Author Archives: AsanoHiroko

Dr. Eng., P.E.Jp., Deputy Manager, Senior Researcher, Comprehensive Energy Technology Group, Energia Research Institute, Chugoku electric power co., Inc.

“One month DSS Supercritical water gasification test plan for Shochu residue to create renewable energy”　(Shochu：　Japanese distilled liquor)

Shochu residue is a kind of wet-biomass. Disposal cost is very high, because of its property as easy to rot and heavy. Supercritical water gasification (SCWG) holds promise as a technology to convert shochu residue as wet-biomass into valuable fuel gas treat residue to clear water and provide steam for distillation process of shochu.　60 h Daly start and stop (DSS) SCWG test was succeeded with Radical Scavenger and Rapid heating rate. Therefore, One month DSS test planned for practical use for Distillers’ factory with remodeled pilot plant as NEDO project will report.

Lecture: Hiroki YOKOYAMA

M1 Student, Graduate School of Engineering, Hiroshima University

“Specification and Quantitation of Fermentation Inhibitor for Hydrothermal Pulverization Pretreatment Using Disk Mill ”

The objective of this research is specification and quantitation of fermentation inhibitor in the liquid sample that was obtained by hydrothermal pulverization pretreatment using disk mill. This pretreatment was conducted using 2.0-2.8 mm particles of eucalyptus for feedstock, and the conditions of gap size between two disks was changed 0.5, 1.0, and 1.5 mm. The liquid samples were analyzed by high performance liquid chromatography and I checked acetic acid and formic acid was detected.

Chair: Nattacha PAKSUNG

Researcher , Graduate School of Engineering, Hiroshima University

The 64th Hiroshima University Biomass Evening Seminar(The33rd Hiroshima University ACE Seminar)

The 64th Hiroshima University Biomass Evening Seminar

(The33rd Hiroshima University ACE Seminar) was held.

Date & Time: Mon .7 May., 2018 16:20-17:50

Place: Engineering 110 Lecture Room, Higashi-Hiroshima Campus, Hiroshima University

Commentary: Yukihiko MATSUMURA

Professor, Graduate School of Engineering, Hiroshima University

Lecture: Shuhei IJI

M1 Student,Graduate School of Advanced Sciences of Matter, Hiroshima University

“Processing of high salinity organic with marine sediment”

High salinity organic matter is a promising feedstock for anaerobic digestion (methane fermentation) that is a technology producing methane from organic matter using microorganisms because it contains high water content. We found that marine sediments are useful microbial resource for anaerobic digestion of high salinity organic matter because of their salt tolerance. In this study, possibility of microorganisms in marine sediment to high salinity organic was investigated. As the result, it was suggested that anaerobic digestion was successful in various food industry wastes such as Miso.

Lecture: Yuto ICHIHARA

M2 Student,Graduate School of Engineering, Hiroshima University

“Decomposition product from algal biomass by hydrothermal treatment and the effect of catalyst”

Algal biomass has a huge amount, carbon neutral and storage. But the decomposition product from algal biomass hasn’t been reported. That’s why the purpose of this study is to indicate the decomposition product of Chlorella vulgaris and Spirulina as algal biomass treated by hydrothermal treatment and catalyst. The experimental condition, residence time was set at 60 min, temperature was 200, 250 and 300 ℃, catalyst was no catalyst, H2SO4, KOH. In the sample, gas sample was analyzed by GC, liquid sample was analyzed by CHNS, and solid sample was observed by SEM. After treatment, the cells of these biomasses were most destroyed under 300 ℃, KOH.

Lecture: Rahmat Iman MAINIL

D2 Student, Graduate School of Engineering, Hiroshima University

” Mechanism of Retroaldol Conversion in Supercritical Water “

Most of studies about behaviour of biomass as model compound under supercritical condition still leave some unclear mechanism which were explained by unknown total organic carbon (TOC) remained. Glyceraldehyde as a simple model compound can be utilized to understand the detail mechanism of retro aldol products which were believed as major products found in decomposition of xylose under hot compress water. In this study, glyceraldehyde was dissolved in deionzed water and then heated in the temperature range of 350-450 °C at 25 MPa in a continous reactor. High-performance liquid comatography was used to identify componds in the liquid effluent. The intermediates observed in this study were retro-aldol products (glycolaldehyde, formaldehyde, dihydroxyacetone, and acetaldehyde). The reaction kinetics were determined by assuming all reaction are first-order. Arrehenius behaviour was used to classify the reaction as free-radical reactions (showing Arrehenius behaviour in supercritical region) and as ionic reactions (not showing Arrehenius behaviour in supercritical region).

Lecture: Hiroki YOKOYAMA

M1 Student,Graduate School of Engineering, Hiroshima University

“Specification and Quantitation of Fermentation Inhibitor for Hydrothermal Pulverization Pretreatment Using Disk Mill ”

The objective of this research is specification and quantitation of fermentation inhibitor in the liquid sample that was obtained by hydrothermal pulverization pretreatment. This pretreatment was conducted using 1.0-2.0, 2.0-2.8, 2.8-3.3, 3.3-4.0 mm particles of eucalyptus. The liquid samples were analyzed by high performance liquid chromatography and I checked acetic acid and formic acid was detected.

Chair: Yukihiko MATSUMURA

Professor, Graduate School of Engineering, Hiroshima University

The 63rd Hiroshima University Biomass Evening Seminar(The32nd Hiroshima University ACE Seminar)

The 63rd Hiroshima University Biomass Evening Seminar

(The32nd Hiroshima University ACE Seminar) was held.

Date & Time: Mon .23 Apr., 2018 16:20-17:50

Place: Engineering 110 Lecture Room, Higashi-Hiroshima Campus, Hiroshima University

Commentary: Yukihiko MATSUMURA

Professor, Graduate School of Engineering, Hiroshima University

Lecture: Yoshiki FUJIWARA

M1 Student,Graduate School of Engineering, Hiroshima University

“Recovery of phosphorus using calcium under hydrothermal condition”

Phosphorus is an important nutrient for all living organization. It is essential for agriculture, like potassium and nitrogen. Plants absorb only inorganic phosphorus and fertilizer for plant is usually produced from phosphate rock. However it takes a long time for phosphorus rock to be form. There is a possibility of exhaustion in the future. Sewage sludge represents an important secondary phosphorus source. Hydrothermal treatment is effective method to recover phosphorus from sewage sludge There is very few study which focused on calcium to recover phosphorus. The research aim of this work is to recover phosphorus as calcium salt under hydrothermal condition.

Lecture: Yukihiko MATSUMURA

Professor, Graduate School of Engineering, Hiroshima University

” Levulinic Acid Production from Glucose by Hydrothermal Treatment using MWCNT”

Levulinic acid is one of the important chemicals because it is the original chemicals to synthesize fuel additives, plastic material and so on. Due to the depletion of fossil fuel, levulinic acid production from woody biomass, such as grass and wood, is needed. So far, the researches about levulinic acid production using strong acid as homogeneous catalyst have been conducted. However, the problem is that those catalyst is strong acid and liquid. It is not suitable for waste liquid treatment and reuse. Therefore, levulinic acid production from glucose by hydrothermal treatment using multi walled carbon nanotubes as heterogeneous catalyst was investigated.

Lecture: Apip AMRULLAH

D3 Student,Graduate School of Engineering, Hiroshima University

“Identification of Sewage Sludge Structure during Hydrothermal Treatment”

This study presents experimental identification of sewage sludge structure during hydrothermal treatment (HT). For identification of the cell structure of sewage sludge, the HT temperature was varied. In this work, active sludge was treated hydrothermally using continuous reactor in the temperature range of 130-250 oC under the fix pressure of 5 MPa. The liquid sample was analyzed using total organic carbon (TOC) analyzer to quantify the total carbon present in the liquid (nonpurgeable organic carbon, NPOC) and in the dissolved gaseous product (inorganic carbon, IC). The solid sample was observed using ZEN microscope 2.3 blue edition, with objective LD A-Plan 40x/0.55 Ph1 and magnification 40x. It was observed at 180 oC the cell started to get broken and the TOC increased with temperature.

“Behavior of Organic Matter in Liquid Phase during Hydrothermal Treatment of Sewage Sludge”

Hydrothermal treatment (HT) is a promising option for pretreatment of organic waste, due to its low energy consumption and contribution to increasing fuel energy density. HT has been also adopted as an energy effective method for dewatering. In this study, sewage sludge was treated in a tubular reactor under hydrothermal condition over temperature range of 130 ̶ 250 °C under the fixed pressure of 5 MPa, and the final products that were liquid and solid were analyzed. The aim of this study was to investigate the behavior of organic matter in liquid phase during HT of sewage sludge by varying the temperature. The total organic carbon increased with temperature.

Chair: Nattacha PAKSUNG

Researcher , Graduate School of Engineering, Hiroshima University

The 62nd Hiroshima University Biomass Evening Seminar(The 29th Hiroshima University ACE Seminar)

The 62nd Hiroshima University Biomass Evening Seminar

(The 29th Hiroshima University ACE Seminar)was held.

Date & Time: Fri .2 Mar., 2018 16:20-17:50

Place: Engineering 110 Lecture Room, Higashi-Hiroshima Campus, Hiroshima University

Commentary: Yukihiko MATSUMURA

Professor, Graduate School of Engineering, Hiroshima University

Lecture: Hiroshi ITO

M2 Student,Graduate School of Engineering, Hiroshima University

“Behavior of Organic Compounds and Kelp Cell during Hydrothermal Pretreatment”

Kelp is known as usable resource for renewable energy because it includes fermentable sugar which are alginic acid and mannitol. However, most of the organic matter exist inside the cell membrane. Hydrothermal process can break the cell structure and make this organic matter released. To make the best of the organic matter, the condition to make this release take place should be elucidated. However, it is yet to be decided. The purpose of this study is to indicate the condition where cells of kelp break under hydrothermal pretreatment. In this research, kelp was treated by continuous flow reactor under hydrothermal condition. The experimental condition, temperature was varied from 110 to 190 ℃, pressure was fixed at 5 MPa, and residence time was set at 10 min.The carbon recovery yield in liquid phase was measured using total organic carbon (TOC) analyzer. The state of kelp cell was observed using optical microscope. After hydrothermal pretreatment, the TOC value increaced when treatment temperature is higher than 130 ℃. Observation by the optical microscope confirmed that cell wall of kelp was destroyed at 130 ℃. This results suggests that hydrothermal pretreatment at 130 ℃, 10 min and 5 MPa in hydrothermal pretreatment of kelp is effective for releasing organic matter.

Lecture: Mutsumi KUROKI

B4 Student, School of Engineering, Hiroshima University

1.”Examination of direct sampling from hydrothermal conditions using a capillary tube”

We developed an in situ mass spectrometry (in situ MS) analysis method using capillary tube for the first time. The in situ MS analysis was performed by coupling a tubular batch reactor with a quadrupole mass analyzer via custom-built connection fittings. The products of glucose decomposition were investigated by in situ MS. We conducted experiment at 120℃ and reaction time is 5, 10, 20 minutes. Pressure reduction was successfully made, and MS analysis was conducted. By making the capillary longer, in situ MS should be applied to reactions under pressure higher than that employed in this study.

“Determination of Hydrothermal Glucose Decomposition Products Using Mass Spectrometry”

We developed an in situ mass spectrometry (in situ MS) analysis method using capillary tube for the first time. The in situ MS analysis was performed by coupling a tubular reactor with a quadrupole mass analyzer via stainless capillary tube. The products of glucose decomposition were investigated by in situ MS. We conducted experiment at 120ºC and reaction time was 5, 10 and 20 min. Pressure reduction was successfully made, and MS analysis was conducted. By making the capillary longer, in situ MS should be applied to reactions under pressure higher than that employed in this study.

Lecture: Satoshi GOTO

M2 Student,Graduate School of Engineering, Hiroshima University

“Discussion on slurry feeding for supercritical water gasification reactor”

Recently biomass energy is attracting attention, but utilization method for wet biomass Can be still developed. Supercritical water gasification is effective to convert wet biomass slurry feedstock into the energy because of water with high reactivity. When such slurry feedstock is used for this gasification, slurry feeder is needed. However there is no solid procedure for feeding slurry and mass balance in many researches are not well closed. That is why this research is focusing on establishing slurry feeder and making sure key parameters of mixing slurry materials. High pressure container was made for this research and the evaluation of this feeder was conducted by the recovery rate with changing the agitation rate, the amount of feedstock and the distance between the plate and the feedstock. In this research, shochu residue and activated carbon was used as slurry feedstock.

Chair: Nattacha PAKSUNG

Researcher , Graduate School of Engineering, Hiroshima University

The 61st Hiroshima University Biomass Evening Seminar(The 27h Hiroshima University ACE Seminar)

The 61st Hiroshima University Biomass Evening Seminar

(The 27h Hiroshima University ACE Seminar)was held.

Date & Time: Wed .14 Feb., 2018 16:20-17:50

Place: Engineering 110 Lecture Room, Higashi-Hiroshima Campus, Hiroshima University

Commentary: Yukihiko MATSUMURA

Professor, Graduate School of Engineering, Hiroshima University

Lecture: Aya NAKAJI

M2 Student,Graduate School of Advanced Sciences of Matter, Hiroshima University

“Functional analysis of formate-tetrahydrofolate ligase (FTL) with sugar and H2 – CO2 metabolism of Moorella thermoacetica”

Recently, production of useful materials using CO2 has been drawing attention. Our laboratory succeeded in producing a genetically engineered ethanol producing mutant derived from thermophilic Moorella thermoacetica ATCC 39073 which ferments carbohydrates, syngas and H2-CO2. However, the mutant produced ethanol only from sugar, but did not from H2 + CO2. At this time, it was considered that formate-tetrahydrofolate ligase (FTL) was a bottleneck of H2 + CO2 metabolism because formate accumulated. Therefore, in this study, I constructed mutant strains in which FTL gene was introduced and analyzed their characteristics.

Lecture: Satoshi GOTO

M2 Student,Graduate School of Engineering, Hiroshima University

“Reaction Model for Supercritical Water Gasification of Shochu Residue”

Supercritical water gasification has the potential of complete gasification especially for wet biomass. However undesirable products such as tarry material and char can cause plugging of the reactor and low gasification efficiency. Acetic acid can be effective as the radical scavenger to suppress these products. The quantitative study for the effect of acetic acid with real biomass has never been conducted yet. In this study, the effect of acetic acid on SCWG of real biomass was determined and reaction model was applied.

Lecture: Nattacha PAKSUNG

Researcher , Graduate School of Engineering, Hiroshima University

1.“Supercritical water gasification of tomato residues”

Among many solutions to cope with fossil fuel depletion, which is a global concern nowadays, lignocellulosic biomass is a good alternative for renewable energy production as a second generation biofuel. Supercritical water gasification (SCWG) can be an efficient conversion technology to convert biomass, most of which has high water composition, into burnable gas. Due to the ability of supercritical water to dissolve biomass, reactions can take place homogenously in the water and reaction rate is enhanced. In this study, tomato residue was employed as lignocellulosic biomass. The SCWG of tomato was investigated in hydrothermal condition under constant pressure of 25 MPa. The reactor employed in this study is a small tubular reactor of SS316 with inner and outer diameters of 2.17 mm and 3.8 mm, respectively. In this work, the effect of temperature on the product distribution is focused.

2.“Catalytic effects of phenol on hydrothermal decomposition of glucose”

Supercritical water is water at fluid phase when temperature and pressure are above its critical values (374 °C, 22.1 MPa). At this state, water has high potential as a solvent for organic components and gases. As a result, biomass could be homogeneously dissolved in supercritical water and consequently obtain high conversion. In this study, interaction between cellulose and lignin that takes place in supercritical water was modeled by interaction between glucose and phenol.

Chair: Yukihiko MATSUMURA

Professor, Graduate School of Engineering, Hiroshima University

The 60th Hiroshima University Biomass Evening Seminar(The 25th Hiroshima University ACE Seminar)

The 60th Hiroshima University Biomass Evening Seminar

(The 25th Hiroshima University ACE Seminar)was held.

Date & Time: Thu .11 Jan., 2018 16:20-17:50

Place: Engineering 110 Lecture Room, Higashi-Hiroshima Campus, Hiroshima University

Commentary: Yukihiko MATSUMURA

Professor, Graduate School of Engineering, Hiroshima University

Lecture: Kiyoto KIHARA

M2 Student,Graduate School of Engineering, Hiroshima University

“Kinetics of Enzymatic Hydrolysis for Dissolved Cellulose”

Biomass energy which is one of the renewable energy is not popular because the efficiency is not good. Because enzymatic hydrolysis which is one of the main process of bioethanol production takes too long time and enzyme is expensive. Dissolved cellulose can be decomposed earlier than crystalline cellulose. However, that kinetics was not analyzed. In this study, kinetics of enzymatic hydrolysis for dissolved cellulose was examined. Dissolved cellulose was produced by hydrolyzing crystalline cellulose at sub-critical condition. (300 oC, 15 MPa) Dissolved cellulose was hydrolyzed by enzymes which were cellulase and β-glucosidase. The result was analyzed by Michaelis-Menten model.

Lecture: Kengo HISHIDA

M2 Student,Graduate School of Engineering, Hiroshima University

“Effect Between Initial Grain Size and Disk Gap under Hydrothermal Disk Milling”

Pretreatment is an important process to obtain high ethanol yield on bioethanol production using lignocellulosic biomass. On this research, the effect of initial grain size and disk gap under hydrothermal disk milling was investigated. The result showed that the optimum initial grain size was different with each disk gap. It is likely that there were different milling mechanisms during hydrothermal disk milling which caused different results.

Lecture: Farida RAHAYU

D3 Student, Graduate School of Advanced Sciences of Matter, Hiroshima University

“Optimization of thermophilic ethanol fermentation from lignocellulosic hydrolysate by ethanol-producing transformant of Moorella thermoacetica ”

A transformant of Moorella thermoacetica was constructed for thermophilic ethanol production from lignocellulosic biomass by deleting two phosphotransacetylase genes, pdul1 and pdul2, and introducing the native aldehyde dehydrogenase gene (aldh) controlled by the promoter from glyceraldehyde-3-phosphate dehydrogenase. The transformant successfully fermented sugars in hydrolysate prepared through the acid hydrolysis of lignocellulose to ethanol, suggesting that this transformant can be used to ferment the sugars in lignocellulosic biomass for ethanol production. In the present study, we used the transformants to determine the ability to ferment hydrolysate from actual lignocellulosic feedstock to ethanol, a fermentation test was conducted for three different types of lignocellulosic hydrolysate; cedar plant, forest residue and rice straw in optimally condition at 55 °C for 168 hours periods of fermentation. Our present findings demonstrated that thermophilic fermentation by genetically engineered M. thermoacetica is a feasible process for producing ethanol from lignocellulosic biomass.

Lecture: Kunassanan Siribunyaroj

M2 Student,Graduate School of Engineering, Hiroshima University

“Glycine Decomposition in Supercritical Water Gasification”

Since non-renewable fossil fuel consumption causes the global warming problems, using energy from renewable source such as biomass instead of fossil fuel to avoid worsening the environmental problem is now being sought. Supercritical water gasification (SCWG) is a favorable technology to convert wet biomass into renewable energy under temperature and pressure above 374 °C and 22.1 MPa, respectively. In the previous study, glycine, which is the simplest amino acid, was chosen as a model protein for investigating the behavior of amino acid decomposition under supercritical water gasification. However, they just followed gasification efficiency. The behavior of both nitrogen and carbon should be followed for the complete understanding of the reaction. The purpose of this study is to gasify glycine in supercritical water, and determine the behavior of both carbon and nitrogen. The experiment was conducted at 25 MPa, 450 °C, with the residence time of 5 s, using tubular flow reactor. The feedstock percentage concentrations are 1-5 percent by weight, respectively. According to this experiment, most of nitrogen compounds in glycine are in form of ammonia and methylamine. Carbon dioxide, hydrogen and methane were the main gaseous products found in this experiment.

Chair: Nattacha PAKSUNG

Researcher , Graduate School of Engineering, Hiroshima University

The 59th Hiroshima University Biomass Evening Seminar(The 24th Hiroshima University ACE Seminar)

The 59th Hiroshima University Biomass Evening Seminar

(The 24th Hiroshima University ACE Seminar)was held.

Date & Time: Wed .6 Dec., 2017 16:20-17:50

Place: Engineering 110 Lecture Room, Higashi-Hiroshima Campus, Hiroshima University

Commentary: Yukihiko MATSUMURA

Professor, Graduate School of Engineering, Hiroshima University

Lecture: Tsunehiro AKI

Professor,Graduate School of Advanced Sciences of Matter, Hiroshima University

“Lipid biorefinery using marine microbes”

We aim at practically using sustainable biorefinery technology to convert underutilized biomass such as food wastes, waste water, non-edible plants and marine macroalgae into a various value-added lipids such as biologically functional polyunsaturated fatty acids, antioxidative carotenoids and hydrocarbons for general chemicals and biofuels by marine oleaginous microbe, Aurantiochytrium sp. This seminar will present our recent progress including microbial breeding.

Lecture: Shota MIYAMOTO

M2 Student,Graduate School of Advanced Sciences of Matter, Hiroshima University

“Degradation mechanism of long-chain fatty acid in methane fermentative flora”

A microbial flora with high methanogenic activity against long chain fatty acid (LCFA), a hardly degradable substance, was found in our laboratory. However, as a result of the microflora analysis, microorganisms presumed to be involved in LCFA decomposition were not detected, suggesting decomposition by complex microorganisms. Therefore, in this study, in order to clarify the mechanism of anaerobic LCFA decomposition, screening method of microorganism population involved in LCFA decomposition activity using centrifugation treatment and dilution method was investigated.

Lecture: Hiroshi ITO

M2 Student,Graduate School of Engineering, Hiroshima University

“Behavior of Kelp Cell under Hydrothermal Pretreatment ”

Kelp is known as usable resource for renewable energy because it includes fermentable sugar which are alginic acid and mannitol. However, most of the organic matter exist inside the cell membrane. Hydrothermal process can break the cell structure and make this organic matter released. To make the best of the organic matter, the condition to make this release take place should be elucidated. However, it is yet to be decided. The purpose of this study is to indicate the condition where cells of kelp break under hydrothermal pretreatment. In this research, kelp was treated by continuous flow reactor under hydrothermal condition. The experimental condition, temperature was varied from 110 to 130 ℃, pressure was fixed at 5 MPa, and residence time was set at 10 min.The carbon recovery yield in liquid phase was measured using total organic carbon (TOC) analyzer. The state of kelp cell was observed using optical microscope. After hydrothermal pretreatment, the TOC value increaced when treatment temperature is higher than 130 ℃. Observation by the optical microscope confirmed that cell wall of kelp was destroyed at 130 ℃. This results suggests that hydrothermal pretreatment at 130 ℃, 10 min and 5 MPa in hydrothermal pretreatment of kelp is effective for releasing organic matter.

Chair: Nattacha PAKSUNG

Researcher , Graduate School of Engineering, Hiroshima University

The 58th Hiroshima University Biomass Evening Seminar(The 23rd Hiroshima University ACE Seminar)

The 58th Hiroshima University Biomass Evening Seminar

(The 23rd Hiroshima University ACE Seminar)was held.

Date & Time: Wed .8 Nov., 2017 16:20-17:50

Place: Engineering 110 Lecture Room, Higashi-Hiroshima Campus, Hiroshima University

Commentary: Yukihiko MATSUMURA

Professor, Graduate School of Engineering, Hiroshima University

Lecture: Yoshiko OKAMURA

Associate Professor,Graduate School of Advanced Sciences of Matter, Hiroshima University

“Summary of CREST project; Wastewater treatment, metal recovery and bio-oil production from macroalgae fermentation residues.”

The big goal of our CREST team is a complete utilization of macroalgae as energy and material resources, or zero waste.

Therefore, we screened and collected photosynthetic bacteria for metal removal and recovery and clarified their adsorption mechanism. As a result, metals were removed and recovered completely.

Moreover, the bacterium that can convert organic acids into low molecular oil was obtained. This bacterium achieved complete consumption of organic acids in actual methane fermentation residues. It is suggested that modified cultivation methods can realize bio-oil production from wastewater.

Lecture: Apip AMRULLAH

D2 Student,Graduate School of Engineering,Hiroshima University

“Effect of Hydrothermal Treatment Condition on Morphology Structures of Sewage Sludge”

The objective of this research is to investigate the effect of temperature for morphology structure of sewage sludge during hydrothermal treatment. Hydrothermal treatment is a promising option for pretreatment of organic waste, due to its low energy consumption. If needed, contribution to increasing fuel energy density or effective drying is also achieved. Hydrothermal treatment results in destruction of organic cell structures, but the experimental investigation on the effect of temperature on morphology structure of sewage sludge has not been studied well. In this study, sewage sludge was treated hydrothermally using continuous reactor in the temperature range of 130-250oC under the fix pressure of 5 MPa. The liquid sample was analyzed using a total organic carbon (TOC) analyzer to quantify the total carbon present in the liquid (nonpurgeable organic carbon, NPOC) and in the dissolved gaseous product (inorganic carbon,IC). The solid sample was observed using ZEN microscope 2.3 blue edition, with objective LD A-Plan 40x/0.55 Ph1 and Magnification 40x. It was indicated that the cell of sewage sludge was broken and the total organic carbon (TOC) increased with increasing temperature.

Lecture: Rahmat Iman Mainil

D1 Student,Graduate School of Engineering, Hiroshima University

“Glyceraldehyde Decomposition in Sub- and Supercritical Water”

The objective of this study was to determine the characteristics of glyceraldehyde decomposition in subcritical and supercritical water. Glyceraldehyde is a triose monosaccharide with chemical formula C3H6O3. It was chosen as feedstock to understand more about behaviour of retro aldol reaction in supercritical gasification of xylose. This study will explain the reactions and intermediate compounds which has not clearly found in decomposition of xylose. The experiment was investigated by dissolving glyceraldehyde in deionzed water and then heated in the temperature range of 350 – 450 0C with fix pressure 25 MPa in a continous reactor. High-performance liquid comatography (HPLC) was used to identify componds existing in the liquid effluent. The intermediates observed in this study were retro-aldol products (glycolaldehyde, formaldehyde, acetaldehyde and dihydroxyacetone), and organic acids (acetic acid and formic acid). The reaction kinetics were determined by assuming all reaction are first-order. Arrehenius behaviour was used to classify the reaction as free-radical reactions (showing Arrehenius behaviour in supercritical region) and as ionic reactions (not showing Arrehenius behaviour in supercritical region).

Chair: Nattacha PAKSUNG

Researcher , Graduate School of Engineering, Hiroshima University

The 57th Hiroshima University Biomass Evening Seminar(The 22nd Hiroshima University ACE Seminar)

The 57th Hiroshima University Biomass Evening Seminar

(The 22nd Hiroshima University ACE Seminar)was held.

Date & Time: Wed .18 Oct., 2017 16:20-17:50

Place: Engineering 110 Lecture Room, Higashi-Hiroshima Campus, Hiroshima University

Commentary: Yukihiko MATSUMURA

Professor, Graduate School of Engineering, Hiroshima University

Lecture: Toshihiro TAKAGAKI

M2 Student,Graduate School of Advanced Sciences of Matter, Hiroshima University

“Degradation of excess sludge and its power conversion by microbial fuel cells ”

Today, industrial wastewater is purified by activated sludge systems. However, these systems produce a large amount of excess sludge and they burn up excess sludge. Therefore, they spend a great amount of energy burning up excess sludge. On the other hand, the microbial fuel cells (MFC) sludge degradation systems do not need additional energy. Furthermore, what is better, electric power can be acquired from MFC. Therefore, this study is aimed at testing sludge degradation in MFC without burning.

Lecture: Mutsumi KUROKI

B4 Student,School of Engineering, Hiroshima University

“ In Situ Mass Spectrometry of Glucose Decomposition under Hydrothermal Reactions Using Capillary ”

The increase in global world energy demand is causing depletion of fossil fuel resources and leading to global warming. Therefore, potential sources of renewable energy to replace fossil fuels are required. One of the most promising renewable energy sources is biomass. Especially, the second generation bioethanol made from inedible biomass is gaining attention. A high-performance pretreatment process is needed to improve process efficiency. Hydrothermal pretreatment is suitable for this process. The process is simple and economical. To improve the process efficiency, it is important to detect other compounds that exist in the reaction field at high temperatures with a short lifetime. Our purpose is to develop an in situ mass spectrometry (in situ MS) analysis system that can detect these compounds under hydrothermal condition using capillary. In this study, we used capillary with inner diameter of 0.1 mm to reduce the high pressure of the reactor to the vacuum pressure required for MS analysis. Pressure reduction was successfully made, and MS analysis was conducted. By making the capillary longer, this technology should be applied to reactions under higher pressure.

Lecture: Hiroki YOKOYAMA

B4 Student,School of Engineering, Hiroshima University

“Effect of 5-HMF on Enzymatic Hydrolysis of Cellulose”

Today, the second-generation ethanol from lignocellulosic biomass is attracting attention. One of the problems for this technology is that 5-hydroxymethylfurfral(5-HMF) produced by hydrothermal treatment inhibits fermentation. However, whether 5-HMF inhibits enzymatic hydrolysis or not has not been well known. The objective of this research is to elucidate the effect of 5-HMF on enzymatic hydrolysis of cellulose adding different quantity of 5-HMF ranging from 0 to 0.2 g. As a result, addition of 5-HMF did not affect the enzymatic hydrolysis.

Lecture: Soshi HASHIMOTO

M1 Student, Graduate School of Engineering, Hiroshima University

“Decomposition characteristics of DNA under hydrothermal condition”

Phosphorus is used for fertilizer to grow plants and its form is inorganic phosphorus. Recently, phosphorus recovery from sewage sludge have been researched and hydrothermal treatment is proposed as one of the method. DNA is one of the organic phosphorus contained in sewage sludge and we determined the characteristics of decomposition and supercritical water gasification in this study. As the result, DNA decomposition was proceeded but it turned out that inorganic phosphorus in supercritical water precipitated.

Chair: Nattacha PAKSUNG

Researcher , Graduate School of Engineering, Hiroshima University

The 56th Hiroshima University Biomass Evening Seminar(The 20h Hiroshima University ACE Seminar)

The 56th Hiroshima University Biomass Evening Seminar

(The 20h Hiroshima University ACE Seminar)was held.

Date & Time: Wed .13 Sep., 2017 16:20-17:50

Place: Engineering 106 Lecture Room, Higashi-Hiroshima Campus, Hiroshima University

Commentary: Yukihiko MATSUMURA

Professor, Institute of Engineering, Hiroshima University

Lecture: Paksung NATTACHA

D3 Student, Graduate School of Engineering, Hiroshima University

“Gasification of Lignocellulosic Biomass under Sub- and Super Critical Water Condition: Interaction between Model Compounds and Process Evaluation”

Supercritical water gasification (SCWG) is promising method to convert biomass into gaseous products. At supercritical state of water, biomass could be homogeneously dissolved in supercritical water and consequently obtain high conversion. However, biomass consists of various compounds that make difficulty to optimize the process. Thereby, reaction scheme and model compound of biomass are keys to achieve the goal. For lignocellulosic biomass, it contains mostly cellulose, hemicellulose and merged by lignin. This research includes fundamental studies, which elucidates mechanisms of model compounds of lignocellulosic biomass in terms of kinetic analysis. A detailed kinetics study allow ones to predict the outcome of the reactions. Furthermore, practical utilization of SCWG system was evaluated to reveal its feasibility in terms of energy, economic and environmental viewpoints.

Lecture: Obie FAEOBIE

Visiting Reseacher, Institute of Engineering, Hiroshima University

“Supercritical biodiesel production: A-state-of-the-art”

An effort to mitigate global climate change and environmental pollution problems has attracted a tremendous attention in researching renewable energy. One of the most promising renewable energy is biodiesel, which can be derived from the biomass including vegetable oil, microalgae, or animal fats. Several methods have been employed so far to produce biodiesel. Nowadays, supercritical biodiesel production has undergone a vigorous development as the technology offers several advantages over other methods, including the fact that it does not require a catalyst, short residence time, high reaction rate, no pretreatment requirement, and applicability to a wide variety of feedstock. This technology was first employed for biodiesel production using methanol and ethanol. Most recently, biodiesel production in supercritical methyl acetate and tert-butyl methyl ether (MTBE) has been developed also. In this paper, supercritical biodiesel production will be discussed in detail. Finally, challenges for improving energy recovery as well as reactant requirement in supercritical biodiesel production and recommendations for future work are provided.

Chair: Yukihiko MATSUMURA

Professor, Institute of Engineering, Hiroshima University