Search

Production of high-grade bio-oil through catalytic pyrolysis technology was of great significance for alleviating the current energy shortage problem. This study synthesized a series of carbon-supported transition metal catalysts and their catalytic influence on the product distribution, behavior and liquid component during cellulose pyrolysis in N 2 and CO 2 atmosphere were analyzed. The obtained results indicated that the unique flower-like structure of carbon significantly elevated strengths to generate gaseous products and the enrichment of furan compounds during pyrolysis. The inclusion of CO 2 further enhanced the secondary reaction of liquid product, and the maximum increment of syngas yield was 14.50 wt% after adding Ni/Co–C catalyst. Moreover, CO 2 participated in thermal conversion process of biomass as an oxygen source and thus more sugars were converted into furans. The Ni/Co–C catalyst and CO 2 produced favorable synergistic effect during cellulose pyrolysis, which resulted in the highest relative content of furans, with the value of 26.77%. Therefore, this study presented an efficient means to access to furan-rich bio-oil via catalytic pyrolysis of biomass. • The flower-like carbon-based catalysts that improve yield of furans are synthesized. • A 15.31% increase in furans is obtained by adding Ni/Co loaded carbon catalyst in CO 2. • The prepared catalysts promote the secondary reaction for generation of syngas. • The mechanism of flower-like carbon catalyst for component variation is given. [ABSTRACT FROM AUTHOR]

In this work, the Zr-Mg bimetallic catalyst is prepared and used to facilitate the conversion of the waste mask to hydrocarbon-rich fuels. The effects of the catalyst and the reaction atmosphere on pyrolysis behaviors of different layers of the mask are discussed, and the interactions between CO 2 and the catalyst are analyzed. The results showed that the synthesized catalyst significantly promoted the conversion of long-chain hydrocarbons to short-chain hydrocarbons. Compared with pyrolysis alone under N 2 atmosphere, the relative contents of hydrocarbon compounds obtained by catalytic pyrolysis in the inner layer and middle layer increased by 12.21% and 16.24%, respectively. Additionally, the relative content of olefins in the liquid product increased by 9.62%. When the pyrolysis atmosphere was changed from N 2 to CO 2 , the selectivity of the cycloalkanes was significantly enhanced. Also, the interactions between CO 2 and the catalyst improved the selectivity of C 2 H 6. These works provide important support for the effective disposal of masks and an in-depth understanding of the CO 2 -assisted pyrolysis process. • A catalyst that promotes the generation of hydrocarbon-rich fuels is synthesized. • The selectivity of short-chained liquid hydrocarbons is increased by 13.87%. • The CO 2 promotes the generation of C 3 H 6 in gaseous hydrocarbon products. • Effects of CO 2 and catalyst converting mask into hydrocarbon-rich fuels are given. [ABSTRACT FROM AUTHOR]

• Catalysts that can effectively promote cellulose decomposition are synthesized. • CO 2 -assisted cobalt-based Ce/Fe/Mg catalyst enhances furans and ketones. • The synthesized catalyst has good oxygen transfer ability. • The performance of catalyst in improving the selectivity of compound is given. The production of high value-added liquid products by catalytic pyrolysis of cellulose has become an effective way to realize the efficient utilization of biomass. This work synthesized a series of Co-Ce, Co-Fe and Co-Mg composite metal catalysts and used them to obtain furans and ketones production. In addition, the CO 2 was used as a pyrolysis atmosphere to investigate the synergistic effect between CO 2 and the prepared catalyst. The results showed that the catalyst effectively promoted the depolymerization of cellulose and improved the oxygen transfer behavior between volatile matters during cellulose pyrolysis. As a reaction medium, CO 2 influenced the carbon distribution of products, thereby increasing syngas yield, and the CO 2 atmosphere promoted the formation of furans and ketones. Compared with those obtained by the non-catalytic pyrolysis in N 2 atmosphere, the relative contents of furans and ketones in the liquid products produced by the catalytic pyrolysis of cellulose in CO 2 atmosphere increased by about 13.38% and 9.8%. In the CO 2 environment, the generation ability for furans was Co-Mg catalyst > Co-Ce catalyst > Co-Fe catalyst, and the generation ability for ketones was Co-Ce catalyst > Co-Mg catalyst > Co-Fe catalyst. These works provide an important way for the efficient preparation of furans and ketones from biomass pyrolysis. [ABSTRACT FROM AUTHOR]

In our work, a series of experiments on pyrolysis of the large particle oil shale (6–15 mm) were carried out in a self-made retorting pyrolyzer, in order to obtain the optimal final pyrolysis temperature of Huadian oil shale and evaluate the catalytic performance of transition metal salts (CoCl 2 ·6H 2 O, MnSO 4 ·H 2 O) in promoting the shale oil yield and product characteristic. The experiment results showed that the retorting temperature significantly influenced the shale oil yield. The maximum oil yield appeared in 520 °C with the result of 21.59 wt%. Meanwhile, the higher retorting temperature promoted the more production of alkanes/olefins, which led to the increase of alkanes from 20.46% to 32.44%. Moreover, the use of CoCl 2 ·6H 2 O salt further increased the oil yield. The pyrolysis behavior and kinetic analysis indicated the transition metal iron could act as the activation center to accelerate the breakdown of chemical bonds in organic matters. In addition, the addition of the Co salt significantly enhanced the formation of aromatic hydrocarbons in the shale oil, which increased about 18% compared to that of non-catalytic pyrolysis. It had demonstrated the Co iron could increase the selectivity of aromatic hydrocarbons and promote olefin aromatization. The acid compounds were observed in the oil produced from the catalytic pyrolysis of MnSO 4 ·H 2 O, which suggested that it was not suitable to be regarded as the candidate catalysis. [ABSTRACT FROM AUTHOR]

The extraction of phenolic compounds from biomass is an important way to replace chemical synthesis techniques, and catalytic pyrolysis of biomass is an effective method to obtain phenolic compounds with high selectivity. In this work, cobalt-modified montmorillonite K-10(CMT) catalyst was prepared by using cobalt salt and montmorillonite K-10(MMT), and used to catalyze the pyrolysis of corn stalk(CS) to produce phenol-rich bio-oil. The catalytic pyrolysis characteristics reflected by the liquid and gaseous components were compared using gas chromatography-mass spectrometry(GC-MS) and online mass spectrometry(online MS), and the catalytic pyrolysis behavior of corn stalk was analyzed by using the thermogravimetric analyzer(TGA). The addition of catalyst resulted in the increase of apparent activation energy of pyrolysis process but increased selectivity for phenolic compounds. Compared with the blank sample, the relative content of phenolic compounds in bio-oil increased by 11.99 %, and the selectivity of alkyl-phenols was stronger. In addition, the results also showed that the synthesized catalyst promoted the production of H 2 and CH 4 during the catalytic pyrolysis. The optimum ratio of the prepared catalyst was 6%Co/15%MMT. These works provide an alternative approach to upgrading bio-oil product. • A catalyst that effectively improves the selectivity of phenols is synthesized. • A 11.99 % increase in phenols is obtained by adding 6%Co/15%MMT catalyst. • The reforming of oxygenates to form phenolic compounds is enhanced. • A pathway for producing phenols via biomass catalytic pyrolysis is presented. [ABSTRACT FROM AUTHOR]