Preparation of biodiesel using s-MWCNT catalysts and the coupling of reaction and separation

Current Trends and Future Prospects of Nanotechnology in Biofuel Production

Biofuel is one of the best alternatives to petroleum-derived fuels globally especially in the current scenario, where fossil fuels are continuously depleting. Fossil-based fuels cause severe threats to the environment and human health by releasing greenhouse gases on their burning. With the several limitations in currently available technologies and associated higher expenses, producing biofuels on an industrial scale is a time-consuming operation. Moreover, processes adopted for the conversion of various feedstock to the desired product are different depending upon the various techniques and materials utilized. Nanoparticles (NPs) are one of the best solutions to the current challenges on utilization of biomass in terms of their selectivity, energy efficiency, and time management, with reduced cost involvement. Many of these methods have recently been adopted, and several NPs such as metal, magnetic, and metal oxide are now being used in enhancement of biofuel production. The unique properties of NPs, such as their design, stability, greater surface area to volume ratio, catalytic activity, and reusability, make them effective biofuel additives. In addition, nanomaterials such as carbon nanotubes, carbon nanofibers, and nanosheets have been found to be cost effective as well as stable catalysts for enzyme immobilization, thus improving biofuel synthesis. The current study gives a comprehensive overview of the use of various nanomaterials in biofuel production, as well as the major challenges and future opportunities.

Ultrasonic process intensification during the preparation of dimethyl carbonate based on the alcoholysis of ethylene carbonate and the kinetic behavior of dimethyl carbonate

Ultrasound can accelerate the reaction rate of alcoholysis of ethylene carbonate and improve the reaction efficiency.

Carbon nanotubes and catalysis: the many facets of a successful marriage

Carbon nanotubes have emerged as unique carbon allotropes that bear very interesting prospects in catalysis.

High performance catalytic distillation using CNTs-based holistic catalyst for production of high quality biodiesel

For production of biodiesel from bio oils by heterogeneous catalysis, high performance catalysts of transesterification and the further utilization of glycerol have been the two points of research. The process seemed easy, however, has never been well established. Here we report a novel design of catalytic distillation using hierachically integrated CNTs-based holistic catalyst to figure out the two points in one process, which shows high performance both for the conversion of bio oils to biodiesel and, unexpectedly, for the conversion of glycerol to more valuable chemicals at the same time. The method, with integration of nano, meso to macro reactor, has overwhelming advantages over common technologies using liquid acids or bases to catalyze the reactions, which suffer from the high cost of separation and unsolved utilization of glycerol.

Biodiesel production from sewage sludge: new paradigm for mining energy from municipal hazardous material

This work demonstrates that the production of biodiesel using the lipids extracted from sewage sludge (SS) could be economically feasible because of the remarkably high yield of oil and low cost of this feedstock, as compared to conventional biodiesel feedstocks. The yield of oil from SS, 980,000 L ha(-1) year(-1), is superior to those from microalgal and soybean oils, 446 and 2200 L ha(-1) year(-1), respectively. According to the case study of South Korea, the price of the lipids extracted from SS was approximately $0.03 L(-1) (USD), which is lower than those of all current biodiesel feedstocks. This work also highlights the insight of a novel methodology for transforming lipids containing high amounts of free fatty acids (FFAs) to biodiesel using a thermochemical process under ambient pressure in a continuous flow system. This allowed the combination of esterification of FFAs and transesterification of triglycerides into a single noncatalytic process, which led to a 98.5% ± 0.5% conversion efficiency to FAME (fatty acid methyl ester) within 1 min in a temperature range of 350-500 °C. The new process for converting the lipids extracted from SS shows high potential to achieve a major breakthrough in minimizing the cost of biodiesel production owing to its simplicity and technical advantages, as well as environmental benefits.

The use of natural materials in nanocarbon synthesis

Nanomaterials are shifting from laboratory-scale preparation to industrial production. The energy costs and starting materials (feedstock, catalyst, and support) consumed or used in the mass production of nanomaterials are issues that limit their broad application. Natural materials, such as sand, rock, and lava, contain small or trace amounts of metals or metal oxides of nanometer-scale sizes and have been recently used as catalysts for the production of carbon nanotubes (CNTs), providing an interesting way to lower the production cost of CNTs. However, the sustainability of the whole production process still needs to be explored. Layered minerals (e.g., clays) are used to produce CNT-clay hybrids, which can be further used to synthesize polymer-CNT-clay nanocomposites. Natural materials and some byproducts of industrial production processes have been explored as carbon sources for nanocarbon synthesis. This Minireview highlights some recent promising work and prospects for the use of natural materials in the synthesis of CNTs, carbon nanofibers (CNFs), and nanocomposites, and their applications in catalysis and in materials science.