Saudi Arabia has the fourth-largest natural gas reserves in the world. Some reserves have a high quantity of impurities such as N2, CO2, and H2S. These impurities need to be removed due to the negative impact on the heating value and the environment. Cryogenic separation processes are promising because due to the tendency of removing the impurities and convert the clean natural gas into the liquid. Liquified natural gas (LNG) is a clean energy source compared to conventional fuels such as diesel, gasoline, and coal. It is rapidly replacing conventional fuels throughout the transportation sector and beyond. The present research is divided into two distinct parts. The first part deals with removing impurities from natural gas and converting clean natural gas into LNG by developing a novel process. The second part deals with the sustainable logistics of LNG. The second part aims to explore a systematic guideline to establish a sustainable LNG supply chain by optimizing cost, transportation logistics, and multi-model alternatives under reduced energy effects.<br />

Natural gas (NG) composition is determined by the geological circumstances of the gas well. Carbon dioxide has been shown to be present in one-third of the global NG reservoirs. The highest concentration of CO2 is in the NG reservoirs is up to 90 mol percent CO2. The carbon dioxide that comes out of the contaminated NG reservoirs needs to be refined (CO2&lt; 2 mol%) before being released to the consumers. Cryogenic technology is an emerging technology used for capturing CO2 from NG and is considered as the most sustainable technology due to eco-friendly process, its high-pressure applications, and low footprint. Reported research from previous several years indicated a range of approaches that could reduce the energy requirements for the cryogenic technology, which makes this technology to be more desirable to researchers. Most of the reported literature shows the use of a single packed bed for the desublimation based cryogenic CO2 capture from NG. However, in a single packed bed the product stream is at very low temperature, and hence cause high energy losses from the system which makes the product unfeasible for the market. Therefore, the proposed research is based on optimization of CO2 capture in cryogenic packed bed network.

Many feedstocks (plastics and biomass) have been utilized to produce biofuels, but they required high pressure, high temperature, and longer reaction time. These extreme conditions make the separation process very expensive and hard to adopt by industries. However, lignin is an attractive renewable biopolymer that can be extracted from lignocellulosic biomass. It can be further used for the production of many values added products. Although it is an attractive alternative, still some economic challenges need to address. The present study proposed using protic ionic liquids (PIL) to extract lignin from the Saudi date palm. PIL are emerging and novel series of solvents. In our previously published work, it has been established that Pyridinium-based PILs extracted lignin holds more phenolic and aromatic contents.