Patent ID: 8513314

Claim:
A method of producing methanol, comprising the step of converting a methanol synthesis gas in a reactor comprising within a common shell a plurality of catalyst tubes with settled catalyst particles on tube side of the catalyst tubes in a ratio of bulk volume of the settled catalyst particles to surface of the catalyst tubes (VCAT/ACOOL) having a value L of between 0.4 and 5 in accordance with equation 2, the synthesis gas comprises hydrogen, carbon monoxide and carbon dioxide each in an amount to provide an inlet module with a value M and containing a fraction of inerts A and reacting the synthesis gas in presence of a liquid cooling agent under pressure being on shell side of the catalyst tubes, wherein the liquid cooling agent is adjusted to a boiling point temperature (TWB) resulting in a value H between 0.5 and 1.8 in accordance with equation 1 and wherein H=E *Exp(−3978/( TBW [° C.]+273)+12.3)*(1+3978* E *(220− TBW [° C.])/(( TBW [° C.]+273) 2 ))/( D*P* 9.87); Equation 1: V CAT/ A COOL[m 3 /m 2 ]=K*L *(( G*DEQ [m]*(220 −TBW )) 0.5 ); Equation 2: where: M=(Y(H 2 )—Y(CO 2 ))/(Y(CO)+Y(CO 2 )); A=1.0-Y(CO)—Y(H 2 )—Y(CO 2 )—Y(CH 3 OH)—Y (H 2 O); B=Y(CO)/Y(CO 2 ); C=1.0 if M is less than 2.0, otherwise C=Exp(−0.2*(M−2.0)); D=(0.072*Ln(B)+0.244)*C*(1.125−2.5*A)*(0.478+P/25.2); E=Exp((P−13.2)/30.1); K=0.027 (geometric constant); G=(MW−Y (CH 3 OH)*32−15.5*J)/((1−D)* 29 *J); J=(Y(CO)+Y(CO 2 )) if M is greater than 2.0, otherwise J=Y(H 2 )*(B+1)/(2*B+3); DEQ 1 =(6*(volume of a particle of the methanol synthesis catalyst [m 3 ]/3.14) 0.33 with catalyst particles of the same size and with catalyst particles of different size: DEQ 2 =(Σw(i)*DEQ(i) 3 ) 0.33 , where w(i) is the weight fraction of catalyst particles with an equivalent diameter of DEQ(i)[m]; and P [MPa] is the absolute pressure of the synthesis gas at reactor inlet; MW [kg/kmol] is the average molecular weight of the synthesis gas at reactor inlet; Y(x) [molar fraction] is the concentration of each component at reactor inlet; LN is the natural logarithm with base number 2.71828; and Exp is the natural antilogarithm or the exponential function with base number 2.71828.