Search

Carbon pricing mechanisms have been identified as a key strategy for reducing global greenhouse gas emissions to achieve the net-zero target. The present study aims to fill the gap by investigating the effects of carbon pricing under different specific target emission constraints and their potential implications for the transportation sector in India. A total of five scenarios have been developed, including a reference scenario with current policy assumptions and four climate policy scenarios. In the climate policy scenarios, emission constraints varied between the year 2030 and the year 2060, with implementation occurring in 10 y intervals until the year 2070. The net-zero year remains constant across all scenarios, which is set at the year 2070. These scenarios are developed using the global change assessment model (GCAM). The study reveals that a reduction in the time gap between the year of implementation and the year of achieving net-zero emissions will lead to an increase in carbon prices. The maximum projected cost of carbon will be 981.36 USD/t of CO₂ emission ($/tCO₂) if the carbon pricing is implemented starting in the year 2030 and 1062.79 $/tCO₂ if it is implemented from the year 2060. The implementation of carbon prices resulted in considerable emission reductions, as well as variations in service demand and energy usage patterns in the transport sector. The findings hold promise for positively influencing SDGs 11 and 13 and have significant implications for policymakers and other stakeholders. [ABSTRACT FROM AUTHOR]

Efficient domestic wastewater management is essential for mitigating the impact of wastewater on human health and the environment. Wastewater management with conventional technologies generates sewage sludge. The present study considered a modelling approach to evaluate various processing pathways to produce energy from the sewage sludge. Anaerobic digestion, gasification, pyrolysis, and hydrothermal liquefaction are analysed in terms of their energy generation potentials with the Aspen Plus software. A techno-economic assessment is performed to assess the economic viability of each pathway. It reveals that gasification appears as the most promising method to produce electricity, with 0.76 kWh/kg drysludge , followed by anaerobic digestion (0.53 kWh/kg drysludge), pyrolysis (0.34 kWh/kg drysludge), and hydrothermal liquefaction (0.13 kWh/kg drysludge). In contrast, the techno-economic analysis underscores the viability of anaerobic digestion with levelized cost of electricity as 0.02 $/kWh followed by gasification (0.11 $/kWh), pyrolysis (0.14 $/kWh), and hydrothermal liquefaction (2.21 $/kWh). At the same time, if the products or electricity from the processing unit is sold, equivalent results prevail. The present study is a comprehensive assessment of sludge management for researchers and policymakers. The result of the study can also assist policymakers and industry stakeholders in deciding on alternative options for energy recovery and revenue generation from sewage sludge. [Display omitted] • Comparative analysis of four sewage sludge processing units. • Gasification produces 41% more electricity than anaerobic digestion. • Anaerobic digestion has 81% lower LCOE than gasification. • Pyrolysis has the highest energy content per kg. • Anaerobic digestion has the highest NPV through electricity or other products. [ABSTRACT FROM AUTHOR]

Transport sector electrification will play a critical role in achieving India's net zero emission target by 2070; however, the adoption of EVs is hindered by challenges such as long charging times, high ownership costs, and limited range. Battery swapping (BS) offers quick recharging, unlike point charging (PC). This study examines BS subscription fees in India's passenger sector (buses, four-wheelers, three-wheelers, and two-wheelers). Furthermore, the assessment of its effects on EV adoption, the energy mix, and CO 2 emissions in India's passenger sector is analysed using the global change analysis model (GCAM). The results show that BS is cost-effective for four-wheelers and two-wheelers without subsidies. Providing similar subsidies to BS as to PC achieves cost parity or lower costs for three-wheelers and buses compared to PC. BS could reduce CO 2 emissions by 9 % by 2070, with a 6 % increase in EV adoption and an 8 % rise in electricity demand. With BS subsidies, EV penetration may increase by 10 %, resulting in a 14 % reduction in CO 2 emissions compared to PC. The study suggests BS is a viable option but may not entirely replace PC. [Display omitted] • Battery swapping (BS) and point charging (PC) for EV charging were compared. • BS business models to compute subscription fees were developed. • BS is feasible for 4W and 2W without subsidy, and with subsidy for 3W and buses. • Compared to PC, EV adoption is projected to increase by 6 % with BS in 2070. • With subsidy, CO 2 emissions will be reduced by 14 % compared to PC in 2070. [ABSTRACT FROM AUTHOR]

Refined bio-crude production from hydrothermal liquefaction of algae holds the potential to replace fossil-based conventional liquid fuels. The microalgae act as natural carbon sequestrators by consuming CO2. However, this absorbed CO2 is released to the atmosphere during the combustion of the bio-crude. Thus, the life-cycle greenhouse gas (GHG) emissions of refined bio-crude are linked to the production and supply of the materials involved and the process energy demands. One prominent raw material is CO2, which is the main source of carbon for algae and the subsequent products. The emissions associated with the supply of CO2 can have a considerable impact on the sustainability of the algae-based refined bio-crude production process. Furthermore, the diurnal algae growth cycle complicates the CO2 supply scenarios. Traditionally, studies have relied on CO2 supplied from existing power plants. However, there is potential for building natural gas or biomass-based power plants with the primary aim of supplying CO2 to the biorefinery. Alternately, a direct air capture (DAC) process can extract CO2 directly from the air. The life-cycle GHG emissions associated with the production of refined bio-crude through hydrothermal liquefaction of algae are presented in this study. Different CO2 supply scenarios, including existing fossil fuel power plants and purpose-built CO2 sources, are compared. The integration of the CO2 sources with the algal biorefinery is also presented. The CO2 supply from biomass-based power plants has the highest potential for GHG reduction, with a GHG footprint of −57 g CO2 eq./MJ refined bio-crude. The CO2 supply from the DAC process has a GHG footprint of 49 CO2 eq./MJ refined bio-crude, which is very similar to the scenario that considers the supply of CO2 from an existing conventional natural gas-based plant and takes credit for the carbon utilization. [ABSTRACT FROM AUTHOR]

Biomass energy is useful in mitigating greenhouse gases as biomass growth captures CO2 from the atmosphere. This captured CO2 is eventually released upon the use of these biomass feedstocks, leading to a short duration carbon cycle. One prominent biomass feedstock is the sugarcane bagasse that is a by-product of sugar mills. Conventionally, the bagasse produced after crushing sugarcane is utilized in mills by directly burning it in the boilers. However, an efficient way of utilizing this biomass fuel would be through gasification. The biomass gasification process produces syngas which can be used as fuel for meeting the heat and power demands of the sugar mill, as well as surplus electricity, which can be supplied to the grid. The present study aims to highlight the efficiency improvement potential of bagasse gasification. The entire sugar mill as well as the bagasse gasification process, have been modeled in the ASPEN Plus® software. Heat integration has been performed to optimize the process flowsheets. The electrical energy generated by combusting bagasse is estimated to be 0.57 kWh/kg of bagasse combusted. In contrast, the gasification process can increase this energy generation up to 1.16 kWh/kg of bagasse at 10 % moisture content (by wt.). This study aims to provide awareness about the cleaner and efficient utilization of the energy that lies dormant in these industrial residues. [ABSTRACT FROM AUTHOR]