Notes

2.1. Today’s cellulose production technologies require extremely expensive instrument
Cellulose is produced via sulfite or sulfate processes. All of them are based on treatment of the woody biomaterials at high temperature (160-180 oC) and high pressure (up to 10 bars) in the special reactors resistant to the harsh conditions of the process.
2.2. Today’s cellulose production technologies cannot process small particles
The present technologies process wood chips in 3-5cm size. The present technologies require closed reactors having limited space in it. Therefore, processing of bulky materials such as sawdusts is unfeasible. However, grinding of the woods to make wood chips also releases tiny particles. These tiny woods are mixed by 20% percent at most with wood chips and processed. Therefore, the present technologies cannot process most of the sawdusts. These sawdusts are burned to make energy (electricity). Therefore, their cellulose content cannot be evaluated.
2.3. Today’s cellulose production technologies require experienced staffs to build factory
Construction of the kraft reactors cannot be performed and operated by any mechanical engineering companies. The complexity of the process requires staffs who worked for construction of the kraft reactors before. In other words, the factories of the present technology can only be constructed and managed by staffs experienced about construction and management of the kraft factories.
2.4. Today’s cellulose production technologies are dangerous
High temperature and high pressure brings safety concerns about the staffs in the pulp factories. Therefore, safety precaution is very important at the pulp factories.
2.5. Today’s cellulose production technologies use foul smelling chemicals
Since the present technologies use high pressure, high temperature and closed reactors, the cooking step must be as short as possible in order to increase the number of cycles using limited and very expensive reactors. In order to shorten the reaction time, foul smelling chemicals are used to catalyze the reaction such as Na2S smelling like rotten eggs.
2.6. Today’s cellulose production technologies use many steps (cooking, many bleaching steps)
Firstly, cellulose resources (mostly woods) are treated at high pressure rectors (cooking). The remaining product is dark. Therefore, the product is whitened (bleaching). However, bleaching is performed at many steps, generally 5 steps. Each step requires separate systems, so additional staffs and additional investments are required.
2.7. Today’s cellulose production technologies are dirty
The present technologies must produce cellulose as short time as possible to be feasible. Therefore, they cannot use cleaner chemicals which produce cellulose at longer times. Thus, in addition to foul smell, the chemicals of the present technologies are very concentrated and release environmentally dangerous wastes which dirty especially water resources. The high concentration of NaOH and Na2S harm environment.
The damage to environment is the very serious problem which sometimes causes international crisis between countries. For example, the biggest pulp mill of the world is found at Uruguay and placed in Uruguay river, which is the border between Uruguay and Argentina. There are many lawsuits between the 2 countries because of the wastes of the pulp mill. (http://www.icj-cij.org/docket/index.php?p1=3&p2=3&case=135&p3=4)
2.8. Control of the today’s cellulose production technologies is very difficult
The core of the present technology is cooking step which is performed at high temperature, high pressure in 2-3 hours. Since the process are performed under high pressure and must end in 2-3 hours, all the chemicals and wood sources are loaded into the reactor at the beginning of the process. Also, it is extremely difficult to change parameters while the cooking process continues.
2.9. Today’s cellulose production technologies consumes chemical and energy resources
The core of the present technology is cooking step which is performed at high temperature, high pressure in 2-3 hours. Since the process are performed under high pressure and must end in 2-3 hours, all the chemicals and wood sources are loaded into the reactor at the beginning of the process. Since all the resources are not homogenous, the exact amount of the required chemical, pressure and operation time special to the biomaterial to be processed are not determined. Therefore, excess of chemicals, temperature, pressure and operation time are used.
2.10. Today’s cellulose production technologies process single type of resources at once
Each type of raw materials require different amount of chemical, process time, temperature and pressure. The limited area of the reactors does not allow classification of many types of raw materials without mixing with each other. Therefore, the raw materials must be single type (such as only beach or only fir woods) per charge in order to produce single type of quality.
2.11. Harsh conditions of today’s cellulose production technologies probably decrease product quality
We have not measured the product quality of the present technologies, but the harsh conditions (high temperature, high pressure, concentrated chemicals) probably breaks cellulose fibers decreasing the product quality.