Thesis (Ph. D.)--Brigham Young University Dept. of Chemical Engineering, 2006. / Includes bibliographical references (p. 141-150).

Disposal of large quantities of surplus straw, which lie in the fields after harvest, is a major annual problem to cereal farmers. The current preferred solution of burning the straw where it lies is environmentally unsatisfactory and appears to be a huge waste of a potentially valuable, renewable energy source. None of the currently available straw packaging systems provides an economically viable alternative. A process is proposed for producing industrial quality fuel briquettes using a tractor towed implement. The economic feasibility of such a system is investigated and comparisons are made with existing straw disposal methods. The projected cost of fuel, produced in this way, is compared with prevailing fossil fuel prices. A multistage continuous process machine concept is described and the various stages are proven workable both experimentally, in the laboratory, and analytically. Laboratory experiments determine the forces required to produce acceptable quality briquettes and comparisons are made between the power available from the tractor, the economical throughput rate and the energy consumed in the compaction process. The mechanism of bonding within the straw packages, under compression, is examined so that the parameters necessary to give the optimum machine design may be understood. The effect, on briquette quality, of variations in die shape within the constraints imposed by the machine concept is fully investigated. Experiments extend to compression at speeds representative of 'live' field operation and a die shape is developed which produces packages of consistently good durability. Many of the design ideas put forward in this thesis have now been incorporated in an original prototype machine, built and successfully field-tested by the company who has supported this project and now holds the relevant patents.

The thesis examines the process of technical change in industrialized and developing country situations, and extracts lessons from this analysis for the design and implementation of forest energy development programmes. It notes how the role of technology users is of great importance in innovation" whether this process involves "high technology" development in large, competitive firms, or "appropriate technology" development to meet basic needs in poor, rural communiti~s. In reviewing the results of the past ten years of work in renewable energy programmes in developing nations, it finds that a major factor in the poor performance of such work is the lack of provision for user participation in innovation. Forest energy development programmes, which have been an important part of renewable energy development assistance, also have suffered from this insufficient attention to technology users. It is postulated that new approaches to forest energy development that provide for a more interactive relationship between R&D establishments and technology Llsers will have greater. success in bringing about innovations in this sector. The experience of charcoal production, charcoal stove, and forestry development under the Sudan Renewable Energy Project, supported by the Sudan Energy Research Council and the US Agency for International Development, demonstrates the positive results of just this sort of interactive innovation strategy. The SREP, in its ~ priori commitment to user participation, uncovers valuable resources of indigenous technical knowledge and skills, which play an integral part in the design and dissemination of these 3 forest energy technologies. The project's success provides an empirical justification of the importance of technology users to the innovation process, and its example h~s larger implications for renewable energy development, government R&D management, and development assistance policy.

This thesis presents research on the co-gasification characteristic of biomass and coal, and mathematical modelling of the co-gasification process in two main parts: i) experimental investigation and mathematical modelling of reaction kinetics of steam gasification of single char particles of pure coal, pure biomass, and blended coal and biomass; and ii) Experimental investigation and mathematical modelling of gasification characteristics of biomass, coal and their blends in pilot scale gasifiers. From the char reactivity study, the instinct difference in gasification characteristics of the two chars has been explained and reactivity of blended char can be predicted. In the pilot scale gasifier study, effects of blending ratio in feedstock and operating conditions on co-gasification of biomass and coal were investigated.

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