The invention relates to a process converting hy drocarbons to products.

WO 2016/151120 relates to a method of and a system (1) for processing a slurry containing organic components, such as biomass, having a water contents of at least 50%, comprising a pump (6) and heater or heat exchanger (7) to bring the liquid in the slurry in a supercritical state, a reactor (8) to convert at least a part of the organic compo nents in the slurry, and a separator (12) to remove gaseous products from the converted slurry, and comprising a mixer (5) for adding fluid from the converted slurry to the slurry upstream from the reactor (8) .

It is an object of the present invention to provide an improved process.

To this end, the process according to the present invention comprises the steps of:

converting hydrocarbons to at least one molecular energy carrier, such as hydrogen and/or one or more hydro carbons, such as methane, and/or heat and carbon dioxide, reacting said carbon dioxide with a divalent metal- containing silicate to form solid divalent metal carbonate and silicate, e.g. solid, liquid, or a mixture ( slurry) of solid and liquid silicate, and

utilizing at least one of said carbonate and sili cate in the production of construction- and/or chemical ma terial .

With the present invention a triple or double re duction or, ideally, a triple or double avoidance of carbon dioxide emissions can be achieved, namely by capturing the carbon dioxide, from the air or resulting from the produc tion of molecular energy carriers, in solids and, in addi tion, avoiding carbon dioxide emission through the use of said solids as a replacement of construction and/or chemical material, the conventional production process of which mate rial traditionally results in carbon dioxide emission. This is illustrated in the drawing (Figure 1) .

In an embodiment, the process comprises the steps of

leaching the divalent metal containing silicate at a pH of below neutral to form divalent metal ions and sili cate in the reaction mixture, then

increasing pH to react the divalent solution with carbon dioxide to form a solid divalent metal salt and/or silicate, and

reacting the solid divalent salt with carbon diox ide to form a solid divalent metal carbonate.

Thus, the solid and/or liquid products are formed using a pH-swing carbon dioxide mineralization process with a recyclable reaction solution.

The advantages of said pH swing process are a

(near) complete dissolution of the divalent metal containing silicates, potential recovery of the components of the diva lent metal containing silicates (silica and metals) and car- bonation reaction of C02 requiring less energy and a com plete conversion towards carbonates.

The advantages of said recyclable process are that the amount of additives consumed are significantly less and the carbon footprint of the overall process significantly is reduced . )

In an embodiment, leaching is conducted at a pH in a range from 1 to below neutral, preferably in a range from <2 to <7, and a temperature in a range from >25 to <100 °C, preferably in a range from 25 to 50°C.

In another embodiment, the neutralizing step is conducted by addition of a base to increase the pH to 7 or above, preferably at a temperature in a range from >25 to <50 °C, and preferably at a pressure in a range from 0.5 to 3 bar, preferably in a range from 1 to 2 bar.

In another embodiment, the reaction of solid diva lent salt with carbon dioxide is conducted at a pressure in a range from 5 to 50 bar, preferably in a range from 10 to 20 bar.

In an embodiment, carbon dioxide and the at least one molecular energy carrier are formed through at least one of a gasification process, preferably a supercritical water gasification process, a gas reforming process, partial oxi dation, a fermentative gas production process, and an enzy matic gas production process. In an embodiment, said carbon dioxide is subsequently reacted with a divalent metal-con taining silicate to form solid divalent metal carbonate and silicate, e.g. fed from a supercritical water gasification reactor to a downstream reactor for forming the carbonate and silicate, e.g. in a continuous process.

In an embodiment, hydrocarbons are converted via a supercritical water gasification process to at least one mo lecular energy carrier and carbon dioxide and said carbon dioxide is subsequently reacted with a divalent metal con taining silicate to form at least solid divalent metal car bonate and silicate. It is preferred that at least one of said carbonate and silicate is utilized in the production of construction- and/or chemical material, e.g. as a replace ment of existing fillers and/or as a replacement of chemical material the current production of which generates fossil C02 emission and/or is utilized in the production of new or virgin construction material.

In an embodiment, the hydrocarbons are at least one of organic material, such as biomass, coal, oil, plastics, and natural gas. Feedstocks containing organic components are a tremendous potential resource for providing energy and value-added products, especially in agricultural areas where waste biomass is abundant or where dedicated energy crops can be produced cheaply and efficiently.

In an example, waste biomass or sewage is converted by means of supercritical water gasification to product, e.g. hydrogen and methane, and the resulting carbon dioxide is reacted with a divalent metal-containing silicate to form solid divalent metal carbonate and silicate, which subse quently is utilized in the production of construction- and/or chemical material, e.g. cement. Thus, useful products with higher economic value are made from waste, while providing triple carbon dioxide relief.

In an embodiment, the molecular energy carrier is hydrogen or a hydrocarbon, preferably a hydrocarbon with 1 to 24 carbon atoms, in particular methane or ethane/ eth ylene .

To accelerate the reaction between carbon dioxide and the divalent metal-containing silicate and/or to improve controlling the process at relatively low temperatures, in an embodiment, the carbon dioxide is in a supercritical state, i.e. at a pressure in excess of 73 bar and a tempera ture in excess of 31 °C, or a subcritical state.

In an embodiment, at least part of the carbonate formed is separated and dried. Preferably, the solid diva lent metal carbonate is at least one of calcium carbonate, iron carbonate and/or magnesium carbonate.

In an embodiment, at least part of the silicate formed is separated and dried to form fumed silica, nano- or micro-silica .

In another embodiment, the divalent metal contain ing silicate is a silicate mineral, or nesosilicates or or thosilicates, having the orthosilicate ion, which constitute isolated silicon tetroxide anion (Si04)4- which has a tetra hedral shape that are connected by divalent metals. In yet another embodiment, the divalent metal con taining silicate is at least one of olivine, wolstanite, serpentine, forsterite, and monticellite .

In another embodiment, all or part of the formed solids and/or liquid products is used

as cementitious material in at least one of geopol ymer, cement, and hybrid (= ordinary portland cement "OPC" combined with non-OPC materials) cement, or

as a component in the production of at least one of paper, polymer, rubber, coatings, food, personal care prod ucts, and pharmaceuticals.

Philip Goldberg et al . "C02 Mineral Sequestration Studies in US", Journal of Energy and Environmental Research (2001), explains that "Carbon sequestration by reacting nat urally occurring Mg and Ca containing minerals with C02 to form carbonates has many unique advantages. Most notably is the fact that carbonates have a lower energy state than C02, which is why mineral carbonation is thermodynamically favor able and occurs naturally (e.g., the weathering of rock over geologic time periods) . Secondly, the raw materials such as magnesium based minerals are abundant. Finally, the produced carbonates are unarguably stable and thus re-release of C02 into the atmosphere is not an issue." A conceptual illustra tion of the process is presented in Figure 1 of Goldberg.

"As illustrated, C02 from one or more power plants is trans ported to a carbonation reactor, combined with crushed oli vine or serpentine from a nearby mine and held at the appro priate reaction conditions until the desired degree of car bonation is reached. Then products of the reaction, which might be a slurry of carbonated minerals and residues in aqueous C02, are separated. The C02 is recycled, useful ma terials are collected and the carbonated materials and resi due are returned to the mine site."

WO 2014/009802 relates to a process for producing magnesium carbonate by carbonating a magnesium silicate ore containing iron is disclosed. It is characterised by the step of contacting a slurry of the ore in water with a gase ous mixture comprising carbon dioxide and oxygen. The pro cess is suitably carried out at elevated temperature and pressure wherein the gaseous mixture is in supercritical fluid form. It is particularly suitable for the processing of olivine and serpentine ores wherein iron is present in the +2 oxidation state. The process also optionally com prises the separation of silica and/or discrete iron oxide or hydroxide phases (s) co-produced with the magnesium car bonate. Also disclosed are downstream processes for convert ing the magnesium carbonate into magnesium oxide and compo sitions derived therefrom having cementitious properties. Cement products and concrete building materials produced from these compositions have useful structural properties and have a low carbon footprint relative to traditional Portland cement.

Santos RM, Knops PCM, Rijnsburger KL and Chiang YW (2016) C02 Energy Reactor - Integrated Mineral Carbona- tion: Perspectives on Lab-Scale Investigation and Products Valorization. Front. Energy Res. 4:5. doi:

10.3389/fenrg.2016.00005, relates to developing a gravity pressure vessel (GPV) reactor technology. "The GPV pro vides intense process conditions through hydrostatic pres surization and heat exchange integration that harvests ex othermic reaction energy, thereby reducing energy demand of conventional reactor designs, in addition to offering other benefits."

WO 2007/069902 relates to a method for industrial manufacture of pure MgC03 comprising providing an olivine containing species of rock, to comminute the olivine con taining species of rock to increase its surface, to con tact the comminuted olivine containing species of rock with water and C02. EP 2 511 003 relates to "A method for an environ ment-friendly process for the manufacture of C02 absorbing cement is provided. In the process energy, heat and C02 generated by a biorefinery unit is utilized. In addition the resulting cement product may be functionalised with biological modifiers comprised in the biorefinery waste streams. Thereby biorefinery waste products can be reduced further . "

Within the framework of the present invention the term "molecular energy carrier" is defined as a substance, in particular a fuel or an intermediate for synthetic com pounds, such a polymers, having the potential to release energy through a chemical reaction, such as oxidation or hydrogenation .

The name "silicate" is used to mean silicate min erals, ionic solids with silicate anions, as well as rock types that consist predominantly of such minerals. In this context, the term also includes the non-ionic compound silicon dioxide (silica, quartz) .

The term "supercritical" refers to a temperature and pressure condition in which at least part of the pro cessing liquid reaches or exceeds its critical point and becomes a fluid with unique properties. The resulting fluid has a density between that of its vapour and its liquid phase at standard conditions and exhibits high gas like diffusion rates along with liquid-like solvation be haviour. In the case of water this means that hydrocar bons, for example, can become soluble in the water and salts might precipitate out of solution. The term "sub- critical" includes conditions which are just below super critical, where the liquid does not retain 'normal' liquid properties but is also not yet fully supercritical.

The invention is not restricted to the above-de scribed embodiments, which can be varied in a number of ways within the scope of the claims.