ON-FARM EVALUATION OF THERMOCHEMICAL CONVERSION OF KENTUCKY BLUEGRASS STRAW TO ENERGY
Forage Seed and Cereal Research
2013 Annual Report
1a.Objectives (from AD-416):
The objective of this cooperative research project is to develop an integrated system for on-farm energy production from straw residues generated during grass seed production including the test of a farm-scale gasification reactor suitable for burning grass seed straw to produce high quality syngas that can be used to generate electricity and other value-added bio-based products to increase on-farm income. Using the seed production cropping system and a test gasification reactor platform, we will determine the most economic technical paths to overcome agronomic, microbiological, and physical chemical limitations to on-farm production of energy and other bio-based products.
1b.Approach (from AD-416):
An integrated system for harvest, collection, storage and transport of the straw to a farm-scale gasification reactor will be evaluated for concept and related technologies of on-farm energy production from Kentucky bluegrass straw. The goal will be to develop an economical and integrated system that will result in the conversion of straw into a high quality syngas with a quality ratio around 12 (H2 + CO)/(CO2 + H2O) and net thermal-to-chemical energy efficiency in the 65-70% range. Documents NFCA with Farm Power.
The goal of this cooperative agreement was to develop an integrated system for on-farm energy production from agricultural residues generated during grass seed production and evaluate the economic and environmental feasibility of utilizing this system to produce bioenergy at the farm-scale. This research directly contributed to Objective 2, Sub-objective 2.2 of the in-house project, "Conduct an on-farm pilot trial to evaluate the feasibility of commercializing local-scale thermochemical conversion of straw into bioenergy within an annual farming operation cycle". We successfully gasified seed screenings resulting from the seed cleaning process and used syngas from the gasification to produce approximately 35 kW of electricity at a feed rate of 180 pounds of screenings per hour. Although electricity generation provides added value to the farm, by itself it does not justify the expense of a gasification system. We investigated the potential use of the carbon-rich biochar produced during gasification as a soil amendment. Application of the gasification biochar to field plots in acidic soils was compared to application of lime and to untreated control plots. Biochar-treated field plots were harvested, but preliminary observations showed that wheat biomass production and soil water retention were significantly increased by the addition of the biochar to the soil. Knowledge of the agronomic value of biochar will enable an estimate of the market value, a key component in the evaluation of the economic feasibility of the on-farm bioenergy system.