TECHNOLOGY FOCUS - CHEMICAL ENGINEERING - Preferred Method: The removing step includes removing the portion of the precipitate from the portion of the chemical hydride solution with a filter; removing the portion of the precipitate from the portion of the chemical hydride solution with a centrifuge; and removing 50-100 (preferably 80)% of the precipitate. The method further comprises:(a) providing the filter as a cross-flow membrane filter;(b) providing a gravity settling tank upstream of the filter, to assist with the removal of the portion of the precipitate;(c) cooling the portion of the chemical hydride solution in a heat exchanger to an intermediate temperature, lower than the first temperature, but higher than the second temperature;(d) further cooling the portion of the chemical hydride solution to the second temperature in a radiator downstream of the heat exchanger;(e) delivering the portion of the chemical hydride solution back through the heat exchanger to heat the portion of the chemical hydride solution to the third temperature;(f) cooling the portion of the chemical hydride solution to the second temperature in the radiator; and(g) heating the portion of the chemical hydride solution to the third temperature in a heater.Preferred Temperatures: The first temperature is 30-60 (preferably 50) degrees C. The second temperature is 15-45 (preferably 20) degrees C. The third and intermediate temperatures are 25-55 (preferably 35) degrees C, respectively.Preferred Apparatus: A part of the cooling element and a part of the heater are provided by the heat exchanger (154). The heat exchanger has one side located in the circuit downstream of the reactor, to transfer heat from the chemical hydride solution leaving the reactor to the chemical hydride solution flowing toward the reactor. The cooling element includes the radiator (142) and a cooling fan (144). The heat exchanger is adapted to cool the chemical hydride solution to the intermediate temperature between the first and second temperatures. It comprises a plate and frame heat exchanger. The radiator and the cooling fan are adapted to cool the chemical hydride solution to the second temperature. The system further comprises an upstream temperature sensor located upstream of the radiator; a downstream temperature sensor located downstream of the radiator; a control unit (146) for controlling the cooling fan; and a mass flow controller located upstream of the heat exchanger and electrically connected to the control unit. The upstream and downstream temperature sensors are adapted to measure the temperature of the chemical hydride solution and communicate the temperature to the control unit. The upstream sensor is located between the heat exchanger and the radiator. The downstream sensor is located between the radiator and the separator. The mass flow controller is adapted to control the flow rate of the chemical hydride solution into the heat exchanger. The reactor comprises a gas-liquid separator. The separator comprises a gravity settling vessel, and a filter located downstream of the gravity separator vessel. The filter is a crossflow filter, a plate and frame filter, a leaf filter or a belt filter. The cooling element is one or more of a refrigeration unit, a heat pump and a Peltier junction.