Attainment of the Theoretical Yield of Carbon from Biomass

Abstract

Previous work has shown that very high yields of charcoal are obtained when pyrolysis of the biomass feedstock is conducted at elevated pressure in a closed vessel, wherein the pyrolytic vapors are held captive and in contact with the solid products of pyrolysis. In this paper, we show that, for some biomass species, the yield of carbon produced by this process effectively attains the theoretical value predicted to exist when thermochemical equilibrium is realized. Various agricultural wastes (e.g., kukui nut, macadamia nut, and pecan shells) and tropical species (e.g., eucalyptus, leucaena, and bamboo) offer higher yields of carbon than the hardwoods traditionally employed by industry in the U.S. and Europe. Moreover, the yields of carbon from oat and rice hulls and from sunflower seed hulls are nearly as high as the yields of carbon from hardwoods. There is a correlation between the yield of carbon and the acid-insoluble lignin content of the feed. Charcoal briquettes made from agricultural wastes and lump charcoal from tropical species are promising sources of renewable carbon for use in the smelting of metal ores.

Review Paper: The Fundamentals of Biochar as a Soil Amendment Tool and Management in Agriculture Scope: An Overview for Farmers and Gardeners

“…Therefore, pyrolysis is distinguished by long residence times and temperate temperatures, liquefaction happens beneath high heating rates, however gasification is defined by great temperatures, regularly with additional, though sub-stoichiometric, oxygen. Pyrolysis typically creates a solid, organized or structured, carbonaceous sub- [55]. Some previous studies for example, assessments by [56] [57] recapitulated the impact of pyrolysis temperature on these characteristics and consequent interactions in soil.…”

Influence of production variables and starting material on charcoal stable isotopic and molecular characteristics

“…The lower δ 13 C values at 300ºC seen in pine can therefore be attributed to the faster thermal degradation of isotopically heavier cellulose in pine. Char yields from lignin are generally higher than from cellulose, due to higher carbon content in this compound (Antal et al, 2000). As the δ 13 C of the respective products following charring of isolated cellulose and lignin (e.g.…”

“…Linear prediction of changes during charcoal production is clearly complicated by complexities within the structure of native wood (Antal et al, 2000), and features specific to different species have potential to induce large variability. Such features include increased thermal resistance of hemi-cellulose by binding in lignincarbohydrate complexes, and protection of carbon within phytoliths, which have the potential to induce significant differences in isotopic variation during charcoal formation (Beramendi-Orosco et al, 2006, Krull et al, 2003 Overall therefore, the results suggest that it is unlikely that charcoal δ 13 C can be calculated in every case by simple mass balance from the δ 13 C value of initial wood components.…”

Düşük Sicaklik Düşük Zaman Alkali̇ Ön İşlemleri̇ni̇n Findik Kabuğunun Bi̇leşi̇mi̇ Ve Enzi̇mati̇k Hi̇droli̇zi̇ Üzeri̇ne Etki̇si̇ni̇n İncelenmesi̇

“…Ancak fındık kabuklarının içermiş oldukları lignin yüzdesi diğer zirai kabuklu biyokütlenin kabuklarında bulunan değerler ile benzerlik göstermektedir. Literatürde lignin yüzdesinin, badem kabukları için %20-28 [27], [29,30], hindistan cevizi kabuğu için %28-34 [30,28], brezilya fındığı için %59 [31] 2 kullanılması durumunda göre daha yüksek sıcaklıklara ihtiyaç duyulmaktadır buda enerji verimliliği ve maliyet açısından NaOH kullanılmasının daha uygun olduğunu göstermektedir [32]. Bizim çalışmamızda sabit sıcaklık ve sürede farklı alkalilerin etkinliği araştırıldığı için NaOH ön işlemi daha etkin sonuçlar vermiştir.…”