadržaj nikotina; toplotna vrijednost.
© 2023 Maja Malnar et al., published by Sciendo.