Combustion characteristics of Malaysian oil palm biomass, sub-bituminous coal and their respective blends via thermogravimetric analysis (TGA).

Biomass as an energy source contributes to a decrease in the dependence on imported fossil fuels, while at the same time, adding value to the countries where biomass fuel sources thrive, in addition to providing a source of renewable energy. Knowledge of the behaviour of fuel is essential in order to design and operate equipment safely and efficiently. In particular, knowledge about mineral content is essential because the ashes play an important role in the dynamics of the generation system. Through knowledge of the chemical composition and physical properties of the ashes, it is possible to predict the tendency to form deposits in the boiler components, as well as their potential to cause corrosion, erosion and abrasion. The behaviour of the ashes in the system is highly dependent on fuel, particularly when it comes from industrial waste or energy crops. These fuels have a higher mineral content, particularly sodium (Na), potassium (K), phosphorous (P) and chloride (Cl). They also have higher ash content with a low melting point and high corrosion potential. This paper focuses on the characteristics of the ashes derived from the combustion of biomass, with particular attention paid to the chemical transformations at high temperatures, as well as its effect on the combustion equipment. Emphasis is placed on the potential problems that occur when biomass-burning technologies are used for energy crops, in order to avoid catastrophic failures. It concludes with recommendations for the management, control and prevention of problems associated with ash.

/pdf/biomass-combustion-systems-a-review-on-the-physical-and-1ak879bd22.pdf

Biomass combustion systems: A review on the physical and chemical properties of the ashes

The energy sector in the global scenario faces a major challenge of providing energy at an affordable cost and simultaneously protecting the environment. The energy mix globally is primarily dominated by fossil fuels, coal being the major contributor. Increasing concerns on the adverse effect of the emissions arising from coal conversion technologies on the environment and the gradual depletion of the fossil fuel reserves had led to global initiatives on using renewables and other opportunity resources to meet the future energy demands in a sustainable manner. Use of coal with biomass as a supplementary fuel in the combustion or gasification based processes is a viable technological option for reducing the harmful emissions. Co-combustion of coal with biomass for electricity generation is gradually gaining ground in spite of the fact that their combustion behavior differ widely due to wide variations in their physical and chemical properties. This article deals with the technical aspects of co-combustion with emphasis on the fundamentals of devolatilization, ignition, burnout and ash deposition behavior along with the constraints and uncertainties associated with the use of different types of biomass of diverse characteristics and the likely impact of partial replacement of coal by biomass on the emission of CO2, SOx, NOx. Other issues of no less importance like sustained availability of biomass, transportation and storage, effect on biodiversity, etc., are left out in the study. The investigations reported in the study reflect the potential of biomass as co-fuel, and the scope of maximizing its proportion in the blend in the coal based power plants and the derived benefits.

Coal–biomass co-combustion: An overview

State-of-the-art applications of fly ash from coal and biomass: A focus on zeolite synthesis processes and issues

Biomass is currently seen as a promising renewable energy source, which can be sustainably utilized in the production of fuels and electric energy adding no carbon dioxide to the environment. Co-gasification has unveiled its potential amongst thermal techniques, as a result of the valuable products obtained, strengthening a solid position in the conversion of residues. Thus, the prevention of a complete depletion of non-renewable sources is supported and the effects of their utilization alleviated. Extensive literature review was conducted and, few reports on co-gasification of biomass and wastes were found. In this context, this review addresses their thermal conversion, highlighting issues related to the equipment, operating conditions and physicochemical phenomena involved in such a complex process. Among other conclusions, the most important finding of this work was the synergy often encountered between the two feedstocks, proving co-gasification can overcome several of the individual gasification issues enhancing products quality and yields over biomass or wastes alone, and attesting its environmental-friendly character, with lower greenhouse gas emissions. It was also possible to depict some trends on the effect of biomass and waste blending ratios, as well as elucidating some of the mechanisms involved in their interaction. These are majorly explained by the response of molecules during pyrolysis and by hydrogen transfer from waste polymers to biomass derivatives. Experimental conditions were also assessed, fluidized beds being reported as the most suitable reactors for biomass and wastes, under several different possible combinations of operational parameters. A critical discussion is presented, aiming to contribute to a more profound understanding of this matter, its key points and noteworthy potential.

S.G. Sahu

Papers

Coal–biomass co-combustion: An overview

Thermogravimetric assessment of combustion characteristics of blends of a coal with different biomass chars

Studies on the combustion behaviour of blends of Indian coals by TGA and Drop Tube Furnace

Co-combustion studies for potential application of sawdust or its low temperature char as co-fuel with coal

Evaluation of combustion behaviour of coal blends for use in pulverized coal injection (PCI)