RIYADH: Saudi Arabian Refineries Co. has signed two non-binding agreements with UK-based Christof Global Impact for the development of renewable energy projects in the Kingdom aimed at reducing carbon emissions. The first project involves constructing a refinery to produce biodiesel — a carbon-negative biofuel derived from algae — with an initial investment of up to SR1 billion ($266.50 million) for the first phase, according to a bourse filing. The second project aims to convert slop oil, oil from shipping ships, waste fuel tanks, and petroleum materials into low carbon raw materials with an estimated total cost of SR130 million for the first phase. These projects are subject to the approval of the Ministry of Energy and to the completion of technical and financial studies, the company said.