A review on advanced catalytic co-pyrolysis of biomass and hydrogen-rich feedstock: insights into synergistic effect, catalyst development and reaction mechanism

The depletion of fossil fuel reserves and the growing demand for alternative energy sources are the main drivers of biomass and carbonaceous waste utilization. Particularly, non-edible lignocellulosic biomass is the most attractive renewable feedstock due to its abundance. Pyrolysis of biomass produces highly oxygenated compounds with oxygen content >35 wt%. The cost-effective elimination of oxygen from the pyrolysis oil is the most challenging task impeding the commercialization of biomass to biofuel processes. The effective hydrogen/carbon ratio in biomass pyrolysis oil is low (0.3), requiring external hydrogen supply to produce hydrocarbon-rich oils. Exploiting hydrogen-rich feedstock particularly, solid waste (plastic, tyre and scum) and other low-cost feedstock (lubricant oil, methane, methanol, and ethanol) offer an eco-friendly solution to upgrade the produced bio-oil. Multi-functional catalysts that are capable of cleaving oxygen, promoting hydrogen transfer and depolymerisation must be developed to produce hydrocarbon-rich oil from biomass. This review compares catalytic co-pyrolysis studies based on zeolites, mesoporous silica and metal oxides. Furthermore, a wide range of catalyst modifications and the role of each feedstock were summarised to give a complete picture of the progress made on biomass co-pyrolysis research and development

Red-mud based porous nanocatalysts for valorisation of municipal solid waste

Red mud samples were used to catalyse in-situ co-pyrolysis of pinewood and low-density polyethylene for the production of high-quality bio-oil. The sodium cation in the crude red-mud was exchanged with barium and calcium cations and further tested to explore their role in oil upgrading. The relationship between red-mud catalytic activity and its constituents was explored using synthetic sodalite. The red-mud catalysts exhibited a considerable aromatisation capacity compared to the thermal co-pyrolysis, as the selectivity towards monocyclic aromatic hydrocarbons increased from 12.7 to 19.6%, respectively. Long-chain molecules cracking was more significant in synthetic sodalite associated with their acidic active sites. The addition of barium and calcium cations to the red-mud largely improved oxygen elimination as a result of the enhanced catalyst basicity. In contrast, the aromatisation ability of red-mud significantly impeded by the large cation size (Ba2+ and Ca2+) due to the limited diffusion of pyrolysis vapours to the active sites. Ba-exchanged red-mud catalysts reduced the content of carboxylic acids in the bio-oil to 1.8 % while maintained a high yield of the organic fraction (34 %). Ca-exchanged red-mud catalysts produced the lowest fraction of oxygenated compounds (35.1 %); however, the organic phase yield was as low as 23.6 %. The modified red-mud catalysts reduced the fraction of oxygenated compounds from 69.9–35.1% during the biomass-plastic co-pyrolysis.</p

Biometric indices and size at first sexual maturity of eight alien fish species from Bangladesh

The biometric indices and size at first sexual maturity of eight alien fish species from several water bodies in Bangladesh were studied for the first time. A total of 273 individuals of eight alien fish species (Barbonymus gonionotus, Clarias gariepinus, Ctenopharyngodon idella, Cyprinus carpio, Hypophthalmichthys molitrix, H. nobilis, Oreochromis niloticus and Pangasianodon hypophthalmus) were collected using traditional fishing gears from June 2014 to May 2015. Among the four condition factors (Allometric condition factor, Fulton’s condition factor, Relative condition factor, and Relative weight) studied, Fulton’s condition factor was the best for assessing the well-being of these alien species in their natural habitat, based on the relationships of condition factors with body weight and total length. The calculated form factor was 0.0270 for B. gonionotus, 0.0077 for C. gariepinus, 0.0119 for C. idella, 0.0194 for C. carpio, 0.0101 for H. molitrix, 0.0092 for H. nobilis, 0.0158 for O. niloticus and 0.0105 for P. hypophthalmus. The size at first sexual maturity was estimated in TL as 12.30 cm for B. gonionotus, 25.53 cm for C. gariepinus, 32.80 cm for C. idella, 18.22 cm for C. carpio, 23.92 cm for H. molitrix, 30.18 cm for H. nobilis, 21.78 cm for O. niloticus, and 21.32 cm for P. hypophthalmus. The present study also calculates form factor and first sexual maturity of these alien species from different water-bodies world over. The findings of this study can be very helpful for sustainable management of these alien species in Bangladesh and similar ecosystems

Proceedings of International Conference on Emerging Trends in Engineering and Advanced Science

This conference proceedings contains articles on the various research ideas of the academic community and practitioners presented at the International Conference on Emerging Trends in Engineering and Advanced Science (ICETEAS-2021). ICETEAS-2021 was organized by the Department of Electrical and Electronic Engineering &amp; Department of Mechatronics Engineering, World University of Bangladesh, Dhaka, Bangladesh on July 4th-5th November 2021. Conference Title: International Conference on Emerging Trends in Engineering and Advanced ScienceConference Acronym: ICETEAS-2021Conference Date: 4-5 November 2021Conference Location: Online (Virtual Mode)Conference Organizers: World University of Bangladesh, Dhaka, Bangladesh