Abstract: Extraction processes for the recovery of sugar from sugar cane can be improved by the incorporation of a fiber depither between one or more of the extraction mills. The cane fiber from an extraction mill is fed to a fiber depither where the cane fibers are macerated to break sugar containing cells. The sugar is removed in a liquid stream and the cane fibers in a solids stream. The cane fibers are preferably fed to a subsequent extraction mill. The liquid stream is preferably flowed countercurrent to the flow of cane fiber to the first extraction mill. From the first extraction mill the liquid stream is sent to sugar recovery.

Abstract: A method of producing high quantities of ethanol and a high quality pulp to produce a variety of papers. The method comprises preparing the bamboo by chipping, shredding and washing. This bamboo fiber is then processed in two stages of prehydrolysis to separate the ethanol producing portion from the pulp producing portion. The ethanol producing portion is condensed and subject to enzymatic hydrolysis and fermentation to produce an ethanol product. The pulp producing portion is processed in two stages of digestion to produce a pulp in high yield that is suitable to produce a variety of papers.

Abstract: The present process produces a long fiber suitable for making various paper products. The long fiber is derived from Crotalaria juncea. The processing consists of a particular technique for preparing the fiber for digestion and a particular digestion sequence. In the preparation of the fiber for digestion it is dried to less than about 30 percent moisture, moist depithed, washed and wet depithed. The fiber is then processed at a high caustic concentration using a sequence of digestion-pressure reduction-digestion. Optionally there can be a third stage of digestion with a pressure reduction prior to the digestion. After digestion has been completed the fiber is refined and sent to blowdown. The fiber is then screened, washed and bleached. The resulting long fiber will product a high quality paper or is admixed with short fibers and various paper products can be made.

Abstract: Bamboo can be formed into a suitable pulp if prior to digestion it undergoes a process of shredding, washing and wet depithing. The fibers are then chemically digested preferably by a process which uses rapid pressure drops to open the fibers using the energy contained in the wet superheated fibers.

Abstract: A process for thermomechanical digestion using a multiple blowdown technique. The digestion chemical is added just prior to blowdown which results in a concentration of digesting chemicals on the fiber. The process can be carried out with a digester having multiple chambers, each at a lower pressure has many advantages in forming pulps suitable for newsprint or fine papers from wood and vegetable fiber sources. The digester should be of a kind where the fiber will have a greater residence time in subsequent chambers.

Abstract: The brightness of a thermomechanical pulp can be improved if a serial multiple blowdown technique is used and a bleachant is present at an effective concentration throughout the thermomechanical pulping process.

Abstract: The fiber depither consists of an upper array of feeder blades and a lower array of fan blades. These blades remove more particulate while resulting in less fiber damage.

Abstract: An improved fiber washer provides for a water recirculation technique which assists in moving the fibers through the washer and assists in the separation of heavy debris from the fibers.

Abstract: A high quality newsprint pulp can be produced from wood or vegetable fibers by thermomechanically pulping one portion of these fibers and thermochemically pulping the remaining portion. After combining these pulps the result is a pulp which has a GE brightness of 55 to 60, an opacity of 93 to 96 percent, and a relatively high tear strength. A pulp useful for making low strength papers can be produced by solely thermomechanically pulping fiber and directly using this pulp to make such products.

Abstract: The debris and pith removal from bagasse fiber is significantly enhanced by the flow of fiber from one depithing zone into a fiber washing zone and then to a second depithing zone without any intermediate settling of piling of the fiber. The fiber is maintained in a separated condition throughout the first depithing zone, the washer and the subsequent depithing zone. The result is a bagasse fiber having a greater quantity of the debris and pith removed with much less fiber damage.

Abstract: The pith removal from bagasse fiber is significantly enhanced by the flow of fiber directly from one depithing zone to a second depithing zone without any intermediate settling or pilings of the fiber. The fiber is maintained in a separated condition during the flow from one depithing zone to another depithing zone. The result is a bagasse fiber having a greater quantity of the pith removed with less fiber damage. It is also advantageous to provide a number of conveyors to transport fibrous material to a dual zone depithers and for the removal of depithed fiber and pitch from these depithers. This reduces fiber handling before, during and after depithing.

Abstract: A dissolving pulp suitable for preparing rayon having a degree of polymerization of greater than about 800 can be produced using bagasse by a sodium hydroxide-sodium sulfite digestion at a ph of about 10.5 to 11.5 and preferably about 10.8 to 11.2 and a caustic-sulfite weight ratio of 1:1 to 1:3 followed by a bleaching sequence of DcEDH or DcEDD. This results in a high purity low silica content fiber which has undergone very little degradation.

Abstract: Method for cleaning fibrous vegetable materials to remove trash components (such as coarse sand, stones, rocks, metallic particles, shives, dirt and the like).