High Lignin Content Research Articles

Recent Update on anaerobic digestion of paddy straw for biogas production: Advancement, limitation and recommendations

At present, development and production of advanced green energy sources are highly demanded, and this may offer a clean and sustainable environment to our modern society. In this reference, biogas is emerging as a promising green energy source and seems to have high potential to replace fossil-fuel based energy sources in the coming future. Further, lignocellulosic biomass (LCB) based biogas production technology has been found to be highly promising owing to several advantages associated therewith. Rich inorganic content, renewable nature, huge availability and low-cost are the key beneficial factors of LCB-based feedstock l to produce biogas. Among the varieties of LCB, paddy straw is one of the most demanding feedstocks and is highly rich in organic compounds that are imperative to producing biogas. Nevertheless, it is noticed that paddy straw as a waste material is usually disposed-off by direct burning, whereas it exhibits low natural digestibility due to the presence of high lignin and silica content which causes severe environmental pollution. On the other hand, paddy straw can be a potential feedstock to produce biogas through anaerobic digestion. Therefore, based on the current ongoing research studies worldwide, this review evaluates the advancements made in the AD process. Meanwhile, existing limitations and future recommendations to improve the yield and productivity of the biogas using paddy straw have been discussed. The emphasis has also been given to various operational parameters developments, related shortcomings, and strategies to improve biogas production at pilot scale.

Enteric Methane Emission from Sheep Fed with Rhodes Grass Hay (Chloris gayana) Alone or Supplemented with Dried Distillers’ Grains with Solubles

Livestock systems based on subtropical and tropical pastures are characterized by the low productivity of livestock due to the poor nutritional value of the forage (low nitrogen concentration and digestibility, and high fiber and lignin concentrations). These conditions lead to low productivity and, consequently, high absolute emissions of methane (CH4) per unit of product. Dry distilled grains with solubles (DDGS) are the main by-product resulting from ethanol production, and they are characterized by their high-energy fibrous and protein content, thus becoming an option for the supplementation of low-quality forage. This research investigated the effects of dietary DDGS inclusion on dry matter digestibility (DMD) and enteric CH4 emission. Eight adult sheep of 64 ± 8 kg live weight were used. The duration of the study was 54 days, divided into two periods (changeover design), which comprised a 17-day pre-experimental period and 10 days for experimental data collection. Animals were allocated to one of two treatments used: hay (H) as a control treatment, where animals were fed with Rhodes grass hay alone; and H + DDGS, where animals were fed with H supplemented with DDGS. CH4 emissions were estimated using the sulfur hexafluoride (SF6) tracer technique. Diets containing DDGS increased DMI by 22% (p < 0.05) and reduced daily CH4 emissions by 24% (g/d), the CH4 yield by 35% (g/kg DMI), and the average value of CH4 energy per gross energy intake (Ym) by 44%, compared to the control treatment (p < 0.05). The experiment demonstrated that supplementation with DDGS in low-quality roughage reduced daily CH4 emissions, yields, and Ym.

Perlite as a Biocarrier for Augmentation of Biogas-Producing Reactors from Olive (Olea europaea) Waste

Biogas is mainly produced by anaerobic digestion (AD), and in the EU, the widely used substrate for AD is maize silage. Due to a rise in silage prices, the intention is to gradually replace maize with lignocellulose biomass. In the Mediterranean area, the olive industry produces large amounts of lignocellulose wastes, namely olive cake and pruned biomass. Still, due to its high lignin content, it is resistant to biodegradation. This issue could be resolved by adding targeted microorganisms that enhance the substrate’s primary degradation, and the cells’ attachment to suitable biocarriers could boost the augmentation process. A microbial consortium customized for biodegradation of olive cake and pruned biomass was isolated, propagated and immobilized onto the biocarrier, perlite, a naturally occurring aluminosilicate material. The perlite proved to be a suitable biocarrier with numbers of immobilized bacteria as high as 2.1 ± 0.9 × 1011 and 3.4 ± 0.6 × 1010 CFU g−1 when preparation was performed in aerobic and anaerobic conditions, respectively. Bioaugmentation of AD reactors significantly increased the biogas yield, but only if olive cake, not the pruned biomass, was used as a substrate.

TaSWEET14 confers low cadmium accumulation in wheat and is regulated by TaMYB41

Sugar will eventually be exported transporter (SWEET) protein involved in various developmental and stress responses in plants. Here, we report the mechanisms and transcriptional regulatory pathway of the wheat TaSWEET14 in response to cadmium stress. Overexpression of TaSWEET14 improves cadmium stress tolerance and decreases cadmium accumulation in wheat grains. The overexpression of TaSWEET14 in wheat seedlings altered the expression pattern of the ion transporter genes NRAMP5 , LCT1 , HMA3 , and IRT1. These genes were remarkably down-regulated in shoot tissues of TaSWEET14 transgenic wheat lines under cadmium stress. However, there was no significant difference in their expression levels in roots between the wild type (WT) and transgenic plants. In addition, the transgenic plants had a strong ability to remove reactive oxygen species and showed increased activity of antioxidant enzymes. Notably, the transgenic lines had significantly lower cellulose content but higher lignin content than the WT under cadmium stress. The cell wall cadmium content was also significantly higher in the transgenic lines. Lastly, we revealed that TaMYB41 binds directly to the promoter of TaSWEET14 to activate its transcription. This study describes a novel cadmium-responsive regulatory pathway in wheat and demonstrates that TaSWEET14 directly controls wheat cadmium accumulation by altering lignin content. • Overexpression of wheat ( Triticum aestivum ) SWEET14 ( TaSWEET14 ) significantly improves resistance to cadmium. • Overexpression of TaSWEET14 in wheat resulted in a change of the contents of lignin and cellulose. • Transcription factor TaMYB41 regulates TaSWEET14 gene transcription.

ETHYLENE RESPONSE FACTOR 34 promotes secondary cell wall thickening and strength of rice peduncles.

Cellulose and lignin are critical cell wall components for plant morphogenesis and adaptation to environmental conditions. The cytoskeleton supports cell wall deposition, but much of the underpinning regulatory components remain unknown. Here, we show that an APETALA2/ETHYLENE RESPONSE FACTOR (ERF) family transcription factor, OsERF34, directly promotes the expression of the actin- and microtubule-binding protein Rice Morphology Determinant (RMD) in rice (Oryza sativa) peduncles. OsERF34 and RMD are highly expressed in sclerenchymatous peduncle cells that are fortified by thick secondary cell walls (SCWs) that provide mechanical peduncle strength. erf34 and rmd-1 mutants contained lower cellulose and lignin contents and thinner SCWs, while ERF34 over-expressing (OE) lines maintained high cellulose and lignin content with thicker SCWs. These characteristics impacted peduncle mechanical strength, that is, reduced strength in erf34 and rmd-1 and increased strength of ERF34 OE plants. Taken together, our results demonstrate that the OsERF34-RMD cascade positively regulates SCW synthesis and mechanical strength in rice peduncles, which is important for yield, and provide a potential guide for improved peduncle breeding efforts in rice.

Bottom‐up effects of plant quantity and quality on arthropod diversity across multiple trophic levels in a semi‐arid grassland

Abstract Plant quantity and quality can independently affect the diversity of the entire arthropod communities and multiple arthropod taxa in grassland ecosystems. However, it remains unclear how these effects on arthropod taxa at one trophic level propagate through food web to influence the diversity of higher trophic levels. We performed a monoculture experiment with 15 herbaceous species in the Inner Mongolian grassland to investigate how natural variations in plant productivity and host leaf traits affect herbivore taxon richness, which, in turn, affects predator taxon richness. For herbivores, plant productivity indirectly promoted herbivore taxon richness by increasing herbivore biomass, which was attributed to the increases in the richness of dominant sucking herbivores and endophytes with high food requirements. However, the high plant quality indicator (e.g. high leaf protein, phosphorus and water contents, and high leaf protein to carbohydrate ratio) directly increased, whereas the low plant quality indicator (e.g. high leaf lignin content) directly decreased herbivore taxon richness. Taxon richness of chewing and sucking herbivores with specific feeding modes (tearing or sucking mouthparts) showed strong positive responses to increasing plant quality. For predators, herbivore taxon richness, rather than herbivore biomass, mainly mediated the positive effects of plant productivity and the high plant quality indicator, but the negative effect of the low plant quality indicator, on predator taxon richness. At the feeding guild level, the taxon richness of parasitoids, other predators and spiders exhibited positive responses to different herbivores, which was attributed to their different diet preferences. Predator diversity could be promoted by prey partitioning among predator guilds facilitating species coexistence. At the family level, the taxon richness of most predator families was positively correlated with that of more than one herbivore family, suggesting that high predator diversity may be caused by balanced diets owing to high prey diversity. Synthesis. Natural variations in plant quantity and quality can substantially affect the diversity of herbivores and cascade up the food web to affect predators. Specificity and mechanisms of feeding have a large impact on the responses of arthropod guilds at each trophic level.

Mechanically Robust, Self-Repairable, Shape Memory and Recyclable Ionomeric Elastomer Composites with Renewable Lignin via Interfacial Metal-Ligand Interactions.

Lignin, the most abundant aromatic polymer in nature, is one of the most promising renewable feedstocks for value-added polymer products. However, it is challenging to prepare high-performance and multifunctional polymer materials with renewable lignin because of its poor compatibility with the elastomer matrix. In fact, lignin often requires solvent fractionation, chemical modification, or prohibitively expensive additives. This work develops a cost-effective strategy to prepare ionomeric elastomer composites based on a commercial carboxyl elastomer and a high content of lignin without purification or chemical modification. The compatibility between the elastomer and lignin is improved by the incorporation of zinc oxide which creates metal-ligand coordination at the interfaces between the carboxyl groups of the elastomer and the oxygen-bearing groups of the lignin. This results in fine dispersion of the lignin in the elastomer matrix, even when its content reaches 50 wt %. The lignin/elastomer composites show excellent mechanical properties, which are attributed to the reinforcing effect of the lignin domains and the presence of abundant sacrificial coordination bonds. Moreover, ionic bonds and ionic aggregates created by the neutralization of the zinc ions with the carboxyl groups of the elastomer behave as physical crosslinks which endow the composites with excellent recyclability; namely, their mechanical properties are retained or even improved after multiple reprocessing cycles. They also show good self-repairability and shape memory. Hence, this work may open up new avenues to utilize lignin as a renewable alternative to petroleum derivatives for designing and fabricating high-performance and multifunctional elastomer materials.

Rice husk integrated biochemical refinery for the production of nano- and bioproducts

Rice husk contains high contents of cellulose, lignin, and inorganic compounds, which can be recovered and utilized in a variety of useful applications. In this study, rice husk was refined using a multistage process for producing nano- and bioproducts. To begin, the material was treated with dilute sulfuric acid for obtaining a pentose solution, which was then used for Candida utilis yeast fermentation. In the next stage, the pre-hydrolyzed rice husk was treated with an alkaline solution under regular pulping conditions to break down all chemical bonds between the substances in the material. Subsequently, cellulose was extracted for nanocellulose production, while lignin and silica were isolated via acid precipitation. Proper conditions for these processes were established. Under suitable conditions, about 55.0% of the rice husk was effectively utilized. Over 75.0% of the rice husk pentosan was converted into xylose and arabinose for single-cell protein fermentation. Lignin was mostly transformed into lower molecular weight compounds or single substances, resulting in a recovery rate of about 17.0%. The precipitation’s pH for silica and lignin recovery was 8.5 and 3.0, respectively. The findings of this work provide an effective solution for the utilization of agricultural residue and contribute significantly to the sustainable development.

Water uptake of soybean pods and seeds with different lignin contents

The identification of pod- and seed-related traits of soybean genotypes and their interaction with water uptake can be applied in breeding programs with a view to establishing cultivars developed for the production and maintenance of high-quality seeds. The objective was to evaluate the water uptake of pods and seeds of soybean cultivars with different lignin contents after different soaking periods. The experimental was arranged in a completely randomized, 7×10 factorial design, with four replications. The factors consisted of seven soybean cultivars and 10 soaking periods (1, 2, 3, 4, 5, 6, 7, 8, 24, 48 hours). The pods and seeds were grown in a greenhouse and harvested at the phenological growth stage R8 (at full maturation, when 95% of the pods had mature color). The following traits were evaluated: lignin content in pod and seed coat, moisture content, and rate of water uptake of pods and seeds. Soybean cultivars with pods with high lignin contents have a lower rate of water uptake. The lignin contents of the seed coats, within the chosen limits, did not affect the seed water uptake.

Enhanced cello-oligosaccharides production from cellulose hydrolysis in molten salt hydrate over lignin-based hyper-cross-linked polymer (LHCP) adsorption

Selective hydrolysis of crystalline cellulose to cello-oligosaccharides in molten salt hydrates (MSHs) is a promising method for valorization of lignocellulose. However, the by-products derived from cellulose hydrolysis can facilitate cello-oligosaccharide degradation and decrease its selectivity. To address this issue, lignin-based hyper cross-linked polymers (LHCPs) were prepared to in situ adsorb by-products during hydrolysis and thus prevent cello-oligosaccharides from degradation. The synthesized LHCP‐33%, with a high lignin content of 33%, showed a remarkable surface area of 708.7 m2 g−1 and good hydrophilicity, exhibiting a promising adsorption capacity of 340 mg g−1 towards 5-hydroxymethylfurfural (5-HMF), which is supposed to be the major cellulose-derived by-product. We showed that 5-HMF adsorption was driven by the formation of CH-π bonds between 5-HMF and aromatic rings on LHCP. When LHCP‐33% was employed in cellulose hydrolysis, the yield of cello-oligosaccharide can be efficiently enhanced from 39.5% to 78.2%. This work offered a new application of lignin in enhanced cello-oligosaccharide production from cellulose.

Coir Pith Lignin as a Reliable Bio-Source for Carbonaceous Nano- Structures: Extraction and Characterization

Background: This paper signifies using coir pith lignin as a cheap and reliable carbon source for preparing bio-based carbonaceous material. Objective: The coir pith is selected as it is abundantly available and has a very high lignin content of 38-59.5%. The soda extraction process does the extraction of lignin from coir pith with a yield of 45%. Method: This extracted lignin is then subjected to a different procedure to transform it into carbon nanofibers with an ID/IG ratio of 0.35 and carbon fillers with a high surface area of 1089.1 m2/g without the presence of an activating agent. Results: Thus prepared carbonaceous fillers are potential reinforcements for polymer matrices as these fillers may provide sufficient mechanical and thermal stability to the composites. Conclusion: Furthermore, due to their excellent electrical conductivity, 0.221 S/cm, the carbonaceous nanomaterials are suitable for multifunctional composite applications. This is the first work based on coir pith lignin as a carbon precursor to the best of our knowledge.

Using Sodium Polyacrylate to Gel-Spin Lignin/Poly(Vinyl Alcohol) Fiber at High Lignin Content.

Lignin is the world’s most naturally abundant aromatic polymer, which makes it a sustainable raw material for engineered polymers and fiber manufacturing. Dry-jet gel-spinning was used to fabricate poly(vinyl alcohol) (PVA) fibers having 30% or more of the lignin biopolymer. To achieve this goal, 0.45 wt.% of aqueous sodium polyacrylate (SPA, at 0.55 wt.% solids) was added to spinning dopes of PVA dissolved in dimethylsulfoxide (DMSO). SPA served to enable the spinning of fibers having high lignin content (i.e., above 30%) while eliminating the aging of as-spun gel fiber prior to elevated temperature drawing. SPA impedes the migration of acetone soluble lignin from the skin of as-spun gel fibers, because SPA is insoluble in acetone, which is also a nonsolvent coagulant for PVA. PVA fibers having 30% lignin exhibited the highest tenacity of 1.3 cN/dtex (centinewton/decitex) and specific modulus 35.7 cN/dtex. The drawn fiber of 70% lignin to PVA, showed tenacity and specific modulus values of 0.94 cN/dtex and 35.3 cN/dtex, respectively. Fourier Transform Infrared (FTIR) spectroscopy showed evidence of hydrogen bonding between lignin and PVA among the drawn fibers. The modification of PVA/lignin dopes with SPA, therefore, allowed for the fabrication of gel-spun biobased fibers without the previously required step of gel aging.

The Larix kaempferi genome reveals new insights into wood properties.

Here, through single-molecule real-time sequencing, we present a high-quality genome sequence of the Japanese larch (Larix kaempferi), a conifer species with great value for wood production and ecological afforestation. The assembled genome is 10.97 Gb in size, harboring 45,828 protein-coding genes. Of the genome, 66.8% consists of repeat sequences, of which long terminal repeat retrotransposonsare dominant and make up 69.86%. We find that tandem duplications have been responsible for the expansion of genes involved in transcriptional regulation and stress responses, unveiling their crucial roles in adaptive evolution. Population transcriptome analysis reveals that lignin content in L. kaempferi is mainly determined by the process of monolignol polymerization. The expression values of six genes (LkCOMT7, LkCOMT8, LkLAC23, LkLAC102, LkPRX148, and LkPRX166) have significantly positive correlations with lignin content. These results indicated that the increased expression of these six genes might be responsible for the high lignin content of the larches' wood. Overall, this study provides new genome resources for investigating the evolution and biological function of conifer trees, and also offers new insights into wood properties of larches.

Construction, Physical Properties and Foaming Behavior of High-Content Lignin Reinforced Low-Density Polyethylene Biocomposites.

Lignin was chemically modified with oligomeric polyethylene (oPE) to form oPE-grafted lignin (oPE-g-lignin) via lignin surface acylation and a radical coupling reaction with oPE. Then, pristine lignin and oPE-g-lignin were successfully compounded with low-density polyethylene (LDPE) through a typical compounding technique. Due to the oligomeric polyethylene chains grafted to the lignin’s surface, the interfacial adhesion between the lignin particles and the LDPE matrix was considerably better in the oPE-g-lignin/LDPE biocomposite than in the pristine-lignin/LDPE one. This demonstrated that oPE-g-lignin can serve as both a biodegradable reinforcing filler, which can be loaded with a higher lignin content at 50 wt-%, and a nucleating agent to increase the crystallization temperature and improve the tensile characteristics of its LDPE biocomposites. Moreover, the foamability of the lignin-reinforced LDPE biocomposites was studied in the presence of a chemical blowing agent (azodicarbonamide) with dicumyl peroxide; for an oPE-g-lignin content up to 20 wt-%, the cell size distribution was quite uniform, and the foam expansion ratios (17.69 ± 0.92) were similar to those of the neat LDPE foam (17.04 ± 0.44).

Characterization of lignocellulosic crop residues for potential biogas production in Zimbabwe

AbstractLignocellulosic biomass is considered to be an abundant and cheap resource for biogas plants. Efficient production of biogas from lignocelluloses depends upon its proximate composition. This short communication characterizes the proximate composition of locally available lignocellulosic crop residues (LCRs) – wheat straw, maize stover and soybean straw – as potential feedstocks for biogas production. Standard Methods for the Examination of Water and Wastewater were used to determine its physicochemical characteristics. Cellulose, lignocellulose and lignin content of the biomass were evaluated after Soxhlet ectraction. Results show that proximate composition varied widely amongst LCRs. Lignocellulosic crop residues were acidic in nature with high total nitrogen (TN) content, hence the need for some buffering in anaerobic digestion (AD). Soybean straw and wheat straw showed the highest pH and TN content, respectively. However, all LCRs contained more than 30% cellulose, suggesting their potential use in AD. Wheat straw reported the highest cellulose (37.8%) and hemicellulose (28.2%) content, and it was thus considered to be the most competitive feedstock for AD. Soybean straw had the lowest cellulose and hemicellulose content but it was found to have the highest lignin content (23.5%). The findings imply that soybean straw will have the lowest AD efficiency. © 2022 Society of Chemical Industry and John Wiley & Sons, Ltd.

The physical characteristics and yield of grey oyster mushroom (Pleurotus sajor-caju) cultivated on sawdust and sago hampas as substrate

In Malaysia, sawdust is widely used as a substrate for the cultivation of grey oyster mushrooms (Pleurotus sajor-caju). Due to the scarcity and increasing cost of sawdust, this research investigated the feasibility of employing sago hampas as an alternative substrate for the cultivation of P. sajor-caju. In Sarawak, sago hampas were discarded into the river together with wastewater or incinerated, causing water and air pollution. In this study, P. sajor-caju was grown in five different formulations which are 100% sawdust (100SD) as control, 100% sago hampas (100SH), 75% sawdust + 25% sago hampas (75SD:25SH), 50% sawdust + 50% sago hampas (50SD:50SH), and 25% sawdust + 75% sago hampas (25SD:75SH). The substrate was mixed with rice bran and calcium carbonate at a dry matter basis in the ratio of 100:10:1. For the biological efficiency, 50SD:50SH recorded the highest yield (115.07%) compared to singular substrate 100SD (19.52%) and 100SH (37.04%). The higher lignin content and moisture-holding capacity in 100SD might not give better physical characteristics of P. sajor-caju. At the end of the study, supplementation sawdust with sago hampas especially formulation 50SD:50SH is recommended as the best formulation to reduce sawdust and utilise sago hampas as an alternative substrate for P. sajor-caju.

IS MERCERIZATION THE ONLY FACTOR FOR (PARTIAL) POLYMORPHIC TRANSITION OF CELLULOSE I TO CELLULOSE II IN CELLULOSE NANOCRYSTALS?

"The present study aims to investigate the influence of factors such as the source of cellulose and cellulose extraction and acid hydrolysis conditions on the partial polymorphic transition of Cellulose I to the allomorphic form Cellulose II in cellulose nanocrystals (CNCs). CNCs were obtained from cellulose fibers extracted from four agro-industrial residues in Ethiopia: teff straw (TS), enset fiber (EF), sugarcane bagasse (SB) and coffee hull (CH). The cellulose fibers were extracted under chlorine-free extraction conditions, comprising alkaline pretreatment (with 17.5% (w/v) sodium hydroxide), then hydrolyzed with 64% (w/w) sulfuric acid to synthesize the CNCs. The as-obtained CNCs were characterized with X-ray diffraction (XRD), Attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy, thermogravimetric analysis (TGA), and transmission electron microscopy (TEM). The XRD results revealed the CNCs isolated from cellulose fibers of EF and SB contained Cellulose I and II allomorphs like their cellulose precursors, but no Cellulose II was found in CH-CNCs. Morphological and dimensional studies of the CNCs by TEM showed shorter needle-shaped nanoscale structures. Higher alkaline conditions, with 17.5% sodium hydroxide, might not necessarily contribute to the polymorphic transition in lignocellulosic materials with higher lignin content, as evidenced in CH. Generally, the formation of Cellulose I and II allomorphs in the as-obtained CNCs was dependent on the cellulose source and cellulose extraction conditions, and less influenced by sulfuric acid hydrolysis."

Extraction of eco-friendly biocomposites from eulaliopsis binata: Mechanical, thermal and anti-bacterial studies

When compared to synthetic fibres, natural fibres are more environmentally friendly, biodegradable, and health-promoting. Novel technologies and methods for the growth of new plant fibres are being developed to replace both old conventional natural fibres and synthetic fibres. Eulaliopsis Binata, also known as Sabai Grass, is believed to have a high lignin concentration of upto 18.5 percent and a cellulose content of up to 55 percent. Natural cellulosic fibres were isolated from Eulaliopsis Binata and examined for their properties in this work. Compositional investigations, morphological studies, tensile properties, physical properties, thermal behaviour studies, and anti-bacterial research are all performed on the fibres obtained. The properties of Eulaliopsis Binata fibres were found to be nearly identical to those of conventional fibres, indicating that they could be employed in the production of coarse fibre fabrics, bio-based materials, and automotive interiors.

Optimizing the gasification reactivity of biochar: The composition, structure and kinetics of biochar derived from biomass lignocellulosic components and their interactions during gasification process

Biochar can become a renewable substitute to coal in the future’s energy mix. This work aims to investigate the optimization of reactivity of biochar samples derived from biomass (Miscanthus) and its lignocellulosic components (i.e. cellulose, hemicellulose and lignin) by studying the material characteristics, composition, thermal behavior and interaction during the CO2 gasification process. For biochar production, the yield increased with lignin content in the biomass, but high lignin content reduced biochar’s porous structure. The conversion characteristic was gradually stimulated by increasing the gasification temperature and heating rate, and the lignin biochar (LB) reactivity was the most promoted. High lignin content was favorable for improving the biochar reactivity. The reactivity of the xylan biochar (XB) was attributed to the high content of alkali and alkaline earth metals, while the activity of the cellulose biochar (CB) was due to the rich porous structure. The activation energy of biochar samples gasification reaction ranged from 109.8 to 196.1 kJ/mol, and the values decreased with the increase of carbon conversion rate. Modelled biomass with 32.5% cellulose, 15% xylan and 52.5% lignin was considered the optimal feedstock to make biochar because of the its low activation energy and high gasification reactivity.

Application of Black Liquor Derived Carbonaceous Compound as Fuel in Direct Carbon Fuel Cell

Direct carbon fuel cell (DCFC) with higher power efficiency and lesser emissions is being viewed as a potential clean energy source. The application of renewable biochar as fuel for DCFC is found to be feasible to replace coal or carbon black for power generation. Black liquor from the paper production might be a suitable fuel source for DCFC due to its high lignin or carbon content. In this study, the feasibility of using compound extracted from black liquor as fuel source for DCFC was investigated in the aspect of physico-chemical and electrochemical properties. Suitable pyrolysis temperature in producing biochar from black liquor compound was first investigated. Results have shown that fixed carbon and ash content increased slightly with increasing pyrolysis temperature. The ash content is made up of majority of silica as depicted in FESEM-EDX results. Oxygen containing functional group was decomposed under high pyrolysis temperature of 700°C and 800°C. Besides, biochar obtained at 500°C of pyrolysis temperature has given the highest power density of 1.22 mW cm-2 whereas 1.44 mW cm-2 was obtained from coal which was used as the control. Future work on ash removal from the black liquor prior to pyrolysis might improve the potential of black liquor derived compound as a fuel source for DCFC.