Biogas is a flammable combination of gases created by microorganisms when animal manure and other biological wastes are allowed to ferment in closed containers or reactors without the presence of oxygen. This process design presents an integrated biogas production system that utilizes U. lactuca to remove nitrogen and phosphorus from polluted seawater and then uses it as a feedstock for biogas generation. Anaerobic digestion is a three-stage process that includes the hydrolysis of insoluble polymers, the fermentation of monomeric breakdown products, the fermentation of acetate and hydrogen from volatile fatty acids, and the production of methane. The concept is based on the production of 1,000 metric tons of purified biogas per year for use in kitchen stoves. It has the potential to increase the use of endemic U. lactuca for saltwater treatment while also providing a source of income for communities and protecting the aquatic environment from pollution. Additionally, utilizing purified biogas as a secondary fuel source helps save the world's decreasing natural gas and oil sources. Purified biogas can be used in place of standard LPG (liquefied petroleum gas) for cooking stoves, as its energy value and cost are comparable.