Linear programming is a technique used to determine the best (or optimal) solution to a problem where there are a number of competing and usually interrelated choices. The technique requires that each restriction on the problem being modeled be formulated as a linear equation. The model consists of a set of linear equations with more unknowns than equations and thus there are many possible solutions. In order to determine the best of these solutions, it is necessary to decide which criteria will be used to determine the best. Once the criteria (usually maximum profit or minimum cost) is chosen, an equation is set up giving the amount each variable (or activity) contributes to the criteria. The linear program then determines which solution will maximize or minimize this criteria. The LP described in this write up was written to determine the best process and set of process conditions for converting steam exploded Aspen wood into a variety of chemical feedstocks. The LP is designed to maximize profit based on the sales value of the chemicals produced, the cost of raw materials and the processing costs incurred. The model is restricted by the raw material availability, the utility and chemical requirements of each process step, the capacity of each process step and the market requirements for each chemical produced. This report will give a detailed description of the model structure, will discuss the validity of the data used in the model as well as future requirements, will discuss the running of the model on the computer and will discuss analysis of the LP solution.
Elimination of saw kerf through the compression slicing process has initiated research into the optimization of the compression slicing parameters. Five of these parameters have been selected for study in the 1979-1980 federal fiscal year, through a contract given to Forintek Canada Corp. by Environment Canada. These parameters are the following: 1) Find an alternative to tires or pads for lateral pressuriza tion, 2) Study knife profile to reduce checking damage, 3) Study knife tensioning to reduce checking damage, 4) Study methods of reducing knife friction, 5) Study the dustribution of stresses in the knife when tensioning and slicing. Following is a detailed description of the work done during the 1979-1980 federal fiscal year on each of these compression slicing parameters.
A literature review was conducted to obtain reliable, experimentally determined calorific data for the various components of Canadian tree species. Information was obtained for 48 tree species native to Canada and is presented in tabular form. For indigenous species, the overall mean calorific value was found to be 21.18 Mj/kg for softwood materials (i.e. stem wood, stem bark, foliage, etc.) compared to 19.35 Mj/kg for hardwoods. Variation between reported values for a component of a particular species was found to be generally less than 5% but, in some instances, exceeded 10%. Calorific data are also presented for hybrid poplar and for several foreign species commonly planted in Canada. It is recommended that experimental research be conducted to form a complete calorific value checklist which could be used to supplement Canadian biomass inventory data.
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Approximately 70% of all wood used goes into residential (50%) and non-residential (17%) construction. In the United States, by the turn of the century the volume of lumber used for these applications will exceed 100 billion bd.ft., of which 15 billion board feet will be 2"x8" and larger dimension lumber. This is the high priced end of the wood products spectrum. Consumption in Canada will be approximately one-tenth of this.