Pyrolysis Of Biomass Feedstocks Research Articles

Enhanced biofuel production by co-pyrolysis of distiller's grains and waste plastics: A quantitative appraisal of kinetic behaviors and product characteristics

Pyrolysis of biomass feedstocks can produce valuable biofuel, however, the final products may present excessive corrosion and poor stability due to the lack of hydrogen content. Co-pyrolysis with hydrogen-rich substances such as waste plastics may compensate for these shortcomings. In this study, the co-pyrolysis of a common biomass, i.e. distiller's grains (DG), and waste polypropylene plastic (PP) were investigated towards increasing the quantity and quality of the production of biofuel. Results from the thermogravimetric analyses showed that the reaction interval of individual pyrolysis of DG and PP was 124–471 °C and 260–461 °C, respectively. Conversely, an interaction effect between DG and PP was observed during co-pyrolysis, resulting in a slower rate of weight loss, a longer temperature range for the pyrolysis reaction, and an increase in the temperature difference between the evolution of products. Likewise, the Coats-Redfern model showed that the activation energies of DG, PP and an equal mixture of both were 42.90, 130.27 and 47.74 kJ mol−1, respectively. It thus follows that co-pyrolysis of DG and PP can effectively reduce the activation energy of the reaction system and promote the degree of pyrolysis. Synergistic effects essentially promoted the free radical reaction of the PP during co-pyrolysis, thereby reducing the activation energy of the process. Moreover, due to this synergistic effect in the co-pyrolysis of DG and PP, the ratio of elements was effectively optimized, especially the content of oxygen-containing species was reduced, and the hydrocarbon content of products was increased. These results will not only advance our understanding of the characteristics of co-pyrolysis of DG and PP, but will also support further research toward improving an efficient co-pyrolysis reactor system and the pyrolysis process itself.

Cover Picture: Hydrodeoxygenation of Pyrolysis Oils (Energy Technol. 1/2017)

Hydrodeoxygenation of Pyrolysis Oils—Fueling a Sustainable Future: The cover art depicts the many applications of biomass-derived fuels and the great degree to which they can fuel our society. Bio-oil produced from the pyrolysis of biomass feedstocks can be hydrotreated to lower its oxygen content and form fuel-grade hydrocarbon products. This work by Professor George Huber's research group of the University of Wisconsin details the hydrodeoxygenation (HDO) of pyrolysis oils and the relative yields of the different types of product fuel produced. The bio-oil and product mixtures were thoroughly characterized to elucidate the HDO reaction chemistry. More details can be found in the Full Paper by K. Routray, K. J. Barnett, and G. W. Huber (DOI: 10.1002/ente.201600084).

Biochar, soil fertility, and environment

Biochar is a carbonaceous material obtained by pyrolysis of biomass feedstock. It is deliberately applied to soils in order to improve fertility and mitigate greenhouse gas emissions. In fact, on one hand, biochar changes physical-chemical soil properties, thereby affecting soil fertility. On the other hand, biochar is resistant to chemical and biochemical degradation. Therefore, its use allows carbon sequestration in soils and consequent reduction of carbon dioxide to the atmosphere. Moreover, biochar is a porous material showing good sorption properties for inorganic and organic pollutants. Because of this, biochar can be applied for environmental remediation. Notwithstanding the positive effects in environmental applications, many studies also report about adverse issues deriving from biochar uses. In fact, controversial results concerning use of biochar as amending material can be found in the literature. Due to the direct relationship between structural/molecular characteristics and chemical/ biochemical properties, it must be pointed out that a deep characterization either by innovative physical-chemical techniques or by traditional chemical investigations is of paramount importance in order to reveal biochar role in environmental compartments, to address its agronomical and environmental uses and to allow meaningful pre-application quality assessments. In the present special issue, a number of papers are presented in order to evaluate the role of biochar in removing heavy metals from contaminated water, in reducing greenhouse gas emissions from arable soils, in considering its role in soil fertility through comparison of its nature to those of humic substances, in affecting root length, and in improving nitrification rate in biochar-amended soils.