Plant biomass solid fuel

Abstract

A solid fuel is formed in a cuber to form body pieces formed of materials extruded through a die with a density greater than 35 lbs / cu ft; an energy content greater than 6500 BTU / lb; transverse dimensions less than 1.5 inches; and a length less than 4 inches; from plant biomass material which contains components when extended of greater than 1.0 inch. Primarily the materials are paper or other cellulose product and crop residue such as wheat straw. The cellulose and lignin from these materials act without additional binders as binders and encasing materials. The moisture content is maintained at a target value by mixing selected quantities of the materials without drying. The cubing machine has a feeding system where the space between the inner rotor and outer casing is smaller than 4 inches and the height of the outer flight is less than 1 inch.

Description

[0001]The invention is related generally to the field of plant biomass solid fuel.[0002]This application relates to and contains common subject matter with two co-pending applications filed on the same date by the same applicants under Attorney Docket Nos. 85776-102 and 85776-202.BACKGROUND OF THE INVENTION[0003]Enormous quantities of agricultural residues or plant biomass materials are produced as by-products of agricultural and commercial processing. Some of these products include Flax Shives which are currently being used for bedding and for heating in large stoker boilers. Other agricultural crop residues found in large quantities include; Wheat Straw, Barley Straw, Corn Stover, Kentucky Blue Grass Screenings, Switch grass and Bagasse. All of these can be collected and cubed to produce solid fuel.[0004]The other product involved in this invention is paper residues collected from recycling facilities. Due to the decrease in demand for recycled paper products, more of these produc...

AI Technical Summary

Benefits of technology

[0029]Preferably substantially all of the body pieces have a length less than 2 inches. This length and transverse dimension allows flow characteristics similar to that of coal and allows passage of the material through a 5 inch diameter auger without blockages.

[0040]More specifically the invention involves cubing biomass material in a mixture that will enhance cube durability and energy content. In particular the invention concerns the use of agricultural crop residues and paper products blended accordingly to produce a high quality solid fuel.

[0041]Described herein is a method of biomass fuel production using a modified cubing system. The invention involves cubing biomass material from a mixture that forms a briquette having enhanced cube durability and energy content. In particular the invention concerns the use of agricultural crop residues and paper products blended accordingly to produce a high quality solid fuel.

[0051]In some embodiments, wood particles can be added to the mixture, as discussed below. As will be appreciated by one of skill in the art, the smaller the wood particles are, the better their binding characteristics become. In other words, the more the wood particles are blended into the mixture that forms the briquettes, the more durable and dense the finished briquette product becomes.

[0053]The wood increases overall energy content of the final product, decreases overall ash content and helps with binding and durability of the briquettes.

Problems solved by technology

Coal is widely available but is increasing in cost and also contains many contaminants which render it less than entirely suitable as a fuel.

However such briquettes are relatively expensive and do not provide the characteristics of coal as a fuel.

Yet further the briquettes are expensive to produce since the materials from which they are produced must be dried and the briquettes tend to produce significant quantities of fines or dust when broken down.

These characteristics reduce the desirability of such briquettes as a replacement for conventional coal in residential or commercial furnaces.

Some attention has been given to the possibility for using such Cubers for compressing other materials but little or no success has been achieved to date.

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