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In recent years, the demand for environmental sustainability has caused a great interest in finding novel polymer materials from natural resources that are both biodegradable and eco-friendly. Natural biodegradable polymers can displace the usage of petroleum-based synthetic polymers due to their renewability, low toxicity, low costs, biocompatibility, and biodegradability. The development of novel starch-based bionanocomposites with improved properties has drawn specific attention recently in many applications, including food, agriculture, packaging, environmental remediation, textile, cosmetic, pharmaceutical, and biomedical fields. This paper discusses starch-based nanocomposites, mainly with nanocellulose, chitin nanoparticles, nanoclay, and carbon-based materials, and their applications in the agriculture, packaging, biomedical, and environment fields. This paper also focused on the lifecycle analysis and degradation of various starch-based nanocomposites. [ABSTRACT FROM AUTHOR]

The current trend of using plastic material in the manufacturing of packaging products raises serious environmental concerns due to waste disposal on land and in oceans and other environmental pollution. Natural polymers such as cellulose, starch, chitosan, and protein extracted from renewable resources are extensively explored as alternatives to plastics due to their biodegradability, biocompatibility, nontoxic properties, and abundant availability. The tensile and water vapor barrier properties and the environmental impacts of natural polymers played key roles in determining the eligibility of these materials for packaging applications. The brittle behavior and hydrophilic nature of natural polymers reduced the tensile and water vapor barrier properties. However, the addition of plasticizer, crosslinker, and reinforcement agents substantially improved the mechanical and water vapor resistance properties. The dispersion abilities and strong interfacial adhesion of nanocellulose with natural polymers improved the tensile strength and water vapor barrier properties of natural polymer-based packaging films. The maximum tensile stress of these composite films was about 38 to 200% more than that of films without reinforcement. The water vapor barrier properties of composite films also reduced up to 60% with nanocellulose reinforcement. The strong hydrogen bonding between natural polymer and nanocellulose reduced the polymer chain movement and decreased the percent elongation at break up to 100%. This review aims to present an overview of the mechanical and water vapor barrier properties of natural polymers and their composites along with the life cycle environmental impacts to elucidate their potential for packaging applications. [ABSTRACT FROM AUTHOR]

The cellulose reinforced polylactic acid (PLA) composites are one of the most widely explored biopolymer composites in packaging applications. In this study, the cellulose microfibers (CMF) isolated from cotton noil were reinforced with 1%, 3%, 5%, 10%, and 20% in PLA matrix by solvent casting method. The strong interfacial adhesion and enhanced dispersion of CMF in PLA polymer matrix increased the tensile, water vapor, ultraviolet (UV) light barrier properties of the composites. The ultimate tensile stress and Young's modulus of 1% CMF reinforced composites were increased by 46% and 30% respectively than that of control films. A further increase in percent CMF reinforcement of up to 20% slightly reduced the tensile strength of composites but was comparable to that of low‐density polyethylene polymer. The water vapor permeability was decreased while increasing the CMF reinforcement due to the increased diffusion path by the dispersed CMF. The UV light absorbance of the composite was improved by up to 90% with the increase in CMF reinforcement by up to 20% due to the increased chromophore groups of cellulose. Hence, the PLA‐CMF composites could be used for packaging and storing light and moisture‐sensitive products. [ABSTRACT FROM AUTHOR]

Protected cultivation in modern agriculture relies extensively on plastic-originated mulch films, nets, packaging, piping, silage, and various applications. Polyolefins synthesized from petrochemical routes are vastly consumed in plasticulture, wherein PP and PE are the dominant commodity plastics. Imposing substantial impacts on our geosphere and humankind, plastics in soil threaten food security, health, and the environment. Mismanaged plastics are not biodegradable under natural conditions and generate problematic emerging pollutants such as nano-micro plastics. Post-consumed petrochemical plastics from agriculture face many challenges in recycling and reusing due to soil contamination in fulfilling the zero waste hierarchy. Hence, biodegradable polymers from renewable sources for agricultural applications are pragmatic as mitigation. Starch is one of the most abundant biodegradable biopolymers from renewable sources; it also contains tunable thermoplastic properties suitable for diverse applications in agriculture. Functional performances of starch such as physicomechanical, barrier, and surface chemistry may be altered for extended agricultural applications. Furthermore, starch can be a multidimensional additive for plasticulture that can function as a filler, a metaphase component in blends/composites, a plasticizer, an efficient carrier for active delivery of biocides, etc. A substantial fraction of food and agricultural wastes and surpluses of starch sources are underutilized, without harnessing useful resources for agriscience. Hence, this review proposes reliable solutions from starch toward timely implementation of sustainable practices, circular economy, waste remediation, and green chemistry for plasticulture in agriscience [ABSTRACT FROM AUTHOR]

The inferior water vapor permeability and water resistance properties are the major challenges that hindered the development of chitosan‐CNF composites for packaging applications. In this study, the chitosan‐CNF composite films were prepared with in situ crosslinking of citric acid (CA) to reduce the percent water uptake (WU) and water vapor permeability (WVP). The composite films were produced by the solvent casting method with 10%, 15%, and 20% CNF as a reinforcement, 20%, 25%, and 30% CA as a crosslinker, and 20% glycerol as a plasticizer. The Fourier transform infrared (FTIR) spectra of composite films with a peak at 1710 cm−1 confirmed the effective crosslinking of citric acid on the chitosan‐CNF matrix. The crosslinked composite films exhibited the lowest WU of 39% and WVP of 9.99 × 10−7 g/Pa s m2 with reduced light transmittance due to CNF reinforcement. The scanning electron microscopy (SEM) study showed the smooth surface morphology of composite films. The CA crosslinking slightly decreased the tensile strength of composite films. However, the composite film with optimal CNF and CA concentration (25% and 20%, respectively) exhibited comparable tensile strength with other synthetic and biopolymer composites and can be used as a potential biopolymer composite for packaging applications. [ABSTRACT FROM AUTHOR]

Woody biomass feedstock that is both high quality and low cost has become increasingly important for the bioenergy and bioproducts industries. Logging generates forest residues – low‐quality feedstock – and additional operations that also incur additional costs, such as biomass sorting and treetops processing (BSTP), micro‐chipping, and screening, which are required to improve the feedstock's quality. Considering recent developments in technologies and BSTP to generate high‐quality feedstocks, economic models were developed in this study to estimate various forest‐residue logistics operational costs and to analyze the economics of delivering feedstocks to biomass conversion technology (BCT) sites near woods or power plants located far away in the form of chips, hog fuel, and bales. The results show that the cost of BSTP can vary between $30 and $82/ODMT (oven dry metric ton) based on the biomass sorting intensity. The most economical way to deliver forest residues was transporting processed stem‐wood from landings to near‐wood BCT sites and comminuting it into woodchips there (~$20/ODMT, assuming a one‐way (32 km) road distance and no cost of BSTP at landings). Grinding slash at the landing and transporting ground‐biomass (i.e., hog fuel) to a plant (< 22 km away) was more economical than transporting bales from landings and grinding at the plant. The economic feasibility of baling and BSTP requires a substantial productivity improvement or recognition and incorporation of benefits including reduced wildfire risk and improved forest health. High bulk density and strong shape of forest residues/slash bales compared to hog fuel may provide additional cost benefits during storage, for example through lower handling costs, which can be studied in the future. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

Cellulose nanofibrils (CNFs) are typically produced via wet milling pretreatment method to facilitate efficient disintegration of cellulose fibers by pre-fibrillation and fiber size reduction. However, the use of high energy and presence of water during wet milling methods leads to the increase in overall energy consumption during CNFs production and pose challenges during storage and handling. The objective of this study is to investigate the dry grinding of cellulose fluff pulp using the shear cutting method to determine the specific energy required to produce cellulose precursors and their characteristics for manufacturing CNFs. The specific energy required to grind cellulose fluff pulp with a screen size of 0.25 mm in three cycles was measured. The ground sample received after each cycle was sampled to characterize its properties and its potential to produce CNF hydrogels. As the number of grinding cycles increased, the specific energy required per cycle decreased with an overall net energy consumption of 894 kWh/Mg for three grinding cycles. The cellulose powder from the third grinding cycle was successfully disintegrated into cellulose nanofibrils with an average diameter of 119 nm without any fiber clogging. In conclusion, the three-cycle shear cutting process was sufficient to produce dry cellulose precursors for CNFs production, while reducing the overall energy consumption and handling and storage problems. [ABSTRACT FROM AUTHOR]

We have developed a sustainable dyeing technology with nanofibrillated cellulose (NFC) fibers that would decrease the amount of water, salt and alkali used in cotton dyeing by one order of magnitude, but with comparable dyeing performance to a conventional exhaust dyeing method. [ABSTRACT FROM AUTHOR]

Storage of agricultural residues and energy crops is essential for preserving and maintaining its economic value, and year-round continuous delivery to a biorefinery. In this study, a dynamic cost model was developed for three storage methods (Indoor, Outdoor-tarped, and Outdoor-open) with two biomass bale types (rectangular and round) to estimate the storage cost of corn stover and switchgrass. The effects of storage time and multiple-use of a storage facility on the storage cost were also evaluated to develop effective storage strategies. The cost of bale storage systems comprised of capital expenses for infrastructures, bale handling, dry matter loss ( DML) and quality loss costs. Among storage methods, the outdoor-tarped storage with rectangular bales was the least expensive options for corn stover ($14.6 dry Mg−1) and switchgrass ($16 dry Mg−1). Indoor storage of round bales was costly due to the large storage footprint requirement and high infrastructure investment. However, the indoor storage cost could be reduced, if the storage facility could be used more than once a year. The sensitivity analysis study illustrated that the DML, biomass cost, loading/unloading time and bale density were the most sensitive parameters influencing the storage cost. An example storage strategy developed for a typical biorefinery could reduce the average annual storage cost (up to $10 dry Mg−1) along with an annual cost saving ranging from 10 to 100% compared with any single storage option. © 2017 Society of Chemical Industry and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Biogas derived from anaerobic digestion of organic wastes, and lignocellulosic biomass can be used to produce drop-in diesel fuel via Fischer-Tropsch ( FT) synthesis. In this study, we developed a process-based simulation model for the biogas to liquid fuel ( BgTL) plant to conduct mass and energy balances and to evaluate techno-economic assessment of producing drop-in FT fuels. The BgTL plant operations consisted of biogas cleaning, biomethane reforming, FT synthesis of syngas and hydrocracking and final distillation to produce drop-in liquid fuels. The unconverted syngas and syncrude were utilized to generate steam and electricity to meet internal plant demand, while the excess power was sold to the grid. The base case BgTL plant (2 000 Nm3/h) produced about 4.6 million gallons per annum of total FT fuels which consisted of 62% diesel, 32% gasoline, 6% LPG with an overall biogas conversion of 54%. A discounted cash flow rate of return ( DCFOROR) approach for the Nth plant was used to estimate the capital and operating costs with the minimum selling price for the FT drop-in fuels of about $5.67/gal ($5.29/ GGE). The increase in plant feed capacity to 20 000 Nm3/h decreased the minimum selling price to $2.06/gal ($1.92/ GGE). The sensitivity analysis conducted on the base case plant demonstrated that the internal rate of return ( IRR), FT conversion rate, plant operating hours, and biogas cost were the most sensitivity parameters to the minimum selling price. Overall, the BgTL technology is deemed to be economically feasible to meet US biofuels demand. © 2017 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

Moisture content of wood chips is an important factor to be known in their utilization as a biomass material. Several moisture measuring instruments are available in the market, but for most of these instruments, some sort of sample preparation is needed that involves sizing, grinding, and weighing. The samples in this process are usually destroyed, and the measurement involves considerable time and labor. The standard methods of oven drying and Karl Fisher also fall in the destructive and laborious category. In this paper, estimation of moisture content of hardwood chips, from the measurement of certain electrical properties of a parallel-plate capacitor, holding the samples of these materials between them at two radio frequencies, is presented. The wood chip samples tested were in the moisture range of 3%–50%. The standard error of prediction was 2.0, and the prediction accuracies were better for the samples with moisture contents below 25%. The construction and performance of a prototype moisture sensing instrument working on these principles is briefly described. This method being nondestructive and rapid would be useful in the biofuel industry. [ABSTRACT FROM PUBLISHER]

Iron supported biochar catalysts were used to decompose toluene, a model tar compound, over a temperature range of 600–900 °C. Toluene conversion and decomposition rates increased linearly with increasing temperature and catalyst loading from 600 to 700 °C. Relative to biochar alone, the iron supported catalysts lowered the activation energy by 47% and decreased the formation of benzene, an intermediate in toluene decomposition. At 800 °C for the 13 and 18.7 wt.% iron loaded catalyst, toluene conversion approached 100% and benzene selectivity (S B ) was zero, compared to an S B of 0.025% and 0.35% for 10% iron and the biochar, respectively. Time on stream studies with the 13 wt.% iron biochar catalyst, over the course of four days, resulted in a mean toluene conversion of 91% and benzene selectivity of 0.02%. These results indicate that inexpensive iron impregnated biochar catalysts could potentially be used to catalytically decompose tar molecules in syngas generated via biomass gasification. [ABSTRACT FROM AUTHOR]

Abstract: Thermal pretreatment or torrefaction of biomass under anoxic condition can produce an energy dense and consistent quality solid biomass fuel for combustion and co-firing applications. This paper investigates the fuel characteristics and grindability of pine chips and logging residues torrefied at temperatures ranging from 225°C to 300°C and 30min residence time. Grinding performance of torrefied biomass evaluated by determining energy required for grinding, particle size distribution and average particle size were compared with raw biomass and coal. Specific energy required for grinding of torrefied biomass decreased significantly with increase in torrefaction temperatures. The grinding energy of torrefied biomass was reduced to as low as 24kWh/t at 300°C torrefaction temperature. The gross calorific value of torrefied chips increased with increase in torrefaction temperature. Torrefaction of biomass clearly showed the improved fuel characteristics and grinding properties closer to coal. [ABSTRACT FROM AUTHOR]

Abstract: Corn stover is a major crop residue for biomass conversion to produce chemicals and fuels. One of the problems associated with the supply of corn stover to conversion plants is the delivery of feedstock at a low cost. Corn stover has low bulk density and it is difficult to handle. In this study, chopped corn stover samples were compacted in a piston cylinder under three pressure levels (5, 10, 15MPa) and at three moisture content levels (5%, 10%, 15% (wb)) to produce briquettes. The total energy requirement to compress and extrude briquette ranged from 12 to 30MJ/t. The briquette density ranged from 650 to 950kg/m3 increasing with pressure. Moisture content had also a significant effect on briquette density, durability and stability. Low moisture stover (5–10%) resulted in denser, more stable and more durable briquettes than high moisture stover (15%). [Copyright &y& Elsevier]

Unprecedented opportunities for biofuel development are occurring as a result of rising fossil fuel prices, the need to reduce greenhouse gases, and growing energy security concerns. An estimated 250 million hectares (ha) of farmland could be utilized globally to develop a bioenergy industry if efficient and economical perennial biomass crops and bioenergy conversion systems are employed. In temperate zones, C 4 or warm-season grass research and development efforts have found switchgrass (Panicum virgatum) and Miscanthus capable of producing biomass yields of 10 to 20 oven dried tonnes (ODT)/ha/yr, while in tropical areas Erianthus and napier grass (Pennisetum purpureum) are producing 25 to 35 ODT/ha/yr. The potential to annually produce 100 barrels of oil energy equivalent/ha with a 25:1 energy output to input ratio appears achievable with high-yielding, N-fixing warm-season grasses grown on marginal lands in the tropics. Commercialization of densified herbaceous plant species has been slow because of the relatively high alkali and chlorine contents of the feedstocks, which leads to clinker formation and the fouling of boilers. This challenge can be overcome by improving biomass quality through advances in plant breeding and cultural management to reduce the chlorine, alkali, and silica content and through the use of new combustion technologies. Warm-season grasses can be readily densified provided suitable grinding and densification equipment and pressure are utilized. The major advantages of producing densified warm-season grasses for BIOHEAT include: it is the most efficient strategy to use marginal farmlands in most temperate and tropical climates to collect solar radiation; it has an excellent energy balance; the feedstocks can be used conveniently in a variety of energy applications; and it is relatively environmentally friendly. Densified warm-season grass biofuels are poised to become a major global fuel source because they can meet some heating requirements at less cost than all other alternatives available today. [ABSTRACT FROM AUTHOR]

We investigated the techno-economic analysis of two integrated torrefaction and pelletization systems: (1) Torrefaction befOre Pelletization and (2) Torrefaction After Pelletization configurations to produce torrefied wood pellets. The detailed mass and energy balances and operating parameters were obtained from the process simulation model developed with the base case plant capacity of 100,000 Mg yr−1 using natural gas as an auxiliary fuel source. A discounted cash flow analysis was conducted for both configurations to estimate the capital expenditure, operating expenses, production cost, and the minimum selling price of torrefied pellets. The minimum selling price of torrefied pellets at the plant gate was $207 Mg−1 ($8.5 GJ−1) for the Torrefaction before Pelletization and $197 Mg−1 ($8.1 GJ−1) for the Torrefaction After Pelletization configurations. An increase in the plant capacity of up to 200,000 Mg yr−1 for both configurations decreased the minimum selling price by 10%. The sensitivity analysis of various operational and financial parameters demonstrated that the feedstock cost and torrefaction product yield were the most sensitive parameters influencing the minimum selling price of torrefied pellets. Future opportunities exist to reduce the minimum selling price of torrefied pellets to become competitive to conventional wood pellets and coal. [Display omitted] [ABSTRACT FROM AUTHOR]

Strip-mined land (SML) disturbed by coal mining is a non-crop land resource that can be utilized to cultivate high-yielding energy crops such as miscanthus for bioenergy applications. However, the biomass yield potential, annual availability, and environmental impacts of growing energy crops in SML are less understood. In this study, we estimated the yield potential of miscanthus (Miscanthus sinensis) in SML and its environmental impacts on local streams using the Soil and Water Assessment Tool (SWAT). After calibration and validation of the SWAT model, the results demonstrated that miscanthus yield potentials were 2.6 (0.8−5.53), 10.0 (1.3−16.0), and 16.0 (1.34−26.0) Mg ha−1 with fertilizer application rates of 0, 100, and 200 kg-N ha−1, respectively. Furthermore, cultivation of miscanthus in SML has the potential to reduce sediment (~20%) and nitrate (2.5−10.0%) loads reaching water streams, with a marginal increase in phosphorus load. The available SML in the United States could produce about 10 to 16 dry Tg of biomass per year without negatively impacting the water quality. In conclusion, SML can provide a unique opportunity to produce biomass for bioenergy applications, while improving stream water quality in a highly dense mining area (the Appalachian region) in the United States. [ABSTRACT FROM AUTHOR]

Abstract Torrefaction of biomass improves the grindability of raw biomass by the transformation from a fibrous structure to a more brittle and friable, coal-like material. Torrefied biomass is a more desirable feedstock for co-firing applications, especially in existing coal-fired power plants. Therefore, measuring the grindability and the specific energy consumption are critical for understanding the comminution behavior of torrefied biomass, and thus selecting appropriate milling equipment. In this study, the effect of torrefaction temperature on the specific grinding energy consumption and the grindability of torrefied wood pellets and wood chips was investigated and compared with that of coal. The applicability of three well-known grinding equations (Kick, Rittinger and Bond) was studied for the torrefied biomass using a knife mill. The specific grinding energy of both torrefied wood chips and pellets linearly decreased with increased torrefaction temperature over a range of 250–290 °C. Rittinger's model was the best-fit for both wood chips (R2 = 0.72–0.90) and wood pellets (R2 = 0.67–0.76). When the intercepts were considered, the Rittinger's and Bond's equations fitted well with the experimental data (R2 = 0.79–0.99) for all torrefied biomass. The grindability of torrefied biomass was measured using the Hardgrove Grindability Index (HGI) and the International Organization for Standardization (ISO) grindability index. A relationship between the Bond Work Index (BWI), based on the Bond's theory and HGI was developed for wood chips and wood pellets. Contrary to HGI index, BWI decreased with an increase in torrefaction temperature. The grindability parameters developed for torrefied biomass can be used for modeling and selecting suitable milling equipment. Highlights • Specific grinding energy required for torrefied wood chips and pellets were determined • Grinding energy decreased linearly with increased torrefaction temperature (250–290 °C) • Rittinger's equation was fitted the best with grinding data for all torrefied biomass. • HGI and BWI for torrefied biomass produced at 290 °C were comparable to that of coal. [ABSTRACT FROM AUTHOR]

Highlights • Economic feasibility of portable systems to utilize forest residues was investigated. • Forest residues were processed into raw and torrefied briquettes and biochar. • Minimum selling price (MSP) of biochar was estimated to $1044/ODMT. • MSP of raw and torrefied-briquettes were $162 and $274/ODMT respectively. • MSPs could be reduced by at least 50% with improved portable systems. Abstract Wildfires are getting extreme and more frequent because of increased fuel loads in the forest and extended dry conditions. Prevention of wildfire by fuel treatment methods will generate forest residues in large volumes, which in addition to available logging residues, can be used to produce biofuels and bioproducts. In this study, the techno-economic assessment of three portable systems to produce woodchips briquettes (WCB), torrefied-woodchips briquettes (TWCB) and biochar from forest residues were evaluated using pilot-scale experimental data. A discounted cash flow rate of return method was used to estimate minimum selling prices (MSPs) for each product, to conduct sensitivity analyses, and to identify potential cost-reduction strategies. Using a before-finance-and-tax 16.5% nominal required return on investment, and a mean transport distance of 200 km, the estimated delivered MSPs per oven-dry metric ton (ODMT) of WCB, TWCB, and biochar were $162, $274, and $1044 respectively. The capital investment (16–30%), labor cost (23–28%), and feedstock cost (10–13%) without stumpage cost were the major factors influencing the MSP of solid biofuels and biochar. However, the MSPs of WCB, TWCB, and biochar could be reduced to $65, $145, and $470/ODMT respectively with technologically improved portable systems. In addition, the MSPs of solid biofuels and biochar could be further reduced by renewable energy and carbon credits, if the greenhouse gas (GHG) reduction potentials are quantified and remunerated. In conclusion, portable systems could be economically feasible to use forest residues and make useful products at current market prices while simultaneously reducing potential wildfires and GHG emissions. [ABSTRACT FROM AUTHOR]

The thermal stability of cellulose nanofibrils (CNFs) can be improved by converting cellulose crystalline structure to cellulose II using an alkaline treatment method. The conventional method requires around 20 wt.% NaOH solutions and causes the cellulose interdigitation and aggregation, making CNFs production difficult. The objective of this study is to develop a new pretreatment method using a low-concentration alkaline solution to produce well-dispersed CNFs with improved thermal stability. CNFs with 90 nm diameter were successfully prepared by treating cellulose powder with 2 wt.% NaOH solution below 0 °C, followed by homogenization through a French pressure cell press. The CNFs had relatively high thermal stability with the mean onset and maximum thermal decomposition temperature of 305 °C and 343 °C, respectively, compared with the CNFs prepared without the NaOH pretreatment (283 °C and 310 °C). The increased thermal stability can create new opportunities for the development of CNF-based bio-composites and electronics. [ABSTRACT FROM AUTHOR]

Energy crops grown on marginal lands offer an alternative supply of renewable resources while avoiding competition with food crops and supporting feed crops. To sustainably grow energy crops, the economic and environmental impacts of various crop management practices such as the adoption of cover crops, fertilization rates, harvesting methods and its end use applications for animal feed or biofuels should be investigated. In this study, we investigated the life cycle analysis (LCA) and economic evaluation of growing two energy crops (energy cane, and napier grass) on the marginal lands with three fertilizer treatments (0, 100, and 200 kg N ha⁻¹), and with a cover crop (clover, Trifolium incarnatum L) in the southeastern United States (US). Energy crop was harvested once a year in the late fall for biofuel applications, while the Napier grass was harvested twice a year: first harvested early in spring for animal feed and later harvested in the fall for biofuel application. Experimental field data such as biomass yield, crop management practices, farm inputs, and carbon stored in the soil, were determined to assess the global warming potential and the delivered cost of each energy crop. Napier grass had lower global warming (GW) impacts and biomass delivery costs, 34–153 kg CO₂ eq. per oven-dry metric ton (ODMT) and $51–$57 perODMT, respectively than that of energy cane. However, both the energy crops provided carbon sequestrations (−17 and −232 kg CO₂ eq. ODMT⁻¹) and thus net GW impact varied between 51 and (−14) kg CO₂ eq. ODMT⁻¹ based on the treatments. When the napier grass was harvested for both biofuel and fodder applications, the overall GW impacts and the delivered costs were reduced. Therefore, energy crops can be grown in marginal lands for increased carbon sequestration while reducing the GW impacts of energy crops for biofuel production. The integrated environmental and economic analyzes further demonstrated that the energy crop delivered costs and GW impacts could be further reduced, if the energy crops can be utilized for both biofuel and feed applications. • Estimated cost and environmental impacts of producing energy crop on marginal land. • Crop management practices, including cover crop and double harvest, were evaluated. • Global warming (GW) impacts and cost of napier grass were lower than energy cane. • Among all, biomass production with cover crop had the lowest GW impacts and cost. • In napier grass, co-production of biomass and fodder reduced GW impacts and costs. [ABSTRACT FROM AUTHOR]