Life cycle analysis of energy production from food waste through anaerobic digestion, pyrolysis and integrated energy system

The environmental performance of industrial anaerobic digestion (AD), pyrolysis, and integrated system (AD sequence with pyrolysis) on food waste treatment were evaluated using life cycle assessment. The integrated treatment system indicated similar environmental benefits to AD with the highest benefits in climate change and water depletion in addition to the increased energy generation potential and the production of valuable products (biochar and bio-oil). Pyrolysis results illustrated higher impact across water, fossil fuel, and mineral depletion, although still providing a better option than conventional landfilling of food waste. The dewatering phase in the AD process accounted for 70% of the treatment impact while the pre-treatment of the food waste was responsible for the main burden in the pyrolysis process. The study indicated that the three treatment options of food waste management are environmentally more favorable than the conventional landfilling of the wastes

Ethical instrumentation of integrated waste management

waste is as old as man and its culture management change with time according to complexity of its formation. the contemporary increase population, industrial development and various anthropogenic activities necessiatate the need for an integrated Waste Management System (IWMS. This study reviews the technological requirement of waste management by considering the ethical significant of entire stakeholders-the waste generators, the policy makers and the waste managers - to achieve a sustainable waste management system in the society. Thus, emphasizing that integrated Waste Management could be realized by incorporating value based regulations and policies moral rearmament, and intrinsic data mining are vital instrument

Sustainable intervention of food waste treatment process and products

Thesis by publication.Includes bibliographical references.Due to resource scarcity and impacts amelioration, efforts are ongoing to widen recycling capacity of organic waste and smartly appropriate its products to ensure optimization and a zero waste system. In this work, food waste is treated with full consideration of two treatment streams (anaerobic digestion and pyrolysis) using the energy, environment, agronomic and socio-economy as indicators to evaluate the sustainability extent of these treatment processes and their products.Review of the organic waste treatment processes and their products was explored to identify treatment gaps and its effects on the products vis-à-vis sustainability. Fresh food wastes were collected from Macquarie and Eastwood shopping centres and sampled compositely for both biochemical (anaerobic digestion) and thermochemical (pyrolysis) treatments. Characterization results of fresh food wastes were compared with food wastes in other part of the world through a review to reflect properties parity. Meanwhile, to reduce experimental cost and save biochemical digestion time, digestate was collected from EarthPower Technologies Sydney Pty Limited (a commercial food waste to green energy company). This was equally characterized analytically to evaluate its organic, inorganic and elemental constituents. The raw food wastes and the digestate were then pyrolysed separately at different temperatures (300,400, 500 and 700°C) to evaluate temperature effect on the products' (biogas, biooiland the biochar) quantity and properties.The energy proficiency of these treatment processes using food waste and its digestate were evaluated through a novel energy harvesting system (EHS) after discrete assessment of the two processes (anaerobic digestion and pyrolysis). The hybrid EHS wherein anaerobic digestion was sequenced with pyrolysis provided the highest transitional energy base products. This was accomplished using industrial pyrolysis temperature (500°C).The biochar produced through pyrolysis from the raw food waste were activated using CO2 (a major constituent of the biogas generated) to drastically reduce greenhouse gas (GHG) emission. This activated and oxidised chars were compared with commercial activated carbon. The produced activated chars(with surface area range of 797.2 to 1024.7m²/g) were evaluated as a component of pressure swing adsorption (PSI) for refinery off gases (ROG) treatment and or purification. Raw food waste oriented chars adsorbed 330 to 380mg/g of benzene gas and 4.1 to 4.4mmol/g of CO2. The abolition of CO2 flaring and scrubbing of C6H6 gas are significant environmental impact amelioration.Similarly, the digestate (DFW) and digestate derived chars (PyD500) potential for soil enhancement and or fertilizer were evaluated. Sand to substrate rate, germination index, water retention capacity and plant availabl ewater were used to assess agronomic capacity of these products (DFW andPyD500). DFW provided the best reaction to plant available water with increasing application rate in the sandy soil considered. However, PyD500 delineated better phytotoxicity, water holding capacity and nutrient sorption rates compared to DFW.Finally, life cycle analysis (LCA) of the three processes (commercial one stage anaerobic digestion, pyrolysis and the integration or sequence of AD and pyrolysis) and their products are considered to gauge the likely environmental impacts putting all in perspective. The sustainability stance of variables (input and outputs) and treatment processes are determining with energy,environment, agronomic and socio-economy as indicators for a life cycle analysis. This is expected to widen and broaden treatment of food wastes and ensure the fitness and robustness of the model developed in most part of the globe.Mode of access: World wide web1 online resource (196 pages) illustration

Product based evaluation of pyrolysis of food waste and its digestate

The aim of this work was to assess the energy potential of food waste energy harvesting system (digestion followed by pyrolysis of digestate). Digestate (DFW) with increased calorific content was produced after a commercial one stage anaerobic digestion of the raw food waste (RFW). Separate pyrolysis of RFW and DFW (digestated food waste) distributed 15.7MJ/kg and 17.2MJ/kg respectively, among the gas, char and bio-oil, while energy of pyrolysis at 0.72MJ/kg for RFW and 0.87MJ/kg for DFW at the heating rate of 10°C/min to 500°C. Increase in the digestate specific heat to 2.5MJ/m³ and its significant ash difference reflects the substrate (RFW) transformation due to biochemical treatment. The thermogravimetric analysis indicated the substrates mass dynamics and stability extent of the treatment products (DFW, RFW₅₀₀ and DFW₅₀₀). Generally, transitional energy base products (biogas and bio-oil) are generated through the energy harvesting system (EHS) of food waste, while energy rich solid fuels can be produced through pyrolysis at 500°C. Thus, the sustainable potential of EHS to widen and broaden recycling capacity of biomass and smartly appropriate its resources are demonstrated to be dependent and pivoted on the adopted treatment method.6 page(s

Agronomic assessment of pyrolysed food waste digestate for sandy soil management

The digestate (DFW) of an industrial food waste treatment plant was pyrolysed for production of biochar for its direct application as bio-fertilizer or soil enhancer. Nutrient dynamics and agronomic viability of the pyrolysed food waste digestate (PyD) produced at different temperatures were evaluated using germination index (GI), water retention/availability and mineral sorption as indicators when applied on arid soil. The pyrolysis was found to enrich P, K and other micronutrients in the biochar at an average enrichment factor of 0.87. All PyD produced at different temperatures indicated significantly low phytotoxicity with GI range of 106–168% and an average water retention capacity of 40.2%. Differential thermogravimetric (DTG) thermographs delineated the stability of the food waste digestate pyrolysed at 500 °C (PyD500) against the degradation of the digestate food waste despite the latter poor nutrient sorption potential. Plant available water in soil is 40% when treated with 100 g of digestate per kg soil, whereas PyD500 treated soil indicated minimal effect on plant available water, even with high application rates. However, the positive effects of PyD on GI and the observed enrichment in plant macro and micronutrients suggest potential agronomic benefits for PyD use, in addition to the benefits from energy production from DFW during the pyrolysis process.7 page(s

Development of compatible fungal mixed culture for composting process of oil palm industrial waste

Trichoderma reesei (Tr), Penicillium sp. (P), Basidiomycete M1 (M1) and Panus tigrinus M609RQY (IMI398363)(M6) were tested to find their mutual growth in the laboratory. Potato dextrose agar (PDA) as a media was used for their fifteen combinations and two different fungi were grown 4 cm apart in every combination. The results of this present study showed that the combinations of T. viride and Penicillium sp. (Tv/P), T. viride and Basidiomycete M1 (Tv/M1), T. reesei and P. tigrinus M609RQY (Tr/M6) may interact as compatible, while A. niger and T. viride (A/Tv), A. niger and T. reesei (A/Tr), T.viride and T. reesei (Tv/Tr) and Penicillium sp. And P. tigrinus M609RQY (P/M6) were partially compatible and the other combinations were incompatible or inhibited by each other. Furthermore, the cellulolytic fungus T. viride was the dominant in all its combinations, and its growth rate and hyphal expansion showed the highest responses as compared to all combinations. These compatible filamentous fungi would be useful for effective composting process in further study

Food wastes derived adsorbents for carbon dioxide and benzene gas sorption

Food wastes are produced worldwide in large quantities that could have potential to produce higher value products, including industrial adsorbents. The present work attempts valorization of food waste by CO₂ activation and functionalization through nitric acid and melamine treatment. The prepared porous materials were subjected to gas phase adsorption of CO₂ and benzene gases. The resultant highly porous carbon materials with surface area range from 797 to 1025 m²/g were synthesized showing uptake capacities of 4.41, 4.07, 4.18 and 4.36 mmol/g of CO₂ and 345, 305, 242.5 and 380.7 mg/g of C₆H₆ respectively for PyF515, PyF520, PyF715 and PyF720 in the absence of doped carbon matrix. Differential thermogravimetric (DTG) analysis showed the thermostability of the precursors to validate selected initial pyrolysis temperatures (500 and 700°C). C₆H₆ sorption lies mainly in the physisorption region for all adsorbents ensuring re-generation potential. PyF720 and PyF520 recorded the highest isosteric enthalpy of 64.4 kJ/mol and 48.7 kJ/mol respectively, despite the low degree of coverage of the latter. Thus, PyF515 and PyF720 demonstrated the potential for use as sustainable and cost effective adsorbents for benzene gas containment suitable for swing adsorption system.7 page(s

Characterization of food waste and its digestate as feedstock for thermochemical processing

The products of a commercial one-stage anaerobic digestion and a laboratory-scale pyrolysis of raw food waste (RFW) and digestated food waste (DFW) were characterized to evaluate the treatment effect, product yield, and physicochemical properties. The pyrolysis of the RFW and DFW resulted in generation of 7.4 and 5.3 wt % of gas and 60.3 and 52.2 wt % of bio-oil, while biochar yields decreased with an increase in the pyrolysis temperature. Differential thermogravimetric tests of RFW and DFW show 20% in both solid residues produced at a temperature of 550 °C, indicating a relatively low impact of the digestion process on the RFW. The mineral matter content was found to be lower for RFW compared to DFW. The variation in the content of fixed carbon and volatile matter reflected the effect of anaerobic degradation of the food waste. The bio-oils showed a low concentration of phenols, esters, and derivatives of hydrocarbons for DFW compared to RFW. The specific heat capacities were determined for RFW and DFW, while their morphological properties at different temperatures were equally considered using scanning electron microscopy and Fourier transform infrared spectroscopy. The results of this study provide indicators for treatment process assessment and measures to increase value-added products from food waste.9 page(s

Life Cycle Analysis of Energy Production from Food Waste through Anaerobic Digestion, Pyrolysis and Integrated Energy System

The environmental performance of industrial anaerobic digestion (AD), pyrolysis, and integrated system (AD sequence with pyrolysis) on food waste treatment were evaluated using life cycle assessment. The integrated treatment system indicated similar environmental benefits to AD with the highest benefits in climate change and water depletion in addition to the increased energy generation potential and the production of valuable products (biochar and bio-oil). Pyrolysis results illustrated higher impact across water, fossil fuel, and mineral depletion, although still providing a better option than conventional landfilling of food waste. The dewatering phase in the AD process accounted for 70% of the treatment impact while the pre-treatment of the food waste was responsible for the main burden in the pyrolysis process. The study indicated that the three treatment options of food waste management are environmentally more favorable than the conventional landfilling of the wastes

Recycling of organic wastes using locally isolated lignocellulolytic strains and sustainable technology

The magnitude and nature of the waste generated across different borders have prompted the need for an appraisal of the conventional method of waste collection and the landfill or incineration that are unsustainable due to their high cost and impact on the environment and public health. This study focuses on the recycling of organic wastes (food waste and yard trimmings) using four isolated fungal strains in an experimental setup that simulates sustainable low-technology treatment for the production compost. Separated food and yard trimmings were composted using Phanerochaete chrysosporium, Lentinus tigrinus, Aspergillus niger and Penicillium sp. in two adopted systems (open and closed) based on a solid-state bioconversion process. The results were obtained at p B 0.05 after ten harvests indicating a pH range of 5.68–8.82, an organic weight loss of 11.92 % and a carbonto-nitrogen (C/N) ratio range of 16.99–18.20 for the open system of the compost. The closed system indicated a relatively lower value of C/N ratio, which is 8.60–13.38 and an organic weight loss of 8.92 % at a pH range of 5.68–7.30. The germination index, ranging between 53–105 and 49–122 %, and the electrical conductivity ranging between 2.57–3.17 and 2.72–2.95 mS/dm for the open and closed systems, respectively, were used to evaluate the toxicity and stability of the compost produced. The technology adopted in this study indicates the viability of the process of the large-scale production of biofertilizer with the C/N ratio of\25 and the significance of the germination index values of[100 % at harvest