||A chemical and process design approach that leads to substantially smaller, cleaner, safer and more energy-efficient process technology. It has the potential of reducing energy usage, major cost saving, smaller plant, safer process, high product purity, high selectivity, less wastes and by product lowering equipment costs, and shrinking the required footprint of a given production facility. The process can be divide two part a) Product upgrade which are special designs that optimize critical parameters (e.g., heat transfer, mass transfer). b) Process modification, where multiple processing steps are integrated into a single unit operation or alternative energy sources are used. Biogas upgrading is the process in which the final output gas consists of higher methane concentration compared to raw biogas, mainly due to removal or transformation of carbon dioxide (and supplementary due to removal of other impurities, such as water, hydrogen sulfide and siloxanes). In case that the upgraded biogas is purified to natural gas standards, then the final gas product is called biomethane.