Method for controlling a heat-consuming hydrocarbon conversion process

A method for controlling a process carried out in an integrated production plant, wherein the integrated production plant comprises:

• (1) supply means MF for providing one or more hydrocarbon feed streams SF to a unit UC for heat-consuming hydrocarbon conversion to obtain from UC one or more product streams S and a light hydrocarbon conversion off-gas stream SO comprising CH4;
• (2) the unit UC which comprises heating means MH for providing heat to the hydrocarbon conversion, wherein said heating means MH comprise means for generating heat from one or more heat sources HS and wherein said one or more heat sources HS comprise H2;
• (3) controllable supply means ME for providing one or more plant-external sustainable heat sources HEXT-S, one or more plant-external fossil heat sources HEXT-F, and one or more plant-internal heat sources HINT, said plant-internal heat sources HINT comprising H2, for passing at least one of said heat sources HEXT-S, HEXT-F and HINT to the heating means MH;
• and
• (4) a methane pyrolysis unit UM for subjecting the light hydrocarbon conversion off-gas stream SO to methane pyrolysis to obtain a hydrogen-rich gas stream SH and a carbon stream SK;
• wherein the process comprises:
• (i) passing one or more heat sources according to (3) from ME to MH in an amount sufficient for generating heat in MH meeting the heat demand EUC of UC;
• (ii) passing at least one hydrocarbon feed stream SF into UC and subjecting the at least one feed stream SF to hydrocarbon conversion in UC, obtaining the one or more product streams S and SO;
• and
• (iii) passing SO into UM and subjecting SO to methane pyrolysis in UM, obtaining SH and SK;
• wherein the method for controlling the process comprises:
• (a) determining the heat demand EUC of the hydrocarbon conversion in UC to be provided by MH;
• (b) determining the amount EEXT-S of heat available for UC from the one or more plant-external sustainable heat sources HEXT-S;
• and
• (c.1)
• if ΔE > 0,
• (c.1.1)
• determining H2N, the amount of H2 necessary to produce ΔE in MH;
• (c.1.2)
• determining H2P, the maximum amount of H2, producible in UM to be
• contained in SH, to produce an amount EH2P of heat in MH;
• (c.1.3)
• determining ΔH = H2N − H2P;
• and
• (c.1.3.1)
• if ΔH > 0,
• controlling the supply means ME so that H2P is passed into
• MH via SH;
• wherein the process further comprises:
• (iv)
• passing the stream SH obtained from UM through
• ME, obtaining a stream S′H being y volume-% of
• SH, with y = 100;
• (v)
• passing the stream S′H obtained from ME as HINT
• into MH;
• and
• (vi)
• passing at least one of the one or more plant-
• external fossil heat sources HEXT-F via ME into MH
• in an amount sufficient to generate heat in an
• amount (ΔE − EH2P) in MH;
• (c.1.3.2)
• if ΔH ≤ 0,
• controlling the supply means ME so that an amount of H2
• is passed into MH via SH which is sufficient to produce
• ΔE in MH;
• wherein the process further comprises:
• (iv′)
• passing the stream SH obtained from UM through
• ME, obtaining a stream S′H being y volume-% of
• SH, with 0 < y ≤ 100;
• (v′)
• passing the stream S′H obtained from ME as HINT
• into MH;
• and
• (c.2)
• if ΔE ≤ 0,
• controlling the suply means ME so that no H2 is passed into MH via SH;
• wherein the process further comprises:
• (iv″)
• passing the stream SH through ME, obtaining a stream S″H being 100
• volume-% of SH;
• and
• (v″)
• removing the stream S″H from ME.
• controlling the supply means ME so that no H2 is passed into MH via SH;