All publications

Torrefaction of Various Biomass Feedstocks and Its Impact on the Reduction of Tar Produced during Pyrolysis

Supatchaya Konsomboon, Jean-Michel Commandré, Suneerat Fukuda

Energy & Fuels · 2019

The aim of this study is to investigate the reduction of tar produced during biomass pyrolysis by torrefaction pretreatment. In this study, various biomass feedstocks (pine, ash wood, miscanthus, and wheat straw) with different particle sizes were torrefied at 280 °C. The results indicated that both particle size and biomass composition have a significant effect on the yield and properties of the torrefied products. With increasing particle size, the yield of solid product increased, while the yield of condensable liquid and noncondensable gases decreased. The raw biomasses and torrefied biomasses were then subjected to pyrolysis at 500 °C. The results clearly showed that torrefaction had a significant effect on the yield and composition of tar generated during subsequent pyrolysis. For all biomasses, the tar yields of biomasses after torrefaction were 42–62% lower compared to direct pyrolysis of raw biomasses. However, when considering the condensable liquid produced combining torrefaction and pyrolysis, the total yield of condensable liquid produced decreased 3–12% compared to the direct pyrolysis. This suggests that not only some volatiles were released during the torrefaction process, but the thermal pretreatment also transformed the biomass structure to less favor tar production in subsequent pyrolysis step.

Bio-MCM-41: a high-performance catalyst support derived from pyrolytic biochar

Yingying Liu, Lingjun Zhu, Shurong Wang, Suneerat Fukuda

New Journal of Chemistry · 2018

Bio-MCM-41 was produced from pyrolytic rice husk char in a sequential stepwise method and then used to prepare Cu/Bio-MCM-41 catalyst with good performance.

Co-firing of coal and rice straw pellet in a circulating fluidized-bed reactor

Thanet Unchaisri, Suneerat Fukuda

Energy Procedia · 2017

This paper presents the experimental investigation of co-firing of coal with rice straw pellet in terms of combustion efficiency, gaseous emissions (CO, NO x and SO 2 ) and occurrence of bed agglomeration. The influence of excess air ratio (EA) and mass share of rice straw in the mixed fuel were investigated in a lab-scale circulating fluidized bed (CFB) reactor. The fuel feed rate was fixed at 14 kg/hr, while the air supply was varied to achieve EA 1.28-1.94. Rice straw pellet was mixed with coal at 25% and 50% mass fraction. The results show that increasing EA generally reduced CO emission. However, at excessively high EA, CO emission started to rise due to the insufficient residence time for complete combustion and the cooling effect. The CO emission clearly reflected the combustion efficiency trend. Higher CO emission was also found when increasing biomass, which may be influenced by the lower combustion temperature and the incomplete combustion of biomass volatiles. NO x and SO 2 emission strongly depended on N and S content in the fuel that is the higher rice straw addition the lower NO x and SO 2 . At lower EA, the observed lower NO x emission could be the effect of reduction by CO and carbon present; while the opposite effect was found at high EA. SO 2 emission was more temperature dependent and continuously decreased with increasing EA. System pressure monitoring and visual observation of the spent bed showed no occurrence of bed agglomeration even at 50% addition of rice straw pellet. However, the size distribution of spent bed moved slightly towards a larger particle size range indicating a tendency of agglomeration.

Economic Analysis of Coal Gasification Plant for Electricity and Thermal Energy Supplies in Indonesia

Prima Zuldian, Suneerat Fukuda, Muhammad Djoni Bustan

Journal of Clean Energy Technologies · 2017

Development of coal gasification plants in Indonesia for electricity and thermal energy supplies has been started officially since 2011.So far, two gasification technologies have been selected for demonstration, including two-stage updraft fixed-bed (Plant A) and twin-fire fixed bed gasifier technologies (Plant B).Economic analysis for electricity generation cost, selling price (with achieve ROI = 11% and 4 year loan installment) and tariff (with transmission cost added) as well as syngas generation cost and selling price was conducted based on these two technologies.The calculated electricity generation cost are 0.189 and 0.204 US$/kWh, electricity selling price are 0.273 and 0.352 US$/kWh and electricity tariff are 0.279 and 0.358 US$/kWh for Plant A and B, respectively.Thermal energy is supplied as synthetic gas (syngas).The calculated syngas generation cost are 0.322 and 0.340 US$/Nm 3 and syngas selling price are 0.38 and 0.512 US$/Nm 3 , for Plant A and B, respectively.The analysis also shows that, based on the studied scenario, the selling prices of electricity from coal gasification are competitive when compared to that from diesel oil (i.e.0.375 US$/kWh) but much less competitive when compared to that natural gas (i.e.0.0864 US$/kWh).The selling prices of syngas is also higher than that of Liquefied Petroleum Gas (LPG) (i.e.0.238 US$/Nm 3 ).

Utilization of Plastic Waste to Solve the Problem in High-Moisture Biomass Gasification

P. Chobthiangtham, Suneerat Fukuda

International Journal of Environmental Science and Development · 2015

With an increased interest in energy production from biomass through gasification, the properties of biomass that influenced gasification performance have been investigated. One of important properties is the moisture content. Generally, the excessive moisture in biomass is reduced to meet the acceptable level for gasification by an additional pretreatment process which always costs extra investment. One possible alternative is the co-processing of high-moisture biomass fuels with other low-moisture fuels. In this study, the utilization of plastic waste to solve the problem of high-moisture biomass gasification was investigated by mixing the high-moisture rubber woodchip (27%M.C.) with plastic waste at various mixing ratios. The results showed a significant improvement of gasification performance. Even at 10% mixing ratio, the higher heating value of the product gas increased by about 50% and 25% compared to the case of high-moisture rubber woodchip (27%M.C.) and pre-dried rubber woodchip (8.5%M.C.), respectively. Compared to mixing with rubber waste at the same weight ratio, the plastic waste addition was found to give a better gasification improvement largely due to the higher carbon and hydrogen content in plastic waste. The findings from this study have shown not only that the high-moisture biomass can be used without pretreatment needed, but also an effective solution to plastic waste disposal.

Pyrolysis Investigation For Bio-Oil Production From Various Biomass Feedstocks In Thailand

Suneerat Fukuda

International Journal of Green Energy · 2014

This study investigated the bio-oil production from vacuum pyrolysis of potential biomass feedstocks in Thailand. Experiments were carried out on palm empty fruit bunch, rice straw, rice husk, eucalyptus wood, rubber wood (Hevea Brasiliensis), and Teng wood (Shorea Obtuse) in a lab-scale-fixed bed reactor. The results showed that the product distribution was strongly dependent on temperature and biomass properties. Maximum oil yields, i.e., 50–60 wt %, were reached at 450–550°C. Due to mild temperature, most of alkalis originally present in biomass concentrated in product char, and only traces were detected in oil. Two-third of energy in biomass was in the product oil.

Ash and deposit characteristics from oil-palm empty-fruit-bunch (EFB) firing with kaolin additive in a pilot-scale grate-fired combustor

T. Madhiyanon, P. Sathitruangsak, S. Sungworagarn, Suneerat Fukuda, Suvit Tia

Fuel Processing Technology · 2013

Yield and Characteristics of Tar Formed during Biomass Fluidised-Bed Gasification

Kaweewong Wongayara, Suneerat Fukuda

Journal of Sustainable Energy and Environment · 2013

In this study, the behavior of gasification tar formed was investigated in a 100 kWth bubbling fluidized-bed gasifier using rubber woodchip as fuel. Tar yield and characteristics as well as the composition of product gas were monitored and correlated with respective gas residence time, which were varied by means of gas sampling at different positions, i.e. four along the height of the gasifier and one after the cyclone. At selected experimental condition (ER=0.33), the significant concentrations of CO and H2 were formed at 4.8 s, after which the increased concentrations of CO and H2 at longer residence times may be attributed to the tar reforming reactions and thermal cracking. The total gravimetric tar increased from 4.5 to 10.5 g/Nm3, when the residence time was increased from 2.5 to 9.8 s. The increasing gravimetric tar yield as the residence time increased inside the gasifier suggests that more tar was formed as it was exposed to high temperature. The concentrations of all tar major species also increased following the trend of gravimetric tar yield, but the ratio of smaller molecular weight materials increased at extended residence time. This therefore suggests that longer residence time would be preferable as it would allow more time for the reaction of tar vapor to crack into smaller molecular weights and to form more product gases.

Bio-oil Production from Vacuum Pyrolysis of Palm Empty Fruit Bunch: Effect of Operating Conditions and Process Energy Balance

Suneerat Fukuda

Journal of Sustainable Energy and Environment · 2013

This study investigated the effect of temperature, heating rate and particle size on the yields of pyrolysis products from palm empty fruit bunch (EFB). Experiments were carried out in a lab-scale fixed bed pyrolysis system under vacuum condition. Under all conditions studied, the liquid product or known as bio-oil appeared to be dominating. The total liquid (organic + water) yield reached its maximum at 550°C with around two-third being organic and the rest being water. Increasing the particle size generally increased gas yield and decreased liquid yield. However, the catalytic effect of inorganic matters could also have some role during pyrolysis. Higher heating rates increased the yield of organic fraction and overall pyrolysis conversions. The mass and energy balance analysis showed that about two-third of the energy from biomass was concentrated in the liquid product. If not being able to utilize the product char due to the high content of alkalis and only the product gas was used to provide energy for pyrolysis reactions, the net efficiency of the process will largely be affected by the required process energy consumption and the import of external energy may be needed.

Design of a new-generation coal-fired marine steam propulsion plant

Atsuo Fukugaki, Suneerat Fukuda, S. Nakamura, Yuki Sakamoto

OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information) · 1982

A new-generation coal-fired marine steam propulsion plant, consisting of all-coal fired twin-boiler installations and their associated coal bunkers, daily service hoppers, coal and ash handling systems, ash retention and disposal systems, etc., to drive a main propulsion turbine rated to develop 19,000 shp, was devised for installation in two 74 700-dwt bauxite carriers. Boilers are equipped with a special automatic combustion control system, and coal transfer from the bunkers to daily hoppers is in the dense phase. As part of this project, a training simulator also was devised for training and education of the ship engine room personnel as well as for use in testing of the plant equipment.