Latest news

New article: Waste tires based biorefinery for biofuels and value-added materials production

Waste tires are a distinct type of waste material that is produced in large quantities. These tires present a significant environmental challenge due to their high toxicity and flammability, as well as their persistence and the difficulty of storing or processing them. Every year, approximately 1.4 billion waste tires are produced, and they typically end up either in landfills or being incinerated, exacerbating these environmental problems. However, waste tires are also a promising source of energy and energetic materials, thanks to their low moisture content, heterogeneous nature, and high heating value. Waste tires are comprised of various materials, including carbon black, fabric, filler, antioxidants, natural rubber, and steel wire, all in different compositions. This study provides an in-depth analysis of the various methods for converting waste tires into biofuels, green chemicals, and innovative materials for energy and environmental applications. The study specifically includes a bibliometric analysis to examine the current research trends, identify knowledge gaps, and explore prospects for waste tire biorefinery. Additionally, a comparative assessment of various traditional strategies for managing waste tires is discussed. The study proposes a new integrated waste tire biorefinery that incorporates multiple methods for the valorization of waste tires, including alternative pathways for integrating thermochemical and biological processes. Bibliometric analysis shows that the frequently used keywords in waste tire-related research include pyrolysis, crumb rubber, recycling, combustion, and activated carbon.

Find the link to the full article here: 

New article: Process design, exergy, and economic assessment of a conceptual mobile autothermal methane pyrolysis unit for onsite hydrogen production

The present study proposes a conceptual mobile autothermal methane pyrolysis unit for onsite hydrogen production. Considering the shortage of hydrogen pipeline infrastructure between production plants and fuelling stations in most places where hydrogen is required, it is imperative to create alternative hydrogen production means. The design combines a catalytic plasma methane pyrolysis unit with a steam char gasification setup, combustion, and biomethanation unit for hydrogen production. The reactor design includes Ni - Br in a bubble column acting as a catalyst. Energy and exergy calculations followed by a comprehensive economic analysis were appraised to evaluate the efficiency and performance of the integrated process. The levelized cost of hydrogen (LCOH) from the conceptual design ranged from 1.3 to 1.47 U.S.$/kg, while the proposed design's net present value (NPV) was in the range of 3.76 – 4.35 M.U.S.$. Factors such as equipment purchase cost (EPC) and feedstock cost significantly influenced the NPV and LCOH. In addition, a positive NPV and lower LCOH outline the proposed design's profitability. Finally, an optimized methane conversion of 76.8 % was obtained from the study. 

Find the link to the full article here:

New article: Pathways for the Valorization of Animal and Human Waste to Biofuels, Sustainable Materials and Value-Added Chemicals

Human and animal waste, including waste products originating from human or animal digestive systems, such as urine, feces, and animal manure, have constituted a nuisance to the environment. Inappropriate disposal and poor sanitation of human and animal waste often cause negative impacts on human health through contamination of the terrestrial environment, soil, and water bodies. Therefore, it is necessary to convert these wastes into useful resources to mitigate their adverse environmental effect. The present study provides an overview and research progress of different thermochemical and biological conversion pathways for the transformation of human- and animal-derived waste into valuable resources. The physicochemical properties of human and animal waste are meticulously discussed, as well as nutrient recovery strategies. In addition, a bibliometric analysis is provided to identify the trends in research and knowledge gaps. The results reveal that the USA, China, and England are the dominant countries in the research areas related to resource recovery from human or animal waste. In addition, researchers from the University of Illinois, the University of California Davis, the Chinese Academy of Sciences, and Zhejiang University are front runners in research related to these areas. Future research could be extended to the development of technologies for on-site recovery of resources, exploring integrated resource recovery pathways, and exploring different safe waste processing methods

Find the link to the full article here:

Conference presentation

Sustainable Bioenergy and Processes Conference. 12th-15th December 2022. Cape Town, South Africa. 

Dr. Okolie will deliver a  guest lecture entitled "Assessing the Economic and Environmental Impacts of different Integrated Biomass Conversion Processes: Current Status And Future Prospects"

New article: Stochastic economic evaluation of different production pathways for renewable propylene glycol production via catalytic hydrogenolysis of glycerol

Hydrogenolysis of crude glycerol is perceived as an alternative route for the production of propylene glycol owing to the environmental challenges and declining petroleum sources. However, the source of hydrogen is still a concern for the implementation of this technology. In this study, we investigated the economic viability of three different renewable propylene glycol (RPG) production pathways. The goal of this study is to determine whether the method used to produce hydrogen affects how economically feasible and environmentally friendly it is to produce RPG from the catalytic hydrogenolysis of glycerol. Our results shows that the source of hydrogen has a significant impact on renewable propylene production pathways. 

Find the link to the full article here: 

New article: Ozone application in different industries: A review of recent developments

Ozone – a powerful antimicrobial agent, has been extensively applied for decontamination purposes in several industries (including food, water treatment, pharmaceuticals, textiles, healthcare, and the medical sectors).  The advent of the COVID-19 pandemic has led to recent developments in the deployment of different ozone-based technologies for the decontamination of surfaces, materials and indoor environments. The pandemic has also highlighted the therapeutic potential of ozone for the treatment of COVID-19 patients, with astonishing results observed. The key objective of this review is to summarize recent advances in the utilisation of ozone for decontamination applications in the above-listed industries while emphasising the impact of key parameters affecting microbial reduction efficiency and ozone stability for prolonged action.   

Find the link to the article below: 

New article: Production of nanoarchitectonics corncob activated carbon as electrode material for enhanced supercapacitor performance

Corncob was utilized as a low-grade and abundant material for the production of activated carbon through impregnation with potassium carbonate (K2CO3) at different ratios (1:1 to 1:3). The impregnated samples were activated at different temperatures (500 °C to 800 °C) and activated carbons were used to fabricate electrodes for energy storage. The results revealed that increasing activation temperature and K2CO3 tailored the surface area (489–884 m2/g), morphological, and topography of the activated carbon to propagate higher energy storage via a predominantly electric double layer (EDL) mechanism. The capacitive performance of the materials obtained at different temperatures is in the order of 650 °C > 500 °C > 800 °C. In 3-electrode cells, a specific capacitance of 325 F/g was reached at a 5 mV/s scan rate. The energy retention and columbic efficiency after 10,000 charge/discharge cycles were maintained at 88 % and 100 %, respectively. 

Find the link to the complete article below: 

New article: Advances in the Applications of Nanomaterials for Wastewater Treatment

Freshwater is in limited supply, and the growing population further contributes to its scarcity. The effective treatment of wastewater is essential now more than ever, because waterborne infections significantly contribute to global deaths, and millions of people are deprived of safe drinking water. Current wastewater treatment technologies include preliminary, primary, secondary, and tertiary treatments, which are effective in removing several contaminants; however, contaminants in the nanoscale range are often difficult to eliminate using these steps. Some of these include organic and inorganic pollutants, pharmaceuticals, pathogens and contaminants of emerging concern. The use of nanomaterials is a promising solution to this problem. Nanoparticles have unique properties allowing them to efficiently remove residual contaminants while being cost-effective and environmentally friendly. In this review, the need for novel developments in nanotechnology for wastewater treatment is discussed, as well as key nanomaterials and their corresponding target contaminants, which they are effective against. The nanomaterials of focus in this review are carbon nanotubes, graphene-based nanosheets, fullerenes, silver nanoparticles, copper nanoparticles and iron nanoparticles. Finally, the challenges and prospects of nanoparticle utilisation in the context of wastewater treatment are presented.

Find the link below: