Jan B. Haelssig

Bio: Jan B. Haelssig is an academic researcher from Dalhousie University. The author has contributed to research in topics: Distillation & Separation process. The author has an hindex of 6, co-authored 24 publications receiving 204 citations. Previous affiliations of Jan B. Haelssig include University of Ottawa & Halifax.

Technical and Economic Considerations for Various Recovery Schemes in Ethanol Production by Fermentation

Abstract: Six alternative ethanol recovery processes were investigated from an economic and technical perspective. The processes were evaluated by use of the commercial simulation software Aspen HYSYS 2004.2 with an integrated fermentation model. The six alternatives included two variations of the flash fermentation process as well as various distillation configurations. Certain weaknesses and potential processing improvements were highlighted, and economic and technical targets were set for future comparisons. Distillation with two columns operating at different pressures and distillation with a vapor recompression system for heat recovery were found to be the best alternatives overall. However, from an energy standpoint, the modified flash fermentation process yielded the highest efficiency.

A Comparison of Thermal Processing Strategies for Landfill Reclamation: Methods, Products, and a Promising Path Forward

Abstract: The development of optimized and efficient alternative energy systems that comply with regulatory requirements is a challenge the world needs to embrace. This study provides a systematic review of thermal processing methods to convert lignocellulosic biomass feedstocks, particularly municipal solid wastes, to biofuels. The vast majority of contemporary biorefineries employ combustion systems for energy recovery and to facilitate downstream processing. Following a detailed assessment of existing technologies to develop biorefineries, an innovative system that couples thermal, biochemical and fuel cell technologies to recover useful products and electricity is proposed. The present study targets two key objectives: (1) introducing the fundamental knowledge to understand the concept of thermal technologies for waste processing, and (2) reviewing different types of existing biorefineries and comparing the thermal processing strategies. This study also introduces the concept of the biorefinery landfill—a biorefinery located within a waste disposal site—which represents a sustainable and efficient approach to develop waste resources. This concept could help to drastically reduce the cost of conventional power plants by lowering logistical and supply chain costs related to waste transportation and lowering operating and capital costs by using existing infrastructure. Furthermore, the thermal processing of waste within a landfill aids volume reduction, which will increase the life expectancy of the site and offers the opportunity for energy recovery. The processing options and analysis presented in this study can contribute to initiatives for the development of sustainable bio-power systems and helps to lay the foundation for comprehensive analysis of waste resource use optimization.

Inductive Teaching and Learning Methods: Definitions, Comparisons, and Research Bases

Abstract: Traditional engineering instruction is deductive, beginning with theories and progressing to the applications of those theories Alternative teaching approaches are more inductive Topics are introduced by presenting specific observations, case studies or problems, and theories are taught or the students are helped to discover them only after the need to know them has been established This study reviews several of the most commonly used inductive teaching methods, including inquiry learning, problem-based learning, project-based learning, case-based teaching, discovery learning, and just-in-time teaching The paper defines each method, highlights commonalities and specific differences, and reviews research on the effectiveness of the methods While the strength of the evidence varies from one method to another, inductive methods are consistently found to be at least equal to, and in general more effective than, traditional deductive methods for achieving a broad range of learning outcomes

Bioethanol production from pentose sugars: Current status and future prospects

Abstract: The utilization of hemicellulose, the second most abundant polysaccharide, is must for the cost-efficient production of ethanol from second generation feedstocks. Xylan, the major hemicellulose in plant biomass yields mainly xylose as pentose sugars on hydrolysis. The progress in fermentation of pentose sugars has gone on slow pace as there are few microorganisms known, which are capable of pentose metabolism. The future perhaps lies in finding organisms that would ferment high density hydrolysates without purification. This obviously has to use the genetic and metabolic engineering routes. Either a direct or a sequential fermentation system needs to be worked out. This review provides an overview of the current pentose bioconversion processes and future prospects for bioethanol production.

Energy optimization of bioethanol production via gasification of switchgrass

Abstract: In this article, we address the conceptual design of the bioethanol process from switchgrass via gasification. A superstructure is postulated for optimizing energy use that embeds direct or indirect gasification, followed by steam reforming or partial oxidation. Next, the gas composition is adjusted with membrane-PSA or water gas shift. Membrane separation, absorption with ethanol-amines and PSA are considered for the removal of sour gases. Finally, two synthetic paths are considered, high alcohols catalytic process with two possible distillation sequences, and syngas fermentation with distillation, corn grits, molecular sieves and pervaporation as alternative dehydration processes. The optimization of the superstructure is formulated as an mixed-integer nonlinear programming problem using short-cut models, and solved through a special decomposition scheme that is followed by heat integration. The optimal process consists of direct gasification followed by steam reforming, removal of the excess of hydrogen and catalytic synthesis, yielding a potential operating cost of $0.41/gal. © 2011 American Institute of Chemical Engineers AIChE J, 2011