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Darpan Das

Bio: Darpan Das is an academic researcher from Johns Hopkins University. The author has contributed to research in topics: Air changes per hour & Coal. The author has an hindex of 3, co-authored 6 publications receiving 25 citations. Previous affiliations of Darpan Das include Indian Institute of Technology Bombay & National Environmental Engineering Research Institute.
Topics: Air changes per hour, Coal, Scrubber, Coal mining, Tar

Papers
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Journal ArticleDOI
TL;DR: In this article, a field study was conducted on a 35 kWe downdraft gasifier to measure and characterize the tar in producer gas using GC-MS, for rice husk and pine needles as the two biomass feeds.
Abstract: Biomass gasification based electricity generation systems are emerging as an important component of the decentralised energy supply systems in rural India. Each type of gasifier has different reaction conditions, temperature, residence time, pressure, feedstock, reactor design, and therefore the tar and particulate matter (PM) compositions and concentrations are found to vary. A field study was conducted on a 35 kWe downdraft gasifier to measure and characterize the tar in producer gas using GC-MS, for rice husk and pine needles as the two biomass feeds. Use of water-based scrubbers for removal of tar and PM is prevalent, however it is often the case that such clean-up is not adequate for meeting the engine manufacturers’ requirements for the quality of intake gas. Limited attempts have been reported for the use of organic solvent based gas cleaning in small scale downdraft gasifiers in the range 15–50 kWe. In the present work, toluene, naphthalene and phenol were selected as representative compounds of tar, and methyl oleate was selected to represent biodiesel as an organic solvent. A bench scale packed bed scrubber was designed for 95% removal of toluene. An 86–97% removal of toluene from the gas stream was achieved, and similar results were obtained for phenol and naphthalene. Further experiments were carried out with actual producer gas from a 1 kWe downdraft wood gasifier. Pongamia pinnata based biodiesel was used as the solvent, and 88–92% of the tar removal from the producer gas stream was achievable.

16 citations

Journal ArticleDOI
TL;DR: The EFs developed for the complete combustion cycle may be used to better represent the impact of coal cookstoves on the ambient air quality and for a more realistic assessment of health effects for exposure in kitchens.
Abstract: Coal is used widely for domestic cooking in many regions of India, which contributes significantly to the particulate matter (PM < 2.5 μm) and CO levels in ambient and indoor air. Modeling and inve...

13 citations

Journal ArticleDOI
TL;DR: In this paper, the authors investigated the effect of temperature of carbonization on the extent of reduction in PM 2.5 emissions for two types of bituminous coals and found that carbonization at 600°C is adequate for minimizing PM emissions while assuring ignitability in the cookstove tested.

9 citations

Journal ArticleDOI
TL;DR: Findings suggest that, although the ICS intervention could significantly improve the indoor air quality, however, it fails to comply with the permissible safe limits; further focus on greener fuels and ventilation characteristics is suggested.
Abstract: Exposure to indoor air pollutants released from traditional cookstoves in rural Indian households is a matter of great concern. While there are various studies over several decades focused towards intervention strategies for reducing air pollutants, limited literature exists towards the identification of appropriate methodology for feasible intervention, adoption and usage of improved cookstoves (ICS). In the present study, PM2.5 and CO microenvironment concentrations are estimated in households using traditional and improved cookstove (NEERDHUR). The reduction in PM2.5 and CO microenvironment concentrations after the introduction of ICS was found to be 89-94% and 35-57%, respectively. Information-education-communication (IEC) activity was used as a tool to increase the adoption and usage rate in the ICS using households. The cost-benefit analysis was also performed to check the benefits of ICS use, and the benefit-cost ratio was found to be 3 to 4 times. Findings of the study suggest that, although the ICS intervention could significantly improve the indoor air quality, however, it fails to comply with the permissible safe limits; further focus on greener fuels and ventilation characteristics is suggested. The outcomes from the study can help decision-makers, corporate social responsibility fund mobilizers and policymakers for effective policy advocacy to design efforts by promoting clean cooking interventions and linking and mapping these with national missions and flagship programs.

6 citations

Journal ArticleDOI
TL;DR: In this paper, a COVID airborne infection risk estimator was used to estimate the probability of infection by aerosol transmission in various commuter micro-environments: (a) air conditioned (AC) taxi (b) non-AC taxi (c) bus and (d) autorickshaw).

3 citations


Cited by
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Journal ArticleDOI
TL;DR: In this article, the main operating parameters of co-pyrolysis, concerns and disputes arising from the technique, and the resultant liquid fuel properties were reviewed, and it was concluded that the co-polymerization is a feasible and sustainable method for recovering biofuel from municipal wastes to obtain green energy and energy security.

103 citations

Journal ArticleDOI
TL;DR: In this article , the authors investigate whether and how better corporate governance practices can lead to philanthropic behavior among companies in the UK and determine whether corporate governance quality in general, as well as its specific mechanisms, affects corporate giving.
Abstract: Purpose This paper aims to investigate whether and how better corporate governance practices can lead to philanthropic behavior among companies in the UK. In particular, this study attempts to determine whether corporate governance quality in general, as well as its specific mechanisms, affects corporate giving. Design/methodology/approach The analysis is based on a sample of Financial Times Stock Exchange All-Share nonfinancial companies. Data on firm donations, including donations amount and donations intensity, were manually collected from companies’ annual reports for the period 2018–2020. This paper uses panel data models to examine the research hypotheses. Findings The results of this study indicate that both donations amount and donations intensity are positively associated with the practice of better corporate governance. Board independence is positively associated with donations amount, but not with the intensity of donations. Furthermore, board size, board gender diversity and the establishment of a corporate social responsibility (CSR) committee are likely to have a positive impact on the amount and the intensity of firms’ donations. However, neither the chief executive officer board membership nor the audit committee’s independence is related to the firm’s donations. Practical implications This study sheds light on specific governance factors that affect firm donations in the context of UK companies. This allows regulators and legislators to evaluate the donations activities in the country and issue more directives to reinforce corporate governance practices that support corporate donations. In addition, the findings of this study are considered crucial to investors who prefer investing in companies with significant CSR-related activities to improve the value relevance of their investments. Originality/value This study provides a shred of unique evidence on the impact of corporate governance practices on firms’ donations.

20 citations

Journal ArticleDOI
TL;DR: Wang et al. as mentioned in this paper conducted 24-hour continuous measurements of CO, PM2.5, SO2, NOx, and CO2 emissions from the chimneys of household stoves fueled with raw coal in four provinces of Northern China to reveal their actual emissions.

19 citations

Journal ArticleDOI
TL;DR: In this article, temperature-dependent differentiation of soil carbon in compliance with the DIN (German Institute for Standardization) 19539 standard has been applied for the first time on 24 agricultural soil samples from the Po River Plain (Italy), with the aim of investigate their thermal behavior in the 50−900 °C interval.

16 citations

Journal ArticleDOI
01 Feb 2023
TL;DR: In this paper , a new type of bio-coal briquette, via a mixture of bituminous and biomass, was tested for its performance and pollutant emissions, and the results indicated that the biocoal briquesettes may be served as a promising substitute cleaner energy, if being confirmed with more future tests in laboratory and real-world pilots, achieving significant co-benefits in environment and human health for rural residents.
Abstract: Coals are important primary energy sources in China, especially for rural household heating, but it also significant sources of CO2 and many hazardous air pollutants. Recognizing abundant biomass fuels and limited anthracite resources, a new type of bio-coal briquette, via a mixture of bituminous and biomass, was tested for its performance and pollutant emissions. Three bio-coal briquettes were made by modeling blends of bituminous coal with corn straw, sewage sludge and cow dung, respectively. The thermogravimetric (TG), combustion performance and pollutant emission factors (EFs) were investigated and compared with those of bituminous briquettes. Results showed that the bio-coal briquettes were much easier to ignite and burn out in comparison with coals, and both the modified combustion efficiencies (MCE) and burning rates of bio-coal briquettes were much higher than those of bituminous. CO2 and CH4 emissions for the three bio-coal briquettes were obviously lower than that for the bituminous, with the CO2 and CH4 EFs declined by 31%–47% and 41%–51%, respectively. Similar reductions were observed in typical air pollutants like CO and NO for the bio-coal briquettes. These results indicated that the bio-coal briquettes may be served as a promising substitute cleaner energy, if being confirmed with more future tests in laboratory and real-world pilots, achieving significant co-benefits in environment and human health for rural residents.

14 citations