Sanjay NagarajanUniversity of Bath | UB · Department of Chemical Engineering
Sanjay Nagarajan
BTech MS PhD
About
43
Publications
5,981
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563
Citations
Citations since 2017
Introduction
Experienced researcher in the area of biomass pre-treatment using advanced oxidation processes (AOP). I particularly work on process intensification for bioenergy production and biorefineries using AOPs such as hydrodynamic cavitation and photocatalysis. A Marie Curie CareerFIT Plus Fellowship awardee, Gianni Astarita Young Investigator awardee and a SWAN Teaching Fellowship awardee, currently working as a Lecturer in Chemical Engineering with the University of Bath.
Additional affiliations
July 2021 - July 2022
University of South Wales
Position
- Research Fellow
Description
- PROJECT: Biorefining sewage sludge biosolids to biofuels and platform chemicals • Design and develop a pilot scale anaerobic digestion system for the production of green H2 and volatile fatty acids (VFA). • Monitor product formation via a range of analytical techniques. • Identify and use optimal VFA separation systems to enhance product yield.
July 2021 - present
October 2017 - June 2021
Position
- Research Fellow
Description
- • Develop vortex based hydrodynamic cavitation pre-treatment processes for treating waste biomass such as distillery spent wash, bagasse, bagasse pith, press mud and cane residue (with or without additives). • Quantify performance enhancement interms of biogas yield realised by pre-treatment processes. • Intensification of biogas production • Field scale trials for pre-treatment of various streams.
Education
February 2015 - February 2017
February 2014 - January 2015
August 2009 - December 2010
Publications
Publications (43)
Diazotrophs in the mangrove rhizosphere play a major role in providing new nitrogen to the mangrove ecosystem and their composition and activity are strongly influenced by anthropogenic activity and ecological conditions. In this study, the diversity of the diazotroph communities in the rhizosphere sediment of five tropical mangrove sites with diff...
This work demonstrates a two-step gram-scale synthesis of presynthesized silver (Ag) nanoparticles impregnated with mesoporous TiO2 and evaluates their feasibility for wastewater treatment and hydrogen gas generation under natural sunlight. Paracetamol was chosen as the model pharmaceutical pollutant for evaluating photocatalytic performance. A sys...
Bio-CNG (compressed natural gas) is being actively promoted in India as a cleaner transportation fuel while also providing a sustainable option for agricultural waste management. This work assesses the commercialization potential of Bio-CNG production from sugarcane bagasse by performing a detailed techno-economic and life cycle assessment (LCA). T...
Green hydrogen—a carbon-free renewable fuel—has the capability to decarbonise a variety of sectors. The generation of green hydrogen is currently restricted to water electrolysers. The use of freshwater resources and critical raw materials, however, limits their use. Alternative water splitting methods for green hydrogen generation via photocatalys...
Hydrodynamic cavitation (HC) has been extensively investigated for effluent treatment applications. Performance of HC devices or processes is often reported in terms of degradation of organic pollutants rather than quantification of hydroxyl (OH) radicals. In this study, generation of OH radicals in vortex based cavitation device using coumarin dos...
Safe water is crucial for humans to live a healthy life, and water disinfection is practiced worldwide as an essential operation toward this end. The removal of harmful microorganisms is typically achieved using chemical methods such as chlorination. Most of the physical or physicochemical methods have limitations either in the form of scalability...
Numerous applications of hydrodynamic cavitation are being developed across the globe. Some of these applications are briefly summarized in this chapter. The discussion is organized by dividing these applications into generic types such as gas–liquid, liquid–liquid, and solid–liquid applications. An example or two for each type of application is di...
Water is used extensively in the manufacturing industry as well as in other sectors, including domestic usage. Most of the used water ends up as wastewater—either as sewage or industrial effluent—which needs to be treated before being discharged into the environment. In fact, it is becoming increasingly essential to recycle and reuse treated wastew...
Renewable energy based on lignocellulosic biomass (LCB) plays a central role in decarbonizing, in a variety of sectors. Biogas and bioethanol are two of the most important renewable energy vectors. To facilitate the biochemical transformation of biomass to these biofuels, it is essential to pre‐treat LCB by opening up the complex structure and rend...
This chapter briefly describes design of the experimental set‐up and methods for characterizing hydrodynamic cavitation devices, and includes some comments on selecting an appropriate pump. Specific recommendations are made for planning and executing hydrodynamic cavitation experiments. The common pitfalls in designing and operating the experimenta...
Hydrodynamic cavitation is a promising technology platform with applications in a wide range of processes and industries. The first part of the book brings together the key aspects of devices used for realizing hydrodynamic cavitation, the experimental setup and procedures needed for characterizing such devices, and the different ways of modeling t...
This chapter introduces the basic principles of cavitation induced in rotational or swirling flow devices, and examines the different types of device designs available in the public domain. Rotational/swirling flow devices can be broadly divided into two types: the first uses rotating components in the device (such as a rotor‐stator); the second us...
Hydrodynamic cavitation is the formation, growth and collapse of vapor bubbles due to pressure changes in the flowing liquid. The collapse of such vapor bubbles or cavities was notorious for more than a century for its harmful effects of erosion. In the recent decades, there has been increasing an interest in harnessing cavitation for beneficial ap...
Processes based on hydrodynamic cavitation (HC) harness intense shear, localized hot spots, and in situ generation of hydroxyl radicals for realizing various physicochemical transformations. These transformations involve molecular scale reactions – micro‐scale cavity formation, growth and implosion of bubbles, meso‐scale cavity clusters, and reacto...
The most widely used flow devices in the area of hydrodynamic cavitation are those that force an axial (or linear) flow through a restriction. This produces a local reduction in static pressure close to or beyond the vapor limit of the working fluid, generating vapor formation. The most common device types used are either of orifice or venturi cons...
Food waste (FW) generated through various scenarios from farm to fork causes serious environmental problems when either incinerated or disposed inappropriately. The presence of significant amounts of carbohydrates, proteins, and lipids enable FW to serve as sustainable and renewable feedstock for the biorefineries. Implementation of multiple substr...
Utilising cavitation for enhancing oxidative desulphurization has been investigated for nearly two decades with recent investigations shifting focus from low-capacity acoustic cavitation (AC) to scalable hydrodynamic cavitation (HC). This work focuses on developing a viable means for removing thiophene’s from fuels. In the first phase of this work,...
Utilising ‘wastes’ as ‘resources’ is key to a circular economy. While there are multiple
routes to waste valorisation, anaerobic digestion (AD)—a biochemical means to breakdown organic
wastes in the absence of oxygen—is favoured due to its capacity to handle a variety of feedstocks.
Traditional AD focuses on the production of biogas and fertilis...
Anaerobic digestion can potentially valorise sugarcane bagasse to biogas and fertiliser. Pretreatment is however required to overcome recalcitrance and enhance the biogas yields. Literature reporting the investigation of various biomass pretreatments often use milled biomass as substrate rather than as-received fibrous biomass. This does not establ...
Bread is the second most wasted food in the UK with annual wastage of 292,000 tons. In the present work, bread waste (BW) was utilized for fermentative production of ethanol by Saccharomyces cerevisiae KL17. Acidic and enzymatic saccharification of BW was carried out resulting in the highest glucose release of 75 and 97.9 g/L which is 73.5 and 95.9...
Bread waste (BW) is a severe solid waste management problem in Europe. The current study demonstrates an environment-friendly solution by valorising BW into lactic acid (LA) and the corresponding solid residues generated during hydrolysis and fermentation to biogas. To this end, BW was saccharified through acidic and enzymatic hydrolysis, and the h...
Bread waste (BW) is a severe solid waste management problem in Europe. The current study demonstrates an environment-friendly solution by valorising BW into lactic acid (LA) and the corresponding solid residues generated during hydrolysis and fermentation to biogas. To this end, BW was saccharified through acidic and enzymatic hydrolysis, and the h...
Current anaerobic digestion (AD) design methods rely on crude empirical models or sophisticated anaerobic digestion models (like ADM1) requiring a large number of parameters which are difficult to obtain experimentally. A simplified model for simulating AD was developed in this work. The model requires knowledge of CH4/CO2 ratio in biogas or indige...
Renewable energy, especially biofuels, has the potential to supplement a part of the existing fossil-based transportation fuels. Biofuels such as bioethanol can be produced from established glucose fermentation processes; however, cheap and efficient glucose production is a hindering factor. Cellulose, the world’s most abundant organic material, is...
We have developed artificial neural network (ANN) based models for simulating two application examples of hydrodynamic cavitation (HC) namely, biomass pre-treatment to enhance biogas and degradation of organic pollutants in water. The first case reports data on influence of number of passes through HC reactor on bio-methane generation from bagasse....
In-situ hydroxyl radical production is a characteristic of advanced oxidation processes (AOPs) and its quantification is crucial for assessing the performance of these processes. Direct OH quantification is however unlikely due to their high reactivity and short life-time (~10⁻⁶ s). Therefore, chemical probes (like coumarin) are often used to indir...
Hydrodynamic cavitation (HC) is being increasingly used in a wide range of applications. Unlike ultrasonic cavitation, HC is scalable and has been used at large scale industrial applications. However, no information about influence of scale on performance of HC is available in the open literature. In this work, we present for the first time, experi...
Distilleries generate high COD (chemical oxygen demand) wastewater streams that are anaerobically digested to produce biogas with sub-optimal yields. In this work, for the first time, novel vortex-based hydrodynamic cavitation (HC) pre-treatment of these waste streams was investigated for significantly enhancing biogas yields. Molasses spent wash (...
➢ The conversion of sustainable feedstocks to both energy and high value products, while minimising harmful emissions, is the ultimate objective in renewable energy research.
➢ Photocatalytic technology has shown potential as a low cost environmentally friendly approach to achieve this objective, especially with a view towards cellulose reforming....
Efficient energy production and waste valorisation are the most challenging fields in photocatalysis. Photocatalytic H2 production, specifically in the past have utilised a variety of sacrificial electron donors (SEDs) as feedstocks. Cellulose I (native micro crystalline cellulose) being the world’s most abundant organic material has previously bee...
Lignocellulosic biomass (LCB) is an abundant renewable resource to produce fuels and chemicals. Valorisation of LCB, is however a challenge due to its recalcitrant nature posed by the strongly interlinked cellulose-lignin-hemicellulose structures. A range of physico-chemical and biological LCB pre-treatment methods have been reported in literature...
Hydrodynamic cavitation is being increasingly pursued for developing intensified and compact wastewater treatment process. Experimental data on the degradation of water contaminated with three commonly used solvents – acetone, ethyl acetate (EA) and isopropyl alcohol (IPA) using vortex based cavitation devices is presented. Influence of operating f...
Alternative renewable energy must emerge to sustainably meet the energy demands of the present and future. Current alternatives to fossil fuels are electricity from solar, wind and tidal energies and biofuels. Biofuels, especially bioethanol could be produced from lignocellulosic feedstock via pre-treatment and fermentation. The cellulose I content...
A simple method for determining hydroxyl radical yields on semiconductor photocatalysts is highly desirable, especially when comparing different photocatalyst materials. This paper reports the screening of a selection of visible light active photocatalysts such as Pt-C3N4, 5% LaCr doped SrTiO3, Sr0.95Cr0.05TiO3 and Yellow TiO2 and compares them aga...
To sustainably meet the global energy demand, unconventional methods to produce renewable energy must emerge. Biofuels from cellulose (via fermentable sugar production) mediated via photocatalysis provides an alternative to conventional fossil fuels. In order to effectively drive photocatalytic processes an effective reactor design is required, the...
Methane production by methanogens in mangrove sediments is known to contribute significantly to global warming, but studies on the shift of methanogenic community in response to anthropogenic contaminations were still limited. In this study, the effect of anthropogenic activities in the mangrove sediments along the north and south coastlines of Sin...
Questions
Questions (3)
Concentration range b/w 100-450 ppm at room temperature.
PS: I am a beginner with XRD.
My point of view is that anything is achievable after proper research. According to Wintershine group a daily oil production of 30000 barrels is necessary to make the algal biofuel efficient and profitable. Ofcourse negative GHG emissions are good in case of algal biofuels but it must be profitable in order to have a long run.
Projects
Projects (3)
To evaluate hydrodynamic cavitation generated using a vortex based cavitation device as a lignocellulosic biomass (grass silage and cattle slurry) pre-treatment method for enhanced biogas production.
The aim of this project is to develop an effective, low-tech but sustainable process for the treatment of food waste to enhance biogas production from AD.
To meet the challenges around both climate change and energy sustainability, there is a growing need for alternative clean energy sources. In particular, in order to minimise the reliance on fossil fuel and to contribute to increasing efforts to decarbonise the transport and energy sector, there has been a significant growth in research around green energy biofuels such as bioethanol. The development and utilization of such biofuels may contribute to future energy security through a reduction in hydrocarbon fuels such as oil and gas. Currently biofuels such as bioethanol contribute around 2% of total transport fuel demand with this predicted to rise to around 27% towards world transport fuel by 2050. By 2020, the European Union will require 10% of the energy sources to be derived from renewable energy sources. Furthermore in the USA it is expected that 30% of energy needs will be derived from biofuel supplies by 2030 (Knocke and Vog, 2009; Viikari et al., 2012). The production of bioethanol however has resulted in a significant impact on food production through the extensive harvesting of food crops (i.e. 1st generation crops) for energy conversation. For instance, in Brazil large-scale bioethanol is produced by the fermentation of sugar cane while in the USA corn is used.
The aim of this research project is the development of a method of releasing fermentable sugars from cellulose. Current methods use expensive enzymes, extreme temperature and caustic chemicals hence we propose the use of ambient temperature low energy photocatalysis for the degradation of cellulose. The released sugars will be rapidly removed from the reaction vessel and immediately fermented to produce bioethanol.
