Evaluation of bio-asphalt binders modified with biochar: a pyrolysis by-product of Mesua ferrea seed cover waste

With growing global concerns related to energy security and sustainability, interest in bio-fuels has increased significantly. Production of biofuel mostly begins with pyrolysis, a process that converts the biomass to liquid biooil, solid biochar and gases. A large amount of carbonaceous biochar is generated as a by-product during the pyrolysis. However, no major effort has been made in the past decade to utilize the biochar in pavement applications, especially as a bio-modifier to asphalt binders. In this study, an attempt was made to evaluate the carbonaceous biochar, obtained during bio-fuel production through pyrolysis of Mesua ferrea seed cover waste, as an asphalt modifier/extender to obtain bio-asphalts. Physical and chemical characterizations of biochar were carried out using scanning electron microscopy, Fourier transform infrared spectroscopy and energy dispersive X-ray analysis. This was followed by rheological characterization of asphalt binders (from two sources) modified with various concentrations of biochar (0, 5, 10, 15, and 20% by weight of binder). Flow behaviour, permanent deformation, and fatigue characteristics of bio-asphalts were evaluated and compared with control binders (no biochar). Aging susceptibility of biochar modified binders was also evaluated and compared for biochar contents and binder sources. Permanent deformation behaviour evaluated through multiple stress creep and recovery (MSCR) test indicated that the use of biochar improved the rutting resistance of binders. Improved binder performance against the effects of aging and deformation with the use of biochar makes it a promising asphalt modifier, especially for the warm tropical climatic conditions prevalent in India

Окислювальний синтез активованого вуглецю із низькосортного індійського третинного вугілля та його хімічні характеристики

Вуглецеві матеріали мають унікальні структурно-хімічні властивості, тому є привабливими для застосування в різних галузях. Вугілля доступне в достатку і є недорогим джерелом енергії. Вугілля також є основним джерелом вуглецю, який можна використовувати як прекурсор для отримання вуглецевих продуктів з доданою вартістю і, таким чином, підвищити його ефективне використання на стійкій основі. У дослідженні активований вуглець готували з третинного вугілля, отриманого з північно-східного регіону Індії. Процес підготовки складався з попередньої обробки вугілля шляхом окислення з подальшим просоченням змішаними лугами і карбонізацією при 600° C. Синтезовані зразки були охарактеризовані за допомогою наближеного та елементного аналізу, аналізу сірки, аналізу площі поверхні та розміру пор, просвічуючої електронної мікроскопії (TEM), інфрачервоної спектроскопії з перетворенням Фур'є (FTIR) та аналізу порошкової рентгенівської дифракції (XRD). Результати показують, що отриманий активований вуглець має покращену питому площу поверхні та розмір пор після хімічної активації і має аморфну, мікромезопористу природу. Таким чином, низькосортне індійське третинне вугілля є потенційним джерелом для отримання вуглецевих продуктів з високою доданою вартістю на основі активованого вуглецю.Carbon materials have unique structural and chemical properties attracting for applications in various fields. Coal is available in abundance and a low-cost energy source. Coal is a major source of carbon which can be used as a precursor to derive value-added carbon products and thereby, enhances its effective utilization in a sustainable manner. In this study, activated carbons were prepared from tertiary coal obtained from North-eastern region of India. The preparation process consisted of pre-treatment of coal by oxidation followed by mixed alkali impregnation and carbonization at 600 °C. The synthesized samples were characterized using proximate and ultimate analysis, sulfur analysis, surface area and pore size analysis, transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and powder X-ray diffraction (XRD) analysis. The results reveal that the produced activated carbons have improved specific surface area and pore size after chemical activation, and they are amorphous, micro-mesoporous in nature. Thus, the low-grade Indian tertiary coals are a potential source to derive activated carbon based high value-added carbon products

Evaluation of bio-asphalt binders modified with biochar: a pyrolysis by-product of Mesua ferrea seed cover waste

With growing global concerns related to energy security and sustainability, interest in bio-fuels has increased significantly. Production of biofuel mostly begins with pyrolysis, a process that converts the biomass to liquid biooil, solid biochar and gases. A large amount of carbonaceous biochar is generated as a by-product during the pyrolysis. However, no major effort has been made in the past decade to utilize the biochar in pavement applications, especially as a bio-modifier to asphalt binders. In this study, an attempt was made to evaluate the carbonaceous biochar, obtained during bio-fuel production through pyrolysis of Mesua ferrea seed cover waste, as an asphalt modifier/extender to obtain bio-asphalts. Physical and chemical characterizations of biochar were carried out using scanning electron microscopy, Fourier transform infrared spectroscopy and energy dispersive X-ray analysis. This was followed by rheological characterization of asphalt binders (from two sources) modified with various concentrations of biochar (0, 5, 10, 15, and 20% by weight of binder). Flow behaviour, permanent deformation, and fatigue characteristics of bio-asphalts were evaluated and compared with control binders (no biochar). Aging susceptibility of biochar modified binders was also evaluated and compared for biochar contents and binder sources. Permanent deformation behaviour evaluated through multiple stress creep and recovery (MSCR) test indicated that the use of biochar improved the rutting resistance of binders. Improved binder performance against the effects of aging and deformation with the use of biochar makes it a promising asphalt modifier, especially for the warm tropical climatic conditions prevalent in India

Bioengineering to Accelerate Biodiesel Production for a Sustainable Biorefinery

Biodiesel is an alternative, carbon-neutral fuel compared to fossil-based diesel, which can reduce greenhouse gas (GHGs) emissions. Biodiesel is a product of microorganisms, crop plants, and animal-based oil and has the potential to prosper as a sustainable and renewable energy source and tackle growing energy problems. Biodiesel has a similar composition and combustion properties to fossil diesel and thus can be directly used in internal combustion engines as an energy source at the commercial level. Since biodiesel produced using edible/non-edible crops raises concerns about food vs. fuel, high production cost, monocropping crisis, and unintended environmental effects, such as land utilization patterns, it is essential to explore new approaches, feedstock and technologies to advance the production of biodiesel and maintain its sustainability. Adopting bioengineering methods to produce biodiesel from various sources such as crop plants, yeast, algae, and plant-based waste is one of the recent technologies, which could act as a promising alternative for creating genuinely sustainable, technically feasible, and cost-competitive biodiesel. Advancements in genetic engineering have enhanced lipid production in cellulosic crops and it can be used for biodiesel generation. Bioengineering intervention to produce lipids/fat/oil (TGA) and further their chemical or enzymatic transesterification to accelerate biodiesel production has a great future. Additionally, the valorization of waste and adoption of the biorefinery concept for biodiesel production would make it eco-friendly, cost-effective, energy positive, sustainable and fit for commercialization. A life cycle assessment will not only provide a better understanding of the various approaches for biodiesel production and waste valorization in the biorefinery model to identify the best technique for the production of sustainable biodiesel, but also show a path to draw a new policy for the adoption and commercialization of biodiesel

Attitudes of food consumers at universities towards recycling human urine as crop fertiliser: A multinational survey dataset

We present here a data set generated from a multinational survey on opinions of university community members on the prospect of consuming food grown with human urine as fertiliser and about their urine recycling perceptions in general. The data set comprises answers from 3,763 university community members (students, faculty/researchers, and staff) from 20 universities in 16 countries and includes demographic variables (age bracket, gender, type of settlement of origin, academic discipline, and role in the university). Questions were designed based on Ajzen's theory of planned behaviour to elicit information about three components of behavioural intention-attitudes, subjective norms, and perceived behavioural control. Survey questions covered perceived risks and benefits (attitudes), perceptions of colleagues (injunctive social norm) and willingness to consume food grown with cow urine/faeces (descriptive social norm), and willingness to pay a price premium for food grown with human urine as fertiliser (perceived behavioural control). We also included a question about acceptable urine recycling and disposal options and assessed general environmental outlook via the 15-item revised New Ecological Paradigm (NEP) scale. Data were collected through a standardised survey instrument translated into the relevant languages and then administered via an online form. Invitations to the survey were sent by email to university mailing lists or to a systematic sample of the university directory. Only a few studies on attitudes towards using human urine as fertiliser have been conducted previously. The data described here, which we analysed in "Willingness among food consumers at universities to recycle human urine as crop fertiliser: Evidence from a multinational survey"[1], may be used to further understand potential barriers to acceptance of new sanitation systems based on wastewater source separation and urine recycling and can help inform the design of future sociological studies. (C) 2021 The Author(s). Published by Elsevier Inc

Willingness among food consumers to recycle human urine as crop fertiliser: Evidence from a multinational survey

Source-separating sanitation systems offer the possibility of recycling nutrients present in wastewater as crop fertilisers. Thereby, they can reduce agriculture's impacts on global sources, sinks, and cycles for nitrogen and phosphorous, as well as their associated environmental costs. However, it has been broadly assumed that people would be reluctant to perform the new sanitation behaviours that are necessary for implementing such systems in practice. Yet, few studies have tried to systematically gather evidence in support of this assumption. To address this gap, we surveyed 3763 people at 20 universities in 16 countries using a standardised questionnaire. We identified and systematically assessed cross-cultural and country-level explanatory factors that were strongly associated with people's willingness to consume food grown using human urine as fertiliser. Overall, 68% of the respondents favoured recycling human urine, 59% stated a willingness to eat urine-fertilised food, and only 11% believed that urine posed health risks that could not be mitigated by treatment. Most people did not expect to pay less for urine-fertilised food, but only 15% were willing to pay a price premium. Consumer perceptions were found to differ greatly by country and the strongest predictive factors for acceptance overall were cognitive factors (perceptions of risks and benefits) and social norms. Increasing awareness and building trust among consumers about the effectiveness of new sanitation systems via cognitive and normative messaging can help increase acceptance. Based on our findings, we believe that in many countries, acceptance by food consumers will not be the major social barrier to closing the loop on human urine. That a potential market exists for urine-fertilised food, however, needs to be communicated to other stakeholders in the sanitation service chain. (C) 2020 The Author(s). Published by Elsevier B.V