Mixed Waste Research Articles

Upgrading Mixed Plastic Waste through Industrial Symbiosis: Pseudoductile Regenerated Cellulose Fiber-Reinforced Shredder Residue Composites

Upgrading Mixed Plastic Waste through Industrial Symbiosis: Pseudoductile Regenerated Cellulose Fiber-Reinforced Shredder Residue Composites

Sensitive imaging of actinide materials in shielded radioactive waste

This paper reports on the development of a method for enhanced non-destructive assay (NDA) of radioactive waste using the novel technique neutron-gamma emission tomography (NGET). The technique relies on the detection of correlated fast neutrons and gamma rays emitted in spontaneous or induced fission. It is based on fast organic scintillators and enables sensitive detection and three-dimensional (3D) localization of the fission events. The technique is passive and does not require moving components. In this work, we apply the NGET technique to the category of radioactive waste which is often referred to as historic or legacy waste. This can include mixed wastes encased in shielded containers many decades ago, before the advent of detailed waste description criteria. These low or intermediate level wastes are often associated with lacking, limited or conflicting documentation. This poses a challenge when assigning the waste to the proper disposal route as well as in deciding whether the waste needs to undergo sorting and conditioning to fulfil waste acceptance criteria both with regards to safe interim storage and to its ultimate disposal. Actinides, such as isotopes of uranium and plutonium, with their typically long half-lives and decay chains are of special interest in this regard since they may challenge the long-term safety assessment in repositories predicated on mainly shorter half-life radionuclides if undetected. Accurate identification and localisation of actinides is also important from a safeguards perspective, especially since they are generally difficult to detect and localise by established passive means due to their relatively weak radiation emissions, in particular in shielded containments and in the presence of strong radiation fields from other radioactive materials. In this paper we present findings of measurements on shielded containments of long-lived radioactive waste performed at the Studsvik site in Sweden, as well as measurements on a laboratory assembly simulating a grouted waste drum. Similarities and differences between the novel NGET technique and a commercially available gamma imaging system are also briefly discussed.

Combined thermochemical-biotechnological approach for the valorization of polyolefins into polyhydroxyalkanoates: Development of an integrated bioconversion process by microbial consortia

Waste management of persistent polymers such as polyolefins (PO)1 still represents a major challenge, often leading to material loss from the value chain and contributing to plastic pollution. This study investigated an integrated process to valorize PO pyrolysis side stream. PO wax was recovered and used as a feedstock for a microbial bioconversion process. A modified emulsification protocol (using two-surfactants system) allowed the successful dispersion and bioconversion of PO wax without the need of the extra oxidation step. Enrichment of plastic landfill inocula allowed to develop efficient mixed microbial consortia (MMC) able to grow on PO wax. Adaptive laboratory evolution improved 4 times cell growth, leading to 2.6–17.3 times shorter lag phase. The bioconversion process using the adapted MMC was performed in a 2 L-bioreactor with PO wax-emulsified media (10 g L−1) at neutral pH and 20% pO2. 87% of substrate was consumed within 12 h and complete consumption was achieved within 48 h (4 times faster than previously reported). A maximum of 2.95 gCDW L−1of biomass was produced, while the intracellular triglycerides reached a maximum of 105.5 mg L−1 at 30 h. Moreover, the conversion of PO wax into polyhydroxyalkanoates (PHAs) was demonstrated and the production was maximized by statistical optimization. Maximum PHA titer of 384 0.1 mg L−1 was achieved, which represents a 1.5–17 times improvement from previous reports. This integrated thermochemical-biotechnological approach might represent an interesting strategy to valorize and upcycle currently unrecyclable PO-rich mixed plastic waste streams, thus improving the circularity of the plastic sector.

Catalytic Conversion of Plastic Waste into Diesel Fuel through Pyrolysis and Hydroprocessing

This study evaluates the potential of hydro-processed plastic pyrolysis oil (HPO) as a sustainable alternative fuel derived from mixed plastic waste. The physicochemical properties of diesel, mixed plastic pyrolysis oil (MPPO), and HPO were thoroughly analyzed according to IS standards, enabling a direct comparison and alignment of HPO characteristics with EN590 diesel fuel standards. Gas chromatography-mass spectrometry (GC-MS) analysis identified key fuel components—n-alkanes, alkenes, benzene, and naphthalene with HPO showing 98% compositional similarity to commercial diesel. The HPO blend with various percentage of pure diesel ratio is (30:70, 60:40 and 90:10). The hydroprocessing technique effectively reduced the alkene content of MPPO, enhancing the purity and quality of the resulting HPO. This refinement was crucial in ensuring that the oil met the necessary fuel standards. Engine performance evaluations further indicated that blending HPO with conventional diesel resulted in emissions with 95% similarity to those of standard diesel fuel. This close match in emission profiles underscores the potential of HPO as a cleaner and more environmentally friendly fuel alternative. Additionally, the increased aromatic content in HPO, due to hydroprocessing, significantly improved combustion properties. This enhancement not only supports the feasibility of using HPO as a substitute for traditional diesel but also suggests that HPO may offer superior performance in specific applications. Overall, these findings highlight the potential of HPO as a sustainable fuel option, capable of addressing the environmental impacts associated with both plastic waste and fossil fuel consumption. The study demonstrates the environmental benefits of converting plastic waste into valuable fuel through pyrolysis and hydroprocessing, offering a promising strategy for sustainable plastic waste management and advancements in environmental sustainability and the fuel industry.

Environmental And Health Implications of Waste Disposal Sites In The Lesotho Lowlands

Many Southern African countries, including Lesotho, face severe health and environmental issues attributed to waste disposal. The purpose of this study is to assessed the environmental and health impacts on residents living in proximity to disposal sites in the lowlands of Lesotho. A descriptive cross-sectional design was employed, using a semi-structured questionnaire and observation method. A mapping device was used, and photographs were taken to validate the findings. Descriptive statistics and the Chi-square test (?²) were employed to analyze the data. Results indicate that in Lesotho, some landfill sites are located as close as 50 meters from residential areas, and most (60%) received hazardous mixed waste streams. Waste burning and backyard dumping were the most frequently used disposal methods by residents. Several perceived health outcomes and environmental issues were noted, with respiratory and gastrointestinal health issues being the most prevalent. There was a statistically significant association between waste burning and respiratory diseases (P < 0.010) and between backyard dumping and gastrointestinal diseases (P < 0.003). The study concludes that regulatory instruments need to be revised and enforced, requiring hazardous waste producers to take responsibility for end-of-life waste and banning the entry of such waste into disposal sites. The application of waste management strategies to initiate other preferable end-of-life waste procedures, such as recycling of WEEE and waste-to-energy technologies for organic waste in Lesotho, could improve the quality of health for residents and their environment.

Utilization of Maggot Larvae (Hermetia illucens) for Processing Food Waste at the UIN Raden Intan Lampung Canteen

Waste management using maggot larvae (Hermetia illucens) can be an innovative strategy for reducing organic waste. This study aims to determine the effectiveness of maggot larvae in processing organic waste at the UIN Raden Intan Lampung Canteen. The research used a Completely Randomized Design (CRD) technique with 3 treatments and 3 replications. The observed parameters were duration, residue, and maggot weight. The organic waste used included vegetables, fruits, rice, and bones. The results showed that for bone and rice waste, maggots were able to reduce waste by 80%, producing an average residue of 141.3 grams with a decomposition duration of 515 minutes and a final maggot weight of 320.67 grams. For fruit and vegetable waste, maggots reduced waste by 58%, producing an average residue of 293 grams with a decomposition duration of 395 minutes and a final maggot weight of 560.33 grams. For mixed waste, maggots reduced waste by 81% with a decomposition duration of 496.6 minutes and a final maggot weight of 430.3 grams.

Photooxidation of Polyolefins to Produce Materials with In-chain Ketones and Improved Materials Properties.

Herein, we report a selective photooxidation of commodity postconsumer polyolefins to produce polymers with in-chain ketones. The reaction does not involve the use of catalyst, metals, or expensive oxidants, and selectively introduces ketone functional groups. Under mild and operationally simple conditions, yields up to 1.23 mol% of in-chain ketones were achieved. Installation of in-chain ketones resulted in materials with improved adhesion of the materials and miscibility of mixed plastics relative to the unfunctionalized plastics. The introduction of ketone groups into the polymer backbone allows these materials to react with diamines, forming dynamic covalent polyolefin networks. This strategy allows for the upcycling of mixed plastic waste into reprocessable materials with enhanced performance properties compared to polyolefin blends. Mechanistic studies support the involvement of photoexcited nitroaromatics in consecutive hydrogen and oxygen atom transfer reactions.

Environmental and economic assessment of mixed plastic waste pelletization in the Gulf Cooperation Council region

Pelletizing mixed plastic wastes (MPW) has gained interest as an upcycling technology and an alternative to conventional recycling. To investigate its potential, we conducted a cost analysis and life-cycle assessment (LCA) for a conceptual pelletization facility designed to produce 1 kg of pellets per batch of MPW (comprising polyethylene—PE and polypropylene—PP). This work has the following merits: (i) evaluating environmental impact (EI), cost analysis, and mechanical strength based on actual experimental data and its comparison with local and international manufacturers; (ii) enabling the evaluation of LCA impacts of MPW pellets; and (iii) emphasizing the significance of waste management in reducing EIs. The following ten EIs were assessed: climate change (CC), net energy, particulate matter formation, natural land transformation, metal depletion, marine ecotoxicity, ionising radiation, freshwater ecotoxicity, freshwater eutrophication, and terrestrial ecotoxicity. The CC of the as-synthesized pellets is 1.26 kg CO2 eq., significantly lower than the data obtained from the Gulf Petrochemicals and Chemicals Association (GPCA) and an actual plant in Gulf Cooperation Council (GCC) countries. Additionally, the net energy required for the production of 1 kg of pellets is 54.1 MJ, while the cost is around 0.55 USD. The tensile strength of MPW pellets (24.63 MPa) falls between that of PE virgin pellets (21.12 MPa) and PP virgin pellets (28.12 MPa). This suggests that the MPW pellets exhibit competitive strength characteristics, warranting its consideration for applications where moderate strength is required. Overall, the competitive cost, coupled with the reduced EIs, demonstrates the potential of pelletization as a sustainable and economically viable waste management solution.

Waste 4.0: transforming medical waste management through digitalization and automated segregation

Medical waste management is a crucial issue due to its potential health risks to humans and harm to the environment. The World Health Organization (WHO) advises separating medical waste into seven groups based on its type. However, despite the implementation of color-coded bin bags, cases of missegregation still occur frequently, leading to injuries and spreading diseases. Infectious waste such as sharps, human tissue, and body parts are often found mixed in waste bins, posing a severe threat to waste employees. To address this issue, this paper proposes exploring the potential of digitalization in waste segregation. The literature on current segregation methods and technology applications is analysed and compared, and a framework for utilizing barcode tagging and scanning to ensure waste is correctly categorized is presented. The barcodes and scanner will be connected through a monitoring system, which can notify waste generators and collectors of misplacing or mixed waste. This digitalization system is expected to serve as a monitoring agent for segregating waste before it is collected from any health facilities. Additionally, the exchanged data from waste generator bins can inform collectors and other waste stakeholders about the waste's condition, potentially opening up opportunities for recycling companies to purchase used plastics or metals from hospital wastes. By implementing digitalization in medical waste management, waste segregation can improve, reduce the spread of diseases and injuries, and promote the recycling of hospital waste materials.

Applications of H2-Enriched syngas and slag products from plastic wastes via novel plasma dual-stage-arc pyrolysis

Sustainable plastic waste management in the prevailing ‘new-normal’ post-pandemic scenario calls for calorific waste plastic up-cycling into high-end product recovery pathways. The present work employed a novel dual-stage arc plasma pyrolysis reactor to recover syngas and slag products from mixed plastics and Low-Density Polyethylene and Polyethylene Terephthalate (LDPE-PET) plastic waste feeds. Syngas product yield decreased while the solid slag yield increased with rising arc current, attaining 75% and 25% for mixed plastic waste feed and 59% and 41% for LDPE-PET wastes, respectively, at 200A arc current. The resultant syngas composition showed 83% and 77% H2 while 1.7% and 2.7% CO for mixed plastic waste-feed and LDPE-PET wastes, respectively, with no significant presence of CO2. Slag characterization studies revealed the presence of scattered pores on the slag surface, graphitic nanostructures due to scraped carbon depositions from electrode tips and the absence of aromatic groups due to complete conversion. High carbon content was observed in the slag due to the dissociation of lighter hydrocarbon and carbon dioxide on dual-arc exposure in two stages, underscoring the higher efficiency. For holistic integrated circular onsite ‘plastic waste-to-resource’ recovery-cum-application, electricity was generated from the resultant syngas and the slag was used for the manufacture of tiles in the community platform. Techno-economic evaluation of an up-scaled plasma pyrolysis facility shows the power recovery of 3.5 kWh/kg of waste plastic, with a net annual profit of $2800 and a payback period of 1.7 years. The findings of the present work suggest that the proposed integrated dual-arc plasma pyrolysis based plastic waste-to-resource recovery in circular-economy model has a viable outcome.

Comparative analysis of N2 and H2 atmospheres in fast pyrolysis of mixed palm waste: Optimizing deoxygenation and hydrocarbon yield

Comparative analysis of N2 and H2 atmospheres in fast pyrolysis of mixed palm waste: Optimizing deoxygenation and hydrocarbon yield

Vision-based sorting in mixed food-inorganic waste stream

Processing food waste is crucial for environmental conservation and resource recovery, but inadequate sorting can lead to inorganic waste mixing with food waste. The mixed waste stream reduces the efficiency of food waste treatment facilities, and the preliminary sorting relies heavily on manual labor. To address the challenge of a non-homogeneous food-inorganic waste stream, this study proposes a vision-based system for effective sorting. A real-life Mixed Food-Inorganic Waste (MFIW) dataset containing over 13,000 samples and four categories of inorganic waste was created. Based on the dataset analysis, a Waste detection model using Deformable Convolution v3 was employed, and the appropriate positioning and classification algorithm was chosen for optimal detection performance. The Waste detection model achieves an mAP50 of 85.21 %, and the average recalls for packages, trash bags, and animal bones exceed 94 %. Additionally, the model runs at a real-time frame rate of 33.61 FPS, highlighting its suitability for industrial applications.

Co-pyrolysis of furniture wood with mixed plastics and waste tyres: assessment of synergistic effect on biofuel yield and product characterization under different blend ratio

Pyrolysis of waste furniture wood, mixed plastics and waste tyres was examined separately and in different combinations from the perspective of improved value products and energy production. The effect of different combinations of furniture wood, plastics and tyres on the product distribution during co-pyrolysis was analyzed. The experimental work throughout this study was performed at a temperature of 500 °C. Prior to the pyrolysis experiments, thermogravimetric analysis was done to assess the thermal degradation behavior of all selected feedstocks. During individual pyrolysis, mixed plastic wastes produced 70.6 wt% of pyrolysis liquid, which is 37.9% and 33.4% more than furniture wood and waste tyres. During co-pyrolysis, a binary blend of mixed plastics and waste tyres produced 63.3 wt% of pyrolysis liquid, which is 7.65% more than the logarithmic mean value, indicating a positive synergistic interaction on liquid production. The liquid yield of the ternary blend was observed to be as low as 54.4 wt% due to the lower volatiles present in the blend. The presence of volatiles in the feedstock is correlated with the production of liquids by individual and co-pyrolysis. For feed-flexible, more efficient, and cleaner operating systems, the increased liquid production offers crucial information. With the use of Fourier transform infrared spectroscopy (FT-IR) and gas chromatography/mass spectroscopy (GC–MS), the impact of different combinations on product characterization was investigated. The characterization study of the pyrolysis liquid obtained from mixed plastics showed the presence of different aromatic and aliphatic compounds. The findings offered viable options for efficiently utilizing waste materials, particularly plastics and tyres to improve the quality and substance of products.

Normative influence on intention to segregate household waste: Reflections from a low-middle income city in urban Africa

ABSTRACT Household waste segregation is crucial for better domestic waste management, successful material recovery programs, environmental pollution reduction, and the promotion of circular economies. While prevalent in developed nations, global adoption of household waste segregation is lacking, particularly evident in emerging economies where city authorities grapple with mounting volumes of mixed waste. Our study, conducted in the Greater Accra Metropolitan Area, surveyed 1,245 households using a multi-stage sampling technique. Employing structural equation modeling, we assessed how descriptive, injunctive, and moral norms influence individuals’ intention to segregate household waste, considering sociodemographic attributes and policy effectiveness. Findings underscore the significance of descriptive and moral norms, affirming their impact on pro-environmental behaviors. The study reiterates the influential role of education, age, and neighborhood characteristics in moderating these norms and recommends the implementation of persuasive policies, like waste-for-cash incentives, backed by logistical support, infrastructure, and public education to foster household waste segregation and elevate waste management practices.

Second Life for Recycled Concrete and Other Construction and Demolition Waste in Mortars for Masonry: Full Scope of Material Properties, Performance, and Environmental Aspects

This review presents the scope of current efforts to utilize recycled construction and demolition waste in mortars for masonry. More than 100 articles are divided into groups pertaining to the type of mortar, different binder systems, the type of construction and demolition waste (CDW), and its utilization specifics. Cement-based mortars dominate this research domain, whereas recycled concrete is the main material employed to replace virgin aggregates, followed by recycled masonry and recycled mixed waste aggregates. Such application in cement-based mortars could increase water demand by 20–34% and reduce strength by 11–50%, with recycled concrete aggregates being the most favorable. Natural aggregate substitution is disadvantageous in strong mortars, whereas weaker ones, such as lime-based mortars, could benefit from this incorporation. The extent of this topic also suggests possibilities for different recycled material use cases in mortars for masonry, although the available literature is largely insufficient to infer meaningful trends. Nonetheless, the most relevant knowledge synthesized in this review offers promising and environment-conscious utilization pathways for recycled concrete and other construction and demolition waste, which brings opportunities for further research on their use in mortars for masonry and industrial-scale applications.

Efficient methane fermentation from the waste of a novel straw alkali-heat pretreatment-butyric acid fermentation process

ABSTRACT The butyric acid biorefinery technology for straw is highly significant for environmental protection and the restructuring of the energy system. However, this process produces waste from alkali-heat pretreatment (PW) and butyric acid fermentation (FW). In this study, the feasibility of methane fermentation from the wastes was confirmed, with the methane production from PW and FW of 351.1 ± 11.8 and 741.5 ± 14.2 mLCH4/gVS, respectively. The initial pH and V FW/V PW of methane fermentation using the mixed waste of PW and FW were optimized at 7.5 and 1.8, respectively. The methane fermentation using the mixed waste was also verified by operating two anaerobic digesters in sequencing batch mode. At the V FW/V PW of 0.25 (actual ratio), methane production was 301.20 mLCH4/gVS with the waste load of 0.64 kgVS/m³/d. When the V FW/V PW was 1.8 (optimal ratio), methane production reached 396.45 mLCH4/gVS at the waste load of 1.20 kgVS/m3/d. This study facilitates the comprehensive utilization of all components within rice straw.

Performance Characteristics of a Compression Ignition (CI) Engine Using an Environmentally Friendly Waste Plastic Fuel

Due to growing demands and depleting reserves of petroleum-based fuel, there is a necessity to find an alternative fuel for IC engines. Also, environmental concerns and globally faced problems like lots of garbage generated through plastics is a major issue in India. There is a significant disparity between plastic production and waste plastic generation. Therefore, the need for alternative fuels derived from municipal plastic waste has emerged to enhance the performance of IC engines, decrease emissions, and address other environmental concerns in line with the “Swachh Bharat Mission of India”. In this study, the alternative fuel was produced from a municipal mix of plastic waste by pyrolysis process. The experiments were carried out with a constant speed of 1500 rpm at different load conditions and fueled with standard diesel, waste plastic fuel and other blends to investigate IC engine performance and combustion and emissions in terms of brake thermal efficiency, brake power, brake specific fuel consumption, cylinder pressure, net heat release, mean gas temperature, rate of pressure rise, andbrake specific CO2, NOx, CO and HC emissions parameters were investigated and it is compared with standard diesel. The overall result shows that WPO20D80 and WPO30D70 exhibit the peak performance (torque, BP, BTE and BSFC) and lowest emissions (HC, CO, NOx) at all load conditions. Moreover, according to all the performance results, the lowest BSFC with maximum brake thermal efficiency and variations was 24.01% and 0.346 Kg/kWh for the WPO30D70 blend at part load condition. The minimum brake-specific NOx produced by the diesel blend at peak load conditions (WPO20D80) is 138.66 ppm, which is higher than other blends. This phenomenon may be attributed to an elevated proportion of pre-combustion and an extended ignition duration, resulting in a high cylinder temperature and an enhanced rate of heat release. This analysis contributes to a deeper understanding of the environmental implications associated with different fuel blends and load conditions. Notably, the blends ranging from 10% to 50% showed good tendencies to be utilized with diesel engines and consistently exhibit favourable brakespecific emission profiles, suggesting its potential as an environmentally friendly alternative fuel.

An innovative technology for producing agricultural Jiaosu from fruit waste without additional sugar and water: Fermentation characteristics, microbial community, and its impact on the growth of pakchoi

Landfilling or incineration of fruit waste causes serious environmental problems and economic losses. Agricultural Jiaosu (AJ) can convert fruit waste into agricultural inputs. However, traditional AJ preparation requires large amounts of brown sugar and water, restricting its large-scale application. In this study, five types of single fruit waste and one type of mixed fruit waste were used to produce AJ without additional of sugar and water. The physicochemical properties and microbial community dynamics of AJ fermentation were analyzed, and the effects and potential mechanism of AJ in promoting pakchoi growth were evaluated. The results showed that during the digestion process, the pH value of all AJ gradually decreased to below 3.6. Organic acids were the main metabolites, lactic acid and acetic acid accounted for 46.55 %–99.22 % of all organic acids. As fermentation progressed, Firmicutes gradually replaced Proteobacteria as the most dominant phylum, accounting for 54.1 %–99.41 % of the microbial communities. After 90 days, Lactobacillus and Lentilactobacillus were the dominant genera in all AJ, accounting for 44.49 %–92.54 % of the communities. Structural equation modeling revealed that AJ promoted plant growth through organic acids and bacterial community. This study is the first time to propose the concept of producing AJ from fruit waste without additional sugar and water and reveals the fermentation characteristics and microbial dynamics of AJ, as well as its potential mechanism as a biological inoculant in promoting plant growth. This study provides a new approach for the large-scale utilization of fruit waste to produce green agricultural inputs.Abbreviations: AJ, agricultural Jiaosu; ANOVA, analysis of variance; ASVs, amplicon sequence variants; DNA, deoxyribonucleic acid; HPLC, high performance liquid chromatography; LDA, linear discriminant analysis; LEfSe, linear discriminant analysis effect size; PCoA, Principal coordinates analysis; PCR, polymerase chain reaction; RDA, redundancy analysis; rRNA, ribosomal RNA; SEM, structural equation modeling.

Characterization of bio-crude produced by graphene carbon tetranitrate catalyzed hydrothermal liquefaction and ultrasonication of Ulva prolifera mixed Chicken waste

<p style="text-align:justify;"><span style="font-family:"Times New Roman",serif;font-size:12pt;line-height:200%;">The utilization of macroalgae, specifically </span><em><span style="font-family:"Times New Roman",serif;font-size:12pt;line-height:200%;">Ulva prolifera</span></em><span style="font-family:"Times New Roman",serif;font-size:12pt;line-height:200%;">, for the manufacture of bio-crude demonstrates great potential as a viable alternative to conventional fossil fuels. This is mostly owing to its abundant availability and renewable characteristics, making it an optimal choice for bio-oil production. This study examined the synthesis of bio-crude through the Hydrothermal Liquefaction (HTL) method. The combination of Ultra-sonicated </span><em><span style="font-family:"Times New Roman",serif;font-size:12pt;line-height:200%;">Ulva prolifera</span></em><span style="font-family:"Times New Roman",serif;font-size:12pt;line-height:200%;">, Chicken Waste, and water facilitated the transformation of the moist biomass into Bio-crude. The study also examined the influence of process parameters, including the optimal operational temperature, retention time, and feedstock mixing ratio (275 <sup>o</sup>C, 30 minutes, and 1:4 ratio) for the graphene-C<sub>3</sub>N<sub>4 </sub>catalyst, KOH. The study's findings verified that a significant amount of bio-oil, specifically 23.5wt.% based on dry weight measurements, was successfully produced. The bio-oil mostly consists of alcohols, esters, phenols, ketones, and acidic chemicals. Furthermore, the bio-oil exhibited a significant heating value of 38.15 MJ/kg, which can be attributed to the presence of carboxylic acid groups and aliphatic hydrocarbons. Furthermore, the carbon content in the bio-oil was found to be double that of the macroalgae used as feedstock. Additionally, the heating value of the bio-oil was shown to be 2.5 times greater than that of the macroalgae. Hydrothermal liquefaction may be used to efficiently create bio-oil from </span><em><span style="font-family:"Times New Roman",serif;font-size:12pt;line-height:200%;">Ulva prolifera</span></em><span style="font-family:"Times New Roman",serif;font-size:12pt;line-height:200%;">, a third-generation fuel that has great potential as an environmentally benign and sustainable energy source.</span></p>

A comprehensive characterisation of food waste for its sustainable and holistic management using thermochemical processes

ABSTRACT This work presents a comprehensive physico-chemical analysis of mixed food waste (MFW) as a good feed for the thermochemical conversion process followed by its utilisation in the pyrolysis and gasification processes. The chemical analysis showed that MFW contained not only typical biomass contents, such as lignin (15.04%), cellulose (26.20%) and hemicellulose (5.05%) but also nutrients, such as protein (12.15%), starch (14.13%) and lipids (25.02%). Additionally, physical analyses, such as TGA, XRD, FTIR and FESEM, shed light on thermal behaviour, morphological structural and functional substituents in food waste. Post-analysis, 100-gm food waste was processed first via pyrolysis to produce bio-oil (40%) and bio-char (27%), then the biochar generated from pyrolysis was used as a feed in the steam gasification process which produced syngas (2.75 m3/Kg) as a main product and food waste ash as a side product. This food waste ash, in turn, was used as a support and promoter for Ni catalyst whose use in steam gasification showed a substantial increase in syngas production (1.26 m3/Kg from RFW and 3.6 m3/kg from bio-char).