Fossil fuel consumption in transportation system and energy-intensive sectors as the principal pillar of civilization is associated with progressive release of greenhouse gases. Hydrogen as a promising energy carrier is a perfect candidate to supply the energy demand of the world and concomitantly reduce toxic emissions. This article gives an overview of the state-of-the-art hydrogen production technologies using renewable and sustainable energy resources. Hydrogen from supercritical water gasification (SCWG) of biomass is the most cost effective thermochemical process. Highly moisturized biomass is utilized directly in SCWG without any high cost drying process. In SCWG, hydrogen is produced at high pressure and small amount of energy is required to pressurize hydrogen in the storage tank. Tar and char formation decreases drastically in biomass SCWG. The low efficiency of solar to hydrogen system as well as expensive photovoltaic cell are the most important barriers for the widespread commercial development of solar-based hydrogen production. Since electricity costs play a crucial role on the final hydrogen price, to generate carbon free hydrogen from solar and wind energy at a competitive price with fossil fuels, the electrical energy cost should be four times less than commercial electricity prices.

Hydrogen production from renewable and sustainable energy resources: Promising green energy carrier for clean development

An overview of hydrogen production from biomass

There has been an enormous amount of research in recent years in the area of thermo-chemical conversion of biomass into bio-fuels (bio-oil, bio-char and bio-gas) through pyrolysis technology due to its several socio-economic advantages as well as the fact it is an efficient conversion method compared to other thermo-chemical conversion technologies. However, this technology is not yet fully developed with respect to its commercial applications. In this study, more than two hundred publications are reviewed, discussed and summarized, with the emphasis being placed on the current status of pyrolysis technology and its potential for commercial applications for bio-fuel production. Aspects of pyrolysis technology such as pyrolysis principles, biomass sources and characteristics, types of pyrolysis, pyrolysis reactor design, pyrolysis products and their characteristics and economics of bio-fuel production are presented. It is found from this study that conversion of biomass to bio-fuel has to overcome challenges such as understanding the trade-off between the size of the pyrolysis plant and feedstock, improvement of the reliability of pyrolysis reactors and processes to become viable for commercial applications. Further study is required to achieve a better understanding of the economics of biomass pyrolysis for bio-fuel production, as well as resolving issues related to the capabilities of this technology in practical application.

https://cyberleninka.org/article/n/1011788.pdf

Biofuels production through biomass pyrolysis - a technological review.

This Critical Review provides an overview of the recent developments in the synthesis and characterization of bimetallic nanoparticles. Initially the review follows a materials science perspective on preparing bimetallic nanoparticles with designer morphologies, after which the emphasis shifts towards recent developments in using these bimetallic particles for catalysing either oxidation or reduction. In the final part of this review we present an overview of the utilization of bimetallic catalyst systems for the transformation of bio-renewable substrates and reactions related to the realization of a bio-refinery. Because of the sheer number of examples of transformations in this area, a few key examples, namely selective oxidation, hydrogenation/hydrogenolysis and reforming of biomass derived molecules, have been chosen for this review. Reports of bimetallic catalysts being used for the aforementioned transformations are critically analysed and the potential for exploiting such bimetallic catalysts have also been highlighted. A specific objective of this review article is to motivate researchers to synthesize some of the “designer” bimetallic catalysts with specific nanostructures, inspired from recent advances in the area of materials chemistry, and to utilize them for the transformation of biomass derived materials that are very complex and pose different challenges compared to those of simple organic molecules. We consider that supported bimetallic nanoparticles have an important role to play as catalysts in our quest for a more green and sustainable society.

Designing bimetallic catalysts for a green and sustainable future

Production and utilization of biochar: A review

Biomass pyrolysis/gasification for product gas production: the overall investigation of parametric effects

Catalytic pyrolysis of biomass for hydrogen rich fuel gas production

Biomass gasification integrated with pyrolysis in a circulating fluidised bed

Thermochemical conversion of brown coal and biomass in a pressurised fluidised bed gasifier with hot gas filtration using ceramic channel filters: measurements and gasifier modelling

Due to the advantages of circulating fluidised bed application, circulating fluidised bed was used to gasify biomass in our laboratory and the preliminary results are presented here. Based on the preliminary results obtained, an improved gasification concept is proposed. In this concept, the riser is divided into several sections according to the sequences of reactions: i.e., devolatilisation (pyrolysis), gasification, cracking and combustion (oxidation). The focus of this concept is to isolate the devolatilisation and gasification processes from the combustion process. Based on this concept, the modelling has been developed inclusive of characteristic fluid-dynamics, kinetic chemical reactions, and mass and energy balance. The model can be expected to predict the overall performance of biomass-fuelled circulating fluidised-bed gasifier incorporating with the emissions release.

J. Andries

Papers

Biomass pyrolysis/gasification for product gas production: the overall investigation of parametric effects

Catalytic pyrolysis of biomass for hydrogen rich fuel gas production

Biomass gasification integrated with pyrolysis in a circulating fluidised bed

Thermochemical conversion of brown coal and biomass in a pressurised fluidised bed gasifier with hot gas filtration using ceramic channel filters: measurements and gasifier modelling

Biomass Gasification in a Circulating Fluidised Bed—Part I: Preliminary Experiments and Modelling Development