The 55th Hiroshima University Biomass Evening Seminar

(The 16th Hiroshima University ACE Seminar)was held.

Date & Time: Wed .19  Jul., 2017   16:20-17:50

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

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Commentary: Yukihiko MATSUMURA

        Professor, Institute of Engineering, Hiroshima University

Lecture: Tanawan CHALERMSAKTRAKUL

M2 Student, Graduate School of Engineering, Hiroshima University

“Novel hydrothermal treatment of xylose with acetic acid addition”                      

The hydrothermal gasification of xylose, as a model substance of hemicellulose, was carried out at high temperatures and pressures (350, 400, 450 °C, 25 MPa) in the presence of acetic acid by using continuous-flow reactor. As acetic acid is one kind of organic compound, environmental friendly, low corrosiveness, and also byproduct of hemicellulose gasification, it was chosen to be the catalyst to understand more about the behavior of each reaction in supercritical gasification of xylose. This study aimed to compare the reaction rate constant of xylose decomposition with and without acetic acid addition. The experiments were investigated to determine the influence of residence time varied from 0.5 to 5 s. The concentration of xylose was 1.5 wt% mixed with 1.5 wt% of acetic acid. When acetic acid was added in supercritical gasification of xylose, it gave radical scavenger effect and provided H+, so the retro-aldol reaction and carbon gasification production, which are radical reactions, were be suppressed. Meanwhile, the dehydration of xylose and xylulose to furfural was be promoted significantly. The different between sub- and supercritical conditions is that xylulose yield decreased with increasing acetic acid at subcritical, but at supercritical xylulose increase with increasing acetic acid. At subcritical, dehydration of xylulose to furfural was faster than that of xylose to furfural. In contrast, at supercritical, furfural was produced from xylose more than xylulose.

Lecture: Mattana TUNCHAI             

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

“ Novel method to control bacterial wilt by disturbing its ability to locate host root ”

Ralstonia solanacearum causes bacterial wilt disease in many economically important crops worldwide. Directed-movement, called chemotaxis, is essential for R. solanacearum to locate the plant root which is considered as a critical early step for host invasion. Therefore, disturbing its chemotaxis system may be able to delay or even suppress the host infection. After having gained knowledge of its attractants and repellants, we tested suppression effect of these compounds on tomato infection. Consequently, we found that malate, identified as one of signal compounds attracting the pathogen to host root, is a promising bacterial wilt control agent.

Lecture: Luo GONGLINFENG           　　　 

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

“Carboxylic acid production by psychrophlie-based simple catalyst”

Production of valuable chemicals from biomass has been regarded as a hopeful approach to reduce the reliance on petroleum chemicals. Organic acids, especially carboxylic acids contained in TCA cycle(tricarboxylic cycle) have a very board application in chemical industry[1] due to their founctioal groups. There are only several carboxylic acids which are produced commercially by fermentation or biotransformation. Since a lot of carboxylic acids are intermediates or precursors for metabolisms, the diffculties on over accumulation in cells and transportation through cell membranes hampered the development of efficient production process. In our research, we conducted a biocatalyst based on psychrophile which is unable to grow and reproduce over 30°C due to inactivited enzymes and membrane damage. when the reaction was carried at over 30°C, the permeability change caused by membrane damge gave the mesophilic enzymes that we introduced into the host a better access to the substance which leaded to a faster production of carboxylic acid.

Lecture: Paksung NATTACHA

 D3 Student, Graduate School of Engineering, Hiroshima University

“Effect of Phenol on the Glucose Decomposition in Supercritical Water”

Supercritical water (SCW) is a promising medium for biomass conversion into chemicals and fuel gases. It has specific properties that make it possible to dissolve biomass homogeneously. Lignocellulosic biomass is a candidate as feedstock because of its abundant availability. Glucose is often used to represent cellulose in the lignocellulosic biomass. It produces tarry material and char at low temperature, but the production is demoted in SCW. Phenol is a derivative of lignin and is believed to provide radicals in SCW. When biomass is treated in SCW, interaction between cellulose and lignin takes place, which should be modeled by interaction between glucose and phenol. However, this interaction has not been studied in detail. The purpose of this study is to determine the interaction. Mixture of glucose and phenol was fed to continuous reactor. Interaction resulted in large increase in tarry material.

Chair: Obie FAROBIE

     Visiting Reseacher, Institute of Engineering, Hiroshima University

The 54th Hiroshima University Biomass Evening Seminar

(The 15th Hiroshima University ACE Seminar)was held.

Date & Time: Thu .8  Jun., 2017   16:20-17:50

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

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Commentary: Yukihiko MATSUMURA

        Professor, Institute of Engineering, Hiroshima University

Lecture: Akihisa KITA

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

“Elucidation of anaerobic degradation mechanism of hardly degradable biomasses by microbial symbiosis and its application to production of useful materials”

Alginate and chitin are promising renewable resources because they are abundant on the Earth. However, alginate and chitin can not be utilized by industrially utilized microorganisms such as Esherichia coli, Yeast and so on. Recently, we have found that the microbial consortia in the environment can easily utilize hardly degradable biomass.

In this seminar, we will introduce the degradation mechanism of alginate by bacterial symbiosis and its application to useful materials.

Lecture: Soshi HASHIMOTO

M1 Student, Graduate School of Engineering, Hiroshima University

“Decomposition behavior of DNA in subcritical and supercritical water”

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 behavior in this study. At this time, the experiment was conducted by changing the temperature from 300 C to 450 C. Total phosphorus yield and Inorganic phosphorus yield decreased with the increase of reaction temperature or residence time under supercritical condition.

Lecture: Pattasuda  DUANGKAEW　　　 

   D3 Student, Graduate School of Engineering, Hiroshima University

“In situ Mass spectrometry of hydrothermal reaction products ”

Recently, with rising prices for petroleum and concern for global warming due to the use of fossil fuels the development of renewable fuel source continues to attract a lot of attention. The technology for conversion of biomass resources into fuels and chemicals are necessary. To determination and manipulation of the primary product during the hydrothermal process of macroalgae.  Therefore, the aims of this research to develop and design the rapid analysis of sugar production under hydrothermal pretreatment conditions via in situ mass spectroscopic method. The products of glucose during hydrothermal; pretreatment under various temperatures (140-220 °C) have been investigated. Moreover, the results from in situ analysis, and commercial HPLC were compared.

Chair: Obie FAROBIE

    Visiting Reseacher,Institute of Engineering, Hiroshima University

The 53rd Hiroshima University Biomass Evening Seminar

(The 13th Hiroshima University ACE Seminar)was held.

Date & Time:Thu .18  May., 2017   16:20-17:50

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

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Commentary: Yukihiko MATSUMURA

        Professor, Institute of Engineering, Hiroshima University

Lecture: Toyokazu MIURA

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

“Biomethane production from brown algae”

Marine macroalgae are receiving increasing attention as a feedstock for biomethane

production because they do not compete with food for farm land and are less resistant to

degradation than lignocellulosic feedstocks. In this study, halophilic microbes were used toproduce methane from brown algae, which contain high levels of salt, without dilution ofsalinity.

Lecture: Shota NAKAI

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

“Lipid production by using short-chain fatty acid-assimilating microorganism and marine biomass.”

Using a marine low organic acid-assimilating bacterium Nitratireducter sp. OM-1 strain, we are aiming to establish biorefinery technology for biofuel production from biomass such as marine macroalgae.

Strain OM-1 can accumulate oils at 60% of dry cell weight intracellular under the stress condition of nitrogen starvation. In this research, we studied on various culture conditions to improve oil production.

Lecture: Kaisei TAKEMURA　　　 

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

“Effect of modification of acetate synthesis pathway on intracellular ATP pool in Moorella thermoacetica ”

Moorella thermoacetica ATCC39073 that can grow on H2-CO2 gas and produces acetate. We modified acetic acid synthesis pathway in M. thermoacetica, and succeeded to breed the mutant strain dpdul::aldh that produced ethanol from fructose. However, the mutant didn’t grow under H2-CO2 gas. We speculated that the decrease in supply of ATP due to the destruction of acetic acid synthesis pathway resulted in the no growth on H2-CO2. To prove the assumption, we measured intracellular ATP pool in the wild type grown on H2-CO2 gas and fructose, and the mutant strain dpdul::aldh grown on fructose. As speculated, the intracellular ATP pools in the wild type with H2-CO2 gas and the mutant with fructose were one-fifth than that in wild type with fructose.

Chair: Obie FAROBIE

     Visiting Reseacher, Institute of Engineering, Hiroshima University

The 52nd Hiroshima University Biomass Evening Seminar

(The 11th Hiroshima University ACE Seminar)was held.

Date & Time:Wed .26  Apr., 2017   16:20-17:50

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

<Program>

Commentary: Yukihiko MATSUMURA

        Professor, Institute of Engineering, Hiroshima University

Lecture: Kiyoto KIHARA

          M2 Student, Graduate School of Engineering, Hiroshima University

“Effect of Carbon Nanotube Catalysts on Hydrothermal Pretreatment and Enzymatic Hydrolysis”

Recently, bioethanol has attracted attention for alternative energy of oil, and water hyacinth (WH) is considered as potential feedstock.  Many researches have studied water hyacinth which is lignocellulosic biomass and does not compete with food.  To obtain bioethanol from lignocellulosic biomass, the biomass has to go through the three processes: pretreatment, enzymatic hydrolysis and fermentation. Lignocellulosic biomass has strong structure that has to be destroyed.  Hydrothermal pretreatment is one of the most famous pretreatment.  Many researchers used some catalyst.  Among them, carbon nanotube (CNT) has a large specific surface area, and CNT treated by sulfonic acid showed good effect on biodiesel production. In this study, we examined the effectiveness of acid treated CNT (A-CNT) catalyst on hydrothermal treatment and enzymatic hydrolysis.  Further, we examined the influence of temperatures.  WH was hydrothermally treated without catalyst, with CNT catalyst, or with A-CNT catalyst.  Temperature was set at 200 ^oC, 250 ^oC or 300 ^oC.  Enzymatic hydrolysis temperature was 50 ^oC. Enzymes were cellulose and β-glucosidase.  Glucose yield was analyzed by HPLC.

Lecture: Novi SYAFTIKA

D2 Student, Graduate School of Engineering, Hiroshima University

“ Hydrothermal pretreatment of rice residues with biodiesel waste as the medium”

Agricultural waste is becoming more popular as cellulosic biomass for bioethanol production because it is not competing with human food supply. Rice is the largest agriculture product of Japan including in the small district in Oasa, Kita Hiroshima, Hiroshima Prefecture.  As the consequence, rice husk is produced annually in large amount in this region. Rice husk is mostly remains unutilized and it contains cellulose. Therefore, it has the potential to be converted into bioethanol. Hydrothermal process is known as environmental friendly pretreatment technique to convert cellulosic biomass into various products including bioethanol since it is using hot compressed water solely as the medium. However, studies shown that catalyst addition improve the yield of products. Alkali catalyst like sodium hydroxide is often used in hydrothermal pretreatment since it is low cost chemical and easily obtained. Nonetheless, the reduction of catalyst cost will be beneficial to make bioethanol more economically competitive. Interestingly, in district of Oasa, Kita Hiroshima Japan, biodiesel has been produced from vegetable cooking oil waste and being utilized for diesel engine vehicles. This biodiesel production generates biodiesel waste that has very high pH (alkaline) and treatment is required to neutralized it before discarding it into the environment. In this research, the possibility of using the alkali characteristic in biodiesel waste to replace commercial alkali catalyst for hydrothermal pretreatment of rice husk is studied. The study was conducted using autoclave reactor made from stainless steel. The experiments were carried out at reaction temperatures of 150, 200 and 250 °C, reaction times of 30 min, and the biodiesel wastewater addition was compared with water with and without alkali catalyst. To measure the effectiveness of pretreatment, enzymatic hydrolysis was employed after pretreatment to obtain glucose yield. The effect of biodiesel waste addition on rice husk conversion to glucose by hydrothermal pretreatment at various temperature was elaborated.

Lecture: Nattacha PAKSUNG　　　 

         D3  Student, Graduate School of Engineering, Hiroshima University

“Hydrothermal gasification of glucose, xylose and guaiacol as model compounds of lignocellulosic biomass ”

Supercritical water gasification (SCWG) is one promising technology to convert biomass into renewable energy because supercritical water behaves like organic solvent, thus biomass could dissolve in the water at this state (temperature and pressure above 374 °C and 22.1 MPa, respectively).  It has high conversion efficiency to produce gas fuel and relatively high hydrogen selectivity. Lignocellulosic biomass composes mainly of cellulose, hemicellulose and lignin, whose smaller units are glucose, xylose, and guaiacol respectively.  Reaction scheme and model compound of biomass are keys to achieve the goal.  Thereby, the objective of research is to study the interaction between model compounds consisted in lignocellulosic biomass in varied composition in hydrothermal conditions

Lecture:  Tanawan  CHALERMSAKTRAKUL                    

         M2  Student, Graduate School of Engineering, Hiroshima University

“Supercritical water gasification of xylose and acetic acid mixture ”

The hydrothermal gasification of xylose, as a model substance of hemicellulose, was carried out at high temperatures and pressures (up to 400-450 °C, 25 MPa) in the presence of acetic acid by using continuous-flow reactor. As acetic acid is one kind of organic compound, environmental friendly, low corrosiveness, and also byproduct of hemicellulose gasification, it was chosen to be the catalyst to understand more about the behavior of each reaction in supercritical gasification of xylose. This study aimed to compare the reaction rate constant of xylose decomposition with and without acetic acid addition. The experiments were investigated to determine the influence of residence time varied from 0.5 to 5 s. The concentration of xylose was 1.5 wt% mixed with 1.5 wt% of acetic acid. When acetic acid was added in supercritical gasification of xylose, it acted as radical scavenger and provided H+, so the retro-aldol reaction and carbon gasification production, which are radical reactions, were be suppressed. Meanwhile, the dehydration of xylose and xylulose to furfural was be promoted significantly.

Chair: Obie FAROBIE

    Visiting Reseacher, Institute of Engineering, Hiroshima University