Torrefaction Research Articles

목질계 바이오매스의 효소당화에서 반탄화 전처리 영향

Abstract - This study is to investigate the effect of torrefact ion on enzymatic hydrolysis of lignocellulosic biomass for bio-ethanol production. As a pretreatment, the torr efaction of lignocellulosic biomass was conducted in temperature of 250 ∼350℃ in the absence of oxygen. Tween-80, nonionic surfactant, was tested to enhance saccharification efficiency by coping with hy drophobicity resulted from torrefaction. As a result, the glucose production from enzymatic hydrolysis of b iomass pretreated by torrefaction was greater than that obtained from the non-pretreated biomass. Sugar conve rsion was higher when the biomass was saccharified with addition of tween-80. It was found that torre faction can be applied as a preptreatment for lignocellulosic biomass and tween-80 is needed to enhance i ts enzyme saccharification. Key words : lignocellulosic biomass, pretreatment, saccharification, Tween-80, enzymatic hydrolysis † To whom corresponding should be addressed.Professor, Department of Environmental Energy Engineering,The Graduate School of Energy and EnvironmentSeoul National University of Science and TechnologyTel : 02-970-6595 E-mail : daewon@seoultech,ac,kr

Comparison of Pretreatment Methods for Wheat Straw Densification by Life Cycle Assessment Study

Abstract. Compaction and pelletization processes increase the bulk density and energy density of biomass, making it easy to handle, transport, and utilize. Abundant amounts of wheat straw biomass are produced every year. This article presents a life cycle assessment (LCA) study to compare five different pretreatment methods during wheat straw pelletization. The system boundary was defined from a wheat straw bale (from field production) to transporting pellets to the customer. Steam explosion (SE), microwave alkaline (MA), binder addition (BD), radio frequency alkaline (RF), and torrefaction (TF) as well as no pretreatment (base case) are potential pretreatment methods prior to pelletization. SimaPro software incorporating the Ecoinvent database and literature data were used to conduct this LCA study. The environmental impact of each pretreatment method was evaluated in terms of global warming potential, acidification, eutrophication, human toxicity, marine aquatic ecotoxicity, ozone layer depletion, abiotic depletion, freshwater aquatic ecotoxicity, photochemical oxidation, terrestrial ecotoxicity, and non-renewable energy use. The results revealed that TF and BD, especially involving the addition of wood residue, had lower environmental impacts compared to the other pretreatment methods including the base case. The SE and RF pretreatment methods had more negative environmental impacts compared to the other pretreatment methods including the base case. All pretreatment options except SE can reduce the global warming potential and human toxicity. A densification system involving BD, TF, and MA can conserve non-renewable energy resources compared to the other pretreatment options.

Upgrading of moist agro-industrial wastes by hydrothermal carbonization

This work focuses in the application of the hydrothermal carbonization (HTC) technology as a possible moist agro-industrial waste management treatment. Through this technique, olive mill, canned artichoke and orange wastes (OMW, CAW and OJW, respectively) were carbonized in a lab-scale high pressure reactor at different temperatures (200–250°C) and durations (2, 4, 8 and 24h) in order to obtain useful bioenergy feedstocks. The effect of the residence time and temperature on the properties of the bio-char obtained was studied through different characterization techniques. Material and energy balances were also performed to determine the potential energy saving of hydrothermal carbonization versus dry thermal treatments like torrefaction (TF). It is found that the moisture content of HTC-hydro-chars decreases as the temperature and duration increase, which implies that wet biomass can be upgraded and, at the same time, dewatered through HTC. The best results are found for the OMW, whose moisture content decreases from over 70% to less than 30% for the experiments carried out under the more severe conditions. Consequently, it is be possible to reach energy savings over 50% by using HTC instead of TF technologies. Regarding the hydro-char properties, the hydrothermal carbonization of the three organic wastes treated leaded to hydro-chars that present carbon contents and heating values closed to those of brown coal and great energy densifications, depending on the type of waste. Accordingly, it can be concluded that it is feasible to manage moist agro-industrial wastes via HTC, which is ostensibly more efficient than TF in terms of energy consumption.

Torrefaction of residues and by-products from sunflower chain

Torrefaction of residues and by-products from sunflower chain

Pretreatment for energy use of rice straw: A review

Utilization of rice straw as renewable energy source has attracted increasing interest since the past two decades. However, rice straw has low heating value, low bulk density and significant amount of alkali and alkaline compounds. This makes it difficult to handle, transport and store efficiently hence limiting the commercial use of rice straw. These properties can be improved by pretreatment of the residue. This paper therefore explores the literature for information on some fundamental pretreatment techniques of rice straw to provide a basis understanding on how it could be improved as an attractive fuel for energy production. The pretreatment technologies discussed in this paper include sizing, torrefaction washing/ leaching, bailing and pelletizing. The aforementioned treatments improve both physical and chemical properties of rice straw by increasing the energy conversion and combustion efficiencies, reduce slag formation in the furnaces and grates etc thus minimizing the associated costs and logistics of handling, transport and storage which could encourage the commercial use of rice straw as a feedstock for heat and power production. Key words: Rice straw, pretreatment, biomass, renewable energy, heating value, bulk density, conversion and combustion efficiency.