https://arrow.tudublin.ie/cgi/viewcontent.cgi?article=1214&context=tfschafart

Emerging technologies for the pretreatment of lignocellulosic biomass.

Valorization of biomass waste to engineered activated biochar by microwave pyrolysis: Progress, challenges, and future directions

Thermochemical conversion of sewage sludge: A critical review

Biomass derived porous carbon for CO2 capture

As a promising approach for carbon dioxide capture, chemical looping combustion has been extensively investigated for more than two decades. However, the chemical looping strategy can be and has been extended well beyond carbon capture. In fact, significant impacts on emission reduction, energy conservation, and value-creation can be anticipated from chemical looping beyond combustion (CLBC). This article aims to demonstrate the versatility and transformational benefits of CLBC. Specifically, we focus on the use of oxygen carriers or redox catalysts for chemical production – a $4 trillion industry that consumes 40.9 quadrillion BTU of energy. Compared to state-of-the-art chemical production technologies, we illustrate that chemical looping offers significant opportunities for process intensification and exergy loss minimization. In many cases, an order of magnitude reduction in energy consumption and CO2 emission can be realized without the needs for carbon dioxide capture. In addition to providing various CLBC examples, this article elaborates on generalized design principles for CLBC, potential benefits and pitfalls, as well as redox catalyst selection, design, optimization, and redox reaction mechanism.

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Chemical looping beyond combustion – a perspective

Activated carbon has been widely used as adsorbents, catalyst support and energy storage materials. Microwave heating is a promising technique for thermochemical treatment and activation of activated carbons due to its fast, selective, uniform and volumetric heating. Previous reviews mainly focused on specific feedstocks (e.g. agricultural biomass or oil palm wastes) or ignored important parameters for microwave activation (e.g. mass of activated carbon precursor). Characteristics of activated carbons prepared from conventional and microwave treatment were not compared and economics of microwave activation were not described in previous studies. This paper presentst a state of the art review of activation under microwave irradiation for various biomass sources (e.g. agricultural wastes, woody biomass and sewage sludge). Characteristics of microwave heating, main activation parameters, research progress and technology status of activated carbon preparation and regeneration under microwave irradiation are investigated with key challenges and economics being addressed. Characteristics of activated carbons made from microwave irradiation and conventional activation are compared and the advantages of microwave-assisted preparation are highlighted. It shows that the BET (Brunauer–Emmett–Teller) surface area, iodine number, methylene blue adsorption capacity and the yield of activated carbons under microwave irradiation are up to 2500–3000 m2/g, 1800–2200 mg/g, 500–700 mg/g and 13–96 wt%, respectively, competitive with conventional methods on the quality of activated carbons and process economics. Potential applications and future perspectives are described with pertinent information on activated carbon preparation under microwave irradiation.

Microwave assisted preparation of activated carbon from biomass: A review

Microwave based technology is an alternative heating method and has already been successfully used in biomass pyrolysis for biochar and biofuel production thanks to its fast, volumetric, selective and efficient heating. Previous review mainly focused on production and analysis of bio-oil and gas instead of biochar. The current paper provides a review of microwave-assisted pyrolysis (MWP) of biomass and its biochar characteristics, including product distribution and biochar yield, biochar properties, microwave absorbers (MWAs) and catalysts commonly used in MWP, as well as comparison of biochar derived from MWP and conventional pyrolysis (CP). MWAs not only absorb microwave energy, they also act as catalysts to interact with gas, vapor and solids in the reactor, adjusting the product distribution and quality of products. It was reported for MWP that the highest biochar yield was >60 wt% and the maximum BET surface area was about 450–800 m2/g. Technology status and economics of MWP of biomass in China were briefly introduced. The Optimization of yield and quality of biochar strongly depends on feedstock properties, reactor types, operating parameters, MWAs and catalysts added to the system.

Biochar from microwave pyrolysis of biomass: A review

The world-wide consumption of natural gas (NG) and other fossil fuels (e.g., coal and crude oil) is ever increasing. However, most CO2 resulting from either NG combustion or other processes is released into the atmosphere without capture. Chemical looping combustion (CLC) is a two-step combustion technology for power and heat generation with inherent CO2 capture, using either gaseous fuels or solid and liquid fuels. A previous review focused on CLC of solid fuels or CLC of all types of fuels but did not give an in-depth and specific discussion of gaseous fuel CLC systems. China is one of the largest consumers of NG, coal, and crude oil in the world, and it is essential to develop an alternative technology to take the place of gaseous fuel (e.g., NG) combustion. This Review summarizes recent research and development work on CLC using gaseous fuels, including a technological and economic assessment, types of oxygen carriers (OCs), reactor types, coke formation and OCs poisoning, efficiency and exergy analys...

Hedong Zhang

Papers

Microwave assisted preparation of activated carbon from biomass: A review

Biochar from microwave pyrolysis of biomass: A review

CO2 Capture with Chemical Looping Combustion of Gaseous Fuels: An Overview

Microwave-assisted pyrolysis of textile dyeing sludge, and migration and distribution of heavy metals.

Microwave pyrolysis of textile dyeing sludge in a continuously operated auger reactor: Char characterization and analysis.