# Co-Production of Hydrogen and Methanol Using Fuel Mix Systems: Technical and Economic Assessment
## 1 Introduction  
Global warming and greenhouse gas emissions have become one of the biggest debated issues around the globe. With recent industrialization and deforestation, the carbon footprint around the world has increased to dangerous levels during the last few decades. The intergovernmental panel on climate change (IPCC) clearly indicates this in its reports about global warming and the depletion of energy resource [1, 2]. A reduction in greenhouse gas emissions can be achieved by either minimizing fuel consumption, by improving the process performance, by reducing the greenhouse gas emissions or by using renewables forms of energy. The current global capacity of renewables is not enough to meet the world energy and supply demand. Therefore, the dependence onconventional fuel resources will remain dominant in the future too. Energy in any form is very valuable around the world to meet societal and industrial needs, and a lot of research has been dedicated to improving the process efficiency or to finding alternative energy resources. Hydrocarbon-based fossil fuels have remained the major source of energy supply during the last few decades, owing to their high efficiency and availability. However, the utilization of fossil fuel based-processes also increased the global CO\({}_{2}\) emissions to the highest level ever. Gasoline, diesel and natural gas are the main fuels that are used in the automotive, chemical, fertilizer and process industries, the use of which steadily increased at a rate of nearly 2-2.5% annually, paralleling the global economic growth, which will be further increased up to 50% by the year 2030 [3]. Compared to conventional fuels used for power generation, methanol and hydrogen are considered not only cleaner fuel sources but also raw materials for many process industries [4]. Oxygenates such as methanol and ethanol are also bended with petroleum fuels to improve various combustion properties such as octane number [5] and emission characteristics such as sooting [6] propensity. Large-scale methanol and hydrogen production processes are based on natural gas feedstocks using intermediate reforming technologies for synthesis gas production. As hydrogen is a key component of methanol production, the increase in methanol production also increases the need for hydrogen production. [PERSON] et al. [7]) also mentioned that the methanol demand has increased two times during the last 5-7 years, which also increases the methanol production requirement by 1.7 times. Methanol can be produced from conventional fuels that can be converted into synthesis gas, mainly composed of CO and H\({}_{2}\). For instance, commercially, natural-gas-to-methanol (NGTM) processes are used where the natural gas is first reformed to generate synthesis gases with higher hydrogen-to-carbon (HCR) ratios followed by methanol synthesis. Coal-to-methanol (CTM) production processes have also received a lot of attention due to the lower cost of coal compared to natural gas and the larger reserves around the world. The CTM production process is slightly more complex compared to the natural-gas-to-methanol processes as it contains more unit processes. [PERSON] et al. [8] demonstrated pathways to produce methanol from coal by developing alternative designs and compared the results in terms of carbon conversion, specific energy consumption and methanol production cost. Reaching a fully sustainable clean energy source for power, electricity and cleaner fuel production is a long ways off, and a lot of research is being focused on finding alternative pathways to increase the efficiency of already existing systems. [PERSON] et al. [9; 10] studied the carbon-neutral process of producing methane, methanol and ammonia using a solar-based renewable hydrogen supply process. Poly-generation processes are under the spotlight for being one of the most promising solutions for this problem.