Process for utilizing at least one waste stream from oxo synthesis plants

Abstract

The present invention concerns a process for utilizing waste streams from an oxo synthesis plant by gasification and an oxo process plant comprising the necessary units for oxo synthesis and at least one gasifier G. The process comprises a conversion of a waste stream W1 purged from the alcohol upgrading unit ALUU and optionally also of a waste stream W2 purged from a hydroformylation reaction unit HRU. The conversion by a gasification process in at least one gasifier G results in synthesis gas which can then be utilized e.g., for as a feedstock for an oxo process or production of other chemicals in another chemical production plant.

Description

[0001] Process for utilizing at least one waste stream from oxo synthesis plants

[0002] Technical area

[0003] The present invention relates to a process utilizing production waste streams from oxo synthesis processes comprising hydroformylation of olefins and / or hydrogenation of aldehydes made by hydroformylation of olefins, an oxo process plant comprising an integrated production waste streams treatment facility and the use of said plant for said process.

[0004] Background of the invention

[0005] Aliphatic C3-C5 aldehydes, C3-C5 alcohols, enals derived from aliphatic C3-C5 aldehydes, and aliphatic C9-C13 alcohols are important intermediate products in the chemical industry from which for example organic acids and esters of organic acids are manufactured. Such acids and esters can then be used as building blocks and / or precursors in the manufacture of solvents, plasticizers, lubricants, and surfactants.

[0006] The usual starting materials for the manufacture of aliphatic C3-C5 aldehydes, aliphatic C3-C5 alcohols, enals derived from aliphatic C3-C5 aldehydes, and aliphatic C9-C13 alcohols are C2-C4 olefins or oligomers thereof and synthesis gas (preferably oxo-synthesis gas, a mixture comprising CO and H2 in a molar ratio CO : H2 of about 1 : 1) which are mostly manufactured from fossil sources such as processed crude oil and natural gas.

[0007] Aliphatic 03-05 aldehydes, aliphatic 03-05 alcohols, and enals derived from aliphatic 03-05 aldehydes are then manufactured from 02-04 olefins and synthesis gas by a hydroformylation reaction, which is also known as oxo- synthesis, in an oxo synthesis plant.

[0008] Aliphatic 09-013 alcohols are manufactured from oligomers of 02-04 olefins, such as 08 olefins and 012 olefins, and synthesis gas by a hydroformylation reaction in an oxo synthesis plant. The aldehydes obtained as primary reaction product of the hydroformylation reaction from such oligomers of 02-04 olefins and synthesis gas usually further react to the corresponding aliphatic 09-013 alcohols. Hence, aliphatic 09-013 aldehydes are usually not isolated.

[0009] Both processes are known as "oxo processes” because the same starting materials and similar reaction mechanisms are used to introduce an aldehyde or alcohol functional group into an 02-04 olefins or an oligomer thereof.

[0010] Said industrial scale oxo processes also form at least one waste stream which needs to be disposed. A standard method for treatment of the production waste streams from oxo processes comprising hydroformylation of olefins and / or hydrogenation of aldehydes made by hydroformylation of olefins is incineration of said waste streams for example in a boiler in which steam can be produced. Thereby, undesired CO2 is formed which, in addition contributes to the product carbon footprint (PCF) of the respective aliphatic C3-C5 aldehydes, C3-C5 alcohols, enals derived from aliphatic C3-C5 aldehydes, and aliphatic C9-C13 alcohols. WO 2021 / 180482 A1 discloses a process for producing synthesis gas by gasification from a carbon-containing material in which at least a portion of the CO2 produced is recycled back into the gasifier.

[0011] WO 2022 / 261158 A1 discloses a process for producing an oxo product or derivative thereof having a recycled content. The process comprises the steps a) preparing a syngas, b) hydroformylating a 02 to 024 olefin with said syngas to form a first oxo product and c) converting said first oxo product in at least one additional reaction with an additional reactant into a second oxo product.

[0012] US 2015 / 080626 A1 discloses a method in which a) biomass is contacted with hydrogen in the presence of a catalyst to form a bottom and an overhead fraction, b) separating said fractions, c) partially oxidize said bottom fraction to form syngas, d) subject said syngas to a water gas shift reaction and thereby produce a mixture of H2 and CO2, and e) providing hydrogen produced in step d) for use in step b). The second product produced in step d), CO2, is not further utilized.

[0013] It is an objective of the present invention to utilize the production waste streams from such oxo processes described above in a more environmentally friendly way than incineration whereby undesired CO2 is formed.

[0014] It is a further objective of the present invention to provide a process and a production plant which convert at least a portion of the production waste stream(s) from oxo processes into feedstocks for the chemical industry.

[0015] It is a further objective to utilize the waste stream(s) from oxo processes for the manufacture of aldehydes and subsequently in the manufacture of alcohols from said aldehydes.

[0016] It is a further objective of the present invention to reduce the product carbon footprint (PCF) of aliphatic C3-C5 aldehydes, C3-C5 alcohols, enals derived from aliphatic C3-C5 aldehydes, and aliphatic C9-C13 alcohols manufactured by oxo processes.

[0017] Summary of the invention

[0018] These problems are solved by a process for utilizing at least one waste stream from an oxo synthesis plant, wherein the oxo synthesis plant comprises a) an hydroformylation reaction unit HRU, b) optionally an aldehyde upgrading unit AUU, c) an aldehyde hydrogenation unit AHU and d) an alcohol upgrading unit ALUU, the process comprising the steps

[0019] (i) providing a first waste stream W1, wherein the first waste stream W1 is separated from the alcohol upgrading unit ALUU, (ii) optionally providing a second waste stream W2, wherein the optional second waste stream W2 is separated from the optional aldehyde upgrading unit AUU,

[0020] (iii) optionally pretreating the first waste stream W1 and / or the optional second waste stream W2,

[0021] (iv) subjecting the first waste stream W1 and optionally the said second waste stream W2 to a gasification process wherein said gasification process comprises at least one gasifier G and whereby a gas stream GS1, said gas stream GS1 comprising CO and H2, is formed by said gasification process from said first waste stream W1 and optionally said optional second waste stream W2.

[0022] These problems are further solved by an oxo process plant comprising an integrated waste stream treatment facility wherein said oxo process plant comprises

[0023] (i) an hydroformylation reaction unit HRU,

[0024] (ii) optionally an aldehyde upgrading unit AUU downstream of and fluidically connected to the hydroformylation reaction unit HRU,

[0025] (iii) an aldehyde hydrogenation unit AHU downstream of and fluidically connected to the hydroformylation reaction unit HRU or downstream of and fluidically connected to the optional aldehyde upgrading unit AUU,

[0026] (iv) an alcohol upgrading unit ALUU, downstream of and fluidically connected to the aldehyde hydrogenation unit AHU,

[0027] (v) at least one gasifier G, downstream of the alcohol upgrading unit ALUU and optionally downstream of the optional aldehyde upgrading unit AUU and wherein the at least one gasifier G is directly or indirectly fluidically connected to the waste stream W1 of the alcohol upgrading unit ALUU and to the optional waste stream W2 of the optional aldehyde upgrading unit AUU.

[0028] The process and plant according to the present invention enable the production of aliphatic C3-C5 aldehydes, aliphatic C3-C5 alcohols, enals derived from aliphatic C3-C5 aldehydes, and aliphatic C9-C13 alcohols by an oxo process with reduced CO2 emissions compared to state-of-the-art oxo synthesis processes in which the waste stream(s) of said process is / are incinerated.

[0029] Furthermore, the product carbon footprint (PCF) of aliphatic C3-C5 aldehydes, aliphatic C3-C5 alcohols, enals derived from aliphatic C3-C5 aldehydes, and aliphatic C9-C13 alcohols manufactured by the process and / or the plant according to the present invention is reduced because the CO2 emissions during treatment of the waste stream W1 and the optional waste stream W2 are reduced.

[0030] Moreover, at least a portion of the gas stream GS2 (formed by purification from gas stream GS1) can be fed into a hydroformylation reaction unit HRU. The waste stream W1 and the optional waste stream W2 are used to provide further synthesis gas for the manufacture of aliphatic C3-C5 aldehydes, aliphatic C3-C5 alcohols, enals derived from aliphatic C3-C5 aldehydes, and aliphatic C9-C13 alcohols, by an oxo synthesis process. Thereby, the product carbon footprint (PCF) of said products is reduced is even more reduced. In addition, the process according to the present invention can be worked in one site, e.g., the gasifier G is at the same site as the oxo synthesis plant or the process can be worked in at least two different sites, e.g., the oxo synthesis plant is located at a first site and the gasifier G is located at a second site which is different from the first site. An optional pretreatment unit for the waste stream W1 and the optional waste stream W2 can located at the same site as the oxo synthesis plant and the gasifier G or at the same site where the gasifier G is located in case the gasifier is located at a different site than the oxo synthesis plant or at a third site which is different from the site where the oxo synthesis plant is located and where the gasifier G is located.

[0031] Figures

[0032] Figure 1 shows the process for utilizing at least the waste stream W1 from an oxo synthesis plant and the oxo process plant according to the present invention which is preferably used for the manufacture of C3-C5 alcohols. Dotted lines represent optional streams and process units.

[0033] Figure 2 shows the process for utilizing at least the waste stream W1 from an oxo synthesis plant and the oxo process plant according to the present invention which is preferably used for the manufacture of C3-C5 alcohols, further comprising a pre-gasifier PG for pretreating the at least one further feedstock F1 to form a converted further feedstock CF. Dotted lines represent optional streams and process units.

[0034] Figure 3 shows the process for utilizing at least the waste stream W1 from an oxo synthesis plant and the oxo process plant according to the present invention which is preferably used for the manufacture of C9-C13 alcohols. Dotted lines represent optional streams and process units.

[0035] Figure 4 shows the process for utilizing at least the waste stream W1 from an oxo synthesis plant and the oxo process plant according to the present invention which is preferably used for the manufacture of C9-C13 alcohols, further comprising a pre-gasifier PG for pretreating the at least one further feedstock F1 to form a converted further feedstock CF. Dotted lines represent optional streams and process units.

[0036] Figure 5 shows the process for utilizing at least the waste stream W1 from an oxo synthesis plant and the oxo process plant according to the present invention, which is preferably used for the manufacture of aliphatic C3-C5 alcohols from enals derived from aliphatic C3-C5 aldehydes as intermediate. Dotted lines represent optional streams and process units.

[0037] Figure 6 shows the process for utilizing at least the waste stream W1 from an oxo synthesis plant and the oxo process plant according to the present invention, which is preferably used for the manufacture of aliphatic C3-C5 alcohols from enals derived from aliphatic C3-C5 aldehydes as intermediate , further comprising a pre-gasifier PG for pretreating the at least one further feedstock F1 to form a converted further feedstock CF. Dotted lines represent optional streams and process units.

[0038] Detailed description of the invention

[0039] The present invention is further described below with reference to the embodiments, but the present invention is not limited to these embodiments, and any modifications of these embodiments, combinations of these embodiments or substitutions within the basic spirit of the present invention are still within the scope of the present invention as claimed.

[0040] Definitions:

[0041] In the context of the present description and the accompanying claims, the term "about” preferably means a deviation of the thus described value of ±10 %. In the context of the present invention, the term “combinations thereof' is inclusive of one or more of the recited elements. In the context of the present invention, the term “mixture thereof” is inclusive of one or more of the recited elements.

[0042] “Refuse-derived fuel” (RDF) is defined herein as a fuel produced form various types of waste such as municipal solid waste (MSW), industrial waste or commercial waste. RDF consists largely of combustible components of such waste, as non-recyclable plastics (not including PVC), paper cardboard, labels, and other corrugated materials. These fractions are separated by different processing steps, such as screening, air classification, ballistic separation, separation of ferrous and non-ferrous materials, glass, stones, and other foreign materials and shredding into a uniform grain size, or also pelletized to produce a homogeneous material which can be used as a feedstock for gasification processes (Y. Yang et al., Gasification of refuse-derived fuel from municipal solid waste for energy production: a review, Environmental Chemistry Letters (2021) 19, 2127-2140 (https: / / doi.org / 10.1007 / s10311-020- 01177-5).

[0043] "Coal” is a combustible organic sedimentary rock that is formed from the accumulation and preservation of plant materials, usually in a swamp environment and defined herein as a fossil feedstock for gasification.

[0044] The term "downstream of” is defined herein in respect to a succession of unit operations as located next to on the side which is in the flow direction of fluids passing said succession of unit operations.

[0045] The term "fluidically connected to” in respect to two or more units is defined herein that a fluid such as a particulate solid, liquids, gases, and mixtures thereof can flow from one of such unit to the other such unit and flow through and / or along such an analytical unit. Two units "fluidically connected to” each other are for example connected by one or more pipes which each other, by pumps, by compressors or combinations thereof or by means such as a truck, a train or a pipeline transporting the waste stream W1 and the optional waste stream W2 from the "oxo synthesis plant” to the gasifier G and / or an optional unit in which waste stream W1 and optional waste stream W2 is / are pretreated before fed into said gasifier G.

[0046] An “oxo synthesis plant’ comprises an hydroformylation reaction unit HRU, optionally an aldehyde upgrading unit AUU, an aldehyde hydrogenation unit AHU, an alcohol upgrading unit ALUU, and no gasifier G.

[0047] An "oxo process plant” comprises the same units as an "oxo synthesis plant” and in addition at least one gasifier G. The term "aldehydes” in the sense of the present invention comprises aliphatic aldehydes and enals derived from aliphatic C3-C5 aldehydes (preferably 2-enals derived from aliphatic C3-C5 aldehydes).

[0048] The process for utilizing waste streams from an oxo synthesis plant and the oxo process plant according to the present invention is schematically shown in Figures 1 to 6 and is described below in detail.

[0049] Oxo synthesis processes, preferably oxo processes for manufacturing aliphatic C3-C5 aldehydes, aliphatic C3-C5 alcohols, enals derived from aliphatic C3-C5 aldehydes, and aliphatic C9-C13 alcohols from C2-C4 olefins and synthesis gas, preferably oxo-synthesis gas comprise the steps a) providing a C2-C4 olefin or an oligomer thereof, b) providing a mixture of CO and H2, preferably having a molar ratio CO : H2 of about 1 : 1, c) contacting the C2-C4 olefin or oligomer thereof provided in step a) and the mixture of CO and H2 provided in step b), preferably in the presence of at least one catalyst, and thereby forming an aliphatic C3-C5 aldehyde or an aliphatic C9-C13 alcohol. Said aliphatic C3-C5 aldehyde is then further converted into a C3-C5 aldehyde or a derived from aliphatic C3-C5 aldehydes (preferably a 2-enal), which is then converted into the respective C3-C5 aliphatic alcohol.

[0050] Several oxo synthesis processes for producing alcohols from olefins are known und commercially used. In general, such processes utilize an oxo synthesis plant comprising an hydroformylation reaction unit HRU, optionally an aldehyde upgrading unit AUU downstream of and fluidically connected to the hydroformylation reaction unit HRU, an aldehyde hydrogenation unit AHU downstream of and fluidically connected to the hydroformylation reaction unit HRU or downstream of and fluidically connected to the optional aldehyde upgrading unit AUU, and an alcohol upgrading unit ALUU, downstream of and fluidically connected to the aldehyde hydrogenation unit AHU.

[0051] The process and the oxo process plant according to the present invention, preferably used for manufacturing aliphatic C3-C5 alcohols from C2-C4 olefins A and synthesis gas SG, is shown in Figures 1 and 2. The oxo process plant in this aspect of the present invention comprises a hydroformylation reaction unit HRU in which the C2-C4 olefins A and the synthesis gas SG are combined by a hydroformylation reaction to form an aldehyde AY. The aldehyde AY is then hydrogenated in the presence of hydrogen H in an aldehyde hydrogenation unit AHU to convert the aldehyde AY into a raw alcohol RAL. Next, the raw alcohol RAL is the purified in the alcohol upgrading unit ALUU to form the clean alcohol CAL. The waste stream W1 is formed in the alcohol upgrading unit ALUU and is purged therefrom. The oxo process plant further comprises at least one gasifier G in which the waste stream W1 and the optional waste stream W2 is / are converted into synthesis gas GS1 . The respective oxo synthesis process of this aspect of the present invention is for example described in detail in EP 0846095 A1 and EP 1255720 A2. The oxo process plant shown in Figure 2 further comprises a pre-gasifier PG in which at least one optional further feedstock F is converted into a converted further feedstock CF before fed into the at least one gasifier G together with waste stream W1 and optional waste stream W2 (or mixed waste stream W12 in case W1 and W2 were mixed in optional step (iii)). The process and the oxo process plant preferably used for manufacturing C9-C13 alcohols from oligomers of C2-C4 olefins OA and synthesis gas SG is shown in Figures 3 and 4. The oxo process plant in this aspect of the present invention comprises a hydroformylation reaction unit HRU in which the oligomers of C2-C4 olefins OA and the synthesis gas SG are combined by a hydroformylation reaction to form a raw aldehyde RAY. The raw aldehyde RAY is then purified in an aldehyde upgrading unit AUU in which the raw aldehyde RAY is purified and a clean aldehyde CAY and a waste stream W2 are formed which waste stream W2 is purged from said aldehyde upgrading unit AUU. The clean aldehyde CAY is then hydrogenated in the presence of hydrogen H in an aldehyde hydrogenation unit AHU to convert the raw aldehyde CAY into a raw alcohol RAL. Next, the raw alcohol RAL is the purified in the alcohol upgrading unit ALUU to form the clean alcohol CAL. The waste stream W1 is formed in the alcohol upgrading unit ALUU and is purged therefrom. The respective oxo synthesis process of this aspect of the present invention is for example described in detail in WO 2021 / 160448 A1 and WO 01 / 36356 A2. The oxo process plant shown in Figure 4 further comprises a pre-gasifier PG in which at least one optional further feedstock F1 is converted into a converted further feedstock OF before fed into the at least one gasifier G together with waste stream W1 and optional waste stream W2 (or mixed waste stream W12 in case W1 and W2 were mixed in optional step (iii)).

[0052] The process and the oxo process plant for manufacturing alcohols from C2-C4 olefins 0 or an oligomer thereof OA and synthesis gas SG is shown in Figures 5 and 6. The oxo process plant in this aspect of the present invention comprises a hydroformylation reaction unit HRU in which the C2-C4 olefin A or an oligomer thereof OA and the synthesis gas SG are combined by a hydroformylation reaction to form a raw aldehyde RAY. The raw aldehyde RAY is then purified in an aldehyde upgrading unit AUU and a clean aldehyde CAY and a waste stream W2 are formed which waste stream W2 is purged from said aldehyde upgrading unit AUU. The clean aldehyde CAY is then converted into an enal EN derived from aliphatic C3-C5 aldehydes, preferably a 2-enal, in an enalization unit EU. Next, said enal EN is converted in the presence of hydrogen H in the aldehyde hydrogenation unit AHU into the respective aliphatic C3-C5 alcohol Next, the raw respective aliphatic C3-C5 alcohol RAL is the purified in the alcohol upgrading unit ALUU to form the clean aliphatic C3-C5 alcohol. The waste stream W1 is formed in the alcohol upgrading unit ALUU and is purged therefrom. The respective oxo synthesis process of this aspect of the present invention is for example described in detail in EP 2925714 A1. The oxo process plant shown in Figure 6 further comprises a pre-gasifier PG in which at least one optional further feedstock F1 is converted into a converted further feedstock CF before fed into the at least one gasifier G together with waste stream W1 and optional waste stream W2 (or mixed waste stream W12 in case W1 and W2 were mixed in optional step (iii)).

[0053] In the process according to the present invention, a C2-C4 olefin A or an oligomer thereof OA is provided. The C2-C4 olefin A is selected from the group consisting of ethylene, propylene, 1 -butene, and 2-butene. Such C2-C4 olefins A can be for example manufactured by steam cracking of fossil feedstocks such as naphtha and / or pyrolysis oils made by pyrolysis from plastic waste. The steam cracking process is preferably conducted in a steam cracking unit. Steam cracking processes and steam cracking units are for example described in H. Zimmermann, R. Walzl, Ullmann's Encyclopedia of Industrial Chemistry, chapter "Ethylene”, Vol. 13, 2013, pages 469 to 515. Said oligomers OA can be manufactured by dimerization or trimerization of said C2-C4 olefins. Oligomers of the C2-C4 olefin comprise 08 to 012 olefins. Such oligomers of 02-04 olefins are preferably selected from the group consisting of di-n-butene, tri-n-butene, 2,4,4-trimethyl-1-pentene, 2,4,4-trimethyl-2-pentene and dodec-1-ene. Di-n- butene and tri-n-butene are 08 alkene and 012 alkene isomers, respectively, which comprise branched 08 isomers and, respectively, 012 isomers. The manufacture of oligomers of 02-04 olefins OA, particularly of condensation of 04 olefins to 08 olefins in the presence of a solid acid catalyst is disclosed for example in US 2014 / 0128652 A1. Solid acid catalysts include silica-alumina, silica-magnesia, silica-boria, alumina-boria, chlorinated alumina, fluorinated alumna, synthetic zeolites and the like. Another method for manufacture of oligomers of 02-04 olefins OA, particularly of condensation of 04 olefins to 08 olefins using a nickel oxide catalyst is disclosed in EP 1171413 B1 . The manufacture of oligomers of 02-04 olefins, particularly condensation of 04 olefins to 012 olefins is disclosed for example in WO 01 / 36356 A2. 04 olefins are contacted with a heterogeneous catalyst comprising a metal such as nickel at an elevated temperature and thereby, a 012 olefin is formed.

[0054] The synthesis gas SG comprises, preferably consists of CO and H2, more preferably of CO and H2 in a molar ratio of 30 : 70 to 50 : 50, most preferably of CO and H2 in a molar ratio of 35 : 65 to 45 : 55. Synthesis gas having a molar ratio CO : H2 of about 1 : 1 is also known as "oxo-synthesis gas” or "oxo-gas”. Synthesis gas can be for example manufactured from fossil feedstocks such as heavy fractions of crude oil processing by partial oxidation or steam reforming of natural gas. Preferably, at least a portion of the synthesis gas is manufactured from non-fossil feedstock such as biomass and / or municipal solid waste by partial oxidation in at least one gasifier. Such partial oxidation processes for manufacture of synthesis gas are known in the art and are for example disclosed in Ullmann's Encyclopedia of Industrial Chemistry, Vol. 16, Chapter: Gas Production, 2. Processes, pages 443-455, 2012. Such partial oxidation processes for manufacture of synthesis gas preferably produce synthesis gas having a molar ratio CO : H2 of about 1 : 1.

[0055] In the hydroformylation reaction unit HRU, a 02-04 olefin is contacted with synthesis gas whereby an aliphatic 03-05 aldehyde is formed, or a condensation product of a 02-04 olefin is contacted with synthesis gas whereby an aliphatic 09-013 alcohol is formed.

[0056] The aliphatic 03-05 aldehyde is preferably selected from the group consisting of propanal, 1 -butanal, 2- methylpropanal, 1-pentanal, and 2-methylbutanal. Accordingly, propanal is formed by an oxo-synthesis from ethene, CO and H2; n-butanal and i-butanal or formed by an oxo-synthesis from propene, CO and H2; n-pentanal and 2- methylbutyral are formed by an oxo-synthesis from 1 -butene and / or 2-butene, CO and H2; 3-methylpenanal is formed by an oxo-synthesis from isobutene, CO and H2.

[0057] Hydroformylation also known as oxo process is an important large-scale industrial process for preparing aldehydes from olefins and synthesis gas (CO and H2). These aldehydes are then hydrogenated without separating said aldehydes in the presence of hydrogen in an aldehyde hydrogenation unit AHU (Figures 1 and 2) or firstly separated as raw aldehyde RAY and then purified in an aldehyde upgrading unit AUU to form a cleaned aldehyde CAY which cleaned aldehyde is then converted onto a raw alcohol RAL in the aldehyde hydrogenation unit AHU in the presence of hydrogen (Figures 3 and 4). The oxo process in which an aliphatic C3-C5 alcohol is formed from an intermediate enal (derived from an aliphatic C3-C5 aldehyde as intermediate), preferably a 2-enal, is shown in Figures 5 and 6.

[0058] Hydroformylation is carried out in the hydroformylation reaction unit HRU in the presence of catalysts which are preferably homogeneous catalyst comprising at least one metal. Said catalyst is preferably homogeneously dissolved in the reaction medium. Catalysts used are preferably carbonyl complexes of metals of transition group VIII, in particular cobalt, rhodium, iridium, palladium, platinum or ruthenium, which may be unmodified or modified with, for example, amine-containing or phosphine-containing ligands. A summarizing account of the processes practiced on a large scale in industry is found in J. Falbe, "New Syntheses with Carbon Monoxide", Springer Verlag 1980, p. 162 ff.

[0059] While short-chain olefins with up to 5 carbon atoms, preferably 4 carbon atoms, are currently predominantly hydroformylated in the hydroformylation reaction unit HRU using ligand-modified rhodium carbonyls as the catalyst, cobalt remains the dominant catalytically active central atom for longer-chained olefins such as oligomers of shortchain olefins, e.g., isooctane and dodecene. This is due, firstly, to the high catalytic activity of the cobalt carbonyl catalyst irrespective of the position of the olefinic double bonds, the branch structure, and the purity of the olefin to be reacted. Secondly, the cobalt catalyst can be separated off from the hydroformylation products and recycled into the hydroformylation reaction relatively easily. Additionally, catalyst losses during working up can be tolerated more easily owing to the lower price of cobalt.

[0060] The pressure during synthesis of C3-C5 aldehydes from C2-C4 olefins, CO and H2 in the hydroformylation reaction unit HRU preferably ranges between 10 bar to about 20 bar or up to about 100 bar. The temperature ranges during synthesis from about 60 to about 130 °C. Preferably, the at least one catalyst comprises rhodium as metal. Catalysts having the general formula [Rh(CO)PR3)3] wherein R = CeHs or S-Ce^SOsNa are most preferred. Further details of the manufacture of aliphatic C3-C5 aldehydes from C2-C4 olefins, CO and H2 by an oxo-synthesis are for example disclosed in H. Bahrmann, H. Basch, G. D. Frey, Ullmann's Encyclopedia of Industrial Chemistry, Chapter "Oxo Synthesis”, pages 1 to 8, 2013 and the references cited therein.

[0061] The aliphatic C3-C5 aldehyde formed in the hydroformylation reaction unit HRU is then further converted into an aliphatic alcohol by a hydrogenation reaction in an aldehyde hydrogenation unit AHU in the presence of hydrogen. The aliphatic C3-C5 alcohol formed from one aliphatic C3-C5 aldehyde is preferably selected from the group consisting of 1-propanol, 2-propanol, 1-butanol, 2-methylpropanol, 1-pentanol, 2-methylbutanol, and 3-methylbutanol. In another aspect, two different aliphatic C3-C5 aldehydes are further converted into an aliphatic alcohol by a hydrogenation reaction in the aldehyde hydrogenation unit AHU. The aliphatic alcohol formed from two aliphatic C3-C5 aldehydes is preferably selected from the group consisting of 2-propy I heptanol and 2-ethylhexanol. C9-C13 alcohols are preferably manufactured from C8-C12 olefins and synthesis gas by the oxo process shown in Figures 1 and 2. Accordingly, only the waste stream W1 is purged from the alcohol upgrading unit ALUU in said oxo process. The manufacture of aliphatic C9 aldehydes and aliphatic C9 alcohols from C8 olefins is for example described in WO 2021 / 160448 A1. The manufacture of aliphatic C13 aldehydes and aliphatic 013 alcohols from 012 olefins in the presence of cobalt catalysts is for example described in WO 01 / 36356 A2. Aliphatic 09-013 alcohols formed from 08 olefins comprise isomeric nonanols. Aliphatic 09-013 alcohols formed from 012 olefins comprise isomeric tridecanols. Aliphatic 09-013 alcohols are preferably formed from 08-012 olefins and synthesis gas by a high-pressure reaction in the presence of a cobalt catalyst. The intermediate aliphatic 09-013 aldehydes are not isolated in an aldehyde upgrading unit AUU. Hence, the aliphatic 09-013 alcohols are directly obtained by such oxo processes in the aldehyde hydrogenation unit AHU without separation of the aldehyde and no waste stream W2 is purged from said oxo process because no aldehyde upgrading unit AUU is utilized. The pressure during the synthesis preferably ranges from about 50 to about 350 bar and the temperature ranges from about 100 to about 200 °C. Such high-pressure oxo-processes in the presence of a cobalt catalyst are for example disclosed in H. Bahrmann, H. Basch, G. D. Frey, Ullmann's Encyclopedia of Industrial Chemistry, Chapter "Oxo Synthesis”, pages 1 to 8, 2013 and the references cited therein.

[0062] The synthesis of alcohols from aldehydes in the aldehyde hydrogenation unit AHU and the subsequent purification of the alcohol formed therein in the aldehyde upgrading unit ALUU is for example described in J. Falbe, H. Bahrmann, W. Lipps, D. Mayer, G. D. Frey, Ullmann's Encyclopedia of Industrial Chemistry, chapter "Alcohols, Aliphatic”, 2013, pages 5 to 6 and references cited therein. C3-C13 aldehydes cam also be converted into aliphatic alcohols by the method described in WO 2018 / 210720 A1. Said aldehydes are contacted with a catalyst containing copper oxide and aluminium oxide at a temperature of 150 to 300 °C and a pressure of 20 to 300 bar in the presence of hydrogen in the aldehyde hydrogenation unit AHU followed by purification of the alcohol formed therein in the aldehyde upgrading unit ALUU. Thereby, alcohols are formed from the respective aldehydes.

[0063] Hence, the waste stream W1 is purged in all these modifications of oxo processes from the alcohol upgrading unit ALUU. In case the oxo process further utilizes an aldehyde upgrading unit AUU (i.e., in case the aldehyde formed in the hydroformylation reaction unit HRU is separated before further conversion into an aldehyde, Figures 3 to 6), in addition, a waste stream W2 is purged from said aldehyde upgrading unit AUU.

[0064] The parameter ranges disclosed for waste streams W1 and W2 herein represent the respective composition of said waste streams prior to any further treatment of optional step (iii).

[0065] Analytical methods suitable for measuring the calorific value of a feedstock such as the waste stream W1 and the optional waste stream W2 comprise combustion of a sample of said feedstock in a bomb calorimeter. Such methods are for example suitable to assess the thermochemical behavior of said feedstock during the gasification reaction and, accordingly, the suitable type of gasifier and gasification process parameters such as temperature, amount, and type of oxidant. Analytical methods suitable for measuring the elemental composition such as the content of chemical elements H, C, and 0 of a feedstock such as the waste stream W1 and the optional waste stream W2 comprise CHNX analysis by combustion combined with thermal conductivity detection and / or infrared spectroscopy. The ranges for calorific values, carbon content, hydrogen content, and oxygen content for waste streams W1 and W2 disclosed below are obtained when converting a C2-C4 olefin or oligomer thereof and synthesis gas in oxo synthesis plants briefly described above and described in detail for example in the references cited above.

[0066] The waste stream W1 is purged in all these modifications of oxo processes from the alcohol upgrading unit ALUU (Figures 1 to 6) and has at least one, preferably all the following properties:

[0067] The first waste stream W1 preferably has a calorific value in the range of 25 to 50 MJ / kg, more preferably of 28 to 46 MJ / kg and most preferably of 32 to 45 MJ / kg.

[0068] The first waste stream W1 preferably has a carbon content in the range of 50 to 90 wt.-%, more preferably 55 to 85 wt.-% and most preferably 60 to 85 wt.-%.

[0069] The first waste stream W1 preferably has a hydrogen content in the range of 2 to 25 wt.-%, more preferably 5 to 22 wt.-% and most preferably 8 to 20 wt.-%.

[0070] The first waste stream W1 preferably has an oxygen content in the range of 2 to 25 wt.-%, more preferably 5 to 22 wt.-% and most preferably 5 to 20 wt.-%.

[0071] The optional waste stream W2 is purged in those modifications of oxo processes comprising an aldehyde upgrading unit AUU from said aldehyde upgrading unit AUU (Figures 3 to 6). The optional second waste stream W2 has at least one, preferably all the following properties:

[0072] The optional second waste stream W2 preferably has a calorific value in the range of 25 to 50 MJ / kg, more preferably of 28 to 46 MJ / kg and most preferably of 32 to 45 MJ / kg.

[0073] The optional second waste stream W2 preferably has a carbon content in the range of 50 to 90 wt.-%, more preferably 55 to 85 wt.-% and most preferably 60 to 80 wt.-%.

[0074] The optional second waste stream W2 preferably has a hydrogen content in the range of 2 to 25 wt.-%, more preferably 5 to 22 wt.-% and most preferably 8 to 20 wt.-%.

[0075] The optional second waste stream W2 preferably has an oxygen content in the range of 2 to 25 wt.-%, more preferably 5 to 22 wt.-% and most preferably 5 to 20 wt.-%. The optional pre-treatment step (ill) is described in the following: the first waste stream W1 and / or the optional second waste stream W2 can be pretreated by distillation, preferably flash distillation (e.g., in an evaporator unit, preferably without trays and / or packing materials), by mixing at least a portion of waste stream W1 and at least a portion of waste stream W2 with each other or by combining distillation and mixing or mixing and distillation. At least a portion of undesired phosphorous-containing compounds and / or alkaline salts which are comprised in waste stream W1 and / or waste stream W2 can be removed therefrom by distillation, preferably flash-distillation. When mixing at least a portion of waste stream W1 and at least a portion of waste stream W2, the resulting mixed waste stream W12 can have a reduced viscosity and thereby improved fluidical properties. For example: in case the waste stream W1 has a higher viscosity than optional waste stream W2, the resulting viscosity of the mixed waste stream W12 is lower than that of waste stream W1.

[0076] Next, the first waste stream W1 and optionally the waste stream W2, optionally pretreated in step (iii), is / are subjected in step (iv) to a gasification process wherein said gasification process comprises at least one gasifier G and whereby a gas stream GS1 is formed.

[0077] The at least one gasifier G has at least one inlet through which a feedstock is fed into said at least one gasifier G and at least one outlet through which the gas stream GS1 is purged from said at least one gasifier G. Preferably, the at least one gasifier G has more than one inlet. Thereby, more than one feedstock can be fed into the at least one gasifier G through separate inlets. The term "inlet” comprises openings in the at least one gasifier G such as flaps and locks but also annual gaps as part of a burner such as in twin fluid atomizers, pressure nozzles and pressure atomizers.

[0078] Optionally, at least one further feedstock F1 is provided and subjected together with the first waste stream W1 and optional waste stream W2 to a gasification process in at least one gasifier G in step (iv).

[0079] Optionally, the at least one further feedstock F1 is subjected to the gasification process in step (iv) wherein said gasification process comprises at least one gasifier G and whereby said at least one further feedstock F1 is inserted into the at least one gasifier G "together” with the first waste stream W1 provided in step (i) and optionally with waste stream W2, optionally pretreated in step (iii). The meaning of "together” depends on the kind of optional further feedstock F1 and the type of gasifier G employed in step (iv) and is explained in detail below.

[0080] Preferably, the optional at least one further feedstock F1 is selected from the group comprising or preferably consisting of biomass, refuse-derived fuel (RDF), pyrolysis oils made from plastic waste, pyrolysis oils made from end of life tires, pyrolysis oils made from biomass, heating oils, vacuum residues, preferably vacuum distillation residues, crude oil residues, heavy crude oils, extra heavy crude oils, tar sand bitumen, visbreaker bottom residues, deasphalter bottom residues, C5 asphalthene fraction, high viscous residues, fuel oils, pyrolysis gasolines, waste oils, used oils, municipal solid waste (MSW), automotive shredder residue (ASR), coal, natural gas, industrial waste streams and mixtures thereof.

[0081] The coal optionally comprised in the at least one further feedstock F1 is selected from the group comprising or preferably consisting of meta-anthracite, anthracite, semianthracite, low volatile bituminous coal, medium volatile bituminous coal, high volatile A bituminous coal, high volatile B bituminous coal, high volatile C bituminous coal, subbituminous A coal, subbituminous B coal, subbituminous C coal, lignite A, lignite B and mixtures thereof. More preferably, the coal is selected from the group comprising or preferably consisting of low volatile bituminous coal, medium volatile bituminous coal, high volatile A bituminous coal, high volatile B bituminous coal, high volatile C bituminous coal, subbituminous A coal, subbituminous B coal, subbituminous C coal, lignite A, lignite B and mixtures thereof. Said terms are in accordance with the respective definition disclosed in ASTM D388-23. Accordingly, bituminous and anthracitic coals are summarized in ASTM D388-23 in "meta-terms” as "high rank coal”, and lignitic and subbituminous coals as "low rank coals”. Because real coal feedstocks used for gasification can be composed of more than one of said coal types according to ASTM D388-23, the "meta-terms” "high rank coals” and "low rank coals” are used in the examples section.

[0082] The coal comprised in optionally comprised in the at least one further feedstock F1 is optionally pretreated before step (iv). Preferably, the coal is pretreated before step (iv) by a method selected from the group comprising or preferably consisting of milling, grinding, classification, drying, converting the coal into a slurry and combinations thereof, whereby optionally coal dust as a side product is formed. Such pre-treatment methods are known to the skilled person and can be selected and applied for a given coal feedstock. Said coal dust can be also subjected to the gasification process in at least one gasifier G in step (v) and thereby further increase the yield in synthesis gas.

[0083] More preferably, the optional at least one further feedstock F1 is selected from the group consisting of biomass, refuse-derived fuel (RDF), pyrolysis oils made from plastic waste, pyrolysis oils made from end-of-life tires, pyrolysis oils made from biomass, municipal solid waste (MSW), automotive shredder residue (ASR) and mixtures thereof.

[0084] The term "biomass” includes but is not limited to wood, wood pellets, wood chips, straw, lignocellulosic biomass, energy crops, algae, bio-based oils, and bio-based fats (preferably hydrated).

[0085] Biomass is preferably torrefied or converted by pyrolysis into a pyrolysis oil before used in step (iv) as at least one further feedstock F1 . Municipal solid waste (MSW) is optionally pre-treated by methods such as drying, shredding, sorting, inert removal and preferably used in step (iv) in form of refuse-derived fuel (RDF). Shredder residues such as automotive shredder residue (ASR) is preferably pre-treated by methods such as sorting, metal removal and the like before used in step (iv) as at least one further feedstock F1. Furthermore, torrefied biomass is preferably pre-heated to a temperature such as 200 °C before fed into a gasifier G as at least one further feedstock F1. Liquid further feedstocks F1 such as bio-based oils and pyrolysis oils are preferably pre-heated and / or pressurized before fed into the gasifier G. In case the gasifier G is a plasma gasifier, the liquid further feedstock F is preferably pressurized to > 1 bar(abs.), more preferably to > 2 bar(abs.) and most preferably to about 4 bar(abs.) before fed into the gasifier G. In case the gasifier G is an entrained flow gasifier, the liquid further feedstock F is preferably pressurized to > 10 bar(abs.), more preferably > 20 bar(abs.) and most preferably > 40 bar(abs.) before fed into the gasifier G. Suitable means for pre-heating and / or pressurizing liquid feedstocks for feeding into a gasifier are known in the art, comprise for example flaps and locks but also annual gaps as part of a burner such as in twin fluid atomizers, pressure nozzles and pressure atomizers, and can be adapted to a given at least one further feedstock F1 and / or gasifier G type by the skilled person.

[0086] In case the gasifier G is an entrained flow gasifier, solid further feedstocks F1 such as municipal solid waste (MSW), refuse-derived fuel (RDF), wood chips, wood pellets and the like, said solid further feedstock is preferably pressurized e.g., in a lock before fed into the gasifier G.

[0087] Preferably, the weight ratio (waste stream W1 optionally with waste stream W2) : (sum of all further feedstocks F1) preferably ranges from 1 : 1 to 1 : 10, more preferably from 1 : 2 to 1 : 10 and most preferably from 1 : 5 to 1 : 10. The at least one gasifier G is selected from entrained flow gasifiers and plasma gasifiers. Preferably, the at least one gasifier G is a plasma gasifier. More preferably, the at least one gasifier G is a plasma fixed-bed gasifier.

[0088] An overview of gasifiers G, especially entrained flow gasifiers G and plasma gasifiers G is for example provided in James G. Speight, Handbook of Gasification Technology, Scrivener Publishing and Wiley, 2020, chapter 8.4.2, pages 259 to 262.

[0089] The first waste stream W1 and optional waste stream W2, optionally pre-treated in step (ill), can be fed into the gasifier G separately or be mixed before to form a waste stream mixture W12 and then the mixture W12 is fed into the gasifier G. The mixture W12 can have a lower viscosity than the individual waste stream W1 and / or the optional waste stream W2 and thereby feeding a waste stream mixture W12 requires simpler equipment than feeding individual waste streams W1 and the optional waste streams W2 into the gasifier G. Feeding a mixture W12 into the gasifier G can also result in an improved atomization of the feedstock in the gasifier G compared to feeding waste stream W1 and the optional waste stream W2 into the gasifier G. Thereby, the residence time and formation of coke inside the gasifier G can be reduced.

[0090] The optional at least one further feedstock F1 is preferably fed separately into the gasifier G, i.e., not mixed with the first waste stream W1 and optional waste stream W2 before being fed into the gasifier G. Thereby, variations in mass flow, calorific value, and other properties of the first waste stream W1 and the optional waste stream W2 can be better balanced and as a result a steady operation of the gasifier G maintained. The optional at least one further feedstock F1 is preferably fed into the gasifier G by means preferably selected from lock, screw conveyor, hopper, and flap. Most preferably, the optional at least one further feedstock F1 is selected from the group consisting of torrefied biomass, pyrolysis oil and bio-based oils wherein the pyrolysis oil can be manufactured by pyrolysis from mixed plastic waste (MPW), end of life tires (ELT) and biomass. Such optional feedstocks F1 have more homogenized properties such as calorific value compared to, for example, municipal solid waste (MSW), and are therefore most preferred.

[0091] In one aspect of the present invention, a CO2 waste stream from one or more chemical processes such as CO2 capture by absorption is also co-fed into the at least one gasifier G.

[0092] Solid fuel particles are injected in an entrained flow gasifier G in a high-velocity stream of gas and are heated to high temperatures (typically between 850 and 1400 °C) in the presence of oxygen and / or steam. The solid particles are provided by the at least one further feedstock F1 and the first waste stream W1 and the optional waste stream W2 or the waste stream mixture W12 are preferably transported in downdraft mode.

[0093] In case the at least one gasifier G in step (iv) is an entrained flow gasifier, the first waste stream W1 and the optional waste stream W2 or the waste stream mixture W12 are preferably compressed up to 40 bar(abs.) or higher before fed into the at least one gasifier G.

[0094] The temperature inside the entrained flow gasifier G preferably ranges from 1000 to 1500 °C, more preferably from 1100 to 1450 °C and most preferably from 1200 to 1400 °C. The pressure inside the entrained flow gasifier preferably ranges from 1 to 55 bar(abs.), more preferably from 5 to 50 bar(abs.) and most preferably from 20 to 45 bar(abs.).

[0095] Addition of at least one further feedstock F1 is preferred because thereby the desired constant operation conditions in the entrained flow gasifier can be maintained and synthesis gas having the desired molar ratio CO : H2 of about 1 is formed.

[0096] Preferably, the first waste stream W1 and the optional waste stream W2 or the waste stream mixture W12 and the optional at least one further feedstock F1 are fed into the entrained flow gasifier via at least one burner whereby said at least one burner comprises one annular gap for the waste stream W1, and the optional waste stream W2 or mixed waste stream W12 and a separate annular gap through which the optional at least one further feedstock F1 is fed. Steam, preferably mixed with oxygen is co-fed into the entrained flow gasifier through a separate annular gap in said at least one burner.

[0097] Plasma gasification is a high-temperature waste treatment process that uses plasma, a gas composed of highly charged particles, to break down organic matter into a gas. In this process, the first waste stream W1 and the optional waste stream W2 or a mixed waste stream W12 are / is fed into a plasma gasifier, preferably a fixed bed plasma gasifier. Preferably, the first waste stream W1 and the optional second waste stream W2 or the mixture W12 thereof are fed into the plasma gasifier, where they / it are / is exposed to an electric arc or microwave radiation or at least one plasma torch, which ionizes the waste stream(s) and creates a plasma. Preferably, the plasma is generated by means of at least one plasma torch, more preferably, the plasma is generated by means of at least two plasma torches. Most preferably, the plasma gasifier comprises one to three plasma torches in the part of the gasifier where the first waste stream W1 and the optional waste stream W2 or the waste stream mixture W12 are / is fed onto the plasma gasifier and one or two plasma torches in the part of the plasma gasifier where the gas stream GS1 leaves the plasma gasifier (most preferably in arrangement which forces the gas stream GS1 to pass said one or two plasma torches). The high temperatures inside the plasma gasifier, which can reach up to about 10000 K, cause the first waste stream W1 and the optional waste stream W2 or the waste stream mixture W12 to vaporize and break down into the constituent components, including hydrogen, carbon monoxide, and methane.

[0098] In case the at least one gasifier G in step (iv) is a plasma gasifier, the first waste stream W1 and the optional second waste stream W2 or the waste stream mixture W12 are preferably compressed up to 4 bar(abs.) before fed into the at least one gasifier G.

[0099] The temperature of the gas stream GS1 leaving the plasma gasifier is preferably in the range of 1100 to 1400 °C, most preferably around 1300 °C. The pressure of the gas leaving the plasma gasifier is preferably at least 0.7 bar(abs.) and more preferably at least 1 bar(abs.). The residence time of the reactants inside the plasma gasifier is at least 2 to 3 s. The plasma is preferably generated from a gas selected from the group comprising steam, CO2, O2, air and mixtures thereof. More preferably, the plasma is generated from steam, CO2 or a mixture of steam and CO2.

[0100] The first waste stream W1 and the optional second waste stream W2 or the mixed waste stream W12 is preferably fed into the plasma gasifier through an opening separate of the opening through which the optional at least one further feedstock F1 is fed. Steam is preferably fed to the plasma gasifier through still another opening.

[0101] Optionally, the at least one further feedstock F1 is converted in a pre-gasifier PG into a converted further feedstock CF1 (Figures 2, 4 and 6). Preferably, said pre-gasifier PG is a fixed bed gasifier or a fluidized bed gasifier. Preferably, the pre-gasifier PG is a fixed bed gasifier, or a fluidized bed gasifier and the gasifier G is an entrained flow gasifier G.

[0102] The gasifier G is downstream of and fluidically connected to the pre-gasifier PG. Preferably, the converted further feedstock CF1 and the first waste stream W1 and optionally the second waste stream W2, optionally after pretreatment of W1 and / or W2, are fed into the entrained flow gasifier G.

[0103] Optionally the process according to the present invention comprises a further step (v) wherein said further step (v) is selected from the group comprising or consisting of cleaning gas stream GS1 and thereby forming gas stream GS2, separating H2 and CO comprised in gas stream GS1 or gas stream GS2 from each other, compressing one or more of gas streams GS1, GS2, H2 and CO, and combinations thereof. Preferably, said step (v) comprises, in this order, cleaning gas stream GS1 and thereby forming gas stream GS2, separating H2 and CO in gas stream GS2 and compressing at least one of H2 and CO separated from gas stream GS2.

[0104] Typical impurities in the gas stream GS1 comprise chlorides, sulfur-containing organic compounds such as sulfur dioxide, trace heavy metals (e.g., as respective salts), tars / condensable hydrocarbons and particulate residues. Various chemical and / or physical methods for removal of such impurities from said gas stream GS1 such as filtration, scrubbing, condensation and ab- / adsorption are known and can be chosen and adapted according to the type and respective concentration of the impurities in said gas stream GS1 and the tolerance to such impurities in a further process FP1 . Some selected methods for removal of impurities from said gas stream GS1 will be discussed in more detail. One or more of said methods can also be implemented into the optional gas treatment unit GTU. However, this selection of methods is not limiting the scope of the present invention.

[0105] Other gaseous substances such as HOI and H2S are formed and / or separated from the gas stream GS1 in the optional gas treatment unit GTU. The impurities are removed from the gas stream GS1 and a gas stream GS2 having a first molar ratio CO : H2 is obtained.

[0106] Particulate impurities can be removed from the gas stream GS1 by a cyclone and / or filters, chlorides by wet scrubbing, trace heavy metals, catalytic hydrolysis for converting sulfur-containing organic compounds to H2S and acid gas removal for extracting sulfur-containing gases such as H2S. Bulky and (fine) particles such as dust in the gas stream GS1 may also be removed with a quench in a soot water washing unit.

[0107] Particulate impurities can be optionally removed from the gas stream GS1 directly by a cyclone and / or filters after the gas stream GS1 leaves the gasifier. Hence, the removal of particles from the gas stream GS1 can be part of a gasifier and / or part of the optional gas treatment unit GTU which is fluidically connected to the at least one gasifiers G.

[0108] Fine particles can be optionally removed from the raw synthesis gas directly with filters after the gas stream GS1 leaves the at least one gasifier G. Hence, the removal of fine particles from the gas stream GS1 can be part of the at least one gasifier G and / or part of the optional gas treatment unit GTU which is fluidically connected to the at least one gasifier G.

[0109] The optional gas treatment unit GTU preferably comprises a washing unit for removing CO2 from the gas stream GS1. Most preferably, said washing unit is an "amine wash” or a "methanol” wash which uses one or more amine compounds such as alcohol amines or methanol to absorb CO2. Such washing units are known in the art and can be adapted for removal of CO2 from a gaseous stream GS1 by the skilled person. CO and / or H2 are optionally separated from the gas stream GS1. CO can be separated from the gas stream GS1 in a synthesis gas separation unit which is, optionally, downstream of and fluidically connected to the at least one gasifier G. CO can be separated from gas stream GS1 by cryogenic separation methods, commonly referred to as a "cold box” which makes use of the different boiling points of CO and H2. H2 can be separated using ^-selective membranes thorough which H2 permeates and is thereby separated from the GS1 stream.

[0110] The gas stream GS1 has a first molar ratio H2 : CO. Optionally, the gas stream GS1 is then preferably subjected to a water-gas shift reaction in a water-gas shift unit. Thereby, the H2 content in the gas stream GS1 is increased by reacting a portion of the CO of the gas stream GS1 with water to form additional H2 and CO2 and thereby gas stream GS2 having a second molar ratio CO : H2 is formed and leaves the water-gas shift unit. The H2 content in said gas stream GS2 leaving the water-gas shift unit and having a second molar ratio CO : H2 is higher than in said gas stream GS1 leaving the at least one gasifier having a first molar ratio CO : H2. The hydrogen content in gas stream GS1 can for example also be increased by adding hydrogen provided by another source such as hydrogen formed by electrolysis of water, preferably using electrical energy from a renewable source such as solar and / or wind energy.

[0111] The water-gas shift reaction will operate with a variety of catalysts (such as copper-zinc-aluminum catalysts and chromium or copper promoted iron-based catalysts) in the temperature range between about 200 and about 480 °C.

[0112] The gas stream GS2 is optionally compressed, preferably, in case the first waste stream W1 and the optional waste stream W2 or mixed gas stream W12 were / was converted to gas stream GS1 in a plasma gasifier. In this case, gas stream GS2 is preferably compressed to a pressure in the range 1.5 to 4 bar(abs.).

[0113] Optionally, the gas stream GS1 and / or the gas stream GS2 are / is then subjected to a further process FP1 selected from the group comprising methanization, methanol synthesis, and Fischer-Tropsch synthesis whereby at least one first product stream PS1 is formed. The gas stream GS2 can also be used as a fuel gas Said optional further processes FP1 are briefly described below:

[0114] Optionally, the gas stream gas stream GS2 can be converted into methane by a methanation reaction. The methanation reaction is described by chemical reaction schemes (1) and (2):

[0115] CO + 3H2-> CH4+ H2O (1) CO2+ 4H2-> CH4+ 2H2O (2)

[0116] The methanation reaction and suitable methanation units are for example described in S. Rdnsch, J. Schneider, S. Matthischke, M. Schluter, M. Gdtz, J. Lefebvre, P. Prabhakaran, S. Bajohr: Review on methanation - From fundamentals to current projects; Fuel 166 (2016) 276-296 and can be selected and adapted by the skilled person. The methanation reaction is for example a catalytic reaction using nickel on alumina catalysts, preferably a honeycomb shape catalyst, at 1 to 70 bar and 200 to 700 °C, preferably 5 to 60 bar, more preferably 10 to 45 bar and preferably 200 to 550 °C, more preferably 10 to 45 bar.

[0117] Methanol is another chemical product which can be manufactured from the gas stream GS2 by an optional further process FP1 . Methanol is preferably produced from synthesis gas by a catalytic gas phase reaction at about 5 to 10 MPa and a temperature of about 200 to about 300 °C using a catalyst in a low-pressure methanol process in e.g., adiabatic reactors or quasi-isothermal reactors. The catalyst is for example a mixture of copper and zinc oxides, supported on alumina. The methanol synthesis and various options thereof suitable to be combined with the production system according to the present invention are disclosed in Ullmann's Encyclopedia of Industrial Chemistry (2012), Chapter "Methanol”, p. 3 to 12.

[0118] The gas stream GS2 can also optionally be converted into hydrocarbons such as light synthetic crude oil in an optional Fischer-Tropsch (FT) reaction unit by the FT process. Such hydrocarbons are also denoted "Fischer- Tropsch hydrocarbons”. The light synthetic oil can be further converted by hydrocracking and / or isomerization to naphtha, light olefins, or diesel fuel. For production of gasoline and light olefins, the FT process is operated in a temperature range of about 330 to about 350 °C and a pressure of about 2.5 MPa (high-temperature FT-process), for production of waxes and / or diesel fuel, in a temperature range of about 220 to about 250 °C and a pressure of about 2.5 to about 4.4 MPa (low-temperature FT-process). Suitable reactors for low-temperature FT-processes comprise tubular fixed-bed reactors and slurry bed reactors. Suitable reactors for high-temperature FT-processes comprise circulating fluidized-bed reactors and SAS (Sasol advanced synthol) reactors. Iron- and / or cobalt-based catalysts are used for the FT-process. The Fischer-Tropsch synthesis and various options thereof suitable to be combined with the production system according to the present invention are disclosed in Ullmann's Encyclopedia of Industrial Chemistry (2012), Chapter "Coal Liquefaction”, p. 20 to 33. Optionally, the products from said FT process are converted into aviation fuel by further process steps such as cracking and isomerization. Such further processes are known to the skilled person and can be applied I adapted accordingly.

[0119] The present invention is further illustrated by the following set of embodiments and combinations of embodiments resulting from the dependencies and back-references as indicated. In particular, it is noted that in each instance where a range of embodiments is mentioned, for example in the context of a term such as "The process of any of embodiments 1 to 3", every embodiment in this range is meant to be explicitly disclosed for the skilled person, i.e. the wording of this term is to be understood by the skilled person as being synonymous to "The process of any of embodiments 1, 2 and 3". Further, it is explicitly noted that the following set of embodiments represents a suitably structured part of the general description directed to preferred aspects of the present invention, and thus, suitably supports the claims of the present invention. A process for utilizing at least one waste stream from an oxo synthesis plant, wherein the oxo synthesis plant comprises a) an hydroformylation reaction unit HRU, b) optionally an aldehyde upgrading unit AUU, c) an aldehyde hydrogenation unit AHU and d) an alcohol upgrading unit ALUU, the process comprising the steps

[0120] (I) providing a first waste stream W1 , wherein the first waste stream W1 is separated from the alcohol upgrading unit ALUU,

[0121] (ii) optionally providing a second waste stream W2, wherein the optional second waste stream W2 is separated from the optional aldehyde upgrading unit AUU,

[0122] (ill) optionally pretreating the first waste stream W1 and / or the optional second waste stream W2,

[0123] (iv) subjecting the first waste stream W1 and optionally the said second waste stream W2 to a gasification process wherein said gasification process comprises at least one gasifier G and whereby a gas stream GS1, said gas stream GS1 comprising CO and H2, is formed by said gasification process from said first waste stream W1 and optionally said optional second waste stream W2. Process according to embodiment 1 wherein the waste stream W1 has at least one, preferably all the following properties: a) a calorific value in the range of 25 to 50 MJ / kg, more preferably of 28 to 46 MJ / kg and most preferably of 32 to 45 MJ / kg, b) a carbon content in the range of 50 to 90 wt.-%, more preferably 55 to 85 wt.-% and most preferably 60 to 85 wt.-%, c) a hydrogen content in the range of 2 to 25 wt.-%, more preferably 5 to 22 wt.-% and most preferably 8 to 20 wt.-%, d) an oxygen content in the range of 2 to 25 wt.-%, more preferably 5 to 22 wt.-% and most preferably 5 to 20 wt.-%. Process according to embodiment 1 or 2 wherein the optional waste stream W2 has at least one, preferably all the following properties: a) a calorific value in the range 25 to 50 MJ / kg, more preferably of 28 to 46 MJ / kg and most preferably of 32 to 45 MJ / kg, b) a carbon content in the range of 50 to 90 wt.-%, more preferably 55 to 85 wt.-% and most preferably 60 to 80 wt.-%, c) a hydrogen content in the range of 2 to 25 wt.-%, more preferably 5 to 22 wt.-% and most preferably 8 to 20 wt.-% and d) an oxygen content in the range of 2 to 25 wt.-%, more preferably 5 to 22 wt.-% and most preferably 5 to 20 wt.-%. Process according to any one of embodiments 1 to 3 wherein the waste stream W1 and / or the optional waste stream W2 is / are pretreated in optional step (ill) by a method selected from the group comprising or consisting of distillation, mixing at least a portion of waste stream W1 and at least a portion of waste stream W2 with each other, and combining distillation and mixing or mixing and distillation. Process according to any one of embodiments 1 to 4 wherein said at least one gasifier G is selected from plasma gasifier and entrained flow gasifier. Process according to any one of embodiments 1 to 5 wherein at least one further feedstock F1 is provided and said at least one further provided feedstock F1 is subjected to the gasification process in step (iv), whereby said at least one further feedstock F1 is inserted into the at least one gasifier G together with the first waste stream W1 provided in step (I) and optionally with the second waste stream W2 provided in optional step (ii), and / or with the first waste stream W1 pretreated in step (ill) and optionally with the second waste stream W2 pretreated in step (ill). Process according to embodiment 6 wherein the at least one further feedstock F1 is selected from the group comprising or preferably consisting of biomass, refuse-derived fuel (RDF), pyrolysis oils made from plastic waste, pyrolysis oils made from end of life tires, pyrolysis oils made from biomass, heating oils, vacuum residues, preferably vacuum distillation residues, crude oil residues, heavy crude oils, extra heavy crude oils, tar sand bitumen, visbreaker bottom residues, deasphalter bottom residues, C5 asphalthene fraction, high viscous residues, fuel oils, pyrolysis gasolines, tire pyrolysis oils (TPO), waste oils, used oils, municipal solid waste (MSW), automotive shredder residue (ASR), coal, natural gas, industrial waste streams and mixtures thereof. Process according to embodiment 6 or 7 wherein the weight ratio (waste stream W1 optionally with waste stream W2) : (sum of all further feedstocks F1) preferably ranges from 1 : 1 to 1 : 10, more preferably from 1 : 2 to 1 : 10 and most preferably from 1 : 5 to 1 : 10. Process according to embodiments 1 to 8 wherein the at least one gasifier G is a plasma gasifier utilizing a plasma and wherein said plasma is formed from one or more sources selected from the group comprising or consisting of steam, CO2, O2, air and mixtures thereof. Process according to any one of embodiments 5 to 9 wherein the plasma is formed by a method selected from the group comprising or consisting of microwave radiation, electrical arc, and plasma torch. Process according to any one of embodiments 5 to 10 wherein the plasma is formed by at least one plasma torch. 12. Process according to any one of embodiments 1 to 11 wherein the at least one gasifier G is a fixed-bed plasma gasifier.

[0124] 13. Process according to any one of embodiments 1 to 8 wherein the at least one gasifier G is an entrained flow gasifier and wherein oxygen and steam are co-fed in step (iv).

[0125] 14. Process according to any one of embodiments 1 to 13 wherein steam is co-fed into the at least one gasifier G in step (iv).

[0126] 15. Process according to any one of embodiments 1 to 14 wherein the gas stream GS1 formed in step (iv) comprises CO, CO2 and H2.

[0127] 16. Process according to any one of embodiments 1 to 15 wherein the molar ratio CO : H2 in the gas stream GS1 formed in step (iv) preferably ranges from 30 : 70 to 50 : 50, more preferably from 35 : 65 to 45 : 55.

[0128] 17. Process according to any one of embodiments 1 to 16 wherein the gas stream GS1 formed in step (iv) preferably comprises < 15 Vol.-% CO2, more preferably < 10 Vol.-% CO2 and most preferably < 8 Vol.-% CO2.

[0129] 18. Process according to any one of embodiments 5 to 17 wherein the at least one further feedstock F1 is converted in a pre-gasifier PG into a converted further feedstock CF1 .

[0130] 19. Process according to embodiment 18 wherein the gasifier G is downstream of and fluidically connected to the pre-gasifier PG.

[0131] 20. Process according to embodiment 18 or 19 wherein the pre-gasifier PG is a fixed bed gasifier or a fluidized bed gasifier.

[0132] 21 . Process according to any one of embodiments 18 to 20 wherein the converted further feedstock CF1 and the first waste stream W1 and optionally the said second waste stream W2, optionally after pretreatment, are fed into the entrained flow gasifier G.

[0133] 22. Process according to any one of embodiments 1 to 21 wherein the process comprises a further step (v) said further step (v) selected from the group comprising or consisting of cleaning the gas stream GS1 and thereby forming a gas stream GS2, separating H2 and CO comprised in the gas stream GS1 or GS2 from each other, compressing at least one of the gas streams GS1 , GS2, H2, CO, and combinations thereof. 23. Process according to embodiment 22 wherein step (v) comprises, in this order, cleaning gas stream GS1 and thereby forming gas stream GS2, separating H2 and CO comprised in gas stream GS2 and compressing at least one of H2 and CO separated from gas stream GS2.

[0134] 24. Process according to any one of embodiment 22 or 23 wherein at least a portion of gas stream GS2 is fed as synthesis gas into a hydroformylation reaction unit HRU.

[0135] 25. An oxo process plant comprising an integrated waste stream treatment facility wherein said oxo process plant comprises

[0136] (I) an hydroformylation reaction unit HRU,

[0137] (ii) optionally an aldehyde upgrading unit AUU downstream of and fluidically connected to the hydroformylation reaction unit HRU,

[0138] (ill) an aldehyde hydrogenation unit AHU downstream of and fluidically connected to the hydroformylation reaction unit HRU or downstream of and fluidically connected to the optional aldehyde upgrading unit AUU,

[0139] (iv) an alcohol upgrading unit ALUU, downstream of and fluidically connected to the aldehyde hydrogenation unit AHU,

[0140] (v) at least one gasifier G, downstream of the alcohol upgrading unit ALUU and optionally downstream of the optional aldehyde upgrading unit AUU and wherein the at least one gasifier G is directly or indirectly fluidically connected to the waste stream W1 of the alcohol upgrading unit ALUU and to the optional waste stream W2 of the optional aldehyde upgrading unit AUU.

[0141] 26. Use of an oxo process plant according to embodiment 25 for the process according to any one of embodiments 1 to 24.

[0142] The process and plant according to the present invention enable the production of aliphatic C3-C5 aldehydes, aliphatic C3-C5 alcohols, aliphatic C9-C13 alcohols, and enals derived from aliphatic C3-C5 aldehydes by an oxo synthesis process with reduced CO2 emissions compared to state-of-the-art oxo synthesis processes in which the waste stream(s) of said process in incinerated.

[0143] Furthermore, also the product carbon footprint (PCF) of said products is reduced when applying the process and / or plant according to the present invention because the CO2 emissions because incineration of waste stream W1 and optional waste stream W2 is not required.

[0144] Moreover, at least a portion or all the gas stream GS2 can be fed into a hydroformylation reaction unit HRU. Step (iv) of the process according to the present invention enables production of synthesis gas from waste stream W1 and optional waste stream W2 having the desired molar ratio CO : H2 of about 1 : 1 which is required for the hydroformylation of the C2-C4 olefins or oligomers thereof in the hydroformylation reaction unit HRU. The waste stream W1 and the optional waste stream W2 are used to provide further synthesis gas for the manufacture of products selected from aliphatic C3-C5 aldehydes, aliphatic C3-C5 alcohols, aliphatic C9-C13 alcohols, and enals derived from aliphatic C3-C5 aldehydes by an oxo process. Thereby, the product carbon footprint (PCF) of said products is reduced is even more reduced.

[0145] In addition, the process according to the present invention can be worked in one site, e.g., the gasifier G is at the same site as the oxo synthesis plant. The exit points from which the waste stream W1 and the optional waste stream W2 are purged are directly fluidically connected with the at least one gasifier G or an optional pretreatment unit for pretreating said waste stream W1 and the optional waste stream W2 before feeding into the gasifier G by e.g., one or more pipes which each other, by pumps, by compressors or combinations thereof.

[0146] Or the process can be worked in at least two different sites, e.g., the oxo synthesis plant is located at a first site and the gasifier G is located at a second site which is different from the first site. The exit points from which the waste stream W1 and the optional waste stream W2 are purged are indirectly fluidically connected with the at least one gasifier G or an optional pretreatment unit for pretreating said waste stream W1 and the optional waste stream W2 before feeding into the gasifier G e.g., by means such as a truck, a train or a pipeline transporting the waste stream W1 and the optional waste stream W2 from the "oxo synthesis plant” to the gasifier G and / or an optional unit in which waste stream W1 and optional waste stream W2 is / are pretreated before fed into said gasifier G. Optionally, the oxo synthesis plant and the gasifier G are operated by different legal entities.

[0147] An optional pretreatment unit for the waste stream W1 and the optional waste stream W2 can located at the same site as the oxo synthesis plant and the gasifier G or at the same site where the gasifier G is located in case the gasifier is located at a different site than the oxo synthesis plant or at a third site which is different from the site where the oxo synthesis plant is located and where the gasifier G is located. The exit points from which the waste stream W1 and the optional waste stream W2 are purged are indirectly fluidically connected with the optional pretreatment unit, e.g., by means such as a truck, a train or a pipeline transporting the waste stream W1 and the optional waste stream W2 from the "oxo synthesis plant” to the optional unit in which waste stream W1 and optional waste stream W2 is / are pretreated before fed into said gasifier G. Optionally, the oxo synthesis plant and the gasifier G (and / or the pretreatment unit) are operated by different legal entities.

[0148] The invention will be further explained by the following non-limiting examples.

[0149] Examples

[0150] General description

[0151] A gasification agent (steam) was injected into the gasifier G, enabling a plasma gasification reaction at a temperature of 1350 °C (Examples 1 to 3) or an entrained flow gasification at 1350 °C (Examples 4 to 9). In Examples 7 to 9, a converted further feedstock CD1 was formed in a pre-gasifier PG before subjected together with W1 or W1 and W2 to the gasification process in the gasifier G. A plasma was formed in case of plasma gasification from the inserted steam at the plasma torch outlets of the gasifier G. The plasma generation was performed by electric energy with a power given for the individual examples. The resulting raw synthesis gas (stream GS1), comprising CO, H2O, CO2, H2 and optionally ash or dust, which left the gasifier G via the gas outlet of the gasifier G was washed and dried to reduce the amount of water and ash comprised therein. Slag was removed from the gasifier G directly. After washing and drying, the gas stream GS1 had a temperature of 25 °C and was subjected to acid gas removal, by amine scrubbing, to separate acids such as CO2. The composition and normalized mass flow of the resulting gas stream GS2 is given in the tables below. All simulations were performed with the Aspen Plus simulation package, version 14. T able 1 : Results from examples 1 to 3. feed stream: mass flow steam: gasifier G, GS2 composition pressure mass flow el. power temperature pressure consumption composition temperature per kg GS2 produced

[0152] Example 1 W1+W2 0.52 kg feed / kg GS2 0.49 kg steam / kg plasma 65.2 mol.-% H2 kg / h, 1 bar(abs.) 100 °C GS2 8392.5 kJ / kg 33.6 mol.-% C0

[0153] 71.6 wt.-% C 5.4 bar (abs.) GS2 rest steam

[0154] 12.5 wt.-% H 180 °C

[0155] 15.9 wt.-% 0

[0156] Example 2 W1 0.48 kg feed / kg GS2 0.52 kg steam / kg plasma 66.4 mol.-% H2 kg / h, 1 bar(abs.) GS2 8616.9 kJ / kg 33.2 mol.-% C0

[0157] 100 °C 5.4 bar(abs.) GS2 rest: steam

[0158] 76.3 wt.-% C 180 °C

[0159] 14.0 wt.-% H 9.7 wt.-% 0

[0160] Example 3 W1+W2+F1 0.82 kg feed / kg GS2 0.3 kg steam / kg plasma 58.0 mol.-% H2

[0161] (=RDF1) kg / h, 1 bar(abs.) GS2 7227.7 kJ / kg 41.3 mol.-% C0

[0162] 100 °C 5.4 bar(abs.) GS2 rest: steam

[0163] 47.4 wt.-% C 180 °C

[0164] 6.6 wt.-% H

[0165] 30.5 wt.-% O 15.5 wt.-% ash

[0166] 1: 45 wt.-% C, 6 wt.-% H, 32 wt.-% 0, 17 wt.-% ash.

[0167] Table 2: Results from examples 4 to 6. feed stream: mass flow Steam and gasifier G, GS2 composition pressure oxygen: temperature mass flow composition pressure temperature

[0168] Example 4 W1+W2 0.59 kg feed / kg GS2 Steam: Entrained flow 50.7 mol.-% H2 kg / h, 47 bar(abs.) 0.06 kg steam / kg gasification 49.1 mol. -% CO

[0169] 100 °C GS2 rest steam

[0170] 71.3 wt.-% C 70 bar (abs.)

[0171] 13.0 wt.-% H 400 °C

[0172] 15.7 wt.-% 0 Oxygen:

[0173] 0.57 kg 02 / kg GS2 47 bar (abs.) 25 °C

[0174] Example 5 W1 + W2 + 0.66 kg feed / kg GS2 Steam: Entrained flow 38.2 mol.-% H2

[0175] F1 kg / h, 47 barfabs.) 0.1 kg steam / kg gasification 61.6 mol. -% CO

[0176] (=torrefied 100 °C GS2 rest: steam wood1) 66.1 wt.-% C 70 bar(abs.)

[0177] 6.3 wt.-% H 400 °C

[0178] 17.6 wt.-% 0 Oxygen:

[0179] 10.0 wt.-% ash 0.46 kg 02 / kg

[0180] GS2 47 bar (abs.) 25 °C

[0181] Example 6 W1 + F1 0.67 kg feed / kg GS2 Steam: Entrained flow 36.3 mol.-% H2

[0182] (=torrefied kg / h, 47 bar(abs.) 0.13 kg steam / kg gasification 65.5 mol. -% CO wood1) 100 °C GS2 rest: steam

[0183] 66.1 wt.-% C 70 bar(abs.)

[0184] 5.8 wt.-% H 400 °C

[0185] 17.2 wt.-% 0 Oxygen:

[0186] 10.9 wt.-% ash 0.45 kg 02 / kg

[0187] GS2 47 bar (abs.) 25 °C

[0188] 1: 65 wt.-% C, 5 wt.-% H, 18 wt.-% 0, 12 wt.-% ash.

[0189] Table 3: Results from examples 7 to 9. feed stream: mass flow Steam and gasifier G, GS2 composition pressure oxygen: temperature mass flow composition pressure temperature

[0190] Example 7 W1+W2 + 0.73 kg feed / kg GS2 Steam: Fluidized bed 42.3 mol.-% H2

[0191] F1 kg / h, 47 barfabs.) 0.33 kg steam / kg gasification 57.3 mol.-% CO (=torrefied 100 °C GS2 (PG) and rest steam wood1) 65.6 wt.-% C 5 bar (abs.) entrained flow

[0192] 5.7 wt.-% H 180 °C gasification

[0193] 17.8 wt.-% 0 Oxygen: (G)

[0194] 10.9 wt.-% ash 0.55 kg 02 / kg

[0195] GS2

[0196] 47 bar (abs.)

[0197] 25 °C

[0198] Example 8 W1 + F1 1.12 kg feed / kg GS2 Steam: Fluidized bed 48.3 mol.-% H2

[0199] (=RDF2) kg / h, 47 bar(abs.) 0.50 kg steam / kg gasification 51.3 mol. -% CO

[0200] 100 °C GS2 (PG) and rest: steam

[0201] 48.5 wt.-% C 5 bar(abs.) entrained flow

[0202] 6.9 wt.-% H 180 °C gasification

[0203] 29.5 wt.-% O Oxygen: (G)

[0204] 15.1 wt.-% ash 0.69 kg 02 / kg

[0205] GS2

[0206] 47 bar (abs.)

[0207] 25 °C

[0208] Example 9 W1 + W2 + 1.07 kg feed / kg GS2 Steam: Fluidized bed 48.3 mol.-% H2

[0209] F1 (=RDF2) kg / h, 47 bar(abs.) 0.45 kg steam / kg gasification 51.4 mol. -% CO

[0210] 100 °C GS2 (PG) and rest: steam

[0211] 49.3 wt.-% C 5 bar(abs.) entrained flow

[0212] 7.2 wt.-% H 180 °C gasification

[0213] 29.3 wt.-% O Oxygen: (G)

[0214] 14.2 wt.-% ash 0.68 kg 02 / kg

[0215] GS2

[0216] 47 bar (abs.)

[0217] 25 °C

[0218] 1: 65 wt.-% C, 5 wt.-% H, 18 wt.-% 0, 12 wt.-% ash.2: 45 wt.-% C, 6 wt.-% H, 32 wt.-% 0, 17 wt.-% ash.

Claims

Claims1. A process for utilizing at least one waste stream from an oxo synthesis plant, wherein the oxo synthesis plant comprises a) an hydroformylation reaction unit HRU, b) optionally an aldehyde upgrading unit AUU, c) an aldehyde hydrogenation unit AHU and d) an alcohol upgrading unit ALUU, the process comprising the steps(I) providing a first waste stream W1 , wherein the first waste stream W1 is separated from the alcohol upgrading unit ALUU,(ii) optionally providing a second waste stream W2, wherein the optional second waste stream W2 is separated from the optional aldehyde upgrading unit AUU,(ill) optionally pretreating the first waste stream W1 and / or the optional second waste stream W2,(iv) subjecting the first waste stream W1 and optionally the said second waste stream W2 to a gasification process wherein said gasification process comprises at least one gasifier G and whereby a gas stream GS1 , said gas stream GS1 comprising CO and H2, is formed by said gasification process from said first waste stream W1 and optionally said optional second waste stream W2.

2. Process according to claim 1 wherein the waste stream W1 has at least one, preferably all the following properties: a) a calorific value in the range of 25 to 50 MJ / kg, more preferably of 28 to 46 MJ / kg and most preferably of 32 to 45 MJ / kg, b) a carbon content in the range of 50 to 90 wt.-%, more preferably 55 to 85 wt.-% and most preferably 60 to 85 wt.-%, c) a hydrogen content in the range of 2 to 25 wt.-%, more preferably 5 to 22 wt.-% and most preferably 8 to 20 wt.-%, d) an oxygen content in the range of 2 to 25 wt.-%, more preferably 5 to 22 wt.-% and most preferably 5 to 20 wt.-%.

3. Process according to claim 1 or 2 wherein the optional waste stream W2 has at least one, preferably all the following properties: a) a calorific value in the range 25 to 50 MJ / kg, more preferably of 28 to 46 MJ / kg and most preferably of 32 to 45 MJ / kg, b) a carbon content in the range of 50 to 90 wt.-%, more preferably 55 to 85 wt.-% and most preferably 60 to 80 wt.-%, c) a hydrogen content in the range of 2 to 25 wt.-%, more preferably 5 to 22 wt.-% and most preferably 8 to 20 wt.-%,d) an oxygen content in the range of 2 to 25 wt.-%, more preferably 5 to 22 wt.-% and most preferably 5 to 20 wt.-%.

4. Process according to any one of claims 1 to 3 wherein the waste stream W1 and / or the optional waste stream W2 is / are pretreated in optional step (ill) by a method selected from the group comprising or consisting of distillation, mixing at least a portion of waste stream W1 and at least a portion of waste stream W2 with each other, and combining distillation and mixing or mixing and distillation.

5. Process according to any one of claims 1 to 4 wherein said at least one gasifier G is selected from plasma gasifier and entrained flow gasifier.

6. Process according to any one of claims 1 to 5 wherein at least one further feedstock F1 or at least one converted further feedstock CF1 is provided and said at least one further provided feedstock F1 or said at least one converted further feedstock CF1 is subjected to the gasification process in step (iv), whereby said at least one further feedstock F1 or said at least one converted further feedstock CF1 is inserted into the at least one gasifier G together with the first waste stream W1 provided in step (I) and optionally with the second waste stream W2 provided in optional step (ii), and / or with the first waste stream W1 pretreated in step (ill) and optionally with the second waste stream W2 pretreated in step (ill).

7. Process according to claim 6 wherein the at least one further feedstock F1 is selected from the group comprising or preferably consisting of biomass, refuse-derived fuel (RDF), pyrolysis oils made from plastic waste, pyrolysis oils made from end of life tires, pyrolysis oils made from biomass, heating oils, vacuum residues, preferably vacuum distillation residues, crude oil residues, heavy crude oils, extra heavy crude oils, tar sand bitumen, visbreaker bottom residues, deasphalter bottom residues, C5 asphalthene fraction, high viscous residues, fuel oils, pyrolysis gasolines, tire pyrolysis oils (TPO), waste oils, used oils, municipal solid waste (MSW), automotive shredder residue (ASR), coal, natural gas, industrial waste streams and mixtures thereof.

8. Process according to claim 6 or 7 wherein the weight ratio (waste stream W1 optionally with waste stream W2) : (sum of all further feedstocks F1) preferably ranges from 1 : 1 to 1 : 10, more preferably from 1 : 2 to 1 : 10 and most preferably from 1 : 5 to 1 : 10.

9. Process according to any one of claims 6 to 8 wherein the at least one further feedstock F1 is converted in a pre-gasifier PG into a converted further feedstock CF1 .

10. Process according to claim 9, wherein the gasifier G is downstream of and fluidically connected to the pre- gasifier PG.11 . Process according to claim 9 or 10 wherein the pre-gasifier PG is a fixed bed gasifier or a fluidized bed gasifier.

12. Process according to any one of claim 1 to 11 wherein the process comprises a further step (v) said further step (v) selected from the group comprising or consisting of cleaning the gas stream GS1 and thereby forming a gas stream GS2, separating H2 and CO comprised in the gas stream GS1 or GS2 from each other, compressing at least one of the gas streams GS1, GS2, H2, CO, and combinations thereof.

13. Process according to any one of claim 12 wherein at least a portion of gas stream GS2 is fed as synthesis gas into a hydroformylation reaction unit HRU.

14. An oxo process plant comprising an integrated waste stream treatment facility wherein said oxo process plant comprises(I) an hydroformylation reaction unit HRU,(ii) optionally an aldehyde upgrading unit AUU downstream of and fluidically connected to the hydroformylation reaction unit HRU,(ill) an aldehyde hydrogenation unit AHU downstream of and fluidically connected to the hydroformylation reaction unit HRU or downstream of and fluidically connected to the optional aldehyde upgrading unit AUU,(iv) an alcohol upgrading unit ALUU, downstream of and fluidically connected to the aldehyde hydrogenation unit AHU,(v) at least one gasifier G, downstream of the alcohol upgrading unit ALUU and optionally downstream of the optional aldehyde upgrading unit AUU and wherein the at least one gasifier G is directly or indirectly fluidically connected to the waste stream W1 of the alcohol upgrading unit ALUU and to the optional waste stream W2 of the optional aldehyde upgrading unit AUU.

15. Use of an oxo process plant according to claim 14 for the process according to any one of claims 1 to 13.

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