Abstract: A high-purity chlorine dioxide gas may use hydrogen peroxide as a reducing agent and may use horizontal generator, evaporation crystallizer, dryer and other devices to produce chlorine dioxide gas (product) and sodium sulfate (by-product). Compared to the conventional chlorine dioxide preparation system, the chlorine dioxide reaction and the sodium sulfate crystallization are performed in two processes. These processes are relatively separate and independent, and continuously produce chlorine dioxide gas with high purity and low moisture content while the by-product salt cake is evaporated, crystallized, filtered and dried, thereby producing sodium sulfate, without generating solid and liquid waste.

Abstract: An efficient electrolysis system for sodium chlorate production may include round or oval cells, reactors, a product pump transfer, a buffer tank, a circulation pump, and explosive clad plate, all of which are connected by way of pipelines. Inlet and the outlet of each cell are separately connected with the reactor via titanium pipes, allowing the electrolyte to recirculate naturally between the cells and the reactors. The outlet of every cell is conical while each reactor includes a standard electrolytic unit with three to eight cells. The electrolytic units are modularly identical and symmetrically linked to the buffer tank. Within each unit, adjacent cells are connected with the explosive clad plates. The buffer tank may be divided into two parts—part A and part B—with part A connecting with the overflow port of the reactor via pipeline, and the part B connecting with the reactor via the circulation pump.

Abstract: An efficient electrolysis system for sodium chlorate production may include round or oval cells, reactors, a product pump transfer, a buffer tank, a circulation pump, and explosive clad plate, all of which are connected by way of pipelines. Inlet and the outlet of each cell are separately connected with the reactor via titanium pipes, allowing the electrolyte to recirculate naturally between the cells and the reactors. The outlet of every cell is conical while each reactor includes a standard electrolytic unit with three to eight cells. The electrolytic units are modularly identical and symmetrically linked to the buffer tank. Within each unit, adjacent cells are connected with the explosive clad plates. The buffer tank may be divided into two parts—part A and part B—with part A connecting with the overflow port of the reactor via pipeline, and the part B connecting with the reactor via the circulation pump.

Abstract: An efficient electrolysis system for sodium chlorate production may include round or oval cells, reactors, a product pump transfer, a buffer tank, a circulation pump, and explosive clad plate, all of which are connected by way of pipelines. Inlet and the outlet of each cell are separately connected with the reactor via titanium pipes, allowing the electrolyte to recirculate naturally between the cells and the reactors. The outlet of every cell is conical while each reactor includes a standard electrolytic unit with three to eight cells. The electrolytic units are modularly identical and symmetrically linked to the buffer tank. Within each unit, adjacent cells are connected with the explosive clad plates. The buffer tank may be divided into two parts—part A and part B—with part A connecting with the overflow port of the reactor via pipeline, and the part B connecting with the reactor via the circulation pump.

Abstract: An efficient electrolysis system for sodium chlorate production may include round or oval cells, reactors, a product pump transfer, a buffer tank, a circulation pump, and explosive clad plate, all of which are connected by way of pipelines. Inlet and the outlet of each cell are separately connected with the reactor via titanium pipes, allowing the electrolyte to recirculate naturally between the cells and the reactors. The outlet of every cell is conical while each reactor includes a standard electrolytic unit with three to eight cells. The electrolytic units are modularly identical and symmetrically linked to the buffer tank. Within each unit, adjacent cells are connected with the explosive clad plates. The buffer tank may be divided into two parts—part A and part B—with part A connecting with the overflow port of the reactor via pipeline, and the part B connecting with the reactor via the circulation pump.

Abstract: A system for the integral chlorine dioxide production with relatively independent sodium chlorate electrolytic production and chlorine dioxide production is provided. The system may feed electrolyte solution into a solid-liquid filter, filtering out the crystal and eliminating sodium chloride and sodium dichromate. The sodium chlorate crystal may be fed into a chlorine dioxide generator after dissolving, while sodium chloride and sodium dichromate solution separately return to electrolyzer for electrolysis process. Sodium chloride may be constantly formed as a by-product in the chlorine dioxide production unit, and solution containing the sodium chloride is withdrawn from the generator and, after filtration, washing and dissolution, recycled back to sodium chlorate production unit. This way, there is no need of sodium chloride make-up.

Abstract: An excess heat recovery apparatus and process for high temperature chlorine dioxide bleaching of pulp is provided. The pulp of the high temperature chlorine dioxide bleaching stage enters a tube-side of a chlorine dioxide preheater through a pipeline. The low-temperature chlorine dioxide in the storage tank enters a shell-side pipeline of the chlorine dioxide preheater. 0.5 mol/L of a stabilizer may be added during preheating to prevent ClO2 from decomposing during the heating process. Preheated chlorine dioxide is then moved into a pulp mixer and the pH is adjusted to 3.2-3.8. The mixed pulp is then moved into a high temperature chlorine dioxide bleaching tower for bleaching. The cooling pulp, now out of the preheater, is washed in an alkaline extraction stage. The waste water from the washing flows directly into an effluent treatment system and is recycled after treatment.

Abstract: The present invention discloses an Up-flow Multi-stage Anaerobic Reactor (UMAR) used for treatment of medium/high concentration organic wastewater. The stated UMAR with forced internal circulation, improved phase separator and added sludge inlet overcomes the disadvantages of a lower load, a longer hydraulic retention time and a larger dimension in traditional anaerobic reactors. The forced internal circulation increases capacity and cycles of internal circulation thus increased efficiency of contaminant removal. The fast jetting is avoided and efficiency of gas/liquid separation is increased by an improved bending outlet of up flow pipe. The simplified sludge addition and usage are obtained by a sludge inlet. The load of UMAR in this invention can reach about 30 kgCOD/(m3d) for treatment of medium/high concentration of organic wastewater from pulp and paper process and similar wastewater, being about four times of load and capacity of traditional Up-flow Anaerobic Sludge Bed (UASB) reactors.

Abstract: The present invention discloses an Up-flow Multi-stage Anaerobic Reactor (UMAR) used for treatment of medium/high concentration organic wastewater. The stated UMAR with forced internal circulation, improved phase separator and added sludge inlet overcomes the disadvantages of a lower load, a longer hydraulic retention time and a larger dimension in traditional anaerobic reactors. The forced internal circulation increases capacity and cycles of internal circulation thus increased efficiency of contaminant removal. The fast jetting is avoided and efficiency of gas/liquid separation is increased by an improved bending outlet of up flow pipe. The simplified sludge addition and usage are obtained by a sludge inlet. The load of UMAR in this invention can reach about 30 kgCOD/(m3d) for treatment of medium/high concentration of organic wastewater from pulp and paper process and similar wastewater, being about four times of load and capacity of traditional Up-flow Anaerobic Sludge Bed (UASB) reactors.