Shahabaddine Sokhansanj

Engineering aspects of collecting corn stover for bioenergy

More than 216 million t (238 million tons) of corn stover (dry basis) is produced annually in the U.S.A of which a portion could possibly be collected for conversion to ethanol and other industrial products. This paper examines published data on collecting corn stover using field machinery, including moisture content, mass fractions, and the amount of stover removed from the field. It is shown that a typical sequence of shredding, windrowing and round baling operations may result in a collection efficiency of less than 40%. Other factors such as weather, season, and leaving stover for environmental reasons may also reduce the amount of stover collected per unit area. Collection cost would depend on amount of stover collected per unit area, the number of operations, machine efficiency in each operation, and bulk density. A typical cost calculated for round baling and delivering the bales to a storage 8 km (5 miles) away from a harvested field amounted to

Analyzing Impact of Intermodal Facilities on Design and Management of Biofuel Supply Chain

21.60/dry t (

Baseline Cost for Corn Stover Collection

19.70/ dry ton).

MECHANICAL PROPERTIES OF CORN STOVER GRIND

The impact of an intermodal facility on location and transportation decisions for biofuel production plants is analyzed. Location decisions affect the management of the inbound and outbound logistics of a plant. This supply chain design and management problem is modeled as a mixed integer program. Input data for this model are location of intermodal facilities and available transportation modes, cost and cargo capacity for each transportation mode, geographical distribution of biomass feedstock and production yields, and biomass processing and inventory costs. Outputs from this model are the number, location, and capacity of biofuel production plants. For each plant, the transportation mode used, timing of shipments, shipment size, inventory size, and production schedule that minimize the delivery cost of biofuel are determined. The model proposed in this research can be used as a decision-making tool for investors in the biofuels industry since it estimates the real cost of the business. The state of Mississippi is considered as the testing grounds for the model.

Biomass Supply Logistics and Infrastructure

From consultations with three experienced farmer–custom operators, two systems were selected for the development of baseline costs for collecting corn stover residue as bales. One system consisted of a combination of shredding–windrowing operations followed by round baling. The other system consisted of separate shredding and windrowing (raking) operations followed by large rectangular baling. Round bales were collected using a pull–type round bale transporter equipped with a loading arm and stacked in storage using a telescopic loader. Rectangular bales were collected using a self–propelled stacker wagon that stacked the bales automatically. An average distance between the farm and storage of 8 km (5 miles) was assumed. The calculated cost for all operations up to and including stacking in a covered storage was

Development of the Integrated Biomass Supply Analysis and Logistics Model (IBSAL)

21.60/dry Mg (

Cost Methodology for Biomass Feedstocks: Herbaceous Crops and Agricultural Residues

19.70/ dry ton) and

Costs of harvesting, storing in a large pile, and transporting corn stover in a wet form.

23.60/dry Mg (

Hygroscopic Moisture Sorption Kinetics Modeling of Corn Stover and its Fractions

21.40/dry ton) for the round baling system and for the rectangular baling system, respectively. The cost included wages but did not include any additional payment to the farmer. The cost difference between the two systems was due to the additional raking operation and higher capital cost of equipment for rectangular baling and transport and smaller load for the rectangular bale transport.

HEAT AND MOISTURE TRANSFER AND QUALITY CHANGES IN CONTAINERIZED ALFALFA CUBES DURING TRANSPORT

Mechanical properties of corn stover grind are important because of the need for accurate input data in the mathematical modeling of densification processes and the design of densification equipment. Mechanical properties of corn stover grind such as particle size distribution, bulk and particle densities, compressibility, particle stiffness, wall friction, and adhesion on steel surfaces were determined with two hammer mill screen sizes (3.18 and 6.35 mm) used in grinding at three different moisture contents (7%, 11%, and 15% w.b.). Compression tests were conducted for each combination of hammer mill screen size and moisture content to establish pressure-density data at different applied pressures. Mechanical properties such as compressibility, initial bulk modulus, porosity index, and particle stiffness were determined from the pressure-density data. Shear tests were conducted to determine the coefficient of friction between the steel plate and corn stover grind at different moisture contents and normal pressures.