Microwave‐assisted catalytic pyrolysis of theEupatorium adenophorumfor obtaining valuable products

Abstract

Eupatorium adenophorum, global exotic weed, is used as feedstock in the presence of two catalysts to produce renewable biofuels and green chemicals combining with the advantage of microwave heating and catalytic pyrolysis. The effect of catalyst on yield of pyrolysis products is studied. And the pyrolysis product produced from with and without catalytic pyrolysis is analyzed for performance comparisons. The results show that catalytic pyrolysis tends to produce more bio‐oil and less bio‐gas. The bio‐oil from catalytic pyrolysis has more alkane and ketone, and less carboxylic acid compound compared to non‐catalytic pyrolysis, indicates that catalytic pyrolysis could upgrade the quality of bio‐oil. Compared to bio‐gas of non‐catalytic pyrolysis, the catalytic pyrolysis has larger CO and less CO2 content, particularly for Sodium chloride (NaCl) catalyst pyrolysis. The bio‐char of NaCl catalytic pyrolysis has higher Brunauer–Emmett–Teller (BET) surface area and total pore volume. The above analysis indicates that catalysts pyrolysis makes the properties of pyrolysis product tend to good tendency.

Comparison of microwave pyrolysis and conventional pyrolysis of Eupatorium adenophorum

“…The reason may be that the dehydrogenation reactions could be favored under microwave heat. 16 Besides, MP promotes to produce H 2 -rich of bio-gas due to hot-spot phenomenon of microwave heat, which is similar with the literature study on microwave-induced pyrolysis rice straw. 45 MP produces more CO and less CO 2 compared to CP.…”

“…Microwave heat has several advantages such as selective heating, fast cooling rates, non‐contact material heating, and energy saving 14,15 . Therefore, microwave heat can promote the generation of bio‐gas and prevent these secondary reactions such as retrogressive and condensation reactions, which usually form of a stable, trapped form of bio‐char or bio‐oil 16 . The temperature of material center is larger than external surface of material in microwave field, unlike conventional heat which promotes the volatilization of pyrolysis vapor and reduces the risk of secondary reactions 17 .…”

“…14,15 Therefore, microwave heat can promote the generation of bio-gas and prevent these secondary reactions such as retrogressive and condensation reactions, which usually form of a stable, trapped form of bio-char or biooil. 16 The temperature of material center is larger than external surface of material in microwave field, unlike conventional heat which promotes the volatilization of pyrolysis vapor and reduces the risk of secondary reactions. 17 Besides, microwave heat has the phenomenon of hot spot, which significantly effects the yield and performance of pyrolysis products.…”

Research progress on catalytic pyrolysis and reuse of waste plastics and petroleum sludge

“…[40] (2) The presence of the catalyst enhances the selectivity of the waste plastic conversion product, so that by appropriately selecting the acidity and pore structure of the catalyst, it is possible to control the different yields of the desired product (such as gases, gasoline or diesel).In addition, the development of undesirable products can be inhibited by an acceptable catalyst (such as chlorinated and brominated hydrocarbons). [41] In the past few decades, researchers all over the world have carried out many works on the catalytic degradation of plastics and researched the catalytic efficiency and mechanism of various catalytic systems. The catalysts commonly used in catalytic pyrolysis of waste plastics mainly include: mesoporous molecular sieve catalysts, transition metal catalysts, oxide catalysts, clay mineral catalysts and other catalysts.…”