Use of Kappaphycus alvarezii Biomass for the Production of Carbohydrate Isopropylidene-Ketal-Based Biocrude

Abstract

The production of bio-hydrocarbons is a challenging task, which stimulated research and the development of different approaches to introduce biomass into the standard refinery. However, they present drawbacks that demonstrate the need for continuous research. Our recent efforts in this area culminated in the development of a new biocrude derived from carbohydrate-derived isospropylidene ketals obtained from lignicelullosic biomass. Such biocrude could be easily stored, and its components could be converted into hydrocarbons under standard catalytic cracking conditions. In the present work, we report the proof of concept in the synthesis of such biocrude from non-lignocellulosic biomass. The biomass from Kappaphycus alvarezii was used as a source for the production of a biocrude enriched in carbohydrate-derived isopropylidene ketals. For such, a two-step procedure was developed, i.e., acid hydrolysis of K. alvarezii biomass yielding a carbohydrate-rich extract, followed by its acid-catalyzed ketalization with acetone. It was observed that the conditions used for acid hydrolysis of K. alvarezii biomass impacted the final biocrude composition of isopropylidene ketals. The best experimental condition for biomass hydrolysis, which resulted in a biocrude with a higher carbohydrate-derived isopropylide ketal content after ketalization, was that using sulfuric acid solution at 0.180 M, 140 °C, and 6.75 min of reaction time. Such biocrude presented 44% (w/w) of 1,2;3,4-di-O-isopropylidene-α-d-galactopyranose. The compound 6-O-methyl-1,2;3,4-di-O-isopropylidene-α-d-galactopyranose was also identified in the biocrude.

Understanding green-hydrocarbon production through the strategy of biomass ketalization reaction

“…According to several papers published by our group, the conversion of biomass into fuel using the regular installations of reneries can be achieved by a two-step process: production of bio-petroleum by hydrolysis-ketalization reactions of biomass followed by catalytic cracking and hydroconversion. [13][14][15][16][17][18][19][20][21]40 The results described here evidenced the existence of bimolecular reactions between DX and hydrocarbons and the primary oxygenate produced from DX. These ndings may be used to increase the efficiency of transforming green carbon into high-value products in two scenarios.…”

“…According to several papers published by our group, the conversion of biomass into fuel using the regular installations of refineries can be achieved by a two-step process: production of bio-petroleum by hydrolysis–ketalization reactions of biomass followed by catalytic cracking and hydroconversion. 13–21,40…”

Red Macroalgae Kappaphycus alvarezii as feedstock for nutraceuticals, pharmaceuticals and fourth generation biofuel production

“…The use of red macroalgae Kappaphycus alvarezii is the main worldwide source for bioethanol production, since its high amount of carrageenan that can be converted in fermentable sugar [16]. However, macroalgae is also used as a food source, more than five centuries ago, since the populations from the Scandinavian Peninsula started using carrageenan, a polysaccharide of galactose, to produce dairy foods [17][18][19]. Therefore, that brings up the food versus fuel dilemma again.…”

Zeolite Chemistry and Applications

“…Recently, we proposed an alternative approach to fuel production from second generation biomass in two steps (Batalha et al, 2014). The biomass was firstly converted in mild conditions into a bio-crude (density of 1.1 gmL −1 and CHO composition ≈ 58, 7, and 35% by weight, respectively) combining acid catalyzed hydrolysis with organic reactions such as ketalization (Garrett et al, 2015;de Souza et al, 2017) and acetylation (Durange et al, 2015). The biocrude is composed by a mixture of isopropylidene ketals containing mono and polyshacharides-ketals (Garrett et al, 2015).…”