# Co-Production of Hydrogen and Methanol Using Fuel Mix Systems: Technical and Economic Assessment
## 1 Introduction
This is because poly-generation processes are flexible in combining multiple energy sources that can enable the sustainable supply of energy demand while meeting environmental regulations in terms of reduced greenhouse gas (GHG) emissions. For a sustainable energy system, available resources should be utilized at the maximum possible efficiency followed by a reduction in GHG emissions. [PERSON] et al. [11] and [PERSON] et al. [12] provided reviews on poly-generation processes using multiple feedstocks with multiple outputs. The poly-generation process can be utilized for co-currently producing multiple chemicals and products including electricity, fuel, chemicals, etc. In this study, poly-generation process models are discussed, in which coal, natural gas and biomass feedstocks are used for the production of two useful and cleaner fuels (H\({}_{2}\) and methanol). Some of the state-of-the-art methanol and H\({}_{2}\) production processes involve syngas production from fossil fuels, which is treated in the cleaning and water-gas shift units before the final production and purification of methanol and H\({}_{2}\). For instance, the natural-gas-to-methanol (NGTM) process has been extensively used in various industries for the production of both H\({}_{2}\) and methanol. The hydrogen-to-carbon (HCR) ratio of 2-2.2 is usually required for methanol production, which can be achieved by steam methane reforming (SMR) processes, which generates a syngas of the HCR ratio of approximately 3:1. Coal to methanol (CTM) has also emerged as an attractive technology to produce H\({}_{2}\) due to higher coal reserves globally, but the syngas produced from coal gasification has a drawback of offering a lower amount of HCR in the synthesis gas. This issue is resolved by using additional WGS (water-gas shift) units to enhance H\({}_{2}\) production by transforming the CO over the nickel-based catalyst using high-pressure steam. The research studies also showed that retrofitting already developed processes does not need major process modifications to enhance the process sustainability by reducing both the fuel consumption and GHG emissions. [PERSON] et al. [13] and [PERSON] et al. [14] demonstrated the pathways for producing methanol and electricity in the poly-generation process integration framework and employed WGS reactors to achieve the desired HCR in the synthesis gas. [PERSON] et al. [15; 16] developed the process models based on coal and natural gas feedstocks for generating hydrogen and methanol in a co-production manner. Recently, [PERSON] et al. [17] discussed the 2030 goal for global energy resources and mentioned the use of biomasses up to 10% with the primary energy resources. Similarly, [PERSON] and [PERSON] [18] developed the process model on using biomasses as a feedstock to explore fuel switch technologies. [PERSON] et al. [19] used various biomass feedstocks in the research and highlighted that the dependencies on the conventional fuels can be reduced by energy mix and fuel switch systems. Recently, [PERSON] et al. [20] and [PERSON] et al. [21] also demonstrated a process integration framework using a combination of both gasification and reforming technologies to enhance the power and H\({}_{2}\) production capacities. The goal of this work is to investigate the development of standalone models for coal and biomass gasification processes followed by their integration with natural gas reforming units to enhance overall syngas production potentials. Furthermore, the heat exchanger network is developed to utilize the heat from the hot and cold streams to minimize the external energy requirements. This process integration resulted in the utilization of three different feedstocks, which reduced the reliance on a single fuel and improves the H\({}_{2}\) and methanol production rates. Finally, a techno-economic analysis is performed for all designs to analyze the project feasibility of the processes.