scholarly journals Alternative pretreatments of rice and tobacco wastes for the production of fermentable sugars

Author(s):  
C. Curbelo Hernández ◽  
E. Véliz Lorenzo ◽  
J. M. Ameneiros Martínez

Thescarce oil supplies and the emissions of gases of greenhouse effect have caused the interest in production and utilization of lignocellulosic bioethanol. This can substitute partially or totally the fossil fuels. The stages of pretreatment and enzymatic hydrolysis are the most expensive. Different pretreatments have been studied for ethanol production from these materials. Their results depend on the method characteristics and on biomass used. The agroindustrial wastes present a composition with possibilities of being evaluated like raw material for bioethanol production. In the present research, the pretreatment stages with Ultrasound and Ozone are studied, in order to decrease the lignin content and to increase the performance of the fermentative sugars in the lignocellulosic wastes (rice hull and dark tobacco vein). In the first pretreatment procedure, time and waste type were studied and in the second stage, the ozone concentration, waste type and moisture content were the studied variables. A combined procedure was applied to the best preliminary results. It is demonstrated that a decrease in the lignin concentration and the structural transformation of the materials under consideration come true. The best results were gotten for the rice hulls. 

Holzforschung ◽  
2018 ◽  
Vol 73 (1) ◽  
pp. 25-34 ◽  
Author(s):  
Jorge Rencoret ◽  
Ana Gutiérrez ◽  
Eulogio Castro ◽  
José C. del Río

AbstractOlive tree pruning (OTP) is an abundant and inexpensive agricultural lignocellulosic residue that is an interesting feedstock for producing bioethanol and other bio-products in the context of lignocellulosic biorefineries. However, the presence of lignin in OTP hinders the transformation processes as it limits the access to cell wall polysaccharides. On the other hand, the aromatic/phenolic structure of the lignin polymer makes it an interesting raw material for producing chemicals, fuels and other commodities that are nowadays produced from fossil fuels. Thus, the knowledge of the OTP lignin structure is crucial to develop tailor-made pretreatments for their removal as well as for additional valorization of the lignin polymer. In this work, the OTP lignin was isolated as milled wood lignin (MWL), a lignin preparation that is considered representative of the native lignin, and characterized by two-dimensional nuclear magnetic resonance (2D-NMR) and thioacidolysis. The results demonstrated that the lignin is mainly composed of guaiacyl (G) and syringyl (S) lignin units in similar abundances (S/G ratio of ~1), with minor amounts ofp-hydroxyphenyl (H) units. The most abundant lignin inter-unit linkages are β-O-4′ alkyl-aryl ethers (75% of all linkages), followed by the condensed phenylcoumarans (12%) and resinols (8%), and with lower amounts of dibenzodioxocins (2%) and spirodienones (3%). The analysis of the thioacidolysis dimers gave additional information regarding the distribution of the lignin units involved in condensed interunit linkages, including 5-5′, 4-O-5′, β-5′, β-1′ and β-β′. The high lignin content (25%), together with the relatively low S/G ratio and the abundance of condensed (carbon-carbon linked) structures, points to a low reactivity of OTP lignin during delignification pretreatments.


2021 ◽  
Vol 13 (24) ◽  
pp. 13919
Author(s):  
Maria Dyah Nur Meinita ◽  
Amron Amron ◽  
Agus Trianto ◽  
Dicky Harwanto ◽  
Wahyu Caesarendra ◽  
...  

The development of macroalgal biorefinery products as an alternative source of renewable fuels is an opportunity to solve the dependence on fossil fuels. Macroalgae is a potential biomass that can be developed as a raw material for producing platform chemicals such as levulinic acid (LA). In the industrial sector, LA is among the top 12 biomass-derived feedstocks designated by the U.S. Department of Energy as a high-value chemical. Several studies have been conducted on the production of LA from terrestrial-based biomass, however, there is still limited information on its production from macroalgae. The advantages of macroalgae over terrestrial and other biomasses include high carbohydrate and biomass production, less cultivation cost, and low lignin content. Therefore, this study aims to investigate the potential and challenge of producing LA from macroalgae in the industrial sector and determine its advantages and disadvantages compared with terrestrial biomass in LA production. In this study, various literature sources were examined using the preferred reporting items for systematic reviews and meta-analyses (PRISMA) method to identify, screen, and analyze the data of the published paper. Despite its advantages, there are some challenges in making the production of levulinic acid from macroalgae feasible for development at the industrial scale. Some challenges such as sustainability of macroalgae, the efficiency of pretreatment, and hydrolysis technology are often encountered during the production of levulinic acid from macroalgae on an industrial scale.


Bio-ethanol, a type of biofuel, is known as renewable energy source as it is derived from biomass as its raw material. Biomass can be found in abundance and sustainable i.e. sources are available continuously, unlike the currently used conventional fossil fuels where these sources are limited and depleting. In this study, biomass from fruit waste, banana peels, were utilized to produce bio-ethanol via hydrolysis and fermentation process. Banana peels, a lignocellulosic biomass, possesses compositions which favour these processes, where the banana peels are rich in cellulose content and low in lignin content. Mechanical pre-treatment of the banana peels was conducted to further ease the hydrolysis process by reducing the particle size of the biomass. Hydrolysis was carried out for 24 hours at 50ºC at different pH using sulfuric acid H2SO4 acid and sodium hydroxide NaOH as the base, to study the effect of pH on the hydrolysis process and hence the final bio-ethanol production, in terms of concentration. Fermentation of the hydrolysis products were carried out using glucose-yeast broth for 4 days at temperature of 35ºC. Water content in the bio-ethanol product from fermentation process was separated using rotary evaporator, prior to ethanol analysis using Gas Chromatography (GC-MS). Concentration of ethanol was found to be the highest at acidic pH conditions; pH 4 to 6. Lowest ethanol concentration was recorded at higher pH values, indicating alkaline conditions do not favour the hydrolysis process.


2021 ◽  
Vol 3 (1) ◽  
pp. 243-259
Author(s):  
Yadhu N. Guragain ◽  
Praveen V. Vadlani

Lignocellulosic biomass feedstocks are promising alternatives to fossil fuels for meeting raw material needs of processing industries and helping transit from a linear to a circular economy and thereby meet the global sustainability criteria. The sugar platform route in the biochemical conversion process is one of the promising and extensively studied methods, which consists of four major conversion steps: pretreatment, hydrolysis, fermentation, and product purification. Each of these conversion steps has multiple challenges. Among them, the challenges associated with the pretreatment are the most significant for the overall process because this is the most expensive step in the sugar platform route and it significantly affects the efficiency of all subsequent steps on the sustainable valorization of each biomass component. However, the development of a universal pretreatment method to cater to all types of feedstock is nearly impossible due to the substantial variations in compositions and structures of biopolymers among these feedstocks. In this review, we have discussed some promising pretreatment methods, their processing and chemicals requirements, and the effect of biomass composition on deconstruction efficiencies. In addition, the global biomass resources availability and process intensification ideas for the lignocellulosic-based chemical industry have been discussed from a circularity and sustainability standpoint.


Author(s):  
K. Malins ◽  
V. Kampars ◽  
R. Kampare ◽  
T. Rusakova

The transesterification of vegetable oil using various kinds of alcohols is a simple and efficient renewable fuel synthesis technique. Products obtained by modifying natural triglycerides in transesterification reaction substitute fossil fuels and mineral oils. Currently the most significant is the biodiesel, a mixture of fatty acid methyl esters, which is obtained in a reaction with methanol, which in turn is obtained from fossil raw materials. In biodiesel production it would be more appropriate to use alcohols which can be obtained from renewable local raw materials. Ethanol rouses interest as a possible reagent, however, its production locally is based on the use of grain and therefore competes with food production so it would implicitly cause increase in food prices. Another raw material option is alcohols that can be obtained from furfurole. Furfurole is obtained in dehydration process from pentose sugars which can be extracted from crop straw, husk and other residues of agricultural production. From furfurole the tetrahydrofurfuryl alcohol (THFA), a raw material for biodiesel, can be produced. By transesterifying rapeseed oil with THFA it would be possible to obtain completely renewable biodiesel with properties very close to diesel [2-4]. With the purpose of developing the synthesis of such fuel, in this work a three-stage synthesis of rapeseed oil tetrahydrofurfurylesters (ROTHFE) in sulphuric acid presence has been performed, achieving product with purity over 98%. The most important qualitative factors of ROTHFE have been determined - cold filter plugging point, cetane number, water content, Iodine value, phosphorus content, density, viscosity and oxidative stability.


Author(s):  
А.В. Вураско ◽  
Е.И. Симонова ◽  
А.Р. Минакова ◽  
Д.Д. Манойлович

Получение доступных сорбентов на основе природных материалов, для визуального колористического определения содержания ионов металлов в загрязненных природных и сточных водах является актуальным направлением исследований. Сорбенты на основе технической целлюлозы удовлетворяют этим требованиям. В работе для получения технической целлюлозы предложено использовать биомассу соломы риса. Для удаления из соломы риса минерального компонента при проведении окислительно-органосольвентной варки используют стадию щелочной обработки, которая приводит к деструкции полисахаридов, снижая выход технической целлюлозы. В связи с этим целью работы является изучение закономерностей проведения щелочной обработки соломы риса для максимального сохранения высокого выхода технической целлюлозы, извлечения минеральной части и возможности применения данной целлюлозы в качестве колористического сорбента. С учетом предварительных исследований найдены оптимальные значения технологических факторов, обеспечивающих высокий выход волокнистого материала из соломы риса при минимальном содержании в нем минеральных компонентов. Последующая органосольвентная варка позволяет получить техническую целлюлозу с выходом – 48,8% от абсолютно сухого сырья (а.с.с), зольностью 0,05% от а.с.с., содержанием лигнина 2,5% от а.с.с., удовлетворительными прочностными характеристиками, высокими сорбционными свойствами, необходимой белизной и рН водной вытяжки. Выявлено, что техническая целлюлоза из соломы риса содержит металлы, накопленные биомассой за вегетативный период. Щелочная обработка и окислительно-органосольвентная делигнификация в большинстве случаев приводят к снижению концентрации металлов в технической целлюлозе. Исключение составляют алюминий, железо и свинец, содержание которых в технической целлюлозе увеличивается. Таким образом, целлюлоза, полученная в оптимальных условиях щелочной обработки и последующей окислительно-органосольвентной варки из соломы риса, с учетом содержащихся в ней металлов, пригодна для использования в качестве сорбента для визуального колористического определения содержания ионов металлов в загрязненных природных и сточных водах. Receive available sorbents based on natural materials for visual color determination of the content of metal ions in contaminated natural and waste waters is a topical area of research. Sorbents on the basis of technical cellulose satisfy these requirements. In the process of obtaining technical cellulose is proposed to use biomass straw rice. Removal of straw rice mineral component when carrying out the oxidation-organosolvent use the cooking stage alkali treatment, which leads to degradation of polysaccharides, reducing the output of technical cellulose. In this regard, the aim of this work is to study the regularities of the alkaline treatment of rice straw for maximum preservation of the high output technical cellulose, extracting the mineral and the possibility of using the cellulose as the colour of the sorbent. Taking into account the preliminary studies, optimal conditions of technological factors were found ensuring a high yield of fibrous material from rice straw with a minimum content of mineral components in it. Subsequent organosolvent pulping yields technical pulp with a yield of 48.8% bone dry raw material (BDRM), an mineral ash content of 0.05% of BDRM, a lignin content of 2.5% of BDRM, satisfactory strength properties, high sorption properties, the necessary whiteness and pH of aqueous extract. It is revealed that the technical cellulose from straw of rice contains metals accumulated biomass during the vegetation period. Alkaline treatment and oxidative-organosolvent the delignification in most cases leads to a decrease of metal concentrations in pulp technical. With the exception of aluminum, iron and lead, the content of which is technical cellulose increases. Thus, cellulose obtained in optimum conditions of alkaline treatment and subsequent oxidation-organosolvent pulping of straw of rice, taking into account the contained metals suitable for use as a sorbent for visual color determination of the content of metal ions in polluted natural and sewage waters.


2007 ◽  
Vol 7 (1 & 2) ◽  
pp. 83
Author(s):  
Mary Grace M. Oliveros ◽  
Amiliza B. Baiting ◽  
Menchie G. Lumain ◽  
Maria Theresa I. Cabaraban

Waste vegetable oil, mainly coming from frying residues, can be used as raw material to obtain a diesel fuel (biodiesel). Biodiesel, a nontoxic, biodegradable, diesel-like fuel, is an important energy alternative capable of decreasing environmental problems caused by the consumption of fossil fuels. The utilization of waste vegetable oils as raw material in biodiesel production was studied. Research was undertaken to establish the availability of used vegetable oil to supply a biodiesel process. It is intended that this work forms an academic study combined with an environmental and technological analysis of the merits of biodiesel as a sustainable fuel. Laboratory experimentation investigated the possibility of using waste vegetable oil from the local fast food chains, and potassium hydroxide as catalyst for the transesterification process. The cleaned waste vegetable oil undergoes transesterification for 4 hours, after which, the biodiesel is separated from the glycerin by gravity. Washing is necessary to remove residual catalyst or soap. Overall material balance for the process gives: 1 kg Waste Vegetable oil + 0.18 kg EtOH + 0.01 kg KOH → 0.74 kg Biodiesel + 0.44 kg Glycerin The biodiesel, in pure form (B100) and in 50% proportion (B50) with petroleum diesel, was run in an essentially unmodified Toyota 2C diesel engine. Smoke density (opacity) and CO exhaust emission both decreased with B50. However, Nox increased with B50. Fuel consumption during engine power testing is significantly greater using the biodiesel, but is also significantly reduced with B50.


2019 ◽  
Vol 48 (3) ◽  
pp. 547-557
Author(s):  
Hui-Jin Liu ◽  
Li Zhang ◽  
Yan-Nian Xu ◽  
Xiao-Ping Zhang ◽  
Xiao-Hong Li

The bark of Pteroceltis tatarinowii Maxim., an endemic tree in Ulmaceae, is the main raw material for manufacturing Xuan Paper which is widely used in calligraphy and painting field. The characteristics of P. tatarinowii bark is the main limiting factor for the quality of Xuan Paper specially the content of cellulose and lignin. The molecular basis related to cellulose and lignin synthesis in P. tatarinowii would be helpful to understand and seek higher quality raw materials for Xuan Paper. RNA-seq was utilized to reveal transcriptome differences in P. tatarinowii from three far isolated localities (AL, JX and XA) under different climate environments. A total of 290 million reads were generated for further analysis in three libraries. In total, 2,850, 2,038 and 1,986 DEGs were identified in XA, JX and AL, respectively. Compared with the sample from XA, there were 822 up-regulated and 1706 down-regulated in AL sample. AL sample has 611 up-regulated genes and 647 down-regulated genes in comparison with JX sample. Comparing XA and JX samples, 443 were up-regulated and 1,783 were down-regulated in XA. Three samples had similar GO enrichment patterns. There were 19 and 9 genes identified as CESA and CSL (E-value less than 1.0E-20), respectively. Although no significant expression differences were found in three samples, KOB1, GPI-anchored protein gene and CTL1 were differently expressed, and KOB1 and GPI-anchored protein gene were up-regulated in JX. A number of the unigenes (474) that were involved in ‘phenylpropanoid biosynthesis’, were mostly not differently expressed. Only a few genes annotated as PAL, 4CL, C4H and CAD were significantly different in expression. In AL, 3 CAD and 1 PAL were up-regulated, whereas 6 CAD, 3 4CL and 1 HCT were up-regulated in XA, and 1 PAL, 2 4CL, 2 C4H in JX. JX sample had the highest cellulose content and XA sample had the highest lignin content, which being consistent with the hierarchical cluster analysis of differently expressed genes. Differences in the expression of these genes might influence the cellulose and lignin content.


2016 ◽  
Vol 78 (5-6) ◽  
Author(s):  
Ivan Smirnov ◽  
Victor Keino ◽  
Ksenia Goryacheva ◽  
Alexander Shunk ◽  
Alexander Bondarev ◽  
...  

The article presents the results of the research hemostimulating activity of aqueous extracts of antler young Siberean stag and drone larvae homogenate. These substrates were obtained from raw materials of animal origin. Altai Krai andAltaiRepublicare subjects of theRussian Federationwhich is the place of production of the raw material. Experiments were conducted in two stages. The first stage - in vitro, which included a research of experimental substrates on the culture of mouse marrow cells. During the experiments were obtained different results. We counted the number of colonies grown in cell culture for this. The second stage of experimenters - in vivo. It included an assessment of the myeloprotector on model of cytostatic myelosuppression of mice and analysis of bone marrow and peripheral blood.


2019 ◽  
Vol 11 (9) ◽  
pp. 2539 ◽  
Author(s):  
Maria Milousi ◽  
Manolis Souliotis ◽  
George Arampatzis ◽  
Spiros Papaefthimiou

The paper presents a holistic evaluation of the energy and environmental profile of two renewable energy technologies: Photovoltaics (thin-film and crystalline) and solar thermal collectors (flat plate and vacuum tube). The selected renewable systems exhibit size scalability (i.e., photovoltaics can vary from small to large scale applications) and can easily fit to residential applications (i.e., solar thermal systems). Various technical variations were considered for each of the studied technologies. The environmental implications were assessed through detailed life cycle assessment (LCA), implemented from raw material extraction through manufacture, use, and end of life of the selected energy systems. The methodological order followed comprises two steps: i. LCA and uncertainty analysis (conducted via SimaPro), and ii. techno-economic assessment (conducted via RETScreen). All studied technologies exhibit environmental impacts during their production phase and through their operation they manage to mitigate significant amounts of emitted greenhouse gases due to the avoided use of fossil fuels. The life cycle carbon footprint was calculated for the studied solar systems and was compared to other energy production technologies (either renewables or fossil-fuel based) and the results fall within the range defined by the global literature. The study showed that the implementation of photovoltaics and solar thermal projects in areas with high average insolation (i.e., Crete, Southern Greece) can be financially viable even in the case of low feed-in-tariffs. The results of the combined evaluation provide insight on choosing the most appropriate technologies from multiple perspectives, including financial and environmental.


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