Like many countries, Indonesia generates large quantities of food waste. Food waste is poorly managed due to inadequate treatment practices, which has a harmful impact on the environment. This paper demonstrates the high potential for food waste valorization in Indonesia and outlines the optimal valorization pathways to inform future decision-making surrounding the management of this waste. This paper also compares various conversion technologies for transforming food waste into liquid, solid, and gaseous biofuels. The challenges and opportunities for wider implementation are also considered, including the integration of supply chains and the logistics of food waste management, the technological feasibility, and the persistent behaviors surrounding food waste and energy in Indonesia. The economic and environmental benefits, the perspectives of improved food waste management practices and sustainable fuels, as well as the policy landscape surrounding waste and sustainable energy are also explored. The challenges of scalability and commercialization are also highlighted in this paper. This review demonstrates the best pathways from food waste valorization to bioenergy, including biogas or biodiesel integrated with a black soldier fly larvae (BSFL) composting system. Despite the scale of resources in Indonesia, the pathways and technologies for processing food waste are lacking. Further in-depth studies are required to demonstrate the sustainability and feasibility of food waste transformation into bioenergy to realize its high value.
A huge quantity of fly ash (FA) that is being generated as a residue from the coal combustion process is nowadays considered as a challenging solid waste all around the globe. The FA production leads to various environmental problems due to the enormous area required for its proper disposal as well as heavy metal toxicity associated with it. A few decades back FA was regarded as solid waste and a major cause of air, soil, and water pollution, and however, over a period FA has proven its value and is now recognized as a valuable material for various applications. The utility of FA in agriculture to amend soil properties is gaining popularity in recent times. FA addition in soil improves electrical conductivity, water holding capacity, organic carbon content, soil porosity and provides essential nutrients for plant growth. FA works as a soil conditioner to improve the physical, chemical, and biological properties of soil. In agriculture, FA application in soil has shown encouraging results concerning crop production due to enhanced nutrient availability and physicochemical properties of FA amended soil. The present review explores the Indian scenario of FA incorporation in different soils for improved crop production, safe consumption, and sustainable agriculture.
Natural gas production from the Appalachian region has reached record levels, primarily due to the rapid increase in development of unconventional oil and gas (UOG) resources. In 2020, over 65,000 conventional wells reported natural gas production; however, this only represented 5% of the total natural gas produced. The remaining 95% of natural gas production can be attributed to 3,901 UOG wells. There has been a wide body of research on disturbance trends related to unconventional development in the region; however, there is limited characterization of disturbance related to production of conventional oil and gas (COG) or research that details energy production in relation to land disturbance. This study compares land disturbance from COG and UOG development as well as energy production. Land disturbance related to COG and UOG development was assessed for wells drilled during 2009–2012. Production data were summarized for the same wells during the period of 2009–2020. The average area disturbed for COG pads was 0.82 ha while UOG pads disturbed 4.02 ha. Results from this study showed that COG wells disturbed significantly less land area during construction; however, UOG wells produced almost 28 times more energy per hectare of land disturbed. This energy production imbalance as well as the over 65,000 COG wells reporting production in 2020, indicates that the retirement and restoration of COG infrastructure could be done without significantly impacting total energy production. Continued research that includes ecosystem services and carbon sequestration opportunities in relation to production losses from retiring existing infrastructure should be considered.
In this paper, the recently developed optimization algorithm, namely equilibrium optimization (EO), will be utilized to solve the optimal power flow problem (OPF), combining stochastic wind power with conventional thermal power generators in the system. The objectives are to minimize generation costs, including those incurred in thermal and stochastic wind power generation, active power loss, voltage deviation, and emission. To evaluate the performance of the EO algorithm in the OPF problem, modified IEEE 30-bus and IEEE 57-bus test systems with stochastic wind power generators will be used. A comparative study will be performed to show the efficiency of the EO algorithm compared with other recently developed metaheuristic algorithms such as the marine predators algorithm (MPA), artificial ecosystem-based optimization (AEO), and slime mould algorithm (SMA), as well as with other well-known algorithms. Based on the obtained results, the EO algorithm offered the best results.
The slow pyrolysis is a viable technology for the production of different solid products. However, its effective implementation requires utilization of material flows occurring in gaseous and liquid phases. Because liquid products of slow pyrolysis, typically referred to as bio-oil, are just by-product, their combustion characteristics are poorly studied. Current article presents the comprehensive experimental studies of the technical conditions of the slow pyrolysis bio-oil retrieved at commercial pyrolysis facility. The studies cover the composition and physicochemical properties of bio-oil, spraying characteristics, droplet ignition and combustion, and analysis of gas-phase combustion products. The bio-oil sample had relatively high density (ρ = 1180 kg/m3) and dynamic viscosity (184.16 mPa s). The pour (T pp = 7 °C) and flashpoint (T fp = 133 °C) were also high. The lower heating value was 25.01 MJ/kg. The majority of properties was consistent with requirements of ASTM 7544, while viscosity, pour point, and ash content were not. The study on bio-oil spraying was carried out using hydrodynamic setup equipped with pneumatic mechanical nozzle and cross-correlation camera. The fuel jet had a homogeneous structure with an average droplet diameter exceeding 0.2 mm. Ignition and combustion were studied using combustion chamber with varying the heating medium temperature in the range of 400–800 °C with a 50 °C step. The ignition delay and total combustion times of the bio-oil sample were exponentially decreasing with increasing heating medium temperature. In the temperature range of 400–500 °C, the thermal transformation proceeded in the oxidation mode, while at temperatures above 500 °C, the flame with periodic formation of microexplosions was observed.
Aromatic hydrocarbons (AH) are valued chemicals used in synthesis and formulation of numerous industrial products. In the current study, pyrolysis of pure algal biomass (AB), cedar wood (CW), digested sludge (DS) and their ternary blends (with and without catalyst) was evaluated for producing AH-enriched bio-oil. Although, non-catalytic pyrolysis of pure biomass did not produce significant amount of AH, catalyst addition enhanced AH content (as high as 84.9%) in the bio-oil. Catalyst to biomass weight ratio was a significant variable in the AH formation. Increasing catalyst: biomass weight ratio from 0:1 to 2:1 wt/wt improved AH production during pyrolysis. The highest AH content of 89.38% in bio-oil was obtained from the 1:1:1 wt/wt biomass blend of AB:CW:DS with ZSM-5 at catalyst: biomass ratio of 2:1 wt/wt. Naphthalene, anthracene, and their methyl derivatives were the main AH found in these bio-oil. ASPEN PLUS simulation software successfully evaluated mass and energy flow through the entire pyrolysis system for the three pure biomass and their non-catalytic blends examined in this study. Heat duty of the pyrolysis reactor was lowest for DS (818.89 MJ/h), but highest for CW (1055.8 MJ/h) processing. Hence, blending biomass from different sources facilitates moderation of the overall energy requirement for the system while aiding production of AH-enriched bio-oils.
The present study investigated the status of the phytoplankton community as a bio-indicator of Ganga River’s water quality under riverbed mining and wastewater disposal impacted regions of Haridwar, India. The data were analyzed using various tools such as coefficient of variation (CV), principal component analysis (PCA), detrended correspondence analysis (DCA), Pearson's correlation, and canonical correspondence analysis (CCA). The PCA analysis showed that the parameters such as electrical conductivity, total dissolved solids, turbidity, total hardness, and alkalinity had the highest factor loadings in the mining-influenced zones. A total of thirty-two phytoplankton species were found belonging to four families: Chlorophyceae (53.82%), Bacillariophyceae (37.02%), Cyanophyceae (7.72%), and Dinophyceae (1.45%). The phytoplankton species identified at DCA, i.e., Diatom sp., Navicula sp., Synendra sp., occurred in greater abundance in the non-mining-influenced zones while Euglena sp., Ulothrix sp., and Volvox sp. occurred in the mining-influenced zones. Moreover, CCA showed a strong relationship between water quality parameters and the phytoplankton community. Overall, this study suggests that anthropogenic activities in the study area had a significant impact (P < 0.05) on phytoplankton diversity and therefore decisive measures should be taken to conserve, which serves as the main food for fish.