# Prospects and Technical Challenges in Hydrogen Production through Dry Reforming of Methane
## 4 Large-Scale Applications of DRM  
The potential benefits of industrial implementation of DRM have driven several research groups into investigating not only the catalyst optimization aspects but also the process scaling up to commercial level [150]. Over the years, different groups have evaluated several aspects of the DRM process on a semi-pilot and pilot scale, aiming at bringing it into commercial application. [PERSON] et al. [151] have demonstrated the use of Pt-based catalysts for DRM at 850-950 \({}^{\circ}\)C and 20 bar and have considered different process aspects such as catalyst position, temperature gradient and feed composition aiming at reducing coking formation at pilot-scale conditions. The authors reported reaching a H\({}_{2}\)/CO = 0.78 at T = 850 \({}^{\circ}\)C, 20 bar, CH\({}_{4}\):CO\({}_{2}\) = 1:1. In addition, studies have also addressed other aspects, such as the type of reactor [152] and catalyst structure (in the case of different shapes of pelletized catalysts) [150], aiming at maximizing DRM activity and reducing deactivation rates at pilot scale. While CH\({}_{4}\) reforming technologies, such as autothermal reforming and steam reforming, are already used in industrial scale, the commercial application of DRM has been limited as a part of some industrial processes, such as the CALCOR(tm), SPARG(tm) and MIDREX(tm) processes [153]. Although such processes do not target H\({}_{2}\) production, understanding the commercial-level applications of DRM is a valuable way of assessing the advantages and limitations of the technology. Table 2 presents a summary of the main aspects of the pilot- and commercial-scale applications of DRM. The CALCOR(tm) process (Caloric GmbH) aims at the production of highly CO-concentrated syngas (Figure 7). In the first stage of this process, syngas with a low H\({}_{2}\)/CO ratio (0.42) is  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Technology** & **Catalyst** & **Feed** & **Operation** & **H\({}_{2}\)/CO** & **TRL** & **Process** & **Application** & **Ref. ** \\ \hline DRM & 10 wt\({}^{\circ}\)s & & & & & & \\  & Ni/Al\({}_{2}\)O\({}_{3}\)-MgO & CO\({}_{2}\)CH\({}_{4}\)N\({}_{2}\) = 2:1:0.5 & 600 \({}^{\circ}\)C, 1 bar & \(>\)1.0 & Semi-pilot & Syngas & [150] \\ DRM & Pt-based & CH\({}_{4}\)CO\({}_{2}\):Ar = & 850-950 \({}^{\circ}\)C, 20 bar & 0.7–0.8 & Pilot-scale & Syngas & [151] \\ CALCOR(tm) & Ni-based & CH\({}_{4}\), LPC, CO\({}_{2}\). Feed & Low pressure, high & & & & \\ Caloric GmbH & Ni-based & CH\({}_{4}\), LPC, CO\({}_{2}\). Feed & Low pressure, high & & & & \\  & & not reported. & temperature & & & & \\  & & CH\({}_{4}\), H\({}_{2}\)O, CO\({}_{2}\), H\({}_{2}\)S & & & & & \\  & Partially & (pre-reforming, for & & & & \\  & & catalyst passivation). & 875–945 \({}^{\circ}\)C & 0.55–3.2 & Commercial & Syngas & [156; 157; 158] \\  & & Ni & CO\({}_{2}\)/CH\({}_{4}\) = 0.07–2.5, & & & & & \\  & & H\({}_{2}\)/CO/CH\({}_{4}\): 0.1–0.26 & & & & & \\ MIDREX(tm) & Ni-based & & & & & & \\ (Midrex) (Midrex) & supported on & & & & & & \\  & & & & & & & \\  & & & & & & \\  & & & & & & \\ Technologies) & &produced from the dry reforming of liquefied petroleum gas (LPG) or natural gas (NG) with excess CO\({}_{2}\), over a Ni-based catalyst [164]. In this process, the coke deposition is minimized by using a catalyst bed with different stages of catalyst reactivity and different catalyst geometries [165]. As DRM is a highly endothermic process [166], part of the fuel is burnt to provide heat for the reaction. The process outlet stream is a mixture of CO, CO\({}_{2}\), H\({}_{2}\), H\({}_{2}\)O and traces of unreacted CH\({}_{4}\). The stream is cooled for H\({}_{2}\)O removal, then it is scrubbed through packed towers with monoethanolamine (MEA) or methyldiethanolamine (MDEA) for CO\({}_{2}\) removal and, finally, is purified by a pressure swing adsorption unit (PSA) for H\({}_{2}\) separation that would operate according to the CO purification requirements (can reach up to 99.95% CO) [155].