Process for producing at least one alkali metal alkoxide of formula M A OR, wherein R is a C 1 to C 6 hydrocarbon radical and wherein M A is a metal selected from sodium, potassium, wherein: a reactant stream S AE1 comprising ROH is reacted with a reactant stream S AE2 comprising M A OH in countercurrent in a reactive rectification column RR A to afford a crude product RP A comprising M A OR, water, ROH, M A OH, wherein a bottoms product stream S AP comprising ROH and M A OR is withdrawn at the lower end of RR A and a vapour stream S AB comprising water and ROH is withdrawn at the upper end of RR A, and optionally, simultaneously with and spatially separate from step, a reactant stream S BE1 comprising ROH is reacted with a reactant stream S BE2 comprising M B OH in countercurrent in a reactive rectification column RR B to afford a crude product RP B comprising M B OR, water, ROH, M B OH, wherein M B is a metal selected from sodium, potassium, wherein a bottoms product stream S BP comprising ROH and M B OR is withdrawn at the lower end of RR B and a vapour stream S BB comprising water and ROH is withdrawn at the upper end of RR B, (b) the vapour stream S AB and, when step is performed, the vapour stream S BB, in admixture with S AB or separately from S AB, is passed into a rectification column RD A and in RD A is separated into an ROH-comprising vapour stream S B2 having a pressure p B2 and a temperature T B2 at the top of RD A and a water stream Sw at the bottom of RD A, (c) at least a portion of the vapour stream S B2 is compressed to obtain a vapour stream S B3 compressed with respect to S B2 having a pressure p B3 > p B2 and a temperature T B3 > T B2, (d) energy from S B3 is transferred to at least one of RP A, S AE1, S AE2, S AP, S AB and, when step is performed, alternatively or additionally, transferred to at least one of RP B, S BE1, S BE2, S BP, S BB, to obtain a vapour stream S B4 having a lower energy content than S B3. a reactant stream S AE1 comprising ROH is reacted with a reactant stream S AE2 comprising M A OH in countercurrent in a reactive rectification column RR A to afford a crude product RP A comprising M A OR, water, ROH, M A OH, wherein a bottoms product stream S AP comprising ROH and M A OR is withdrawn at the lower end of RR A and a vapour stream S AB comprising water and ROH is withdrawn at the upper end of RR A, and optionally, simultaneously with and spatially separate from step, a reactant stream S BE1 comprising ROH is reacted with a reactant stream S BE2 comprising M B OH in countercurrent in a reactive rectification column RR B to afford a crude product RP B comprising M B OR, water, ROH, M B OH, wherein M B is a metal selected from sodium, potassium, wherein a bottoms product stream S BP comprising ROH and M B OR is withdrawn at the lower end of RR B and a vapour stream S BB comprising water and ROH is withdrawn at the upper end of RR B, (b) the vapour stream S AB and, when step is performed, the vapour stream S BB, in admixture with S AB or separately from S AB, is passed into a rectification column RD A and in RD A is separated into an ROH-comprising vapour stream S B2 having a pressure p B2 and a temperature T B2 at the top of RD A and a water stream Sw at the bottom of RD A, (c) at least a portion of the vapour stream S B2 is compressed to obtain a vapour stream S B3 compressed with respect to S B2 having a pressure p B3 > p B2 and a temperature T B3 > T B2, (d) energy from S B3 is transferred to at least one of RP A, S AE1, S AE2, S AP, S AB and, when step is performed, alternatively or additionally, transferred to at least one of RP B, S BE1, S BE2, S BP, S BB, to obtain a vapour stream S B4 having a lower energy content than S B3.