A Review of Microwave-Assisted Reactions for Biodiesel Production

Nomanbhay, Saifuddin; Ong, Mei Yin

doi:10.3390/bioengineering4020057

Cited by 127 publications

(29 citation statements)

References 79 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Microwave-assisted activation produces AC with wider micropores and mesopores than the conventional products. The pore size, surface area and adsorption efficiency in both conventional and microwave activation processes are affected by activation temperature, dwell time, heating rate, type of activating agent, activation agent-feedstock ratio, particle size, inert gas flow rate, microwave power and weight of sample [75].…”

Section: A Comparison Of Activation By Microwave and The Conventional Processmentioning

confidence: 99%

A Review of Chemicals to Produce Activated Carbon from Agricultural Waste Biomass

et al. 2019

View full text Add to dashboard Cite

The choice of activating agent for the thermochemical production of high-grade activated carbon (AC) from agricultural residues and wastes, such as feedstock, requires innovative methods. Overcoming energy losses, and using the best techniques to minimise secondary contamination and improve adsorptivity, are critical. Here, we review the importance and influence of activating agents on agricultural waste: how they react and compare conventional and microwave processes. In particular, adsorbent pore characteristics, surface chemistry interactions and production modes were compared with traditional methods. It was concluded that there are no best activating agents; rather, each agent reacts uniquely with a precursor, and the optimum choice depends on the target adsorbent. Natural chemicals can also be as effective as inorganic activating agents, and offer the advantages that they are usually safe, and readily available. The use of a microwave, as an innovative pyrolysis approach, can enhance the activation process within a duration of 1–4 h and temperature of 500–1200 °C, after which the yield and efficiency decline rapidly due to molecular breakdown. This study also examines the biomass milling process requirements; the influence of the dielectric properties, along with the effect of washing; and experimental setup challenges. The microwave setup system, biomass feed rate, product delivery, inert gas flow rate, reactor design and recovery lines are all important factors in the microwave activation process, and contribute to the overall efficiency of AC preparation. However, a major issue is a lack of large-scale industrial demonstration units for microwave technology.

show abstract

Section: A Comparison Of Activation By Microwave and The Conventional Processmentioning

confidence: 99%

A Review of Chemicals to Produce Activated Carbon from Agricultural Waste Biomass

et al. 2019

View full text Add to dashboard Cite

show abstract

“…In recent years microwave has been suggested by several researchers as a technique to reduce time and energy when producing AC from biomass [45,46]. This technique has been demonstrated in several studies but has not reached commercial scale due to various challenges.…”

Section: Introductionmentioning

confidence: 99%

Preparation and Characterisation of Activated Carbon from Palm Mixed Waste Treated with Trona Ore

et al. 2020

View full text Add to dashboard Cite

This study explores the use of a novel activating agent and demonstrates the production and characterisation of activated carbon (AC) from a combine palm waste (CPW) in 3:2:1 proportion by weight of empty fruit bunch, mesocarp fibre and palm kernel shell. The resulting biomass was processed by a microwave-assisted method using trona and compared with material produced by conventional routes. These results demonstrate the potential of trona ore as an activating agent and the effectiveness of using a combined palm waste for a single stream activation process. It also assesses the effectiveness of trona ore in the elimination of alcohol, acids and aldehydes; with a focus on increasing the hydrophilicity of the resultant AC. The optimum results for the conventional production technique at 800 °C yielded a material with SBET 920 m2/g, Vtotal 0.840 cm3/g, a mean pore diameter of 2.2 nm and an AC yield 40%. The optimum outcome of the microwave assisted technique for CPW was achieved at 600 W, SBET is 980 m2/g; Vtotal 0.865 cm3/g; a mean pore diameter 2.2 nm and an AC yield of 42%. Fourier transform infrared spectrometry analyses showed that palm waste can be combined to produce AC and that trona ore has the capacity to significantly enhance biomass activation.

show abstract

“…The scaling up potential of microwave-assisted reactions has been thoroughly reviewed by La Hoz et al (2011) [ 56 ], which reported that a microwave reactor up to 12 L was studied in organic chemistry reaction. In 2017, the use of microwave-assisted transesterification for biodiesel was still undergoing laboratory-scale experiments [ 57 ]. To date, its application has yet to be implemented at the industry level.…”

Section: Recent Stand-alone Microwave Applicationsmentioning

confidence: 99%

Prospects and Challenges of Microwave-Combined Technology for Biodiesel and Biolubricant Production through a Transesterification: A Review

et al. 2021

View full text Add to dashboard Cite

Biodiesels and biolubricants are synthetic esters produced mainly via a transesterification of other esters from bio-based resources, such as plant-based oils or animal fats. Microwave heating has been used to enhance transesterification reaction by converting an electrical energy into a radiation, becoming part of the internal energy acquired by reactant molecules. This method leads to major energy savings and reduces the reaction time by at least 60% compared to a conventional heating via conduction and convection. However, the application of microwave heating technology alone still suffers from non-homogeneous electromagnetic field distribution, thermally unstable rising temperatures, and insufficient depth of microwave penetration, which reduces the mass transfer efficiency. The strategy of integrating multiple technologies for biodiesel and biolubricant production has gained a great deal of interest in applied chemistry. This review presents an advanced transesterification process that combines microwave heating with other technologies, namely an acoustic cavitation, a vacuum, ionic solvent, and a supercritical/subcritical approach to solve the limitations of the stand-alone microwave-assisted transesterification. The combined technologies allow for the improvement in the overall product yield and energy efficiency. This review provides insights into the broader prospects of microwave heating in the production of bio-based products.

show abstract

A Review of Microwave-Assisted Reactions for Biodiesel Production

Cited by 127 publications

References 79 publications

A Review of Chemicals to Produce Activated Carbon from Agricultural Waste Biomass

A Review of Chemicals to Produce Activated Carbon from Agricultural Waste Biomass

Preparation and Characterisation of Activated Carbon from Palm Mixed Waste Treated with Trona Ore

Prospects and Challenges of Microwave-Combined Technology for Biodiesel and Biolubricant Production through a Transesterification: A Review

Contact Info

Product

Resources

About