Common Agricultural Residues Research Articles

Utilization of corn cob, an essential agricultural residue difficult to disposal: Composite board manufactured improved thermal performance using microencapsulated PCM

Among agricultural residues, corn cob (CC) is an essential residue of corn. Unlike common agricultural residues, CC is nutrient-dense and difficult to recycle as fertilizer or feed. Its fiber composition is similar to that of wood, allowing it to act as a wood substitute. In this study, we evaluated the usability of CC in buildings by preparing a composite board composed of CC powder and microencapsulated phase-change material (MPCM). The fibrous and porous sponge structures of CC were confirmed using field-emission scanning electron microscopy (FE-SEM). The sponge structure can be impregnated with MPCM, as confirmed by the SEM image of the CCB (corn-cob composite board with MPCM). In addition, contact angle measurements confirmed the adhesiveness of the composite board, where CCB50 showed the best adhesive strength. To determine the effect of the MPCM on the composite, the thermal performance was evaluated using differential scanning calorimetry (DSC) and dynamic thermal analysis. The DSC analysis confirmed that CCB50 had a latent heat of 20.11 J/g at a melting point of 27.8 °C, and the thermal performance was greatly improved. The temperature behavior of the specimen was investigated by heating and cooling using a heating film. During the heating process, the thermal storage effect was apparent in the temperature data of CCB25 and CCB50, and a time-delay effect was observed during the cooling process; these phenomena were clearly visible in the thermal image and were caused by the thermal preservation of the MPCM. CCB is a composite manufactured from biomaterials and can be used as a building material with high thermal performance.

Investigation of Biochar Production from Copyrolysis of Rice Husk and Plastic.

Biomass renewable energy has become a major target of the Thailand Alternative Energy Development Plan (AEDP) since the country’s economy is largely based on agricultural production. Rice husk (RH) is one of the most common agricultural residues in Thailand. This research aims to investigate yields and properties of biochar produced from copyrolysis of RH and plastic (high-density polyethylene (HDPE)) at different ratios, temperatures, and holding times. For both individual and copyrolysis, the temperature variation generated more pronounced effects than the holding time variation on both biochar yields and properties. For individual pyrolysis of RH, the maximum biochar yield of ∼54 wt % was obtained at 400 °C. A shift in temperature from 400 to 600 °C resulted in RH biochars with higher fixed carbon (FC) and carbon (C) contents by ∼1.11–1.28 and 1.06–1.22 times, respectively, while undetectable changes in higher heating values (HHVs) were noticed. For copyrolysis, obvious negative synergistic effects were observed due to the radical interaction between the rich H content of HDPE and RH biochars, which resulted in lower biochar yields as compared to the theoretical estimation based on individual pyrolysis values. However, the addition of HDPE positively impacted the FC and C contents, especially when 10 and 20 wt % HDPE were added to the feedstock. Besides, higher HDPE blending ratios resulted in biochars with improved HHVs, and >1.5 times improvement in HHV was reported in the biochar with 50 wt % HDPE addition in comparison with RH biochar obtained under the same conditions. In summary, biochars generated in this study have the potential to be utilized as a solid fuel or soil amendment.

Integrating LCA with Process Modeling for the Energetic and Environmental Assessment of a CHP Biomass Gasification Plant: A Case Study in Thessaly, Greece

The energetic and environmental performance of a cogeneration biomass gasification plant, situated in Thessaly, Greece is evaluated via a methodology combining process simulation and Life Cycle Assessment (LCA). Initially, the gasification process of the most common agricultural residues found in the Thessaly region is simulated to establish the effect of technical parameters such as gasification temperature, equivalence ratio and raw biomass moisture content. It is shown that a maximum gasification efficiency of approximately 70% can be reached for all feedstock types. Lower efficiency values are associated with increased raw biomass moisture content. Next, the gasifier model is up-scaled, achieving the operation of a 1 MWel and 2.25 MWth cogeneration plant. The Life Cycle Assessment of the operation of the cogeneration unit is conducted using as input the performance data from the process simulation. Global Warming Potential and the Cumulative Demand of Non-Renewable Fossil Energy results suggest that the component which had the major share in both impact categories is the self-consumption of electricity of the plant. Finally, the key conclusion of the present study is the quantification of carbon dioxide mitigation and non-renewable energy savings by comparing the biomass cogeneration unit operation with conventional reference cases.

Quantification and technological assessment of bioenergy generation through agricultural residues in Punjab (Pakistan)

High dominance of imported oil and gas with constantly depleting natural resources has resulted in a vast energy crisis for Pakistan. Hence, renewable substitutes need to be sought whose utilization and technological availability is a significant issue for a developing country. Opportunely, Pakistan has agricultural potential through which energy can be harnessed for both transport and power sectors. However, to ensure a sustainable supply, it is critical to assess the availability of feedstock and the technologies for its processing. This study quantifies both technical and theoretical potential of bioenergy generation through common agricultural residues and mainly non-edible oilseeds available in Punjab as it is the largest province of Pakistan with the most substancial availability of agricultural land. The appraisal method used WTE conversion processes, feedstock availability, residue characteristics, and cost factors in Bio-IRENA and NREL simulators for quantification of bioenergy, to provide an outlook for its use in energy-consuming sectors, and economic feasibility based on Levelized Cost of Energy (LCOE). The methodological framework adopted in this study can be used to perform technological assessment of bioenergy in any region. Punjab annually produces 70 Million ton of crops which can further produce up to 50 million tons of biomass in the form of agricultural residues. Based on technological considerations, it can produce 21–25 TWh of electricity through Methane Engines, 60 TWh from Combustion and up to 53 TWh from Gasification Steam Turbines. However, due to feedstock availability, and the farmer's willingness to sell, the technical potential falls in a range of 12–50% depending on the crop. Further, considering the annual consumption of Pakistan in the power and transport sector, it can fuel up to 2.3 Million Cars and supply electricity to 23% of the population.

Characterization of different types of agricultural biomass and assessment of their potential for energy production in China

Agricultural residues are among the most important and abundant biomass resources in the world. This study aimed to highlight the characterization of common agricultural residues in China. Six indicators, including biomass, cellulose, hemicelluloses, lignin, caloric value, and ash, were selected to evaluate agricultural residue for its potential energy utilization using grey relational analysis. The results showed that residues of grain crops, including corn (439.1 million tons, 46.6%), rice (207.1 million tons, 21.5%), and wheat (150.7 million tons, 16.0%) were the top three agricultural residues, accounting for 84.1% of total Chinese agricultural residues. Among the agricultural residue samples, rice, wheat, and corn exhibited relatively low ash content; and sugarcane, cotton, and rape residue exhibited low lignin content. Rape, corn, and hemp showed higher cellulose content; and rice, wheat, and corn exhibited higher hemicellulose content. Among the agricultural residues, hemp, corn, and sugarcane showed higher caloric value compared to other residues. According to the grey relational analysis, these combined properties have shown that corn, rice, and wheat can act as potential candidates for energy utilization. The evaluation results were essentially identical to the performance of agricultural residues. Therefore, the comprehensive evaluation of agricultural residues provides sound scientific evidence for their use in energy production.

Ash–Bed Material Interaction during the Combustion and Steam Gasification of Australian Agricultural Residues

The time-dependent layer-formation process of the agglomerates for three common agricultural residues in Australia with different ash-forming elements, together with quartz sand as the bed material, were investigated in a lab-scale, fixed-bed reactor under combustion (5% v/v O2) and steam-gasification (50% v/v steam) atmospheres at 900 °C. The impact of the atmosphere on the ash–bed material interaction was studied from the elemental composition and the morphology of the agglomerates, which were characterized with scanning electron microscopy in combination with energy-dispersive X-ray spectroscopy. The ash–bed material interaction mechanisms for the three feedstock were identified as part of the alkali metals react to form ash particles, which, for wheat straw and cotton stalks, consist of Na, Mg, Si, P, K, and Ca and, for grape marc, is composed mostly of KCaPO4; the remaining alkali metals react with either Si from the quartz sand (for grape marc and cotton stalk) or reactive Si from the fuel (for wheat straw) to form a low-melting-point alkali silicate coating layer; Ca dissolves or diffuses into the coating layer (for wheat straw and cotton stalk); and the ash particles formed in the first step then deposit on, and progressively embed in, the coating layer. The elemental composition of the coating layer is relatively independent of both the reaction time and the gas atmosphere. The coating layer increases in thickness with an increase in the reaction time. The addition of steam results in the production of more liquid alkali silicates, which augment the agglomeration. Any residual S may form sulfate particles with K, Ca, or Na in a combustion atmosphere, while in a steam-gasification atmosphere, the S is released to the gas phase so that more alkali metal may remain to form the low-melting-point alkali silicate.

Comparison of bio-hydrogen production yield capacity between asynchronous and simultaneous saccharification and fermentation processes from agricultural residue by mixed anaerobic cultures

Taken common agricultural residues as substrate, dark fermentation bio-hydrogen yield capacity from asynchronous saccharification and fermentation (ASF) and simultaneous saccharification and fermentation (SSF) was investigated. The highest hydrogen yield of 472.75mL was achieved with corncob using ASF. Hydrogen yield from corn straw, rice straw, corncob and sorghum stalk by SSF were 20.54%,10.31%,13.99% and 5.92% higher than ASF, respectively. The experimental data fitted well to the modified Gompertz model. SSF offered a distinct advantage over ASF with respect to reducing overall process time (60h of SSF, 108h of ASF). Meanwhile, SSF performed better than SSF with respect to shortening the lag-stage. The major metabolites of anaerobic fermentation hydrogen production by ASF and SSF were butyric acid and acetic acid.

Fungal pretreatment of agricultural residues for bioethanol production

The biological pretreatment of lignocellulosic biomass for the production of ethanol is an environmentally friendly process that needs to be evaluated with different feedstocks in order to avoid dependence on a single feedstock. In this study, four agricultural residues (corn stover, barley straw, corncob and wheat straw), selected in terms of their composition and geographic availability, were pretreated using the white-rot fungus Irpex lacteus. After the fungal pretreatment, the biggest reduction in lignin content (45.8±3.5%), lowest sugars consumption (11.5±1.4%) and highest lignin selectivity removal (2.1±0.15) were achieved with corn stover. Moreover, total holocellulose digestibility was significantly increased after the biological pretreatment with all the substrates (37–103%), excepting corncob. In this study, fungal pretreatment was successfully applied to three of the most common agricultural residues available in Europe for producing ethanol, demonstrating that it is capable of handling feedstocks of variable origin.

Pretreatment of Siam weed stem by several chemical methods for increasing the enzymatic digestibility

Siam weed [Chromolaena odorata (L.) King & Robinson], an invasive exotic weed in China, was proposed as a feedstock for bioethanol production. This would be a promising way of using for an invasive weed that needs management and control. It was found that the glucan content of the weed stem was similar to that of sugarcane bagasse, but higher than those of corn stover and wheat straw. Several chemical pretreatment methods were applied to the weed stem to increase its enzymatic digestibility. Mild sulfuric acid (<120 degrees C) or alkali pretreatment did not markedly increase the enzymatic digestibility. However, peracetic acid (PAA) pretreatment dramatically enhanced the enzymatic hydrolysis of the weed stem. Compared to some other common agricultural residues, the weed stem was more difficult to pretreat and digest by cellulase. Fourier transform infrared (FTIR) spectra analysis indicated that the cellulose-related bands became more intensive after pretreatment, especially for PAA-pretreated samples. According to X-ray diffraction spectra, the biomass solids had higher crystallinity indices after pretreatment, although these indices were similar for all of the pretreated samples.

99/00528 Experimental determination of bed agglomeration tendencies of some common agricultural residues in fluidized bed combustion and gasification

The ability of grazing animals to enhance quality of diet by selection is important in production. The study determined the effects of selection on dietary quality of cattle grazing monocultures of smooth bromegrass (Bromus inermis Leyss; SB), switchgrass (Panicum virgatum L.; SG), and big bluestem (Andropogon gerardii Vitman; BB) as influenced by plant maturity. Three ruminally-fistulated steers (295 kg) strip-grazed SB, SG, and BB at vegetative, elongation, early reproductive, and a regrowth stage of development. Selection was maximized by providing cattle access to 40 kg of DM/d per head. Clipped samples were compared with dietary samples accumulated during 45 min grazing following total rumen evacuation. Dietary CP was enhanced 3 to 4% for SG and BB, and 8% for SB (P < 0.05). Dietary IVDMD was enhanced at elongation and reproductive stages for SG and BB and vegetative and reproductive stages for SB. Dietary NDF was 7 to 13% less (P < 0.05).- in SG compared with forage-on-offer, whereas there was no effect with SB and BB diets. Diets of cattle grazing SG and BB had less ADF than clipped forage at elongation and reproductive stages, whereas ADF for the SB diet was less at the elongation phase (P < 0.05). Dietary lignin did not exceed 4% whereas the grass-on-offer was much greater. Regrowth produced forage and diets comparable to the elongation stage. If adequate forage is available, the selection ability of cattle can provide a superior diet compared with forage-on-offer. When the quality of warm-season grasses has declined, animal selection allows for potentially greater animal gain when grass quality is not optimum.

Experimental determination of bed agglomeration tendencies of some common agricultural residues in fluidized bed combustion and gasification

Ever increasing energy demand and the polluting nature of existing fossil fuel energy sources demonstrate the need for other non-polluting and renewable sources of energy. The agricultural residues available in abundance in many countries can be used for power generation. The fluidized bed technology seems to be suitable for converting a wide range of agricultural residues into energy, due to its inherent advantages of fuel flexibility, low operating temperature and isothermal operating condition. The major ash-related problem encountered in fluidized beds is bed agglomeration which, in the worst case, may result in total defluidization and unscheduled downtime. The initial agglomeration temperature for some common tropical agricultural residues were experimentally determined by using a newly developed method based on the controlled fluidized bed agglomeration test. The agricultural residues chosen for the study were rice husk, bagasse, cane trash and olive flesh. The results showed that the initial agglomeration temperatures were less than the initial deformation temperature predicted by the ASTM standard ash fusion tests for all fuels considered. The initial agglomeration temperatures of rice husk and bagasse were more than 1000°C. The agglomeration of cane trash and olive flesh was encountered at relatively low temperatures and their initial agglomeration temperatures in gasification were lower than those in combustion with both bed materials. The use of lime as bed material instead of quartz improved the agglomeration temperature of cane trash and olive flesh in combustion and decreased the same in gasification. The results indicate that rice husk and bagasse can be used in the fluidized bed for energy generation since their agglomeration temperatures are sufficiently high.