Valorization of Agricultural Residues for Hydrogen-Based Electricity Generation towards Circular Bioeconomy

Global crises, notably climate shocks, degraded ecosystems, and growing energy demand, enforce sustainable production and consumption pathways. A circular bioeconomy offers the opportunities to actualize resource and eco-efficiency enhancement, valorization of waste streams, reduction of fossil energy and greenhouse gas (GHG) emissions. Albeit biomass resources are a potential feedstock for bio-hydrogen (bio-H2) production, Ghana’s agricultural residues are not fully utilized. This paper examines the economic and environmental impact of bio-H2 electricity generation using agricultural residues in Ghana. The bio-H2 potential was determined based on biogas steam reforming (BSR). The research highlights that BSR could generate 2617 kt of bio-H2, corresponding to 2.78% of the global hydrogen demand. Yam and maize residues contribute 50.47% of the bio-H2 produced, while millet residues have the most negligible share. A tonne of residues could produce 16.59 kg of bio-H2 and 29.83 kWh of electricity. A total of 4,705.89 GWh of electricity produced could replace the consumption of 21.92% of Ghana’s electricity. The economic viability reveals that electricity cost is $0.174/kWh and has a positive net present value of $2135550609.45 with a benefit-to-cost ratio of 1.26. The fossil diesel displaced is 1421.09 ML, and 3862.55 kt CO2eq of carbon emissions decreased corresponding to an annual reduction potential of 386.26 kt CO2eq. This accounts for reducing 10.26% of Ghana’s GHG emissions. The study demonstrates that hydrogen-based electricity production as an energy transition is a strategic innovation pillar to advance the circular bioeconomy and achieve sustainable development goals.

Production of Producer Gas from Densified Agricultural Biomass in Downdraft Gasifier and Its Application to Small Diesel Engines

Biomass is becoming one of the most popular renewable energy sources,especially from agricultural wastes.These wastes can be gasified and utilized in various industries.This experimental study investigated producer gas generation from densified agricultural fuels such as corncobs,rice husks,wood chips,and oil palm fronds in a 50 kWth throatless downdraft gasifier.This system produced combustible gases such as H_(2),CO,and CH_(4),which were utilized as a substitute for diesel fuel in a small diesel engine for power generation.The results showed that the gasifier performs successfully and seems to prefer pellets to briquettes.Producer gas contains 18%–20%carbon monoxide,1%–6%hydrogen,and 0.9%–1.9%methane.Maximum gasification efficiencies of 53%–71%were achieved with biomass pellets from wood chips,corncobs,oil palm fronds,and rice husks,with producer gas calorific value of 2.94–3.85 MJ/Nm^(3).The average fuel consumption rate was between 6.72–14.43 kg/h,while the producer gas yield was between 2–3 Nm^(3)/kg.The average gravimetric concentration of biomass tar in the raw product gas was found to be in the range of 23–50 g/Nm^(3),in which pelletized fuel appeared to show slightly lower tar than briquette fuel.The tar was primarily composed of five compounds:Benzo(a)pyrene,chrysene,pyrene,phenanthrene,1-methylnaphthalene,and several other polycyclic aromatic compounds.The producer gas from oil palm frond briquettes and biodiesel were tested in a gas engine system in a dual fuel mode.A thermal efficiency of 22.21%was achieved with 2500 W electric load and a 72%biodiesel displacement rate,respectively.

Climate change adaptation, greenhouse gas mitigation and economic profitability of conservation agriculture: Some examples from cereal systems of Indo-Gangetic Plains

Achieving sustainability of the cereal system in the Indo-Gangetic Plains（IGP）of India under progressive climate change and variability necessitates adoption of practices and technologies that increase food production,adaptation and mitigation in a sustainable way.This paper examines conservation agriculture（CA）from the perspective of：（i）increased yield and farm income,（ii）adaptation to heat and water stresses,and（iii）reduction in greenhouse gas（GHGs）emissions.The analyses and conclusions are based on the literature and evidences from a large number of on-station as well as farmers’field trials on CA in the cereal systems of IGP.Our analyses show that CA-based system substantially reduces the production cost（up to 23%）but produces equal or even higher than conventional system;thereby increasing economic profitability of production system.CA-based production systems also moderated the effect of high temperature（reduced canopy temperature by 1–4°C）and increased irrigation water productivity by 66–100%compared to traditional production systems thus well adapting to water and heat stress situations of IGP.Our continuous monitoring of soil flux of CO2,N2O and CH4 revealed that CA-based rice-wheat systems emit 10–15%less GHGs than conventional systems.This is the first time that CA and its components are synthesized and analyzed from food security-climate change nexus.From this holistic analysis,we suggest that wide-scale promotion of suitable CA practices by integrating into national agriculture development strategy is a way forward to address food security,climate change adaptation and mitigation challenges faced by present agriculture.

Development and characterization of mycelium bio-composites by utilization of different agricultural residual byproducts

Mycelium bio-composites was developed by incubating Pleurotus ostreatus fungi on different sub-strates from agricultural residual byproducts,including rice straw,bagasse,coir-pith,sawdust,and corn straw.The scanning electron microscope(SEM)results showed that the hypha of com-posite derived from bagasse was the densest,and the diameter of hypha was the biggest(0.77μm),which was presumably due to the existence of cellulose in bagasse in the form of dextran and xylan.The maximum and minimum compression strength for sawdust substrate and corn straw substrate were 456.70 and 270.31 kPa,respectively.The flexural strength for bagasse sub-strate and rice straw substrate were 0.54 and 0.16 MPa,respectively.The two composites derived from rice straw and bagasse exhibited higher hydrophobic properties than others.In comparison,mycelium bio-composite derived from bagasse showed the best comprehensive properties.Except for a little worse anti-creep ability and waterproof performance,other properties of mycelium bio-composites could be comparable to commercially expanded polystyrene(EPS)packaging mate-rial.Derived from this study,mycelium material provided a good way to use agricultural residual byproducts and could be a good alternative to non-biodegradable materials for packaging appli-cations.

Influence of agricultural activities,forest fires and agro-industries on air quality in Thailand

Annual and monthly-based emission inventories in northern, central and north-eastern provinces in Thailand, where agriculture and related agro-industries are very intensive,were estimated to evaluate the contribution of agricultural activity, including crop residue burning, forest fires and related agro-industries on air quality monitored in corresponding provinces. The monthly-based emission inventories of air pollutants, or, particulate matter（PM）, NOx and SO2, for various agricultural crops were estimated based on information on the level of production of typical crops： rice, corn, sugarcane, cassava, soybeans and potatoes using emission factors and other parameters related to country-specific values taking into account crop type and the local residue burning period. The estimated monthly emission inventory was compared with air monitoring data obtained at monitoring stations operated by the Pollution Control Department, Thailand（PCD） for validating the estimated emission inventory. The agro-industry that has the greatest impact on the regions being evaluated, is the sugar processing industry, which uses sugarcane as a raw material and its residue as fuel for the boiler. The backward trajectory analysis of the air mass arriving at the PCD station was calculated to confirm this influence. For the provinces being evaluated which are located in the upper northern, lower northern and northeast in Thailand, agricultural activities and forest fires were shown to be closely correlated to the ambient PM concentration while their contribution to the production of gaseous pollutants is much less.

Mapping of energy potential through annual crop residues in Turkey

The objective of this study was to determine the annual crop residue potential in terms of types,quantities and mapping in Turkey.The calorific values of agricultural residues were determined by calorimeter according to ASTM D 5865 Standard Test Method for Coal and Coke 2002.In this study,the energy potential of annual crop residues was evaluated by ArcGIS^(TM) which is a geographical information system program.The total amount of unused annual crop residues was approximately 15.24 Mt/a.It was found that the total calorific value of the field crop residues was around 268 PJ/a for the 2012 production period in Turkey.The major crops included in the ratio of the total calorific value were maize(45.81%),wheat(21.30%),sunflower(15.10%)and cotton(18.1%).The amount of CO_(2) emitted into the atmosphere can be reduced by 30 Mt/a year through the use of agricultural residues.

A Novel Fluorescence Tool for Monitoring Agricultural Industry Chain Based on AIEgens

With the development of the global economy,the safety of agricultural production has attracted intense attention.To minimize the risk of harmful ingredients in the whole industry chain,it is very necessary to cover the entire process of safety inspections from planting to production to environmental management.Fluorescence sensing as a promising and powerful screening tool is widely used for the detection of ions,toxic gases,biological molecules and so on.However,traditional fluorescent probes often suffer from aggregation-induced quenching(ACQ)effects,which limits their practical applications.In this regard,aggregation-induced emission luminogens(AIEgens)can perfectly address this notorious issue and have shown great potential in agricultural safety analysis.In this review,we briefly summarize their applications in agricultural safety monitoring,including the fabrication of agricultural film,agricultural sewage treatment and selective detection of harmful residues in agricultural products.The challenge and future development of AIEgens in this field are also discussed and highlighted.Hopefully,this review can inspire more researchers to participate in this fascinating area.

Filling agricultural waste into coal mine goafs:a potential carbon sequestration in China

China is a significant atmospheric carbon dioxide producer.Burning of agricultural waste in China is also a problematic issue,raising environmental and carbon-emission-related concerns.Furthermore,the coal-dependent economy is accompanied by the formation of large coal mine goaf areas,particularly in Shanxi Province.In this context,the idea of filling crop residues into the coal mine goafs is proposed.This concept addresses multi-functions:(1)carbon sequestration,(2)an alternative disposal method of crop residue in rural areas,and(3)coal mine goaf remedy.

A techno-economic assessment for viability of some waste as cooling pads in evaporative cooling system

The viability of some waste as cooling pads for evaporative cooling application in South-Western Nigeria was experimentally assessed.This is to ascertain their effectiveness as a substitute for costly imported pads in a low income environment.Also presented was the feasibility of utilizing standalone evaporative coolers for storage and selling of fruits in South-Western Nigeria.Natural ambient air was forced through the various pads at three different fan speeds and constant cooling pad thickness of 30 mm.Performance characteristics were considered based on daily analysis using temperature and humidity data measured from morning to evening at location co-ordinates latitude 7°10′N and longitude 5°05′E for 6 weeks.The daily temperature T and humidity h ranged between 26℃≤T≤45℃ and 28%≤h_(2)≤80%.Temperature differenceDT and humidity differenceDh of 0.6℃≤ΔT≤18.3℃ and 1.0%≤Δh≤53%was achieved for the four cooling pad materials tested at three fan speeds.HighestDT andDh was recorded at fan speed of 4 m/s with shredded latex foam and jute sack respectively.The cooling efficiency(η)calculated for all the pads under the three speeds ranged from 17.3%≤η≤98.8%.Payback period(PBP)analysis indicated the considered EVC is economically feasible and investors will break even in 1.75 years.

Chemical constituents and pharmacological effects of durian shells in ASEAN countries:A review

Durio zibethnus is mainly distributed in Southeast Asia.Traditional Chinese medicine believes that durian shells have the effects of clearing heat and purging fire,nourishing yin and moisturizing dryness.Therefore,it is often used as a pharmaceutic food in the Chinese folk to assist treating diseases.At present,the chemical constituents isolated from durian shell include phenolic acids,phenolic glycosides,flavonoids,coumarins,triterpenes,simple glycosides and other compounds.Modern pharmacological studies show that durian shell has many pharmacological activities,such as antioxidant,antiinflammatory,regulation of glucose and lipid metabolism.The chemical composition and pharmacological effects of durian shells are summarized in order to provide references for the further research and application of durian shell.

Impact of hydrolysis on surface area and energy storage applications of activated carbons produced from corn fiber and soy hulls

Complete utilization of lignocellulosic biomass through the creation of value-added coproducts is one of the key strategies of the Bioenergy Technologies Office(BETO)for the cost-effective production of biofuels and biochemicals.A green approach to producing lightweight and high specific surface area(SSA)activated carbons(ACs)from sustainable biomass sources is of great interest to producers and users of energy devices such as batteries and supercapacitors.While direct conversion from biomass has been studied extensively,AC with relatively high surface areas can be produced more cost-effectively when leveraged as a co-product from a biorefinery.In this paper,we discuss the production of high specific surface area activated carbons from residual fiber(fiber remaining after extraction of C5-sugars)generated as part of a C5 biorefinery.The surface,morphological characteristics using SEM and TEM,and energy storage behavior of ACs produced using the C5 extracted residual fiber were evaluated in the present study.The ACs produced from the residual fiber delivered an order of magnitude higher surface area than the one directly from corn pericarp fiber and soy hulls.The surface area of the ACs produced from pre-hydrolysis DDG was only 10 m^(2)/g compared to 689 m^(2)/g for soy hulls whereas after hydrolysis these values increased significantly(DDG:1700 m^(2)/g and soy hulls:1300 m^(2)/g).TEM images indicated high exfoliation,explaining the change in surface area values.Under the same current density(500 mA/g)the cycling performance of the ACs increased as the surface area increased significantly.

Review in life cycle assessment of biomass conversion through pyrolysis-issues and recommendations

Biomass,widespread and carbon-neutral energy,can provide electric energy and replace fossil fuel-derived production.Pyrolysis is the main way of converting biomass to different bioenergy products with the consumption of material and energy,which will cause environmental impacts.To confirm the actual environmental impact of biomass conversion,life cycle assessment(LCA)is used for analyzing the process.Due to choosing different LCA methods,the results for the same thing in different reports will show obvious fluctuation.This review is devoted to providing recommendations on how to handle methodological issues when analyzing LCA study,by which researchers can better realize the similarities and differences in biomass conversion system.In this review,multiple clarifications and methodological recommendations on the four steps of the LCA process(including goal and scope definition,life cycle inventory,life cycle impact assessment,and interpretation)are provided.Furthermore,the LCA results are discussed systematically,in which the global warming potential gets extra attention.Meanwhile,different biomass feedstocks are divided into agricultural residues,forest residues,and microalgae carefully.Finally,the current challenges and future framework of biomass conversion are expounded in detail from the perspective of LCA.

Development of chemometric model for characterization of non-wood by FT-NIR data

In this study,a model for prediction of lignocellulose components of agricultural residues has been developed with Fourier Transformed Near Infrared(FT-NIR)spectroscopy data.Two calibration techniques(Principal Component Regression(PCR)and Partial Least Square Regression(PLSR))were assessed for prediction of lignin,holocellulose,α-cellulose,pentosan and ash,and found the PLSR better for lignin,holocellulose andα-cellulose.The PCR also produced better results for quantification of pentosan and ash.Spectral range(7000-5000 cm^(-1))showed more informative than other parts of the spectral data.The PLSR showed maximum value of R^(2)(R^(2)=0.91%)for prediction of holocellulose.For the prediction of pentosan,the PCR was better(R^(2)=0.68%).The PCR also showed better results(R^(2)=86%)for quantification of ash.To determine amount of lignin,the PLSR was the best(R^(2)=0.83%)when the spectral data were de-trained and smoothed with Savitzky-Golay(S-G)filtering simultaneously.For prediction ofα-cellulose,the PLSR was the best model(R^(2)=0.94%)when the data were pretreated with mean normalization.Considering the best alternatives inNear Infrared(NIR)data preprocessing and calibration techniques,methods for quantification of lignocellulose components of agricultural residues have been developed which is rapid,cost effective,and less chemical intensive and easily usable in pulp and paper industries and pulp testing laboratories.