Pretreated Sawdust Research Articles

A review of technoeconomic benefits of torrefaction pretreatment technology and application in torrefying sawdust

Economic analysis of torrefaction process centers on assessment of the economic feasibility of the production and utilization of torrefied biomass using developed models such as costs of biomass, electricity, labour, investment, transportation etc. to evaluate the cost of biomass torrefaction. The increase in energy usage over the past century has raised concern over the energy insecurity and environmental unsustainability of current fossil fuel utilization; therefore, there is need for energy diversification. An attractive alternative is the biomass. However, the poor performance of raw biomass in energy generation further necessitate development of refined technologies to enhance its performance, particularly at low temperatures between 200–300 ℃. This study therefore reviews the technoeconomic benefits of torrefaction technology and reactors and its application in the pretreatment of sawdust. An overview of torrefaction technology, torrefied product characteristics, and economic analysis of torrefier reactor and torrefaction cost/ton were reviewed. From the review, torrefaction significantly improved the physical, combustion and performance characteristics of torrefied products, with comparable durability and storability to raw biomass. Comparing with other thermal pretreatment methods, torrefaction is an economical way of improving biomass properties.

Enhanced abundance of oxygen-containing intermediates from pre-oxidation of poplar sawdust facilitates generation of porous structures in activation with phosphoric acid

Pretreatment of biomass in oxidative atmosphere could induce partial oxidation of organic components on surface of biochar, which might affect evolution of pore structures in subsequent activation of biochar. This was investigated herein by pretreatment of sawdust at 150 to 300 °C in an air or nitrogen flow and the followed activation of the resulting biochar with phosphoric acid. The results indicated that the oxidation in the pretreatment in air became substantial at 250 °C, reducing the yield of biochar, crystallinity of cellulose while introducing abundant oxygen-containing functionalities in form of OH, COC, CO, etc. Some of these oxygen-containing species even can be reserved in the activated carbon (AC) formed, making the oxygen-rich AC with high hydrophilicity. More importantly, these abundant oxygen-containing functionalities were beneficial for the subsequent activation with phosphoric acid for creating developed pore structures (1314.3 m2g−1 of AC-250-air versus 1056.5 m2g−1 of AC-250-N2). This resulted in superior adsorption capacity towards tetracycline over AC-250-air. The in-situ IR characterization suggested that abundant oxygen-containing species bearing ester/carboxyl functionalities were generated during activation of the sawdust pretreated in air, which played essential roles in generation of especially micropores. The deficiency of these oxygen-containing species in activation of the sawdust pretreated in nitrogen negatively affected development of pores.

Steam Explosion of Eucalyptus grandis Sawdust for Ethanol Production within a Biorefinery Approach

In this work, Eucalyptus grandis sawdust was subjected to steam explosion as the first step in cellulosic ethanol production within a biorefinery approach. The effect of the moisture content in the eucalypt sawdust (8 and 50%) and pretreatment process variables, such as temperature and residence time, were evaluated along with the influence of the water washing of steam-exploded solids on enzymatic hydrolysis and C6 fermentation yields. All other process streams were characterized to evaluate the recovery yield of valuable co-products. A recovery of nearly 100% glucans in the solid fraction and 60% xylans in the liquid fraction, mainly as partially acetylated oligomers, was obtained. The best enzymatic hydrolysis efficiencies (66–67%) were achieved after pretreatment at 205 °C for 10 min. The washing of pretreated sawdust with water improved the hydrolysis efficiencies and ethanol production yields by 10% compared to the unwashed pretreated solids under the same experimental condition. The highest ethanol yields were achieved after pretreatment of the sawdust with an 8% moisture content at 205 °C for 10 min, enzymatic hydrolysis at 13 wt% total solids with 25 FPU/g glucans, and fermentation with S. cerevisiae PE-2. In this case, 227 L ethanol and 40 kg total xylose (including xylo-oligomers) were obtained per ton of dry eucalypt sawdust.

Thermal pretreatment of poplar sawdust at 100 °C in water or with microwave heating impacts the pyrolysis behaviors

Drying at 100 °C is a common practice for processing many biomasses for their further thermochemical conversion via the routes such as pyrolysis. The drying temperature of 100 °C is low, but might not be too low to cause any impact on pyrolytic behaviors of a biomass feedstock. In this study, varied scenarios of thermal pretreatment of poplar sawdust (oven-drying, boiling in water and microwave heating) at 100 °C were screened for probing their potential influence on the pyrolytic behaviors at 500 and 750 °C. Comparing with oven-drying, boiling in water (cooking) and microwave heating at 100 °C could remove some oxygen-containing species, increasing carbon content of the pretreated sawdust and promoting carbonization in pyrolysis. This enhanced formation of biochar, heavy π-conjugated organics in bio-oil, but suppressed generation of gas. The cooking or microwave heating pretreatment also promoted aromatization to form the biochar of higher thermal stability, higher crystallinity, and higher aromatic degree, due to the enhanced deoxygenation reactions in the pyrolysis. The in-situ IR characterization suggested that microwave pretreatment promoted generation of unsaturated ketones and also the species with olefinic C = C, favoring their further aromatization. The cooking pretreatment impacted transformation routes of the oxygen-containing organics, thus modifying pyrolysis behaviors of the pretreated sawdust.

Influence of torrefaction with microwave and furnace heating on pyrolysis of poplar sawdust

Microwave heating is different from furnace heating in terms of heat transfer direction and heating mechanism. The torrefaction with microwave or furnace heating might further impact evolution of the pyrolytic products in further pyrolysis. This was investigated herein via thermal pretreatment of sawdust at 150 to 250 °C and the subsequent pyrolysis at 600 °C. The results showed that the microwave pretreatment led to more pronounced pyrolysis at 200/250 °C, which enhanced aromatic degree of semi-char and created difficulty for its further cracking in pyrolysis at 600 °C but not affected gasification. This led to the formation of more biochar and much more gases but less bio-oil with less heavy components than that from furnace heating plus pyrolysis. Additionally, the microwave pretreatment could enhance deoxygenation but the enhanced aromatic degree of the semi-char created difficulty for creating micropores and development of the pore structures (176.2 m2g−1 with 67.3% micropores from microwave pretreatment versus 441.1 m2g−1 with 78.5% micropores from furnace pretreatment). The characterization of the pyrolysis of semi-char with in-situ IR technique confirmed that the microwave pretreatment substantially removed the aliphatic structures and made the biochar with more fragmented morphology.

Optimal Integrated Plant for Biodegradable Polymer Production.

An integrated facility for the production of biodegradable polymers from biomass residues has been developed. Lignocellulosic residues (sawdust), CO2, and organic waste such as manure or sludge are the raw materials. Manure and sludge are digested to provide the nutrients needed to grow algae. Algae are used in full to oil and starch production. The oil is transesterified with methanol generated via biogas dry reforming to obtain biodiesel and glycerol. The starch is used together with glycerol and the pretreated sawdust for the production of the biodegradable polymer. A mathematical optimization approach is used to identify the best use of each resource and the optimal operation of the integrated facility for each case. 4732 kt/yr of manure or 4653 kt/yr of sludge was processed to produce 354 kt/yr of biopolymer and 84 Mgal/yr of fatty acid methyl ester, capturing 2.47 kg of CO2 per kg of biopolymer with production costs of 0.89 and 0.95 $/kg, respectively, and an investment capital of 717 and 712 M$, respectively.

Phenol Liquefaction of Waste Sawdust Pretreated by Sodium Hydroxide: Optimization of Parameters Using Response Surface Methodology.

In this study, a two-step method was used to realize the liquefaction of waste sawdust under atmospheric pressure, and to achieve a high liquefaction rate. Specifically, waste sawdust was pretreated with NaOH, followed by liquefaction using phenol. The relative optimum condition for alkali-heat pretreatment was a 1:1 mass ratio of NaOH to sawdust at 140 °C. The reaction parameters including the mass ratio of phenol to pretreated sawdust, liquefaction temperature, and liquefaction time were optimized by response surface methodology. The optimal conditions for phenol liquefaction of pretreated sawdust were a 4.21 mass ratio of phenol to sawdust, a liquefaction temperature of 173.58 °C, and a liquefaction time of 2.24 h, resulting in corresponding liquefied residues of 6.35%. The liquefaction rate reached 93.65%. Finally, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction (XRD) were used to analyze untreated waste sawdust, pretreated sawdust, liquefied residues, and liquefied liquid. SEM results showed that the alkali-heat pretreatment and liquefaction reactions destroyed the intact, dense, and homogeneous sample structures. FT-IR results showed that liquefied residues contain aromatic compounds with different substituents, including mainly lignin and its derivatives, while the liquefied liquid contains a large number of aromatic phenolic compounds. XRD showed that alkali-heat pretreatment and phenol liquefaction destroyed most of the crystalline regions, greatly reduced the crystallinity and changed the crystal type of cellulose in the sawdust.

Steam Explosion Pre-Treatment of Sawdust for Biofuel Pellets

The current study explores steam explosion pre-treatment of wood sawdust to develop high-quality biofuel pellets. In order to determine optimized conditions (temperature and residence time) for steam-treated biomass, seven test responses were chosen, including bulk, particle and pellet densities as well as tensile strength, dimensional stability, ash content and higher heating value (HHV). Parameters tested for steam treatment process included the combination of temperatures 180, 200 and 220 °C and durations of 3, 6 and 9 min. Results showed that when the severity of steam pre-treatment increased from 2.83 to 4.49, most of the qualities except HHV and ash content were favorable for steam pretreated materials. The pellet density of pretreated sawdust in comparison to raw sawdust resulted in 20% improvement (1262 kg/m3 for pretreated material compared with 1049 kg/m3 for non-treated material). Another important factor in determining the best pellet quality is tensile strength, which can be as high as 5.59 MPa for pretreated pellets compared with 0.32 MPa for non-treated pellets. As a result, transportation and handling properties can be enhanced for steam pretreated biomass pellets. After optimization, the selected treatment was analyzed for elemental and chemical composition. Lower nitrogen and sulfur contents compared with fossil fuels make steam pretreated pellets a cleaner option for home furnaces and industrial boilers. High-quality pellets were produced based on optimized pre-treatment conditions and are therefore suggested for bioenergy applications.

Investigation of Steam Explosion Pretreatment of Sawdust and Oat Straw to Improve Their Quality as Biofuel Pellets

Steam explosion pretreatment of sawdust and oat straw under mild, medium, and severe conditions was conducted to improve the quality of pellets generated from these feedstocks. This work examined the effects of temperature, time, and moisture content on the mechanical properties of biomass pellets. From the ANOVA conducted, the p-values of the regression models for all the response variables (dimensional stability, tensile strength, and pellet density) studied were significant (p < 0.05), except for the pellet density of steam-pretreated oat straw pellets. The interaction of these three factors did not significantly affect the response variables of oat straw pellets. In addition, the higher heating value (HHV) of treated biomass increased up to a maximum of about 9.5% and 7% as compared with the non-treated sawdust and oat straw, respectively. In addition, an increment of about 3.6-fold and 3.1-fold in pellet tensile strength of steam-pretreated sawdust and oat straw was observed, respectively. Microstructural examination of the pellets from steam-pretreated biomass revealed that the material contained particles that were more closely bonded and featured a cemented surface with fewer pores when compared to particles from untreated oat straw and sawdust.

Pigment Production by Paracoccus spp. Strains through Submerged Fermentation of Valorized Lignocellulosic Wastes

Due to the increasing emphasis on the circular economy, research in recent years has focused on the feasibility of using biomass as an alternative energy source. Plant biomass is a potential substitute for countering the dependence on depleting fossil-derived energy sources and chemicals. However, in particular, lignocellulosic waste materials are complex and recalcitrant structures that require effective pretreatment and enzymatic saccharification to release the desired saccharides, which can be further fermented into a plethora of value-added products. In this context, pigment production from waste hydrolysates is a viable ecological approach to producing safe and natural colorings, which are otherwise produced via chemical synthesis and raise health concerns. The present study aims to evaluate two such abundant lignocellulosic wastes, i.e., wheat straw and pinewood sawdust as low-cost feedstocks for carotenoid production with Paracoccus strains. An alkali pretreatment approach, followed by enzymatic saccharification using an indigenous lab-isolated fungal hydrolase, was found to be effective for the release of fermentable sugars from both substrates. The fermentation of the pretreated sawdust hydrolysate by Paracoccus aminophilus CRT1 and Paracoccus kondratievae CRT2 resulted in the highest carotenoid production, 631.33 and 758.82 μg/g dry mass, respectively. Thus, the preliminary but informative research findings of the present work exhibit the potential for sustainable and economically feasible pigment production from lignocellulosic feedstocks after optimal process development on the pilot scale.

Effect of dry torrefaction pretreatment of the microwave-assisted catalytic pyrolysis of biomass using the machine learning approach

This study employs the Leave-One-Out cross-validation approach to build a machine-learning model using polynomial regression to predict pyro product yield through microwave-assisted pyrolysis of sawdust over KOH catalyst and graphite powder a susceptor. The determination of coefficient (R2) validates the developed models. All the developed models achieved a high prediction accuracy with R2 > 0.93, which signifies that the experimental values are in good agreement with the predicted one. The dependence of the catalyst loading and pretreatment temperature on dominating process parameters such as heating rate, pyrolysis temperature, susceptor thermal energy, and pyro products, namely bio-oil, biochar, and biogas, are explored. The yield of biochar is reduced; however, bio-oil and biogas are enhanced as the catalyst loading increased. On the other hand, increasing the temperature of pretreated sawdust decreased bio-oil and biogas yields while increasing biochar yields. Further, microwave conversion efficiency, and susceptor thermal energy increased with increased catalyst quantity and pretreatment temperatures of sawdust. It was observed that the average heating rate was increased by increasing the catalyst quantity while maintaining the same pyrolysis time until pretreatment temperatures of 150 °C were reached, after which the heating rate dropped due to the continuous microwave energy input to the system.

Sustainable Production of Bioethanol Using Levulinic Acid Pretreated Sawdust.

The sustainability and economic viability of the bioethanol production process from lignocellulosic biomass depend on efficient and effective pretreatment of biomass. Traditional pretreatment strategies implicating the use of mineral acids, alkalis, and organic solvents release toxic effluents and the formation of inhibitory compounds posing detrimental effects on the environment and interfering with the enzymatic saccharification process, respectively. Ionic liquids (ILs) as green solvents were used to overcome this issue, but the deep eutectic solvent as an emerging class of ionic liquids performed better in terms of making the process environmentally and economically viable. The green solvent-based pretreatment strategy applied in the current research was levulinic, acid-based natural deep eutectic solvent (NADES). Three different hydrogen bond acceptors (HBAs)—acetamide, betaine, and choline chloride—in combination with levulinic acid as hydrogen bond donor (HBD) in (HBD: HBA) molar ratio 2:1, were screened for biomass pretreatment. The best deep eutectic solvent was levulinic acid: choline chloride in an optimized molar ratio of 1:0.5, resulting in 91% delignification. The physicochemical parametric optimization of saccharification exhibited maximum enzymatic hydrolysis of 25.87% with 125 mg of pretreated sawdust via simultaneous addition of three thermostable cellulases [i.e., endo-1,4-β-D-glucanase (240 U), exo-1,4-β-D-glucanase (180 U), and β-glucosidase (320 U)] for 5 h of incubation at 75°C. The reducing sugar slurry obtained from the saccharified biomass was then added to a fermentation medium for bioethanol production, and a maximum of 11.82% of production was obtained at 30°C, 72 h, and 180 rpm using a 2.5% 24 h old Saccharomyces cerevisiae seed culture. The current study revealed that the levulinic-based deep eutectic solvent exhibited remarkable delignification, which led to the efficient enzymatic hydrolysis of sawdust and hence bioethanol production. Furthermore, it will prospect new avenues in bioethanol production using a deep eutectic solvent. Deep eutectic solvent overcame the issues posed by ionic liquids: toxicity, expensive and complex preparation, and non-biodegradability.

Physicochemical Assessment, Pyrolysis and Thermal Characterization of Albizia Zygia Tree Sawdust

Standard methods were used to obtain proximate and ultimate parameters of Albizia zygia tree sawdust. The HHV of 16.01 MJ/ Kg, H/C of 0.127, O/C of 0.96, high volatile matter of 87.85 wt.% and low ash content of 1.55 wt.% Albizia zygia sawdust makes it a good biofuel. Its empirical formula from elemental ratios combination is CH0.127 O0.96 N0.057 . There were insignificant volumes of oxides of nitrogen and sulphur produced during its pyrolysis since %N & %S are relatively low (2.63 & 0) wt.% respectively. Its TG/DTG profile showed devolatilization of sawdust began at 230 o C and the pyrolysis temperature was in the range of 420- 600 o C. Its fixed bed pyrolysis recorded maximum value of bio-oil at 450 o C. FTIR analysis confirmed the presence of oxygenated compounds in the sawdust and its crude bio-oil. The analysis of the obtained bio-oil using GC-FID showed that significant quantity of -OH compounds were produced from the sawdust through pyrolysis though the obtained quantity is not economical. Sintering and slagging-fouling indicators such as; [Na2 O + K2 O] / [SiO2 ]= 0.0695 showed (unlikely sintering inclination); Base/Acid=0.438 (low ash deposition tendency); [SiO2 ]/([Al2 O3 ]=5.44 & [Fe2 O3 ] / [CaO]=0.28 (low ash deposition tendencies respectively); slagging viscosity index= 68.58 (low slagging tendency); %(SiO2 )=55.18 (high); Babcock (Rs)= 4.38x 10-5 & Fouling indices (Fu)= 1.68x10-2 (low deposition tendencies); Total alkalis (TA) =0.0097 ( Low fouling tendency). It can be projected that improvement on pyrolysis process parameters and pre-treatment of sawdust can be used to achieve higher yield of bio-oil then consequently leading to higher quantity of alcohol compounds.

The Effect of Sawdust as Substitution of Fine Aggregate on Compressive Strength of Concrete

The need for concrete is growing as the construction industry grows around the world. This is a problem for the environment because almost all the materials used to make concrete come from excavated mines. The use of waste materials as a substitute for aggregates can be a solution to reduce the impact of environmental damage. This study used sawdust as a substitute for fine aggregate. The sawdust was partially pretreated using 20% lime-water to reduce the levels of lignin and hemicellulose in the sawdust. The study was conducted to determine the effect of the use of sawdust, with or without pretreatment, on the compressive strength of concrete and the workability value based on the slump value of the concrete at 0%, 5%, 10%, and 15% substitution variations. The slump value of concrete decreases as the percentage of fine aggregate substitution increases. The compressive strength of concrete at the age of 28 concrete decreases with the increase in the percentage of fine aggregate substitution. Concrete that fine aggregate was substituted using pretreated sawdust had better slump and compressive strength values at 28 days of age than concrete that fine aggregate was substituted using non-pretreated sawdust.

Acid-catalyzed mechanocatalytic pretreatment to improve sugar release from birch sawdust: Structural and chemical aspects

This study examined acid-catalyzed mechanocatalytic pretreatment of birch sawdust without a separate impregnation step. Catalyst amount and pretreatment time were the key variables. Pretreated material was mixed with water for hydrolysis (100 °C, 60 min). The efficient release of total reducing sugars from birch sawdust is significant to the path towards biofuels and biochemicals. Based on the results, the structure and surface of birch sawdust changed as a function of mechanocatalytic pretreatment. Milling time caused significant transformations in birch structure and also increased the yields of reducing sugars. The highest yield of total reducing sugar from pretreated sawdust was 23.0% after 30 min of hydrolysis with 1.0 mmol/g acid catalyst, whereas the highest glucose yield was 23.8 g/kg (1.5 mmol/g catalyst, 60 min) and the highest xylose yield was 37.5 g/kg (1.0 mmol/catalyst, 30 min). Overall, acid-catalyzed mechanocatalytic treatment seems to improve sugar yields from birch.

Construction of a novel microbial consortium valued for the effective degradation and detoxification of creosote-treated sawdust along with enhanced methane production

Lignocellulosic biomass represents an unlimited and ubiquitous energy source, which can effectively address current global challenges, including climate change, greenhouse gas emissions, and increased energy demand. However, lignocellulose recalcitrance hinders microbial degradation, especially in case of contaminated materials such as creosote (CRO)-treated wood, which necessitates appropriate processing in order to eliminate pollution. This study might be the first to explore a novel bacterial consortium SST-4, for decomposing birchwood sawdust, capable of concurrently degrading lignocellulose and CRO compounds. Afterwards, SST-4 which stands for molecularly identified bacterial strains Acinetobacter calcoaceticus BSW-11, Shewanella putrefaciens BSW-18, Bacillus cereus BSW-23, and Novosphingobium taihuense BSW-25 was evaluated in terms of biological sawdust pre-treatment, resulting in effective lignocellulose degradation and 100% removal of phenol and naphthalene. Subsequently, the maximum biogas production observed was 18.7 L/kg VS, while cumulative methane production was 162.8 L/kg VS, compared to 88.5 without microbial pre-treatment. The cumulative energy production from AD-I and AD-II through biomethanation was calculated as 3177.1 and 5843.6 KJ/kg, respectively. The pretreatment process exhibited a significant increase in the energy yield by 83.9%. Lastly, effective CRO detoxification was achieved with EC50 values exceeding 90%, showing the potential for an integrated process of effective contaminated wood management and bioenergy production.

Influence of delignification and reaction conditions in the aqueous phase transformation of lignocellulosic biomass to platform molecules

The effect of oxidative and reductive delignification processes on the hydrolysis of pine sawdust at mild conditions (200–1000 ppm of HCl and 140–220 °C) is studied in this work. Dimers and reduced sugars are the main products obtained with the fresh sawdust (>82%), reaching a maximum liquid phase yield of 17% after 8 h, at the strongest conditions. This conversion increases up to almost 40% with the pretreated sawdust, obtaining selectivities higher than 87% of levulinic acid and a well-defined distribution of the relevant platform molecules (sugars, HMF, furfural, levulinic acid) as function of the severity of the reaction, decreasing the humins formation and being possible to define different conditions to maximize each yield. These conclusions were corroborated by the kinetic analysis, obtaining a clear decrease in the energy activation for all the individual steps involved in this process.

Modified Spruce Sawdust for Sorption of Hexavalent Chromium in Batch Systems and Fixed-Bed Columns.

This study investigated the potential use of spruce sawdust that was pretreated with diethylene glycol and sulfuric acid for the removal of hexavalent chromium from wastewater. The sawdust pretreatment process was conducted at different temperatures and times. The adsorbent was characterized by quantitative saccharification, scanning electron microscopy, and Brunauer–Emmet–Teller surface area analysis. Adsorption capacity was studied for both batch and column processes. The experimental adsorption isotherms were simulated using seven isotherm models, including Freundlich and Langmuir models. By using the Langmuir isotherm model, the maximal Cr(VI) adsorption capacity of organosolv-pretreated spruce sawdust (qm) was 318.3 mg g−1. Furthermore, the kinetic data were fitted to Lagergren, pseudo-second-order, and intraparticle diffusion models, revealing that the adsorption of Cr(VI) onto spruce sawdust pretreated with diethylene glycol and sulfuric acid is best represented by the pseudo-second-order kinetic model. Three kinetic models, namely, the Bohart–Adams model, Thomas model, and modified dose–response (MDR) model, were used to fit the experimental data obtained from the column experiments and to resolve the characteristic parameters. The Thomas adsorption column capacity of the sawdust was increased from 2.44 to 31.1 mg g−1 upon pretreatment, thus, demonstrating that organosolv treatment enhances the adsorption capability of the material.

Eco-Friendly Technique for Invertase Immobilization and Oligosaccharide Synthesis at Low Temperature

Eco-friendly technique for invertase immobilization has been created. It is very simple and does not need a preparation of highly pure enzyme or an expensive carrier. The technique relies on mixing pretreated sawdust with baker's yeast in a closed system and comparing it with that in an open system. The technique introduces a practical and new insight into the role of carbon dioxide in modification of sawdust's surface and invertase immobilization. It also provides vital insights on the role of immobilization technique on the stability and activity of the enzyme. The storage stability of the immobilized invertase retained 93% of its activity after storage of 2 years at 4 oC. Although Invertase has been largely immobilized on different cellulosic materials, but the novelty of this study is the enzymatic synthesis of oligosaccharide by cold-adapted invertase at 20 oC.

Enzymatic Hydrolysis of Two-way Pretreated Sawdust of <i>Eucalyptus globulus</i> and <i>Cupressus lusitanica</i>

Sawdust in Ethiopia, despite of its abundance, is not being properly utilized. Pre-treatment has been found to be crucial step before enzymatic hydrolysis of lignocellulosic resources to obtain sugars from such resources. Various pre-treatment methods have been developed to facilitate these bio-conversion processes. This research was aimed at investigating the effects of the combined pretreatments of steam and mild NaOH with white rot fungi (WRF) on sawdust samples from Eucalyptus globulus and Cupressus lusitanica were investigated. The amounts of losses of lignin, cellulose and hemicellulose contents of the pretreated sawdust samples were measured. Samples of the pretreated sawdust samples were then subjected to the enzymes from the hydrolytic wood rot fungi for hydrolysis into fermentable sugars. It was observed that lignin, cellulose and hemicellulose losses of the two sawdust types increased with the increasing incubation days but lignin and hemicellulose were preferentially degraded than cellulose. Sugar yield obtained from the sawdust pretreated in the combination of NaOH with WRF and steam with WRF was significantly higher compared to the yield obtained from the NaOH and steam alone pretreated sawdust samples. Pretreatment by the combination of NaOH with the wood rot fungi significantly modified the recalcitrance nature of the sawdust samples than when steam combined with the fungi. Similarly, with increasing enzymatic hydrolysis periods, sugar yields significantly increased. Higher sugar yields were obtained from sawdust samples of E. globulus than C. lusitanica. The ligninolytic and cellulolytic fungi tested resulted in a notable sugar yields indicating the possible application of the wood rot fungi in sugar production from lignocellulosic sawdust wastes which could be used for different industrial applications.