A gasification system for the partial oxidation of a carbonaceous feedstock to at least provide a synthesis gas, the system comprising: a reactor chamber for receiving and partially oxidizing the carbonaceous feedstock; a quench section below the reactor chamber for holding a bath of liquid coolant; and an intermediate section connecting the reactor chamber to the quench section, the intermediate section comprising: a reactor chamber floor provided with a reactor outlet opening through which the reactor chamber communicates with the quench section to conduct the synthesis gas from the reactor chamber into the bath of the quench section; at least one layer of refractory bricks arranged on and supported by the reactor chamber floor, the refractory bricks enclosing the reactor outlet opening; and a membrane wall (60; 86, 87, 110) comprising tubes for liquid coolant, the membrane wall (60; 86, 87, 110) comprising at least a first wall section extending downwardly from the reactor outlet opening of the reactor chamber floor; the system further comprising: a pump system communicating with a source of a liquid coolant for circulating the liquid coolant through the tubes of the membrane wall (60; 86, 87, 110); and a dip tube extending from the reactor outlet opening to the bath of the quench section, an upper end of the dip tube being provided with a quench ring for providing liquid coolant to the inner surface of the dip tube, the quench ring having a lower end, the quench ring enclosing an outer surface of the first wall section of the membrane wall (60; 86, 87, 110); wherein the lower end of the quench ring is arranged at a vertical distance (72; 90) above the lower end of the membrane wall (60; 86, 87, 110). a reactor chamber for receiving and partially oxidizing the carbonaceous feedstock; a quench section below the reactor chamber for holding a bath of liquid coolant; and an intermediate section connecting the reactor chamber to the quench section, the intermediate section comprising: a reactor chamber floor provided with a reactor outlet opening through which the reactor chamber communicates with the quench section to conduct the synthesis gas from the reactor chamber into the bath of the quench section; at least one layer of refractory bricks arranged on and supported by the reactor chamber floor, the refractory bricks enclosing the reactor outlet opening; and a membrane wall (60; 86, 87, 110) comprising tubes for liquid coolant, the membrane wall (60; 86, 87, 110) comprising at least a first wall section extending downwardly from the reactor outlet opening of the reactor chamber floor; the system further comprising: a pump system communicating with a source of a liquid coolant for circulating the liquid coolant through the tubes of the membrane wall (60; 86, 87, 110); and a dip tube extending from the reactor outlet opening to the bath of the quench section, an upper end of the dip tube being provided with a quench ring for providing liquid coolant to the inner surface of the dip tube, the quench ring having a lower end, the quench ring enclosing an outer surface of the first wall section of the membrane wall (60; 86, 87, 110); wherein the lower end of the quench ring is arranged at a vertical distance (72; 90) above the lower end of the membrane wall (60; 86, 87, 110). a reactor chamber floor provided with a reactor outlet opening through which the reactor chamber communicates with the quench section to conduct the synthesis gas from the reactor chamber into the bath of the quench section; at least one layer of refractory bricks arranged on and supported by the reactor chamber floor, the refractory bricks enclosing the reactor outlet opening; and a membrane wall (60; 86, 87, 110) comprising tubes for liquid coolant, the membrane wall (60; 86, 87, 110) comprising at least a first wall section extending downwardly from the reactor outlet opening of the reactor chamber floor; the system further comprising: a pump system communicating with a source of a liquid coolant for circulating the liquid coolant through the tubes of the membrane wall (60; 86, 87, 110); and a dip tube extending from the reactor outlet opening to the bath of the quench section, an upper end of the dip tube being provided with a quench ring for providing liquid coolant to the inner surface of the dip tube, the quench ring having a lower end, the quench ring enclosing an outer surface of the first wall section of the membrane wall (60; 86, 87, 110); wherein the lower end of the quench ring is arranged at a vertical distance (72; 90) above the lower end of the membrane wall (60; 86, 87, 110). a pump system communicating with a source of a liquid coolant for circulating the liquid coolant through the tubes of the membrane wall (60; 86, 87, 110); and a dip tube extending from the reactor outlet opening to the bath of the quench section, an upper end of the dip tube being provided with a quench ring for providing liquid coolant to the inner surface of the dip tube, the quench ring having a lower end, the quench ring enclosing an outer surface of the first wall section of the membrane wall (60; 86, 87, 110); wherein the lower end of the quench ring is arranged at a vertical distance (72; 90) above the lower end of the membrane wall (60; 86, 87, 110).