Carbon-neutral and carbon-negative chemical looping processes using glycerol and methane as feedstock

Carbon-negative and neutral methods to produce H2 and other syngas-derived chemicals are tested and demonstrated in this study through chemical looping reforming of methane or glycerol. A chemical looping reactor provides the heat required to reform the glycerol or methane while having inherent CO2 capture. This is achieved using dynamically operated packed beds. If the glycerol or methane is from a biological source this gives the system the potential for negative emissions. To evaluate the potential of this system, 500 g packed bed of oxygen carriers were cyclically reduced, oxidized, and used to carry out reforming experiments. The reforming process was tested at various pressure (1 – 9 bar) and temperature (600 – 900 °C). These conditions were tested at this scale for the first time. Complete conversion of glycerol is achievable with only small quantities of CH4 slip. The maximum H2 production was achieved at 1 bar and 700 °C producing a H2/CO ratio of 10, this lowered to 9 when the temperature was increased to 900 °C. Adding CO2 to the feed stream along with H2O allows for a H2/CO ratio suitable for the Fischer Tropsch (FT) synthesis. Chemical looping reforming of CH4 with steam was successfully demonstrated in a lab reactor setup at 1 and 5 bar for multiple cycles with CH4 conversion > 99% and controlled heat losses. The temperature and concentration profiles provided identical results for consecutive cycles verifying the continuity and the feasibility of the process

Experimental assessment of reverse water gas shift integrated with chemical looping for low-carbon fuels

Chemical looping integrated with reverse water gas (CL-RWGS) shift is presented in this study using Cu-based oxygen carrier (OC) supported on Al2O3 has been used to convert the CO2 and H2 mixture stream into a syngas stream with a tailored H2 to CO ratio and relevant conditions. The results demonstrated consistent breakthrough curves during redox cycles, confirming the chemical stability of the material. In 10 consecutive cycles at 600 °C and 1 bar, bed temperatures increased by 184 °C and 132 °C across the bed during oxidation and reduction stages respectively. The cooling effects during RWGS showed a decline in solid temperatures demonstrating the effectiveness of the heat removal strategy while attaining a CO2-to-CO conversion close >48%. The outlet gas maintains a H2/CO ratio above 2, confirming the material's dual role as OC and catalyst. During complete CL-RWGS cycles, varying temperature from 500 °C to 600 °C at a constant H2/CO2 molar ratio (1.3) and pressure (1 bar) reduces the H2/CO molar ratio from 3.14 to 2.35, respectively with a remarkable continuous CO2-to-CO conversion > 40%. The decrease in H2/CO molar ratio with the increase in temperature is consistent with the expected results of equilibrium limited conditions. Additionally, in CL-RWGS cycles, pressure insignificantly affects product molar composition. The study showed the capability of Cu material in converting CO2 into syngas through the CL-RWGS technique

Experimental assessment of reverse water gas shift integrated with chemical looping for low-carbon fuels

Chemical looping integrated with reverse water gas (CL-RWGS) shift is presented in this study using Cu-based oxygen carrier (OC) supported on Al2O3 has been used to convert the CO2 and H2 mixture stream into a syngas stream with a tailored H2 to CO ratio and relevant conditions. The results demonstrated consistent breakthrough curves during redox cycles, confirming the chemical stability of the material. In 10 consecutive cycles at 600 °C and 1 bar, bed temperatures increased by 184 °C and 132 °C across the bed during oxidation and reduction stages respectively. The cooling effects during RWGS showed a decline in solid temperatures demonstrating the effectiveness of the heat removal strategy while attaining a CO2-to-CO conversion close &gt;48%. The outlet gas maintains a H2/CO ratio above 2, confirming the material's dual role as OC and catalyst. During complete CL-RWGS cycles, varying temperature from 500 °C to 600 °C at a constant H2/CO2 molar ratio (1.3) and pressure (1 bar) reduces the H2/CO molar ratio from 3.14 to 2.35, respectively with a remarkable continuous CO2-to-CO conversion &gt; 40%. The decrease in H2/CO molar ratio with the increase in temperature is consistent with the expected results of equilibrium limited conditions. Additionally, in CL-RWGS cycles, pressure insignificantly affects product molar composition. The study showed the capability of Cu material in converting CO2 into syngas through the CL-RWGS technique.</p

Lab-scale experimental demonstration of Ca-Cu chemical looping for hydrogen production and in-situ CO2 capture from a steel-mill

In the present work, a lab-scale packed bed reactor has been used to decarbonize mixtures of inlet gases simulating the typical composition of blast furnace gases (BFG) and convert them to H2-rich streams by means of the Casingle bondCu chemical looping concept. The reactor was packed with 355 g of Cu-based oxygen carrier (OC) supported on Al2O3 and natural Ca-based sorbent. The three main reaction stages; namely (i) Calcium Assisted Steel-mill Off-gas Hydrogen (CASOH), (ii) Cu oxidation and (iii) Regeneration of carbonated Ca-based sorbent were examined. In CASOH stage, BFG is converted into H2-rich stream (17% by vol.) under the experimental conditions of 600 °C, 5.0 bar and S/CO molar ratio of 2.0. A controlled oxidation causes a mere 3.5% of CaCO3 to decompose during the Cu-oxidation stage. This resulted in a nearly pure N2 stream at 600 °C and 5.0 bar operating conditions. During the regeneration stage, BFG and mixture of BFG and CH4 is used as a reducing fuel. To ensure the amount of heat needed for the decomposition of CaCO3 during the reduction of CuO, a 1.4 CuO/CaCO3 molar ratio has been used. It resulted in 46% CO2 in N2 at the end of the reduction/calcination stage

Chemical Looping Reforming for syngas generation at real process conditions in packed bed reactors: an experimental demonstration

Chemical looping reforming (CLR) is a promising technology for syngas production combining autothermal operation with integrated CO2 capture. At large scale, reformer outlet pressure during syngas production is an important factor for the overall plant’s process efficiency and defines the energy requirements for downstream processing. Packed bed reactors are widely used and established in industry for high pressure operating conditions due to their robust and, compared to other reactor types, simpler engineering. In this paper, CLR in packed bed reactors (CLR-PB) is demonstrated under a pressure range of 1 – 5 bar in a lab scale reactor, using NiO/CaAl2O4 as the oxygen carrier (OC). Oxidation, reduction and dry reforming processes were examined in a wide range of temperature (400 – 900 °C), pressure (1 – 5 bar), flowrate (10 – 40 NLPM) and different inlet gas compositions, providing an important foreground for the optimal operating conditions for each process.Furthermore, a full CLR-PB pseudo-continuous cycle has been successfully demonstrated for the first time in a lab reactor setup. During the full cycle operation, CH4 conversion &gt; 99% has been achieved, while the temperature and concentration profiles provided identical results for consecutive cycles verifying the continuity and the feasibility of the process. These results constitute the basis for the scale-up of the process, where heat losses would be minimized and the energy efficiency of the process would be significantly higher

A disruptive innovation for upgrading methane to c3 commodity chemicals: Technical challenges faced by the c123 european consortium

C123 is a €6.4 million European Horizon 2020 (H2020) integrated project running from 2019 to 2023, bringing together 11 partners from seven different European countries. There are large reserves of stranded natural gas waiting for a viable solution and smaller scale biogas opportunities offering methane feedstocks rich in carbon dioxide, for which utilisation can become an innovation advantage. C123 will evaluate how to best valorise these unexploited methane resources by an efficient and selective transformation into easy-to-transport liquids such as propanol and propanal that can be transformed further into propylene and fed into the US$6 billion polypropylene market. In C123 the selective transformation of methane to C3 hydrocarbons will be realised via a combination of oxidative conversion of methane (OCoM) and hydroformylation, including thorough smart process design and integration under industrially relevant conditions. All C123 technologies exist at TRL3 (TRL = technology readiness level), and the objectives of C123 will result in the further development of this technology to TRL5 with a great focus on the efficient overall integration of not only the reaction steps but also the required purification and separation steps, incorporating the relevant state-of-the-art engineering expertise

A Disruptive Innovation for Upgrading Methane to C3 Commodity Chemicals

C123 is a €6.4 million European Horizon 2020 (H2020) integrated project running from 2019 to 2023, bringing together 11 partners from seven different European countries. There are large reserves of stranded natural gas waiting for a viable solution and smaller scale biogas opportunities offering methane feedstocks rich in carbon dioxide, for which utilisation can become an innovation advantage. C123 will evaluate how to best valorise these unexploited methane resources by an efficient and selective transformation into easy-to-transport liquids such as propanol and propanal that can be transformed further into propylene and fed into the US$6 billion polypropylene market. In C123 the selective transformation of methane to C3 hydrocarbons will be realised via a combination of oxidative conversion of methane (OCoM) and hydroformylation, including thorough smart process design and integration under industrially relevant conditions. All C123 technologies exist at TRL3 (TRL = technology readiness level), and the objectives of C123 will result in the further development of this technology to TRL5 with a great focus on the efficient overall integration of not only the reaction steps but also the required purification and separation steps, incorporating the relevant state-of-the-art engineering expertise

Thermochemical syngas generation via solid looping process: An experimental demonstration using Fe-based material

Chemical looping is investigated for the production of syngas via reforming or reverse water gas shift in a packed bed reactor using 500 g of Fe on Al2O3 was demonstrated. Oxidation, reduction of the OC and subsequent catalytic reactions of reforming or reverse water gas shift were examined in a temperature range of 600–900 °C and a pressure range of 1–3 bara at high flowrate. Different inlet gas compositions were explored for the considered gas–solid and catalytic reaction stages. Oxidation with air successfully heated the reactor. CH4 resulted ineffective at reducing the Fe-based oxygen carrier while H2 and CO-rich stream were able to achieve full reduction to FeO of the material. In terms of catalytic activity, the maximum conversion of CH4 achieved during the reforming was limited to 62.8 % at 900 °C and 1 bara.Thermally integrated chemical looping reverse water gas shift was studied as option for CCU in combination with green H2 to produce renewable fuels. A H2/CO value of 2 could be achieved by feeding H2/CO2 of 2. The pressure did not substantially affect the conversion and the bed did not present carbon deposition.The ability of a Fe-based packed bed chemical looping reactor to recover after the carbon deposition was also explored. It was found that using a mixture of CH4 and CO2 achieved 92% recovery of the original capacity

A disruptive innovation for upgrading methane to c3 commodity chemicals: Technical challenges faced by the c123 european consortium

C123 is a €6.4 million European Horizon 2020 (H2020) integrated project running from 2019 to 2023, bringing together 11 partners from seven different European countries. There are large reserves of stranded natural gas waiting for a viable solution and smaller scale biogas opportunities offering methane feedstocks rich in carbon dioxide, for which utilisation can become an innovation advantage. C123 will evaluate how to best valorise these unexploited methane resources by an efficient and selective transformation into easy-to-transport liquids such as propanol and propanal that can be transformed further into propylene and fed into the US$6 billion polypropylene market. In C123 the selective transformation of methane to C3 hydrocarbons will be realised via a combination of oxidative conversion of methane (OCoM) and hydroformylation, including thorough smart process design and integration under industrially relevant conditions. All C123 technologies exist at TRL3 (TRL = technology readiness level), and the objectives of C123 will result in the further development of this technology to TRL5 with a great focus on the efficient overall integration of not only the reaction steps but also the required purification and separation steps, incorporating the relevant state-of-the-art engineering expertise.publishedVersio