The Kingdom of Saudi Arabia has been grappling with the problem of solid waste in recent years. Around 15 million tons of municipal solid waste is generated in the country each year with per capita average of 1.4 kg per day. Depending on the population density and urban activities of that area, the major ingredients of Saudi Arabian MSW are food waste (40-51 %), paper (12-28 %), cardboard (7 %), plastics (5-17 %), glass (3-5 %), wood (2-8 %), textile (2-6 %), metals (2-8 %) etc.
Due to high population growth rate, (3.4% per annum), rapid urbanization (1.5% per annum) and fast economic development (3.5% yearly GDP rate), the generation rate of MSW is expected to reach 30 million tons per year by 2033. Waste management issues in Saudi Arabia are not only related to water, but also to land, air and the marine resources. The sustainable integrated solid waste management (ISWM) is still at the infancy level in the oil-rich kingdom
In Saudi Arabia, MSW is collected and sent to landfills or dumpsites after partial segregation and recycling. The major portion of collected waste is ends up in landfills untreated. Recycling of metals and cardboard is the main waste management practice in Saudi Arabia, which covers 10-15% of the total waste and usually carried out by the informal sector.
The landfill requirement in KSA is very high, about 28 million m3 per year. The problems of leachate, waste sludge, and methane and odor emissions are occurring in the landfills and its surrounding areas due to mostly non-sanitary or un-engineered landfills. However, in many cities the plans of new sanitary landfills are in place, or even they are being built by municipalities with capturing facilities of methane and leachate.
Waste-to-Energy provides the cost-effective and eco-friendly solutions to both energy demand and MSW disposal problems in Saudi Arabia. The choice of conversion technology depends on the type and quantity of waste (waste characterization), capital and operational cost, labor skill requirements, end-uses of products, geographical location and infrastructure.
Several waste to energy technologies such as pyrolysis, anaerobic digestion (AD), trans-esterification, fermentation, gasification, incineration, etc. have been developed. As per conservative estimates, electricity potential of 3 TWh per year can be generated, if all of the KSA food waste is utilized in biogas plants. Similarly, 1 and 1.6 TWh per year electricity can be generated if all the plastics and other mixed waste (i.e. paper, cardboard, wood, textile, leather, etc.) of KSA are processed in the pyrolysis, and refuse derived fuel (RDF) technologies respectively.
The current SWM activities of KSA require a sustainable and integrated approach with implementation of waste segregation at source, waste recycling, waste-to-energy and value-added product recovery. By 2032, Saudi government is aiming to generate about half of its energy requirements (about 72 GW) from renewable sources such as solar, nuclear, wind, geothermal and waste-to-energy systems.
