This paper provides an insight to the feasibility of adopting hydrogen as a key energy carrier and fuel source in the near future. It is shown that hydrogen has several advantages, as well as few drawbacks in using for the above purposes. The research shows that hydrogen will be a key player in storing energy that is wasted at generation stage in large-scale power grids by off-peak diversion to dummy loads. The estimations show that by the year of 2050 there will be a hydrogen demand of over 42 million metric tons or 45 billion gallon gasoline equivalent (GGE) in the United States of America alone which can fuel up 342 million light-duty vehicles for 51 × 1011 miles (82 × 1011 km) travel per year. The production at distributed level has also been discussed. The paper also presents the levels of risk in production, storage and distribution stages and proposes possible techniques to address safety issues. It is shown that the storage in small to medium scale containers is much economical compared to doing the same at large-scale containers. The study concludes that hydrogen has a promising future to be a highly feasible energy carrier and energy source itself at consumer level.

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Hydrogen as an energy carrier: Prospects and challenges

Sewage sludge, the inevitable by-product of municipal wastewater treatment plant operation, is a key issue in many countries due to its increasing volume and the impacts associated with its disposal. Thermochemical processing offers a new way of managing sewage sludge, not only by providing effective volume reduction, but also enabling transformation of carbon-rich organic fraction into valuable energy and fuel. Owing to some unique properties, sewage sludge differs from other solid fuels such as lignocellulosic biomass and coal, making its thermochemical conversion application somewhat complicated and challenging. This paper reviews the options of converting sewage sludge to energy and fuel via three main thermochemical conversion processes namely pyrolysis, gasification and combustion. The fundamental aspects of sewage sludge and its behaviour in each of thermochemical process are summarised. The challenges in adopting thermochemical conversion technology in sewage sludge management are addressed, and various alternative approaches deserving further consideration, such as the incorporation of pre-processing and co-utilisation, are discussed.

Thermochemical processing of sewage sludge to energy and fuel: Fundamentals, challenges and considerations

Biodiesel, which could be derived from plant oils and animal fats, is considered as a promising substitute for petroleum diesel fuel because of its advantages, such as renewability, biodegradability, less environmental toxicity, and superior combustion efficiency. The feedstock used for biodiesel production primarily include edible oils, non-edible oils, waste oils, and animal fats. Consistent scientific investigations are performed to locate innovative oil resources and minimize the utilization of expensive food-grade oils for biodiesel production. The extensive research information is available on the determination of physico-chemical properties of different plant oils. This review will present a general information related to the existing varieties of oil feedstocks, their lipid content, and fatty acid composition. This article further discusses different methods employed to enable the usage of plant oils as biofuel, such as its direct use, blending, thermal cracking, microemulsion, and alcoholysis process. Among the possible methodologies for biodiesel production, alcoholysis process, in the presence or absence of a catalytic material, have been frequently employed. The benefits and limitations of using homogeneous, heterogeneous, enzyme catalysts, and supercritical method for the alcoholysis process are comprehensively discussed. In the current article, efforts have been made to review the recent inventions in homogeneous and heterogeneous catalytic materials utilized for biodiesel production. The present study shall provide a tool for the selection of an optimal catalyst for a large-scale biodiesel production.

A review on recent advancement in catalytic materials for biodiesel production.

Biodiesel Production from Waste Cooking Oil: an Efficient Technique to Convert Waste into Biodiesel

The production of biofuels from renewable sources is a major challenge in research. Methanol, ethanol, dimethyl ether (DME), synthetic natural gas (SNG), and hydrogen can be produced from syngas which is the result of the gasification of biomasses. Syngas composition varies according to the gasification technology used (such as fixed bed reactors, fluidized bed reactors, entrained flow reactors), the feedstock characteristics, and the operating parameters. This paper presents a review of the predominant biomass gasification technologies and biofuels obtained from syngas by biomass gasification.

https://www.mdpi.com/1996-1073/11/4/811/pdf

Biofuels production by biomass gasification: A review

Biodiesel production and comparison of emissions of a DI diesel engine fueled by biodiesel-diesel and canola oil-diesel blends at high idling operations

Murari Mohon Roy

Papers

Biodiesel production and comparison of emissions of a DI diesel engine fueled by biodiesel-diesel and canola oil-diesel blends at high idling operations

An experimental study of combustion and emissions of biomass briquettes in a domestic wood stove

Performance and emissions of a diesel engine fueled by biodiesel-diesel, biodiesel-diesel-additive and kerosene-biodiesel blends.

Experimental Investigation on a Diesel Engine Fueled by Diesel-Biodiesel Blends and their Emulsions at Various Engine Operating Conditions

An experimental study of combustion and emissions of biomass pellets in a prototype pellet furnace