The replacement of fossil resources that currently provide more than 90% of our energy needs and feedstocks of the chemical industry in combination with reduced emission of carbon dioxide is one of the most pressing challenges of mankind. Biomass as a globally available resource has been proposed as an alternative feedstock for production of basic building blocks, which could partially or even fully replace the currently utilized fossil-based ones in well-established chemical processes. The destruction of lignocellulosic feed followed by oxygen removal from its cellulose and hemicellulose content by catalytic processes results in the formation of initial platform chemicals (IPCs). However, their sustainable production strongly depends on the availability of resources, their efficient or even industrially viable conversion processes, and replenishment time of feedstocks. Herein, we overview recent advances and developments in catalytic transformations of the carbohydrate content of lignocellulosic biomass ...

Catalytic Conversion of Carbohydrates to Initial Platform Chemicals: Chemistry and Sustainability

Hydroxymethylfurfural (HMF) and levulinic acid (LA) are two of the most promising chemicals derived from biomass owing to their convertibility into a large number of chemicals having applications in diverse industries. Their transition from niche products to mass-produced chemicals, however, requires their production from sustainable biomass feedstocks at low costs using environment-friendly techniques. In this review, the numerous reaction systems that have been developed to produce HMF and LA from various substrates have been looked at and their merits, demerits and requirements for commercialisation outlined. Special attention has been paid to microwave irradiation-heated systems due to their dual advantages of high product yields and low environmental footprint.

Review: Sustainable production of hydroxymethylfurfural and levulinic acid: Challenges and opportunities

Targeted chemical upgrading of lignocellulosic biomass to platform molecules

Catalytic conversion of renewable biomass to “green” chemicals and fuel additives has been extensively investigated in the past few decades. Interests on two top platform intermediates for biofuel production, i.e. levulinic acid (LA) and 5-hydroxymethylfurfural (HMF), have increased significantly. These two chemicals are generally produced from biomass through acid hydrolysis. This review summarizes the discoveries of the most recent studies on acid-catalyzed hydrolysis, including (i) biomass pretreatment, (ii) glucose production from cellulose hydrolysis, (iii) fructose formation from glucose isomerization, (iv) HMF formation from glucose/fructose dehydration and (v) LA production from HMF rehydration. Humins, the main byproducts, are also discussed in the aspect of their influence on the hydrolysis process, structure, formation mechanism, and applications.

From lignocellulosic biomass to levulinic acid: A review on acid-catalyzed hydrolysis

The rise in fuel and oil prices has driven the hunt for alternative renewable resources for production of chemical intermediates or biofuels since they provide a sustainable solution to an increasing demand. Levulinic acid (LA), one of the platform chemicals, can be produced chemically using renewable resources such as starch waste and lignocellulosic biomass which sounds to be an attractive alternative owing to its abundance and environmentally benign nature. The presence of acidic carboxyl and ketone carbonyl groups in LA impart a remarkable pattern of reactivity to levulinic acid and allow it to form several derivatives having significant applications in various fields, thereby making it a versatile green chemical. The present review deals with the current status of the technologies available for levulinic acid production, its recovery and the array of applications in several areas along with the gridlocks involved at each step of conversion process and suggest some possible remedies. Further, it not only throws light on the recent advancements in LA production approaches along with the avant-garde biotechnological approach for its biosynthesis but also depicts the current market scenario of commercial LA industry. The review also discusses the future R&D scope with an aim to enhance the yield of levulinic acid production and to make the process energy-efficient and cost-effective.

Levulinic acid production from renewable waste resources: Bottlenecks, potential remedies, advancements and applications

The hydrothermal conversion of waste biomass to levulinic acid was investigated in the presence of homogeneous acid catalysts. Different cheap raw materials (poplar sawdust, paper mill sludge, tobacco chops, wheat straw, olive tree pruning) were employed as substrates. The yields of levulinic acid were improved by optimization of the main reaction parameters, such as type and amount of acid catalyst, temperature, duration, biomass concentration, and electrolyte addition. The catalytic performances were also improved by the adoption of microwave irradiation as an efficient heating method, allowing significant energy and time savings. The hydrothermal conversions of inulin and wheat straw were carried out in the presence of niobium phosphate, which up to now have never been employed in these reactions. The preliminary results appeared to be in need of further optimization.

https://ojs.cnr.ncsu.edu/index.php/BioRes/article/download/BioRes_07_2_1824_RaspolliGalletti_ADLLN_Levulinic_Acid_Prodn_Waste_Biomass/1462

Nicoletta Nassi

Papers

Levulinic acid production from waste biomass