Keyword: catalysts

4 results found.

Review Article
Agricultural Biomass to Adipic Acid–An Industrially Important Chemical
European Journal of Sustainable Development Research, 2022, 6(2), em0184,
ABSTRACT: Adipic acid is widely used in the production of nylon, plasticizers, polyurethane resins, adhesives, lubricants, etc. and hence the compound annual growth rate of adipic acid is expected to be 4.4% with a market size of over USD 7,000 million. At present adipic acid is commercially manufactured using petrochemical feedstock like benzene, hexane, hexene, hexanone, etc. using nitric acid as the catalyst. The research community is exploring newer methodologies to synthesize adipic acid and other industrially valuable chemicals using renewable feedstock one of them being biomass. There are mainly two routes of synthesizing adipic acid from biomass–chemocatalytic and biological. Within these routes, there are a variety of processes like deoxydehydrogenation (DODH), hydrodeoxygenation, direct synthesis via oxidation-hydrogenation that help convert biomass to adipic acid. With heterogeneous catalysis as a developing domain, researchers have developed a variety of catalysts like zeolites, silica-based catalysts, biological catalysts, deep utectic solvents as catalysts and a variety of other heterogeneous catalysts that convert that biomass containing cellulose, hemicellulose, lignin, other sugars to adipic acid efficiently. The paper reviews all the methodologies, catalysts for conversion and market demand of adipic acid.
Review Article
Trends in Sonochemical and Hydrodynamic Reactor Strategies for Catalytic Production of Biodiesel: Effects of the Influencing Process Parameters and Kinetics
European Journal of Sustainable Development Research, 2021, 5(3), em0164,
ABSTRACT: Biodiesel researchers need to understand the optimal conditions involved in the production of biodiesel from readily available biological sources, as several research works have reported on biodiesel production. Therefore, this paper emphasizes specifically, the process parameters involved in biodiesel production and how they affect biodiesel yields. These parameters include, but not limited to the feedstock selection, catalyst type to use, free fatty acid, temperature, kinetics, hydrodynamics and reactor conditions. In biodiesel synthesis, a high fatty acid methyl ester yield of up to 100%w/w at 60 oC has been reported, which occurred with a methanol to oil molar ratio of 3.75, and 60 min reaction time. Homogeneous catalysts seems promising for the production of biodiesel, although they possess disposal challenges and reusability issues. In addition, carbon-based catalysts from natural sources have been used to resolve the presence of free fatty acids in biodiesel synthesis that results in the formation of soap. These carbon-derived catalysts prove their efficiency when modified with acids. The reactor suitable for biodiesel reaction, assume several configurations, like the batch, fixed bed and semi-batch configurations, with their respective reaction conditions. Furthermore, in the design of a hydrodynamic cavitation reactor operating on the rotor-stator mechanism, research has shown that the ratio of rotor to stator diameter Dr/Ds is maintained at 0.73 for efficient operation. Hence, a proper understanding of the process chemistry and techniques involved in biodiesel synthesis would ensure a high desired yield and sustainable process route.
Review Article
Selected Thermo-Chemical Biorefining: Evaluation of the Current Trends and Progressions
European Journal of Sustainable Development Research, 2021, 5(2), em0154,
ABSTRACT: The review paper embodies the current trends and advancements involved in the transformation of biomass to enhanced products, bioenergy, and chemicals. Some selected chemical process like the slow-fast pyrolysis, catalytic fast pyrolysis, hydrothermal liquefaction, transesterification and lignin valorization by depolymerization are aptly suited for biorefinery processing, and were discussed in this review. The (catalytic) fast pyrolysis and hydrothermal liquefaction are quite similar, but differ in their feedstock preparations, reactor configuration and thermal or energy optimization. The review covers the biomass selection, chemical conversion techniques and most importantly the required heterogeneous catalysts (where applicable). The work further suggests the superiority of dedicated chemicals over drop-in and smart drop-in chemicals, due the complete usage of biomass. Relative to the oil refinery process, biorefining is quite novel and accompanied by its drawbacks. These challenges range from catalyst poisoning and deactivation to energy intensiveness and eventually as being cost-ineffective. The challenge encountered in biorefinery is in the economic feasibility, as it is inferred from this review that the pre-treatment process takes up to about 20% of the conversion cost. Although the biorefinery plant employ lignocellulosic biomass, but study shows that the use of biomass is largely under-utilized. The solid products/ wastes from pyrolysis for example, can be utilized as source of energy for the process. In the pursuit for sustainability, it is essential to ensure a balance-energy-mix, where every other type of energy will have a role to play to avoid dependence on only one solution for the future. Therefore, in contrast to the dwindling fossil fuels, it can be generally speculated that the future for biorefining is bright. It was concluded that with vast knowledge on the suitable heterogeneous catalysts and proper optimization of process parameters (temperatures, pressure, and reactant species); some of the biorefining processes will result into a significant increase in industrial fuels and bio-based drop-in chemicals leading towards commercialization.
Research Article
Chemical and Enzymatic Valorisation of Confectionery Waste into Biofuel: An Application of Circular Economy
European Journal of Sustainable Development Research, 2021, 5(1), em0146,
ABSTRACT: Waste oil was extracted from lollipop effluent stream using a mixture of organic solvents viz. n-hexane and ethyl acetate. Lollipop effluent samples found to contain ~ 10-18 wt.% oil. Subsequently, the oil was subjected to biodiesel synthesis under solvent free condition using chemical and enzymatic catalysts. Among the base catalysts used, KOH catalyzed reaction gave highest biodiesel yield (99 %) in 20 minutes. Furthermore, nine different lipases were screened as catalysts for biodiesel preparation from lollipop effluent oil. The screening experiments revealed that Novozyme-435 was best among the lipases which gave 94 % biodiesel in 18 h at 40 0C.